qcodes.instrument_drivers.HP package
Submodules
qcodes.instrument_drivers.HP.HP8133A module
- class qcodes.instrument_drivers.HP.HP8133A.HP8133A(*args: Any, **kwargs: Any)[source]
Bases:
qcodes.instrument.visa.VisaInstrument
This is the code for Hewlett Packard 8133A Pulse Generator
- __getitem__(key: str) Union[Callable[[...], Any], qcodes.instrument.parameter.Parameter]
Delegate instrument[‘name’] to parameter or function ‘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 yourInstrument
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: type = <class 'qcodes.instrument.parameter.Parameter'>, **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
instrument.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
parameter.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 aChannelTuple
.- 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
- property ancestors: List[qcodes.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 callsuper().ask(new_cmd)
. Subclasses that define a new hardware communication should instead overrideask_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
- 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.
- 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 isself._t0
, set at start ofInstrument.__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 ofself
.
- 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 toself
.
- 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[qcodes.instrument.base.T]] = None) qcodes.instrument.base.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
- 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[qcodes.instrument.base.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: qcodes.instrument.base.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.
- 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.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. IfFalse
, 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: qcodes.instrument.base.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: qcodes.instrument.base.Instrument) None
Remove a particular instance from the record.
- Parameters
instance – The instance to remove
- property root_instrument: qcodes.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: str) None
Change the read terminator to use.
- Parameters
terminator – Character(s) to look for at the end of a read. eg.
\r\n
.
- 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
qcodes.utils.helpers.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
- 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 callsuper().write(new_cmd)
. Subclasses that define a new hardware communication should instead overridewrite_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, _BaseParameter] = {}
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 instrument_modules of this instrument Usually populated via
add_submodule()
.
qcodes.instrument_drivers.HP.HP8753D module
- class qcodes.instrument_drivers.HP.HP8753D.HP8753D(*args: Any, **kwargs: Any)[source]
Bases:
qcodes.instrument.visa.VisaInstrument
This is the QCoDeS driver for the Hewlett Packard 8753D Network Analyzer
- run_N_times(N: int) None [source]
Run N sweeps and then hold. We wait for a response before returning
- invalidate_trace(cmd: str, value: Union[float, int, str]) None [source]
Wrapper for set_cmds that make the trace not ready
- __getitem__(key: str) Union[Callable[[...], Any], qcodes.instrument.parameter.Parameter]
Delegate instrument[‘name’] to parameter or function ‘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 yourInstrument
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: type = <class 'qcodes.instrument.parameter.Parameter'>, **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
instrument.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
parameter.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 aChannelTuple
.- 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
- property ancestors: List[qcodes.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 callsuper().ask(new_cmd)
. Subclasses that define a new hardware communication should instead overrideask_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
- 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.
- 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 isself._t0
, set at start ofInstrument.__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 ofself
.
- 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 toself
.
- 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[qcodes.instrument.base.T]] = None) qcodes.instrument.base.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
- 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[qcodes.instrument.base.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: qcodes.instrument.base.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.
- 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.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. IfFalse
, 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: qcodes.instrument.base.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: qcodes.instrument.base.Instrument) None
Remove a particular instance from the record.
- Parameters
instance – The instance to remove
- property root_instrument: qcodes.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: str) None
Change the read terminator to use.
- Parameters
terminator – Character(s) to look for at the end of a read. eg.
\r\n
.
- 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
qcodes.utils.helpers.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
- 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 callsuper().write(new_cmd)
. Subclasses that define a new hardware communication should instead overridewrite_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, _BaseParameter] = {}
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 instrument_modules of this instrument Usually populated via
add_submodule()
.
- class qcodes.instrument_drivers.HP.HP8753D.HP8753DTrace(name: str, instrument: qcodes.instrument_drivers.HP.HP8753D.HP8753D)[source]
Bases:
qcodes.instrument.parameter.ArrayParameter
Class to hold a the trace from the HP8753D
Although the trace can have two values per frequency, this class only returns the first value
- property full_name: str
Name of the parameter including the name of the instrument and submodule that the parameter may be bound to. The names are separated by underscores, like this:
instrument_submodule_parameter
.
- get_ramp_values(value: Union[float, Sized], step: Optional[float] = None) Sequence[Union[float, Sized]]
Return values to sweep from current value to target value. This method can be overridden to have a custom sweep behaviour. It can even be overridden by a generator.
- Parameters
value – target value
step – maximum step size
- Returns
List of stepped values, including target value.
- property instrument: Optional[InstrumentBase]
Return the first instrument that this parameter is bound to. E.g if this is bound to a channel it will return the channel and not the instrument that the channel is bound too. Use
root_instrument()
to get the real instrument.
- property inter_delay: float
Delay time between consecutive set operations. The actual time will not be shorter than this, but may be longer if the underlying set call takes longer.
Typically used in conjunction with step to create an effective ramp rate, but can also be used without a step to enforce a delay between sets.
- Getter
Returns the current inter_delay.
- Setter
Sets the value of the inter_delay.
- Raises
TypeError – If delay is not int nor float
ValueError – If delay is negative
- 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 parameter. This is identical to
short_name()
.
- property post_delay: float
Delay time after start of set operation, for each set. The actual time will not be shorter than this, but may be longer if the underlying set call takes longer.
Typically used in conjunction with step to create an effective ramp rate, but can also be used without a step to enforce a delay after every set. One might think of post_delay as how long a set operation is supposed to take. For example, there might be an instrument that needs extra time after setting a parameter although the command for setting the parameter returns quickly.
- Getter
Returns the current post_delay.
- Setter
Sets the value of the post_delay.
- Raises
TypeError – If delay is not int nor float
ValueError – If delay is negative
- property raw_value: Any
Note that this property will be deprecated soon. Use
cache.raw_value
instead.Represents the cached raw value of the parameter.
- Getter
Returns the cached raw value of the parameter.
- restore_at_exit(allow_changes: bool = True) qcodes.instrument.parameter._SetParamContext
Use a context manager to restore the value of a parameter after a
with
block.By default, the parameter value may be changed inside the block, but this can be prevented with
allow_changes=False
. This can be useful, for example, for debugging a complex measurement that unintentionally modifies a parameter.Example
>>> p = Parameter("p", set_cmd=None, get_cmd=None) >>> p.set(2) >>> with p.restore_at_exit(): ... p.set(3) ... print(f"value inside with block: {p.get()}") # prints 3 >>> print(f"value after with block: {p.get()}") # prints 2 >>> with p.restore_at_exit(allow_changes=False): ... p.set(5) # raises an exception
- property root_instrument: Optional[InstrumentBase]
Return the fundamental instrument that this parameter belongs too. E.g if the parameter is bound to a channel this will return the fundamental instrument that that channel belongs to. Use
instrument()
to get the channel.
- set_raw(value: Any) None
set_raw
is called to perform the actual setting of a parameter on the instrument. This method should either be overwritten to perform the desired operation or alternatively forParameter
a suitable method is automatically generated ifset_cmd
is supplied to the parameter constructor. The method is automatically wrapped to provide aset
method on the parameter instance.
- set_to(value: Any, allow_changes: bool = False) qcodes.instrument.parameter._SetParamContext
Use a context manager to temporarily set a parameter to a value. By default, the parameter value cannot be changed inside the context. This may be overridden with
allow_changes=True
.Examples
>>> from qcodes import Parameter >>> p = Parameter("p", set_cmd=None, get_cmd=None) >>> p.set(2) >>> with p.set_to(3): ... print(f"p value in with block {p.get()}") # prints 3 ... p.set(5) # raises an exception >>> print(f"p value outside with block {p.get()}") # prints 2 >>> with p.set_to(3, allow_changes=True): ... p.set(5) # now this works >>> print(f"value after second block: {p.get()}") # still prints 2
- property setpoint_full_names: Optional[Sequence[str]]
Full names of setpoints including instrument names if available
- property short_name: str
Short name of the parameter. This is without the name of the instrument or submodule that the parameter may be bound to. For full name refer to
full_name()
.
- 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 parameter as a JSON-compatible dict (everything that the custom JSON encoder class
qcodes.utils.helpers.NumpyJSONEncoder
supports).If the parameter has been initiated with
snapshot_value=False
, the snapshot will NOT include thevalue
andraw_value
of the parameter.- Parameters
update – If True, update the state by calling
parameter.get()
unlesssnapshot_get
of the parameter isFalse
. Ifupdate
isNone
, use the current value from thecache
unless the cache is invalid. IfFalse
, never callparameter.get()
.params_to_skip_update – No effect but may be passed from superclass
- Returns
base snapshot
- property step: Optional[float]
Stepsize that this Parameter uses during set operation. Stepsize must be a positive number or None. If step is a positive number, this is the maximum value change allowed in one hardware call, so a single set can result in many calls to the hardware if the starting value is far from the target. All but the final change will attempt to change by +/- step exactly. If step is None stepping will not be used.
- Getter
Returns the current stepsize.
- Setter
Sets the value of the step.
- Raises
TypeError – if step is set to not numeric or None
ValueError – if step is set to negative
TypeError – if step is set to not integer or None for an integer parameter
TypeError – if step is set to not a number on None
- property underlying_instrument: Optional[InstrumentBase]
Returns an instance of the underlying hardware instrument that this parameter communicates with, per this parameter’s implementation.
This is useful in the case where a parameter does not belongs to an instrument instance that represents a real hardware instrument but actually uses a real hardware instrument in its implementation (e.g. via calls to one or more parameters of that real hardware instrument). This is also useful when a parameter does belong to an instrument instance but that instance does not represent the real hardware instrument that the parameter interacts with: hence
root_instrument
of the parameter cannot be thehardware_instrument
, howeverunderlying_instrument
can be implemented to return thehardware_instrument
.By default it returns the
root_instrument
of the parameter.
- validate(value: Any) None
Validate the value supplied.
- Parameters
value – value to validate
- Raises
TypeError – If the value is of the wrong type.
ValueError – If the value is outside the bounds specified by the validator.
qcodes.instrument_drivers.HP.HP_83650A module
- class qcodes.instrument_drivers.HP.HP_83650A.HP_83650A(*args: Any, **kwargs: Any)[source]
Bases:
qcodes.instrument.visa.VisaInstrument
Driver for HP_83650A
- __getitem__(key: str) Union[Callable[[...], Any], qcodes.instrument.parameter.Parameter]
Delegate instrument[‘name’] to parameter or function ‘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 yourInstrument
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: type = <class 'qcodes.instrument.parameter.Parameter'>, **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
instrument.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
parameter.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 aChannelTuple
.- 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
- property ancestors: List[qcodes.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 callsuper().ask(new_cmd)
. Subclasses that define a new hardware communication should instead overrideask_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
- 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.
- 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 isself._t0
, set at start ofInstrument.__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 ofself
.
- 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 toself
.
- 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[qcodes.instrument.base.T]] = None) qcodes.instrument.base.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
- 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[qcodes.instrument.base.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: qcodes.instrument.base.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.
- 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.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. IfFalse
, 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: qcodes.instrument.base.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: qcodes.instrument.base.Instrument) None
Remove a particular instance from the record.
- Parameters
instance – The instance to remove
- property root_instrument: qcodes.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: str) None
Change the read terminator to use.
- Parameters
terminator – Character(s) to look for at the end of a read. eg.
\r\n
.
- 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
qcodes.utils.helpers.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
- 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 callsuper().write(new_cmd)
. Subclasses that define a new hardware communication should instead overridewrite_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, _BaseParameter] = {}
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 instrument_modules of this instrument Usually populated via
add_submodule()
.