qcodes.instrument_drivers.Lakeshore package

Submodules

qcodes.instrument_drivers.Lakeshore.Model_325 module

qcodes.instrument_drivers.Lakeshore.Model_325.read_curve_file(curve_file: TextIO) → Dict[Any, Any][source]

Read a curve file with extension .330 The file format of this file is shown in test_lakeshore_file_parser.py in the test module

The output is a dictionary with keys: “metadata” and “data”. The metadata dictionary contains the first n lines of the curve file which are in the format “item: value”. The data dictionary contains the actual curve data.

qcodes.instrument_drivers.Lakeshore.Model_325.get_sanitize_data(file_data: Dict[Any, Any]) → Dict[Any, Any][source]: Data as found in the curve files are slightly different then the dictionary as expected by the ‘upload_curve’ method of the driver

class qcodes.instrument_drivers.Lakeshore.Model_325.Status(value)[source]

Bases: IntFlag

An enumeration.

sensor_units_overrang = 128

sensor_units_zero = 64

temp_overrange = 32

temp_underrange = 16

invalid_reading = 1

class qcodes.instrument_drivers.Lakeshore.Model_325.Model_325_Curve(parent: Model_325, index: int)[source]

Bases: InstrumentChannel

valid_sensor_units = ['mV', 'V', 'Ohm', 'log Ohm']

temperature_key = 'Temperature (K)'

get_data() → Dict[Any, Any][source]

classmethod validate_datadict(data_dict: Dict[Any, Any]) → str[source]

A data dict has two keys, one of which is ‘Temperature (K)’. The other contains the units in which the curve is defined and must be one of: ‘mV’, ‘V’, ‘Ohm’ or ‘log Ohm’

This method validates this and returns the sensor unit encountered in the data dict

set_data(data_dict: Dict[Any, Any], sensor_unit: Optional[str] = None) → None[source]

Set the curve data according to the values found the the dictionary.

Parameters

data_dict (dict) – See validate_datadict to see the format of this dictionary
sensor_unit (str) – If None, the data dict is validated and the units are extracted.

__getitem__(key: str) → Union[Callable[[...], Any], Parameter]: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Custom repr to give parent information

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only. If your case is more complicated, you’re probably better off simply making a new method in your Instrument subclass definition.

Parameters

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: Optional[Type[ParameterBase]] = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: Union[InstrumentModule, ChannelTuple]) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: List[qcodes.instrument.instrument_base.InstrumentBase]: Returns a list of instruments, starting from the current instrument and following to the parent instrument and the parents parent instrument until the root instrument is reached.

ask(cmd: str) → str

ask_raw(cmd: str) → str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns

The return value of the function.

delegate_attr_dicts: List[str] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: List[str] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

property full_name: str

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters: param_name – The name of a parameter of this instrument.
Returns: The current value of the parameter.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters: metadata – Metadata to load.

property name: str: Name of the instrument This is equivalent to full_name for backwards compatibility.

property name_parts: List[str]

omit_delegate_attrs: List[str] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: qcodes.instrument.instrument_base.InstrumentBase: Returns the parent instrument. By default this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

property root_instrument: qcodes.instrument.instrument_base.InstrumentBase

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters

param_name – The name of a parameter of this instrument.
value – The new value to set.

property short_name: str: Short name of the instrument

snapshot(update: Optional[bool] = False) → Dict[Any, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters: update – Passed to snapshot_base.
Returns: Base snapshot.

snapshot_base(update: Optional[bool] = False, params_to_skip_update: Optional[Sequence[str]] = None) → Dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters

update – If True, update the state by querying the instrument. If None update the state if known to be invalid. If False, just use the latest values in memory and never update state.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns

base snapshot

Return type

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

write_raw(cmd: str) → None

parameters: Dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: Dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: Dict[str, Union['InstrumentModule', 'ChannelTuple']] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: Dict[str, 'InstrumentModule'] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

class qcodes.instrument_drivers.Lakeshore.Model_325.Model_325_Sensor(parent: Model_325, name: str, inp: str)[source]

Bases: InstrumentChannel

A single sensor of a Lakeshore 325.

Parameters

parent (Model_325) – The instrument this heater belongs to
name (str) –
inp (str) – Either “A” or “B”

static decode_sensor_status(sum_of_codes: int) → str[source]

property curve: qcodes.instrument_drivers.Lakeshore.Model_325.Model_325_Curve

__getitem__(key: str) → Union[Callable[[...], Any], Parameter]: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Custom repr to give parent information

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only. If your case is more complicated, you’re probably better off simply making a new method in your Instrument subclass definition.

Parameters

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: Optional[Type[ParameterBase]] = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: Union[InstrumentModule, ChannelTuple]) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: List[qcodes.instrument.instrument_base.InstrumentBase]: Returns a list of instruments, starting from the current instrument and following to the parent instrument and the parents parent instrument until the root instrument is reached.

ask(cmd: str) → str

ask_raw(cmd: str) → str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns

The return value of the function.

delegate_attr_dicts: List[str] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: List[str] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

property full_name: str

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters: param_name – The name of a parameter of this instrument.
Returns: The current value of the parameter.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters: metadata – Metadata to load.

property name: str: Name of the instrument This is equivalent to full_name for backwards compatibility.

property name_parts: List[str]

omit_delegate_attrs: List[str] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: qcodes.instrument.instrument_base.InstrumentBase: Returns the parent instrument. By default this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

property root_instrument: qcodes.instrument.instrument_base.InstrumentBase

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters

param_name – The name of a parameter of this instrument.
value – The new value to set.

property short_name: str: Short name of the instrument

snapshot(update: Optional[bool] = False) → Dict[Any, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters: update – Passed to snapshot_base.
Returns: Base snapshot.

snapshot_base(update: Optional[bool] = False, params_to_skip_update: Optional[Sequence[str]] = None) → Dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters

update – If True, update the state by querying the instrument. If None update the state if known to be invalid. If False, just use the latest values in memory and never update state.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns

base snapshot

Return type

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

write_raw(cmd: str) → None

parameters: Dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: Dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: Dict[str, Union['InstrumentModule', 'ChannelTuple']] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: Dict[str, 'InstrumentModule'] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

class qcodes.instrument_drivers.Lakeshore.Model_325.Model_325_Heater(parent: Model_325, name: str, loop: int)[source]

Bases: InstrumentChannel

Heater control for the Lakeshore 325.

Parameters

parent (Model_325) – The instrument this heater belongs to
name (str) –
loop (int) – Either 1 or 2

__getitem__(key: str) → Union[Callable[[...], Any], Parameter]: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Custom repr to give parent information

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only. If your case is more complicated, you’re probably better off simply making a new method in your Instrument subclass definition.

Parameters

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: Optional[Type[ParameterBase]] = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: Union[InstrumentModule, ChannelTuple]) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: List[qcodes.instrument.instrument_base.InstrumentBase]: Returns a list of instruments, starting from the current instrument and following to the parent instrument and the parents parent instrument until the root instrument is reached.

ask(cmd: str) → str

ask_raw(cmd: str) → str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns

The return value of the function.

delegate_attr_dicts: List[str] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: List[str] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

property full_name: str

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters: param_name – The name of a parameter of this instrument.
Returns: The current value of the parameter.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters: metadata – Metadata to load.

property name: str: Name of the instrument This is equivalent to full_name for backwards compatibility.

property name_parts: List[str]

omit_delegate_attrs: List[str] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: qcodes.instrument.instrument_base.InstrumentBase: Returns the parent instrument. By default this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

property root_instrument: qcodes.instrument.instrument_base.InstrumentBase

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters

param_name – The name of a parameter of this instrument.
value – The new value to set.

property short_name: str: Short name of the instrument

snapshot(update: Optional[bool] = False) → Dict[Any, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters: update – Passed to snapshot_base.
Returns: Base snapshot.

snapshot_base(update: Optional[bool] = False, params_to_skip_update: Optional[Sequence[str]] = None) → Dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters

update – If True, update the state by querying the instrument. If None update the state if known to be invalid. If False, just use the latest values in memory and never update state.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns

base snapshot

Return type

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

write_raw(cmd: str) → None

parameters: Dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: Dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: Dict[str, Union['InstrumentModule', 'ChannelTuple']] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: Dict[str, 'InstrumentModule'] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

class qcodes.instrument_drivers.Lakeshore.Model_325.Model_325(*args: Any, **kwargs: Any)[source]

Bases: VisaInstrument

Lakeshore Model 325 Temperature Controller Driver

upload_curve(index: int, name: str, serial_number: str, data_dict: Dict[Any, Any]) → None[source]

Upload a curve to the given index

Parameters

index – The index to upload the curve to. We can only use indices reserved for user defined curves, 21-35
name –
serial_number –
data_dict – A dictionary containing the curve data

upload_curve_from_file(index: int, file_path: str) → None[source]: Upload a curve from a curve file. Note that we only support curve files with extension .330

__del__() → None: Close the instrument and remove its instance record.

__getitem__(key: str) → Union[Callable[[...], Any], Parameter]: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Simplified repr giving just the class and name.

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only. If your case is more complicated, you’re probably better off simply making a new method in your Instrument subclass definition.

Parameters

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: Optional[Type[ParameterBase]] = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: Union[InstrumentModule, ChannelTuple]) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: List[qcodes.instrument.instrument_base.InstrumentBase]: Returns a list of instruments, starting from the current instrument and following to the parent instrument and the parents parent instrument until the root instrument is reached.

ask(cmd: str) → str

Write a command string to the hardware and return a response.

Subclasses that transform cmd should override this method, and in it call super().ask(new_cmd). Subclasses that define a new hardware communication should instead override ask_raw.

Parameters: cmd – The string to send to the instrument.
Returns: response
Raises: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

ask_raw(cmd: str) → str

Low-level interface to visa_handle.ask.

Parameters: cmd – The command to send to the instrument.
Returns: The instrument’s response.
Return type: str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns

The return value of the function.

check_error(ret_code: int) → None

Default error checking, raises an error if return code !=0. Does not differentiate between warnings or specific error messages. Override this function in your driver if you want to add specific error messages.

Parameters: ret_code – A Visa error code. See eg: https://github.com/hgrecco/pyvisa/blob/master/pyvisa/errors.py
Raises: visa.VisaIOError – if ret_code indicates a communication problem.

close() → None: Disconnect and irreversibly tear down the instrument.

classmethod close_all() → None

Try to close all instruments registered in _all_instruments This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.

Examples

>>> atexit.register(qc.Instrument.close_all())

connect_message(idn_param: str = 'IDN', begin_time: Optional[float] = None) → None

Print a standard message on initial connection to an instrument.

Parameters

idn_param – Name of parameter that returns ID dict. Default IDN.
begin_time – time.time() when init started. Default is self._t0, set at start of Instrument.__init__.

delegate_attr_dicts: List[str] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: List[str] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

device_clear() → None: Clear the buffers of the device

static exist(name: str, instrument_class: Optional[type] = None) → bool

Check if an instrument with a given names exists (i.e. is already instantiated).

Parameters

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

classmethod find_instrument(name: str, instrument_class: Optional[Type[T]] = None) → T

Find an existing instrument by name.

Parameters

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

Returns

The instrument found.

Raises

KeyError – If no instrument of that name was found, or if its reference is invalid (dead).
TypeError – If a specific class was requested but a different type was found.

property full_name: str

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters: param_name – The name of a parameter of this instrument.
Returns: The current value of the parameter.

get_idn() → Dict[str, Optional[str]]

Parse a standard VISA *IDN? response into an ID dict.

Even though this is the VISA standard, it applies to various other types as well, such as IPInstruments, so it is included here in the Instrument base class.

Override this if your instrument does not support *IDN? or returns a nonstandard IDN string. This string is supposed to be a comma-separated list of vendor, model, serial, and firmware, but semicolon and colon are also common separators so we accept them here as well.

Returns: A dict containing vendor, model, serial, and firmware.

classmethod instances() → List[Instrument]

Get all currently defined instances of this instrument class.

You can use this to get the objects back if you lose track of them, and it’s also used by the test system to find objects to test against.

Returns: A list of instances.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

static is_valid(instr_instance: Instrument) → bool

Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a “valid” instrument.

Parameters: instr_instance – Instance of an Instrument class or its subclass.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters: metadata – Metadata to load.

property name: str: Name of the instrument This is equivalent to full_name for backwards compatibility.

property name_parts: List[str]

omit_delegate_attrs: List[str] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: Optional[qcodes.instrument.instrument_base.InstrumentBase]: Returns the parent instrument. By default this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

classmethod record_instance(instance: Instrument) → None

Record (a weak ref to) an instance in a class’s instance list.

Also records the instance in list of all instruments, and verifies that there are no other instruments with the same name.

This method is called after initialization of the instrument is completed.

Parameters: instance – Instance to record.
Raises: KeyError – If another instance with the same name is already present.

classmethod remove_instance(instance: Instrument) → None

Remove a particular instance from the record.

Parameters: instance – The instance to remove

property root_instrument: qcodes.instrument.instrument_base.InstrumentBase

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters

param_name – The name of a parameter of this instrument.
value – The new value to set.

set_address(address: str) → None

Set the address for this instrument.

Parameters: address – The visa resource name to use to connect. The address should be the actual address and just that. If you wish to change the backend for VISA, use the self.visalib attribute (and then call this function).

set_terminator(terminator: Optional[str]) → None

Change the read terminator to use.

Parameters: terminator – Character(s) to look for at the end of a read and to end each write command with. eg. \r\n. If None the terminator will not be set.

shared_kwargs = ()

property short_name: str: Short name of the instrument

snapshot(update: Optional[bool] = False) → Dict[Any, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters: update – Passed to snapshot_base.
Returns: Base snapshot.

snapshot_base(update: Optional[bool] = True, params_to_skip_update: Optional[Sequence[str]] = None) → Dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters

update – If True, update the state by querying the instrument. If None only update if the state is known to be invalid. If False, just use the latest values in memory and never update.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns

base snapshot

Return type

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

Write a command string with NO response to the hardware.

Subclasses that transform cmd should override this method, and in it call super().write(new_cmd). Subclasses that define a new hardware communication should instead override write_raw.

Parameters: cmd – The string to send to the instrument.
Raises: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

write_raw(cmd: str) → None

Low-level interface to visa_handle.write.

Parameters: cmd – The command to send to the instrument.

parameters: Dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: Dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: Dict[str, Union['InstrumentModule', 'ChannelTuple']] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: Dict[str, 'InstrumentModule'] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

qcodes.instrument_drivers.Lakeshore.Model_336 module

class qcodes.instrument_drivers.Lakeshore.Model_336.Output_336_CurrentSource(parent: Model_336, output_name: str, output_index: int)[source]

Bases: BaseOutput

Class for control outputs 1 and 2 of model 336 that are variable DC current sources referenced to chassis ground

MODES: ClassVar[Dict[str, int]] = {'closed_loop': 1, 'off': 0, 'open_loop': 3, 'zone': 2}

RANGES: ClassVar[Dict[str, int]] = {'high': 3, 'low': 1, 'medium': 2, 'off': 0}

__getitem__(key: str) → Union[Callable[[...], Any], Parameter]: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Custom repr to give parent information

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only. If your case is more complicated, you’re probably better off simply making a new method in your Instrument subclass definition.

Parameters

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: Optional[Type[ParameterBase]] = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: Union[InstrumentModule, ChannelTuple]) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: List[qcodes.instrument.instrument_base.InstrumentBase]: Returns a list of instruments, starting from the current instrument and following to the parent instrument and the parents parent instrument until the root instrument is reached.

ask(cmd: str) → str

ask_raw(cmd: str) → str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns

The return value of the function.

delegate_attr_dicts: List[str] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: List[str] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

property full_name: str

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters: param_name – The name of a parameter of this instrument.
Returns: The current value of the parameter.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters: metadata – Metadata to load.

property name: str: Name of the instrument This is equivalent to full_name for backwards compatibility.

property name_parts: List[str]

omit_delegate_attrs: List[str] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: qcodes.instrument.instrument_base.InstrumentBase: Returns the parent instrument. By default this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

property root_instrument: qcodes.instrument.instrument_base.InstrumentBase

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters

param_name – The name of a parameter of this instrument.
value – The new value to set.

set_range_from_temperature(temperature: float) → str

Sets the output range of this given heater from a given temperature.

The output range is determined by the limits given through the parameter range_limits. The output range is used for temperatures between the limits range_limits[i-1] and range_limits[i]; that is range_limits is the upper limit for using a certain heater current.

Parameters: temperature – temperature to set the range from
Returns: the value of the resulting output_range, that is also available from the output_range parameter itself

set_setpoint_and_range(temperature: float) → None

Sets the range from the given temperature, and then sets the setpoint to this given temperature.

Note that the preferred units of the heater output are expected to be kelvin.

Parameters: temperature – temperature in K

property short_name: str: Short name of the instrument

snapshot(update: Optional[bool] = False) → Dict[Any, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters: update – Passed to snapshot_base.
Returns: Base snapshot.

snapshot_base(update: Optional[bool] = False, params_to_skip_update: Optional[Sequence[str]] = None) → Dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters

update – If True, update the state by querying the instrument. If None update the state if known to be invalid. If False, just use the latest values in memory and never update state.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns

base snapshot

Return type

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters: verbose – If True, then information about the parameters that are being check is printed.

wait_until_set_point_reached(wait_cycle_time: Optional[float] = None, wait_tolerance: Optional[float] = None, wait_equilibration_time: Optional[float] = None) → None

This function runs a loop that monitors the value of the heater’s input channel until the read values is close to the setpoint value that has been set before.

Note that if the setpoint value is in a different range, this function may wait forever because that setpoint cannot be reached within the current range.

Parameters

wait_cycle_time – this time is being waited between the readings (same as wait_cycle_time parameter); if None, then the value of the corresponding wait_cycle_time parameter is used
wait_tolerance – this value is used to determine if the reading value is close enough to the setpoint value according to the following formula: abs(t_reading - t_setpoint)/t_reading < wait_tolerance (same as wait_tolerance parameter); if None, then the value of the corresponding wait_tolerance parameter is used
wait_equilibration_time – within this time, the reading value has to stay within the defined tolerance in order for this function to return (same as wait_equilibration_time parameter); if None, then the value of the corresponding wait_equilibration_time parameter is used

write(cmd: str) → None

write_raw(cmd: str) → None

parameters: Dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: Dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: Dict[str, Union['InstrumentModule', 'ChannelTuple']] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: Dict[str, 'InstrumentModule'] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

class qcodes.instrument_drivers.Lakeshore.Model_336.Output_336_VoltageSource(parent: Model_336, output_name: str, output_index: int)[source]

Bases: BaseOutput

Class for control outputs 3 and 4 of model 336 that are variable DC voltage sources

MODES: ClassVar[Dict[str, int]] = {'closed_loop': 1, 'monitor_out': 4, 'off': 0, 'open_loop': 3, 'warm_up': 5, 'zone': 2}

RANGES: ClassVar[Dict[str, int]] = {'high': 3, 'low': 1, 'medium': 2, 'off': 0}

__getitem__(key: str) → Union[Callable[[...], Any], Parameter]: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Custom repr to give parent information

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only. If your case is more complicated, you’re probably better off simply making a new method in your Instrument subclass definition.

Parameters

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: Optional[Type[ParameterBase]] = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: Union[InstrumentModule, ChannelTuple]) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: List[qcodes.instrument.instrument_base.InstrumentBase]: Returns a list of instruments, starting from the current instrument and following to the parent instrument and the parents parent instrument until the root instrument is reached.

ask(cmd: str) → str

ask_raw(cmd: str) → str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns

The return value of the function.

delegate_attr_dicts: List[str] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: List[str] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

property full_name: str

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters: param_name – The name of a parameter of this instrument.
Returns: The current value of the parameter.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters: metadata – Metadata to load.

property name: str: Name of the instrument This is equivalent to full_name for backwards compatibility.

property name_parts: List[str]

omit_delegate_attrs: List[str] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: qcodes.instrument.instrument_base.InstrumentBase: Returns the parent instrument. By default this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

property root_instrument: qcodes.instrument.instrument_base.InstrumentBase

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters

param_name – The name of a parameter of this instrument.
value – The new value to set.

set_range_from_temperature(temperature: float) → str

Sets the output range of this given heater from a given temperature.

The output range is determined by the limits given through the parameter range_limits. The output range is used for temperatures between the limits range_limits[i-1] and range_limits[i]; that is range_limits is the upper limit for using a certain heater current.

Parameters: temperature – temperature to set the range from
Returns: the value of the resulting output_range, that is also available from the output_range parameter itself

set_setpoint_and_range(temperature: float) → None

Sets the range from the given temperature, and then sets the setpoint to this given temperature.

Note that the preferred units of the heater output are expected to be kelvin.

Parameters: temperature – temperature in K

property short_name: str: Short name of the instrument

snapshot(update: Optional[bool] = False) → Dict[Any, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters: update – Passed to snapshot_base.
Returns: Base snapshot.

snapshot_base(update: Optional[bool] = False, params_to_skip_update: Optional[Sequence[str]] = None) → Dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters

update – If True, update the state by querying the instrument. If None update the state if known to be invalid. If False, just use the latest values in memory and never update state.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns

base snapshot

Return type

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters: verbose – If True, then information about the parameters that are being check is printed.

wait_until_set_point_reached(wait_cycle_time: Optional[float] = None, wait_tolerance: Optional[float] = None, wait_equilibration_time: Optional[float] = None) → None

This function runs a loop that monitors the value of the heater’s input channel until the read values is close to the setpoint value that has been set before.

Note that if the setpoint value is in a different range, this function may wait forever because that setpoint cannot be reached within the current range.

Parameters

wait_cycle_time – this time is being waited between the readings (same as wait_cycle_time parameter); if None, then the value of the corresponding wait_cycle_time parameter is used
wait_tolerance – this value is used to determine if the reading value is close enough to the setpoint value according to the following formula: abs(t_reading - t_setpoint)/t_reading < wait_tolerance (same as wait_tolerance parameter); if None, then the value of the corresponding wait_tolerance parameter is used
wait_equilibration_time – within this time, the reading value has to stay within the defined tolerance in order for this function to return (same as wait_equilibration_time parameter); if None, then the value of the corresponding wait_equilibration_time parameter is used

write(cmd: str) → None

write_raw(cmd: str) → None

parameters: Dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: Dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: Dict[str, Union['InstrumentModule', 'ChannelTuple']] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: Dict[str, 'InstrumentModule'] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

class qcodes.instrument_drivers.Lakeshore.Model_336.Model_336_Channel(parent: Model_336, name: str, channel: str)[source]

Bases: BaseSensorChannel

SENSOR_STATUSES: ClassVar[Dict[int, str]] = {0: 'OK', 1: 'Invalid Reading', 16: 'Temp Underrange', 32: 'Temp Overrange', 64: 'Sensor Units Zero', 128: 'Sensor Units Overrange'}

__getitem__(key: str) → Union[Callable[[...], Any], Parameter]: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Custom repr to give parent information

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only. If your case is more complicated, you’re probably better off simply making a new method in your Instrument subclass definition.

Parameters

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: Optional[Type[ParameterBase]] = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: Union[InstrumentModule, ChannelTuple]) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: List[qcodes.instrument.instrument_base.InstrumentBase]: Returns a list of instruments, starting from the current instrument and following to the parent instrument and the parents parent instrument until the root instrument is reached.

ask(cmd: str) → str

ask_raw(cmd: str) → str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns

The return value of the function.

delegate_attr_dicts: List[str] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: List[str] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

property full_name: str

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters: param_name – The name of a parameter of this instrument.
Returns: The current value of the parameter.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters: metadata – Metadata to load.

property name: str: Name of the instrument This is equivalent to full_name for backwards compatibility.

property name_parts: List[str]

omit_delegate_attrs: List[str] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: qcodes.instrument.instrument_base.InstrumentBase: Returns the parent instrument. By default this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

property root_instrument: qcodes.instrument.instrument_base.InstrumentBase

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters

param_name – The name of a parameter of this instrument.
value – The new value to set.

property short_name: str: Short name of the instrument

snapshot(update: Optional[bool] = False) → Dict[Any, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters: update – Passed to snapshot_base.
Returns: Base snapshot.

snapshot_base(update: Optional[bool] = False, params_to_skip_update: Optional[Sequence[str]] = None) → Dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters

update – If True, update the state by querying the instrument. If None update the state if known to be invalid. If False, just use the latest values in memory and never update state.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns

base snapshot

Return type

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

write_raw(cmd: str) → None

parameters: Dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: Dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: Dict[str, Union['InstrumentModule', 'ChannelTuple']] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: Dict[str, 'InstrumentModule'] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

class qcodes.instrument_drivers.Lakeshore.Model_336.Model_336(*args: Any, **kwargs: Any)[source]

Bases: LakeshoreBase

Lakeshore Model 336 Temperature Controller Driver

channel_name_command: Dict[str, str] = {'A': 'A', 'B': 'B', 'C': 'C', 'D': 'D'}

CHANNEL_CLASS: alias of Model_336_Channel

input_channel_parameter_values_to_channel_name_on_instrument: Dict[Any, str] = {'A': 'A', 'B': 'B', 'C': 'C', 'D': 'D'}

__del__() → None: Close the instrument and remove its instance record.

__getitem__(key: str) → Union[Callable[[...], Any], Parameter]: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Simplified repr giving just the class and name.

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only. If your case is more complicated, you’re probably better off simply making a new method in your Instrument subclass definition.

Parameters

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: Optional[Type[ParameterBase]] = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: Union[InstrumentModule, ChannelTuple]) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: List[qcodes.instrument.instrument_base.InstrumentBase]: Returns a list of instruments, starting from the current instrument and following to the parent instrument and the parents parent instrument until the root instrument is reached.

ask(cmd: str) → str

Write a command string to the hardware and return a response.

Subclasses that transform cmd should override this method, and in it call super().ask(new_cmd). Subclasses that define a new hardware communication should instead override ask_raw.

Parameters: cmd – The string to send to the instrument.
Returns: response
Raises: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

ask_raw(cmd: str) → str

Low-level interface to visa_handle.ask.

Parameters: cmd – The command to send to the instrument.
Returns: The instrument’s response.
Return type: str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns

The return value of the function.

check_error(ret_code: int) → None

Default error checking, raises an error if return code !=0. Does not differentiate between warnings or specific error messages. Override this function in your driver if you want to add specific error messages.

Parameters: ret_code – A Visa error code. See eg: https://github.com/hgrecco/pyvisa/blob/master/pyvisa/errors.py
Raises: visa.VisaIOError – if ret_code indicates a communication problem.

close() → None: Disconnect and irreversibly tear down the instrument.

classmethod close_all() → None

Try to close all instruments registered in _all_instruments This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.

Examples

>>> atexit.register(qc.Instrument.close_all())

connect_message(idn_param: str = 'IDN', begin_time: Optional[float] = None) → None

Print a standard message on initial connection to an instrument.

Parameters

idn_param – Name of parameter that returns ID dict. Default IDN.
begin_time – time.time() when init started. Default is self._t0, set at start of Instrument.__init__.

delegate_attr_dicts: List[str] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: List[str] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

device_clear() → None: Clear the buffers of the device

static exist(name: str, instrument_class: Optional[type] = None) → bool

Check if an instrument with a given names exists (i.e. is already instantiated).

Parameters

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

classmethod find_instrument(name: str, instrument_class: Optional[Type[T]] = None) → T

Find an existing instrument by name.

Parameters

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

Returns

The instrument found.

Raises

KeyError – If no instrument of that name was found, or if its reference is invalid (dead).
TypeError – If a specific class was requested but a different type was found.

property full_name: str

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters: param_name – The name of a parameter of this instrument.
Returns: The current value of the parameter.

get_idn() → Dict[str, Optional[str]]

Parse a standard VISA *IDN? response into an ID dict.

Even though this is the VISA standard, it applies to various other types as well, such as IPInstruments, so it is included here in the Instrument base class.

Override this if your instrument does not support *IDN? or returns a nonstandard IDN string. This string is supposed to be a comma-separated list of vendor, model, serial, and firmware, but semicolon and colon are also common separators so we accept them here as well.

Returns: A dict containing vendor, model, serial, and firmware.

classmethod instances() → List[Instrument]

Get all currently defined instances of this instrument class.

You can use this to get the objects back if you lose track of them, and it’s also used by the test system to find objects to test against.

Returns: A list of instances.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

static is_valid(instr_instance: Instrument) → bool

Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a “valid” instrument.

Parameters: instr_instance – Instance of an Instrument class or its subclass.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters: metadata – Metadata to load.

property name: str: Name of the instrument This is equivalent to full_name for backwards compatibility.

property name_parts: List[str]

omit_delegate_attrs: List[str] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: Optional[qcodes.instrument.instrument_base.InstrumentBase]: Returns the parent instrument. By default this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

classmethod record_instance(instance: Instrument) → None

Record (a weak ref to) an instance in a class’s instance list.

Also records the instance in list of all instruments, and verifies that there are no other instruments with the same name.

This method is called after initialization of the instrument is completed.

Parameters: instance – Instance to record.
Raises: KeyError – If another instance with the same name is already present.

classmethod remove_instance(instance: Instrument) → None

Remove a particular instance from the record.

Parameters: instance – The instance to remove

property root_instrument: qcodes.instrument.instrument_base.InstrumentBase

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters

param_name – The name of a parameter of this instrument.
value – The new value to set.

set_address(address: str) → None

Set the address for this instrument.

Parameters: address – The visa resource name to use to connect. The address should be the actual address and just that. If you wish to change the backend for VISA, use the self.visalib attribute (and then call this function).

set_terminator(terminator: Optional[str]) → None

Change the read terminator to use.

Parameters: terminator – Character(s) to look for at the end of a read and to end each write command with. eg. \r\n. If None the terminator will not be set.

shared_kwargs = ()

property short_name: str: Short name of the instrument

snapshot(update: Optional[bool] = False) → Dict[Any, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters: update – Passed to snapshot_base.
Returns: Base snapshot.

snapshot_base(update: Optional[bool] = True, params_to_skip_update: Optional[Sequence[str]] = None) → Dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters

update – If True, update the state by querying the instrument. If None only update if the state is known to be invalid. If False, just use the latest values in memory and never update.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns

base snapshot

Return type

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

Write a command string with NO response to the hardware.

Subclasses that transform cmd should override this method, and in it call super().write(new_cmd). Subclasses that define a new hardware communication should instead override write_raw.

Parameters: cmd – The string to send to the instrument.
Raises: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

write_raw(cmd: str) → None

Low-level interface to visa_handle.write.

Parameters: cmd – The command to send to the instrument.

parameters: Dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: Dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: Dict[str, Union['InstrumentModule', 'ChannelTuple']] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: Dict[str, 'InstrumentModule'] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

qcodes.instrument_drivers.Lakeshore.Model_372 module

class qcodes.instrument_drivers.Lakeshore.Model_372.Output_372(parent: Model_372, output_name: str, output_index: int)[source]

Bases: BaseOutput

Class for control outputs (heaters) of model 372

MODES: ClassVar[Dict[str, int]] = {'closed_loop': 5, 'monitor_out': 1, 'off': 0, 'open_loop': 2, 'still': 4, 'warm_up': 6, 'zone': 3}

POLARITIES: ClassVar[Dict[str, int]] = {'bipolar': 1, 'unipolar': 0}

RANGES: ClassVar[Dict[str, int]] = {'100mA': 8, '100μA': 2, '10mA': 6, '1mA': 4, '3.16mA': 5, '31.6mA': 7, '31.6μA': 1, '316μA': 3, 'off': 0}

__getitem__(key: str) → Union[Callable[[...], Any], Parameter]: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Custom repr to give parent information

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only. If your case is more complicated, you’re probably better off simply making a new method in your Instrument subclass definition.

Parameters

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: Optional[Type[ParameterBase]] = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: Union[InstrumentModule, ChannelTuple]) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: List[qcodes.instrument.instrument_base.InstrumentBase]: Returns a list of instruments, starting from the current instrument and following to the parent instrument and the parents parent instrument until the root instrument is reached.

ask(cmd: str) → str

ask_raw(cmd: str) → str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns

The return value of the function.

delegate_attr_dicts: List[str] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: List[str] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

property full_name: str

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters: param_name – The name of a parameter of this instrument.
Returns: The current value of the parameter.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters: metadata – Metadata to load.

property name: str: Name of the instrument This is equivalent to full_name for backwards compatibility.

property name_parts: List[str]

omit_delegate_attrs: List[str] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: qcodes.instrument.instrument_base.InstrumentBase: Returns the parent instrument. By default this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

property root_instrument: qcodes.instrument.instrument_base.InstrumentBase

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters

param_name – The name of a parameter of this instrument.
value – The new value to set.

set_range_from_temperature(temperature: float) → str

Sets the output range of this given heater from a given temperature.

The output range is determined by the limits given through the parameter range_limits. The output range is used for temperatures between the limits range_limits[i-1] and range_limits[i]; that is range_limits is the upper limit for using a certain heater current.

Parameters: temperature – temperature to set the range from
Returns: the value of the resulting output_range, that is also available from the output_range parameter itself

set_setpoint_and_range(temperature: float) → None

Sets the range from the given temperature, and then sets the setpoint to this given temperature.

Note that the preferred units of the heater output are expected to be kelvin.

Parameters: temperature – temperature in K

property short_name: str: Short name of the instrument

snapshot(update: Optional[bool] = False) → Dict[Any, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters: update – Passed to snapshot_base.
Returns: Base snapshot.

snapshot_base(update: Optional[bool] = False, params_to_skip_update: Optional[Sequence[str]] = None) → Dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters

update – If True, update the state by querying the instrument. If None update the state if known to be invalid. If False, just use the latest values in memory and never update state.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns

base snapshot

Return type

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters: verbose – If True, then information about the parameters that are being check is printed.

wait_until_set_point_reached(wait_cycle_time: Optional[float] = None, wait_tolerance: Optional[float] = None, wait_equilibration_time: Optional[float] = None) → None

This function runs a loop that monitors the value of the heater’s input channel until the read values is close to the setpoint value that has been set before.

Note that if the setpoint value is in a different range, this function may wait forever because that setpoint cannot be reached within the current range.

Parameters

wait_cycle_time – this time is being waited between the readings (same as wait_cycle_time parameter); if None, then the value of the corresponding wait_cycle_time parameter is used
wait_tolerance – this value is used to determine if the reading value is close enough to the setpoint value according to the following formula: abs(t_reading - t_setpoint)/t_reading < wait_tolerance (same as wait_tolerance parameter); if None, then the value of the corresponding wait_tolerance parameter is used
wait_equilibration_time – within this time, the reading value has to stay within the defined tolerance in order for this function to return (same as wait_equilibration_time parameter); if None, then the value of the corresponding wait_equilibration_time parameter is used

write(cmd: str) → None

write_raw(cmd: str) → None

parameters: Dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: Dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: Dict[str, Union['InstrumentModule', 'ChannelTuple']] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: Dict[str, 'InstrumentModule'] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

class qcodes.instrument_drivers.Lakeshore.Model_372.Model_372_Channel(parent: Model_372, name: str, channel: str)[source]

Bases: BaseSensorChannel

SENSOR_STATUSES: ClassVar[Dict[int, str]] = {0: 'OK', 1: 'CS OVL', 2: 'VCM OVL', 4: 'VMIX OVL', 8: 'VDIF OVL', 16: 'R. OVER', 32: 'R. UNDER', 64: 'T. OVER', 128: 'T. UNDER'}

__getitem__(key: str) → Union[Callable[[...], Any], Parameter]: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Custom repr to give parent information

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only. If your case is more complicated, you’re probably better off simply making a new method in your Instrument subclass definition.

Parameters

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: Optional[Type[ParameterBase]] = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: Union[InstrumentModule, ChannelTuple]) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: List[qcodes.instrument.instrument_base.InstrumentBase]: Returns a list of instruments, starting from the current instrument and following to the parent instrument and the parents parent instrument until the root instrument is reached.

ask(cmd: str) → str

ask_raw(cmd: str) → str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns

The return value of the function.

delegate_attr_dicts: List[str] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: List[str] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

property full_name: str

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters: param_name – The name of a parameter of this instrument.
Returns: The current value of the parameter.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters: metadata – Metadata to load.

property name: str: Name of the instrument This is equivalent to full_name for backwards compatibility.

property name_parts: List[str]

omit_delegate_attrs: List[str] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: qcodes.instrument.instrument_base.InstrumentBase: Returns the parent instrument. By default this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

property root_instrument: qcodes.instrument.instrument_base.InstrumentBase

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters

param_name – The name of a parameter of this instrument.
value – The new value to set.

property short_name: str: Short name of the instrument

snapshot(update: Optional[bool] = False) → Dict[Any, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters: update – Passed to snapshot_base.
Returns: Base snapshot.

snapshot_base(update: Optional[bool] = False, params_to_skip_update: Optional[Sequence[str]] = None) → Dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters

update – If True, update the state by querying the instrument. If None update the state if known to be invalid. If False, just use the latest values in memory and never update state.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns

base snapshot

Return type

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

write_raw(cmd: str) → None

parameters: Dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: Dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: Dict[str, Union['InstrumentModule', 'ChannelTuple']] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: Dict[str, 'InstrumentModule'] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

class qcodes.instrument_drivers.Lakeshore.Model_372.Model_372(*args: Any, **kwargs: Any)[source]

Bases: LakeshoreBase

Lakeshore Model 372 Temperature Controller Driver

Note that interaction with the control input (referred to as ‘A’ in the Computer Interface Operation section of the manual) is not implemented.

channel_name_command: Dict[str, str] = {'ch01': '1', 'ch02': '2', 'ch03': '3', 'ch04': '4', 'ch05': '5', 'ch06': '6', 'ch07': '7', 'ch08': '8', 'ch09': '9', 'ch10': '10', 'ch11': '11', 'ch12': '12', 'ch13': '13', 'ch14': '14', 'ch15': '15', 'ch16': '16'}

input_channel_parameter_values_to_channel_name_on_instrument: Dict[Any, str] = {1: 'ch01', 2: 'ch02', 3: 'ch03', 4: 'ch04', 5: 'ch05', 6: 'ch06', 7: 'ch07', 8: 'ch08', 9: 'ch09', 10: 'ch10', 11: 'ch11', 12: 'ch12', 13: 'ch13', 14: 'ch14', 15: 'ch15', 16: 'ch16'}

CHANNEL_CLASS: alias of Model_372_Channel

__del__() → None: Close the instrument and remove its instance record.

__getitem__(key: str) → Union[Callable[[...], Any], Parameter]: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Simplified repr giving just the class and name.

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only. If your case is more complicated, you’re probably better off simply making a new method in your Instrument subclass definition.

Parameters

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: Optional[Type[ParameterBase]] = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: Union[InstrumentModule, ChannelTuple]) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: List[qcodes.instrument.instrument_base.InstrumentBase]: Returns a list of instruments, starting from the current instrument and following to the parent instrument and the parents parent instrument until the root instrument is reached.

ask(cmd: str) → str

Write a command string to the hardware and return a response.

Subclasses that transform cmd should override this method, and in it call super().ask(new_cmd). Subclasses that define a new hardware communication should instead override ask_raw.

Parameters: cmd – The string to send to the instrument.
Returns: response
Raises: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

ask_raw(cmd: str) → str

Low-level interface to visa_handle.ask.

Parameters: cmd – The command to send to the instrument.
Returns: The instrument’s response.
Return type: str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns

The return value of the function.

check_error(ret_code: int) → None

Default error checking, raises an error if return code !=0. Does not differentiate between warnings or specific error messages. Override this function in your driver if you want to add specific error messages.

Parameters: ret_code – A Visa error code. See eg: https://github.com/hgrecco/pyvisa/blob/master/pyvisa/errors.py
Raises: visa.VisaIOError – if ret_code indicates a communication problem.

close() → None: Disconnect and irreversibly tear down the instrument.

classmethod close_all() → None

Try to close all instruments registered in _all_instruments This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.

Examples

>>> atexit.register(qc.Instrument.close_all())

connect_message(idn_param: str = 'IDN', begin_time: Optional[float] = None) → None

Print a standard message on initial connection to an instrument.

Parameters

idn_param – Name of parameter that returns ID dict. Default IDN.
begin_time – time.time() when init started. Default is self._t0, set at start of Instrument.__init__.

delegate_attr_dicts: List[str] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: List[str] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

device_clear() → None: Clear the buffers of the device

static exist(name: str, instrument_class: Optional[type] = None) → bool

Check if an instrument with a given names exists (i.e. is already instantiated).

Parameters

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

classmethod find_instrument(name: str, instrument_class: Optional[Type[T]] = None) → T

Find an existing instrument by name.

Parameters

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

Returns

The instrument found.

Raises

KeyError – If no instrument of that name was found, or if its reference is invalid (dead).
TypeError – If a specific class was requested but a different type was found.

property full_name: str

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters: param_name – The name of a parameter of this instrument.
Returns: The current value of the parameter.

get_idn() → Dict[str, Optional[str]]

Parse a standard VISA *IDN? response into an ID dict.

Even though this is the VISA standard, it applies to various other types as well, such as IPInstruments, so it is included here in the Instrument base class.

Override this if your instrument does not support *IDN? or returns a nonstandard IDN string. This string is supposed to be a comma-separated list of vendor, model, serial, and firmware, but semicolon and colon are also common separators so we accept them here as well.

Returns: A dict containing vendor, model, serial, and firmware.

classmethod instances() → List[Instrument]

Get all currently defined instances of this instrument class.

You can use this to get the objects back if you lose track of them, and it’s also used by the test system to find objects to test against.

Returns: A list of instances.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

static is_valid(instr_instance: Instrument) → bool

Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a “valid” instrument.

Parameters: instr_instance – Instance of an Instrument class or its subclass.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters: metadata – Metadata to load.

property name: str: Name of the instrument This is equivalent to full_name for backwards compatibility.

property name_parts: List[str]

omit_delegate_attrs: List[str] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: Optional[qcodes.instrument.instrument_base.InstrumentBase]: Returns the parent instrument. By default this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

classmethod record_instance(instance: Instrument) → None

Record (a weak ref to) an instance in a class’s instance list.

Also records the instance in list of all instruments, and verifies that there are no other instruments with the same name.

This method is called after initialization of the instrument is completed.

Parameters: instance – Instance to record.
Raises: KeyError – If another instance with the same name is already present.

classmethod remove_instance(instance: Instrument) → None

Remove a particular instance from the record.

Parameters: instance – The instance to remove

property root_instrument: qcodes.instrument.instrument_base.InstrumentBase

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters

param_name – The name of a parameter of this instrument.
value – The new value to set.

set_address(address: str) → None

Set the address for this instrument.

Parameters: address – The visa resource name to use to connect. The address should be the actual address and just that. If you wish to change the backend for VISA, use the self.visalib attribute (and then call this function).

set_terminator(terminator: Optional[str]) → None

Change the read terminator to use.

Parameters: terminator – Character(s) to look for at the end of a read and to end each write command with. eg. \r\n. If None the terminator will not be set.

shared_kwargs = ()

property short_name: str: Short name of the instrument

snapshot(update: Optional[bool] = False) → Dict[Any, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters: update – Passed to snapshot_base.
Returns: Base snapshot.

snapshot_base(update: Optional[bool] = True, params_to_skip_update: Optional[Sequence[str]] = None) → Dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters

update – If True, update the state by querying the instrument. If None only update if the state is known to be invalid. If False, just use the latest values in memory and never update.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns

base snapshot

Return type

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

Write a command string with NO response to the hardware.

Subclasses that transform cmd should override this method, and in it call super().write(new_cmd). Subclasses that define a new hardware communication should instead override write_raw.

Parameters: cmd – The string to send to the instrument.
Raises: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

write_raw(cmd: str) → None

Low-level interface to visa_handle.write.

Parameters: cmd – The command to send to the instrument.

parameters: Dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: Dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: Dict[str, Union['InstrumentModule', 'ChannelTuple']] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: Dict[str, 'InstrumentModule'] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

qcodes.instrument_drivers.Lakeshore.lakeshore_base module

class qcodes.instrument_drivers.Lakeshore.lakeshore_base.BaseOutput(parent: LakeshoreBase, output_name: str, output_index: int, has_pid: bool = True)[source]

Bases: InstrumentChannel

Base class for the outputs of Lakeshore temperature controllers

Parameters

parent – instrument that this channel belongs to
output_name – name of this output
output_index – identifier for this output that is used in VISA commands of the instrument
has_pid – if True, then the output supports closed loop control, hence it will have three parameters to set it up: ‘P’, ‘I’, and ‘D’

MODES: ClassVar[Dict[str, int]] = {}

RANGES: ClassVar[Dict[str, int]] = {}

set_range_from_temperature(temperature: float) → str[source]

Sets the output range of this given heater from a given temperature.

The output range is determined by the limits given through the parameter range_limits. The output range is used for temperatures between the limits range_limits[i-1] and range_limits[i]; that is range_limits is the upper limit for using a certain heater current.

Parameters: temperature – temperature to set the range from
Returns: the value of the resulting output_range, that is also available from the output_range parameter itself

set_setpoint_and_range(temperature: float) → None[source]

Sets the range from the given temperature, and then sets the setpoint to this given temperature.

Note that the preferred units of the heater output are expected to be kelvin.

Parameters: temperature – temperature in K

wait_until_set_point_reached(wait_cycle_time: Optional[float] = None, wait_tolerance: Optional[float] = None, wait_equilibration_time: Optional[float] = None) → None[source]

This function runs a loop that monitors the value of the heater’s input channel until the read values is close to the setpoint value that has been set before.

Note that if the setpoint value is in a different range, this function may wait forever because that setpoint cannot be reached within the current range.

Parameters

wait_cycle_time – this time is being waited between the readings (same as wait_cycle_time parameter); if None, then the value of the corresponding wait_cycle_time parameter is used
wait_tolerance – this value is used to determine if the reading value is close enough to the setpoint value according to the following formula: abs(t_reading - t_setpoint)/t_reading < wait_tolerance (same as wait_tolerance parameter); if None, then the value of the corresponding wait_tolerance parameter is used
wait_equilibration_time – within this time, the reading value has to stay within the defined tolerance in order for this function to return (same as wait_equilibration_time parameter); if None, then the value of the corresponding wait_equilibration_time parameter is used

__getitem__(key: str) → Union[Callable[[...], Any], Parameter]: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Custom repr to give parent information

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only. If your case is more complicated, you’re probably better off simply making a new method in your Instrument subclass definition.

Parameters

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: Optional[Type[ParameterBase]] = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: Union[InstrumentModule, ChannelTuple]) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: List[qcodes.instrument.instrument_base.InstrumentBase]: Returns a list of instruments, starting from the current instrument and following to the parent instrument and the parents parent instrument until the root instrument is reached.

ask(cmd: str) → str

ask_raw(cmd: str) → str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns

The return value of the function.

delegate_attr_dicts: List[str] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: List[str] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

property full_name: str

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters: param_name – The name of a parameter of this instrument.
Returns: The current value of the parameter.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters: metadata – Metadata to load.

property name: str: Name of the instrument This is equivalent to full_name for backwards compatibility.

property name_parts: List[str]

omit_delegate_attrs: List[str] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: qcodes.instrument.instrument_base.InstrumentBase: Returns the parent instrument. By default this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

property root_instrument: qcodes.instrument.instrument_base.InstrumentBase

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters

param_name – The name of a parameter of this instrument.
value – The new value to set.

property short_name: str: Short name of the instrument

snapshot(update: Optional[bool] = False) → Dict[Any, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters: update – Passed to snapshot_base.
Returns: Base snapshot.

snapshot_base(update: Optional[bool] = False, params_to_skip_update: Optional[Sequence[str]] = None) → Dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters

update – If True, update the state by querying the instrument. If None update the state if known to be invalid. If False, just use the latest values in memory and never update state.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns

base snapshot

Return type

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

write_raw(cmd: str) → None

parameters: Dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: Dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: Dict[str, Union['InstrumentModule', 'ChannelTuple']] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: Dict[str, 'InstrumentModule'] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

class qcodes.instrument_drivers.Lakeshore.lakeshore_base.BaseSensorChannel(parent: LakeshoreBase, name: str, channel: str)[source]

Bases: InstrumentChannel

Base class for Lakeshore Temperature Controller sensor channels

Parameters

parent – instrument instance that this channel belongs to
name – name of the channel
channel – string identifier of the channel as referenced in commands; for example, ‘1’ or ‘6’ for model 372, or ‘A’ and ‘C’ for model 336

SENSOR_STATUSES: ClassVar[Dict[int, str]] = {}

__getitem__(key: str) → Union[Callable[[...], Any], Parameter]: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Custom repr to give parent information

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only. If your case is more complicated, you’re probably better off simply making a new method in your Instrument subclass definition.

Parameters

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: Optional[Type[ParameterBase]] = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: Union[InstrumentModule, ChannelTuple]) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: List[qcodes.instrument.instrument_base.InstrumentBase]: Returns a list of instruments, starting from the current instrument and following to the parent instrument and the parents parent instrument until the root instrument is reached.

ask(cmd: str) → str

ask_raw(cmd: str) → str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns

The return value of the function.

delegate_attr_dicts: List[str] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: List[str] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

property full_name: str

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters: param_name – The name of a parameter of this instrument.
Returns: The current value of the parameter.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters: metadata – Metadata to load.

property name: str: Name of the instrument This is equivalent to full_name for backwards compatibility.

property name_parts: List[str]

omit_delegate_attrs: List[str] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: qcodes.instrument.instrument_base.InstrumentBase: Returns the parent instrument. By default this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

property root_instrument: qcodes.instrument.instrument_base.InstrumentBase

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters

param_name – The name of a parameter of this instrument.
value – The new value to set.

property short_name: str: Short name of the instrument

snapshot(update: Optional[bool] = False) → Dict[Any, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters: update – Passed to snapshot_base.
Returns: Base snapshot.

snapshot_base(update: Optional[bool] = False, params_to_skip_update: Optional[Sequence[str]] = None) → Dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters

update – If True, update the state by querying the instrument. If None update the state if known to be invalid. If False, just use the latest values in memory and never update state.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns

base snapshot

Return type

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

write_raw(cmd: str) → None

parameters: Dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: Dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: Dict[str, Union['InstrumentModule', 'ChannelTuple']] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: Dict[str, 'InstrumentModule'] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

class qcodes.instrument_drivers.Lakeshore.lakeshore_base.LakeshoreBase(*args: Any, **kwargs: Any)[source]

Bases: VisaInstrument

This base class has been written to be that base for the Lakeshore 336 and 372. There are probably other lakeshore modes that can use the functionality provided here. If you add another lakeshore driver please make sure to extend this class accordingly, or create a new one.

In order to use a variation of the BaseSensorChannel class for sensor channels, just set CHANNEL_CLASS to that variation of the class inside your LakeshoreBase’s subclass.

In order to add heaters (output channels) to the driver, add BaseOutput instances (subclasses of those) in your LakeshoreBase’s subclass constructor via add_submodule method.

CHANNEL_CLASS: alias of BaseSensorChannel

channel_name_command: Dict[str, str] = {}

input_channel_parameter_values_to_channel_name_on_instrument: Dict[Any, str]

__del__() → None: Close the instrument and remove its instance record.

__getitem__(key: str) → Union[Callable[[...], Any], Parameter]: Delegate instrument[‘name’] to parameter or function ‘name’.

__getstate__() → None: Prevent pickling instruments, and give a nice error message.

__repr__() → str: Simplified repr giving just the class and name.

add_function(name: str, **kwargs: Any) → None

Bind one Function to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real function of the instrument.

This functionality is meant for simple cases, principally things that map to simple commands like *RST (reset) or those with just a few arguments. It requires a fixed argument count, and positional args only. If your case is more complicated, you’re probably better off simply making a new method in your Instrument subclass definition.

Parameters

name – How the Function will be stored within instrument.Functions and also how you address it using the shortcut methods: instrument.call(func_name, *args) etc.
**kwargs – constructor kwargs for Function

Raises

KeyError – If this instrument already has a function with this name.

add_parameter(name: str, parameter_class: Optional[Type[ParameterBase]] = None, **kwargs: Any) → None

Bind one Parameter to this instrument.

Instrument subclasses can call this repeatedly in their __init__ for every real parameter of the instrument.

In this sense, parameters are the state variables of the instrument, anything the user can set and/or get.

Parameters

name – How the parameter will be stored within parameters and also how you address it using the shortcut methods: instrument.set(param_name, value) etc.
parameter_class – You can construct the parameter out of any class. Default parameters.Parameter.
**kwargs – Constructor arguments for parameter_class.

Raises

KeyError – If this instrument already has a parameter with this name and the parameter being replaced is not an abstract parameter.
ValueError – If there is an existing abstract parameter and the unit of the new parameter is inconsistent with the existing one.

add_submodule(name: str, submodule: Union[InstrumentModule, ChannelTuple]) → None

Bind one submodule to this instrument.

Instrument subclasses can call this repeatedly in their __init__ method for every submodule of the instrument.

Submodules can effectively be considered as instruments within the main instrument, and should at minimum be snapshottable. For example, they can be used to either store logical groupings of parameters, which may or may not be repeated, or channel lists. They should either be an instance of an InstrumentModule or a ChannelTuple.

Parameters

name – How the submodule will be stored within instrument.submodules and also how it can be addressed.
submodule – The submodule to be stored.

Raises

KeyError – If this instrument already contains a submodule with this name.
TypeError – If the submodule that we are trying to add is not an instance of an Metadatable object.

property ancestors: List[qcodes.instrument.instrument_base.InstrumentBase]: Returns a list of instruments, starting from the current instrument and following to the parent instrument and the parents parent instrument until the root instrument is reached.

ask(cmd: str) → str

Write a command string to the hardware and return a response.

Subclasses that transform cmd should override this method, and in it call super().ask(new_cmd). Subclasses that define a new hardware communication should instead override ask_raw.

Parameters: cmd – The string to send to the instrument.
Returns: response
Raises: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

ask_raw(cmd: str) → str

Low-level interface to visa_handle.ask.

Parameters: cmd – The command to send to the instrument.
Returns: The instrument’s response.
Return type: str

call(func_name: str, *args: Any) → Any

Shortcut for calling a function from its name.

Parameters

func_name – The name of a function of this instrument.
*args – any arguments to the function.

Returns

The return value of the function.

check_error(ret_code: int) → None

Default error checking, raises an error if return code !=0. Does not differentiate between warnings or specific error messages. Override this function in your driver if you want to add specific error messages.

Parameters: ret_code – A Visa error code. See eg: https://github.com/hgrecco/pyvisa/blob/master/pyvisa/errors.py
Raises: visa.VisaIOError – if ret_code indicates a communication problem.

close() → None: Disconnect and irreversibly tear down the instrument.

classmethod close_all() → None

Try to close all instruments registered in _all_instruments This is handy for use with atexit to ensure that all instruments are closed when a python session is closed.

Examples

>>> atexit.register(qc.Instrument.close_all())

connect_message(idn_param: str = 'IDN', begin_time: Optional[float] = None) → None

Print a standard message on initial connection to an instrument.

Parameters

idn_param – Name of parameter that returns ID dict. Default IDN.
begin_time – time.time() when init started. Default is self._t0, set at start of Instrument.__init__.

delegate_attr_dicts: List[str] = ['parameters', 'functions', 'submodules']: A list of names (strings) of dictionaries which are (or will be) attributes of self, whose keys should be treated as attributes of self.

delegate_attr_objects: List[str] = []: A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.

device_clear() → None: Clear the buffers of the device

static exist(name: str, instrument_class: Optional[type] = None) → bool

Check if an instrument with a given names exists (i.e. is already instantiated).

Parameters

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

classmethod find_instrument(name: str, instrument_class: Optional[Type[T]] = None) → T

Find an existing instrument by name.

Parameters

name – Name of the instrument.
instrument_class – The type of instrument you are looking for.

Returns

The instrument found.

Raises

KeyError – If no instrument of that name was found, or if its reference is invalid (dead).
TypeError – If a specific class was requested but a different type was found.

property full_name: str

get(param_name: str) → Any

Shortcut for getting a parameter from its name.

Parameters: param_name – The name of a parameter of this instrument.
Returns: The current value of the parameter.

get_idn() → Dict[str, Optional[str]]

Parse a standard VISA *IDN? response into an ID dict.

Even though this is the VISA standard, it applies to various other types as well, such as IPInstruments, so it is included here in the Instrument base class.

Override this if your instrument does not support *IDN? or returns a nonstandard IDN string. This string is supposed to be a comma-separated list of vendor, model, serial, and firmware, but semicolon and colon are also common separators so we accept them here as well.

Returns: A dict containing vendor, model, serial, and firmware.

classmethod instances() → List[Instrument]

Get all currently defined instances of this instrument class.

You can use this to get the objects back if you lose track of them, and it’s also used by the test system to find objects to test against.

Returns: A list of instances.

invalidate_cache() → None

Invalidate the cache of all parameters on the instrument. Calling this method will recursively mark the cache of all parameters on the instrument and any parameter on instrument modules as invalid.

This is useful if you have performed manual operations (e.g. using the frontpanel) which changes the state of the instrument outside QCoDeS.

This in turn means that the next snapshot of the instrument will trigger a (potentially slow) reread of all parameters of the instrument if you pass update=None to snapshot.

static is_valid(instr_instance: Instrument) → bool

Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a “valid” instrument.

Parameters: instr_instance – Instance of an Instrument class or its subclass.

load_metadata(metadata: Mapping[str, Any]) → None

Load metadata into this classes metadata dictionary.

Parameters: metadata – Metadata to load.

property name: str: Name of the instrument This is equivalent to full_name for backwards compatibility.

property name_parts: List[str]

omit_delegate_attrs: List[str] = []: A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: Optional[qcodes.instrument.instrument_base.InstrumentBase]: Returns the parent instrument. By default this is None. Any SubInstrument should subclass this to return the parent instrument.

print_readable_snapshot(update: bool = False, max_chars: int = 80) → None

Prints a readable version of the snapshot. The readable snapshot includes the name, value and unit of each parameter. A convenience function to quickly get an overview of the status of an instrument.

Parameters

update – If True, update the state by querying the instrument. If False, just use the latest values in memory. This argument gets passed to the snapshot function.
max_chars – the maximum number of characters per line. The readable snapshot will be cropped if this value is exceeded. Defaults to 80 to be consistent with default terminal width.

classmethod record_instance(instance: Instrument) → None

Record (a weak ref to) an instance in a class’s instance list.

Also records the instance in list of all instruments, and verifies that there are no other instruments with the same name.

This method is called after initialization of the instrument is completed.

Parameters: instance – Instance to record.
Raises: KeyError – If another instance with the same name is already present.

classmethod remove_instance(instance: Instrument) → None

Remove a particular instance from the record.

Parameters: instance – The instance to remove

property root_instrument: qcodes.instrument.instrument_base.InstrumentBase

set(param_name: str, value: Any) → None

Shortcut for setting a parameter from its name and new value.

Parameters

param_name – The name of a parameter of this instrument.
value – The new value to set.

set_address(address: str) → None

Set the address for this instrument.

Parameters: address – The visa resource name to use to connect. The address should be the actual address and just that. If you wish to change the backend for VISA, use the self.visalib attribute (and then call this function).

set_terminator(terminator: Optional[str]) → None

Change the read terminator to use.

Parameters: terminator – Character(s) to look for at the end of a read and to end each write command with. eg. \r\n. If None the terminator will not be set.

shared_kwargs = ()

property short_name: str: Short name of the instrument

snapshot(update: Optional[bool] = False) → Dict[Any, Any]

Decorate a snapshot dictionary with metadata. DO NOT override this method if you want metadata in the snapshot instead, override snapshot_base().

Parameters: update – Passed to snapshot_base.
Returns: Base snapshot.

snapshot_base(update: Optional[bool] = True, params_to_skip_update: Optional[Sequence[str]] = None) → Dict[Any, Any]

State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).

Parameters

update – If True, update the state by querying the instrument. If None only update if the state is known to be invalid. If False, just use the latest values in memory and never update.
params_to_skip_update – List of parameter names that will be skipped in update even if update is True. This is useful if you have parameters that are slow to update but can be updated in a different way (as in the qdac). If you want to skip the update of certain parameters in all snapshots, use the snapshot_get attribute of those parameters instead.

Returns

base snapshot

Return type

dict

validate_status(verbose: bool = False) → None

Validate the values of all gettable parameters

The validation is done for all parameters that have both a get and set method.

Parameters: verbose – If True, then information about the parameters that are being check is printed.

write(cmd: str) → None

Write a command string with NO response to the hardware.

Subclasses that transform cmd should override this method, and in it call super().write(new_cmd). Subclasses that define a new hardware communication should instead override write_raw.

Parameters: cmd – The string to send to the instrument.
Raises: Exception – Wraps any underlying exception with extra context, including the command and the instrument.

write_raw(cmd: str) → None

Low-level interface to visa_handle.write.

Parameters: cmd – The command to send to the instrument.

parameters: Dict[str, ParameterBase] = {}: All the parameters supported by this instrument. Usually populated via add_parameter().

functions: Dict[str, Function] = {}: All the functions supported by this instrument. Usually populated via add_function().

submodules: Dict[str, Union['InstrumentModule', 'ChannelTuple']] = {}: All the submodules of this instrument such as channel lists or logical groupings of parameters. Usually populated via add_submodule().

instrument_modules: Dict[str, 'InstrumentModule'] = {}: All the InstrumentModule of this instrument Usually populated via add_submodule().

qcodes.instrument_drivers.Lakeshore package

Submodules

qcodes.instrument_drivers.Lakeshore.Model_325 module

qcodes.instrument_drivers.Lakeshore.Model_336 module

qcodes.instrument_drivers.Lakeshore.Model_372 module

qcodes.instrument_drivers.Lakeshore.lakeshore_base module

Module contents