Keithley Drivers

Classes:

Keithley2000(name, address[, reset])	Driver for the Keithley 2000 multimeter.
Keithley2400(name, address, **kwargs)	QCoDeS driver for the Keithley 2400 voltage source.
Keithley2450(name, address, **kwargs)	The QCoDeS driver for the Keithley 2450 SMU
Keithley2450Buffer(parent, name[, size, style])	Treat the reading buffer as a submodule, similar to Sense and Source
Keithley2450Sense(parent, name, proper_function)	The sense module of the Keithley 2450 SMU.
Keithley2450Source(parent, name, proper_function)	The source module of the Keithley 2450 SMU.
Keithley2600MeasurementStatus(value)	Keeps track of measurement status.
Keithley2601B(name, address, **kwargs)	QCoDeS driver for the Keithley 2601B Source-Meter
Keithley2602A(name, address, **kwargs)	QCoDeS driver for the Keithley 2602A Source-Meter
Keithley2602B(name, address, **kwargs)	QCoDeS driver for the Keithley 2602B Source-Meter
Keithley2604B(name, address, **kwargs)	QCoDeS driver for the Keithley 2604B Source-Meter
Keithley2611B(name, address, **kwargs)	QCoDeS driver for the Keithley 2611B Source-Meter
Keithley2612B(name, address, **kwargs)	QCoDeS driver for the Keithley 2612B Source-Meter
Keithley2614B(name, address, **kwargs)	QCoDeS driver for the Keithley 2614B Source-Meter
Keithley2634B(name, address, **kwargs)	QCoDeS driver for the Keithley 2634B Source-Meter
Keithley2635B(name, address, **kwargs)	QCoDeS driver for the Keithley 2635B Source-Meter
Keithley2636B(name, address, **kwargs)	QCoDeS driver for the Keithley 2636B Source-Meter
Keithley3706A(name, address[, terminator])	This is the QCoDeS instrument driver for the Keithley 3706A-SNFP System Switch.
Keithley6500(name, address[, reset_device])	Driver for the Keithley 6500 multimeter. Based on the Keithley 2000 driver,
Keithley7510(name, address[, terminator])	The QCoDeS driver for the Keithley 7510 DMM
Keithley7510Buffer(parent, name[, size, style])	Treat the reading buffer as a submodule, similar to Sense.
Keithley7510DigitizeSense(parent, name, ...)	The Digitize sense module of the Keithley 7510 DMM.
Keithley7510Sense(parent, name, proper_function)	The sense module of the Keithley 7510 DMM, based on the sense module of Keithley 2450 SMU.
KeithleyS46(name, address, **kwargs)
KeithleyS46RelayLock(relay_name)	The S46 either has six pole or a four pole relays.

Data:

Keithley26xx

All Keithley 26xx SMUs supported by QCoDeS.

Exceptions:

Keithley3706AInvalidValue
Keithley3706AUnknownOrEmptySlot
Keithley6500CommandSetError
KeithleyS46LockAcquisitionError

class qcodes.instrument_drivers.Keithley.Keithley2000(name: str, address: str, reset: bool = False, **kwargs: Any)

Bases: VisaInstrument

Driver for the Keithley 2000 multimeter.

Methods:

trigger()
__del__()	Close the instrument and remove its instance record.
__getitem__(key)	Delegate instrument['name'] to parameter or function 'name'.
__getstate__()	Prevent pickling instruments, and give a nice error message.
__repr__()	Simplified repr giving just the class and name.
add_function(name, **kwargs)	Bind one Function to this instrument.
add_parameter(name[, parameter_class])	Bind one Parameter to this instrument.
add_submodule(name, submodule)	Bind one submodule to this instrument.
ask(cmd)	Write a command string to the hardware and return a response.
ask_raw(cmd)	Low-level interface to visa_handle.ask.
call(func_name, *args)	Shortcut for calling a function from its name.
close()	Disconnect and irreversibly tear down the instrument.
close_all()	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.
connect_message([idn_param, begin_time])	Print a standard message on initial connection to an instrument.
device_clear()	Clear the buffers of the device
exist(name[, instrument_class])	Check if an instrument with a given names exists (i.e.
find_instrument(name[, instrument_class])	Find an existing instrument by name.
get(param_name)	Shortcut for getting a parameter from its name.
get_component(full_name)	Recursively get a component of the instrument by full_name.
get_idn()	Parse a standard VISA *IDN? response into an ID dict.
instances()	Get all currently defined instances of this instrument class.
invalidate_cache()	Invalidate the cache of all parameters on the instrument.
is_valid(instr_instance)	Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a "valid" instrument.
load_metadata(metadata)	Load metadata into this classes metadata dictionary.
print_readable_snapshot([update, max_chars])	Prints a readable version of the snapshot.
record_instance(instance)	Record (a weak ref to) an instance in a class's instance list.
remove_instance(instance)	Remove a particular instance from the record.
set(param_name, value)	Shortcut for setting a parameter from its name and new value.
set_address(address)	Set the address for this instrument.
set_terminator(terminator)	Change the read terminator to use.
snapshot([update])	Decorate a snapshot dictionary with metadata.
snapshot_base([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).
validate_status([verbose])	Validate the values of all gettable parameters
write(cmd)	Write a command string with NO response to the hardware.
write_raw(cmd)	Low-level interface to visa_handle.write.

Attributes:

ancestors	Ancestors in the form of a list of InstrumentBase
delegate_attr_dicts	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	A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.
full_name	Full name of the instrument.
label	Nicely formatted label of the instrument.
name	Full name of the instrument
name_parts	A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.
omit_delegate_attrs	A list of attribute names (strings) to not delegate to any other dictionary or object.
parent	The parent instrument.
root_instrument	The topmost parent of this module.
short_name	Short name of the instrument.
visabackend
visa_handle	The VISA resource used by this instrument.
visalib
parameters	All the parameters supported by this instrument.
functions	All the functions supported by this instrument.
submodules	All the submodules of this instrument such as channel lists or logical groupings of parameters.
instrument_modules	All the InstrumentModule of this instrument Usually populated via add_submodule().
log
metadata

trigger() → None

__del__() → None

Close the instrument and remove its instance record.

__getitem__(key: str) → 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.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

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[qcodes.parameters.parameter_base.ParameterBase] | None = 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: 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: tuple[qcodes.instrument.instrument_base.InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent 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.

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: float | None = 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: type | None = 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: type[T] | None = 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

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

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_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:

name – The name of the component to get.

Returns:

The component with the given name.

Raises:

KeyError – If the component does not exist.

get_idn() → dict[str, str | None]

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[T]

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.

property label: str

Nicely formatted label of the instrument.

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

Load metadata into this classes metadata dictionary.

Parameters:

metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]

A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: List[str] = []

A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase | None

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: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

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) → 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.

property short_name: str

Short name of the instrument.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → Dict[str, 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: bool | None = True, params_to_skip_update: Sequence[str] | None = 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.

visabackend: str = visabackend

visa_handle: pyvisa.resources.MessageBasedResource = visa_handle

The VISA resource used by this instrument.

visalib: str | None = visalib

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, 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().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: Dict[str, Any] = {}

class qcodes.instrument_drivers.Keithley.Keithley2400(name: str, address: str, **kwargs: Any)

Bases: VisaInstrument

QCoDeS driver for the Keithley 2400 voltage source.

Methods:

reset()	Reset the instrument.
__del__()	Close the instrument and remove its instance record.
__getitem__(key)	Delegate instrument['name'] to parameter or function 'name'.
__getstate__()	Prevent pickling instruments, and give a nice error message.
__repr__()	Simplified repr giving just the class and name.
add_function(name, **kwargs)	Bind one Function to this instrument.
add_parameter(name[, parameter_class])	Bind one Parameter to this instrument.
add_submodule(name, submodule)	Bind one submodule to this instrument.
ask(cmd)	Write a command string to the hardware and return a response.
ask_raw(cmd)	Low-level interface to visa_handle.ask.
call(func_name, *args)	Shortcut for calling a function from its name.
close()	Disconnect and irreversibly tear down the instrument.
close_all()	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.
connect_message([idn_param, begin_time])	Print a standard message on initial connection to an instrument.
device_clear()	Clear the buffers of the device
exist(name[, instrument_class])	Check if an instrument with a given names exists (i.e.
find_instrument(name[, instrument_class])	Find an existing instrument by name.
get(param_name)	Shortcut for getting a parameter from its name.
get_component(full_name)	Recursively get a component of the instrument by full_name.
get_idn()	Parse a standard VISA *IDN? response into an ID dict.
instances()	Get all currently defined instances of this instrument class.
invalidate_cache()	Invalidate the cache of all parameters on the instrument.
is_valid(instr_instance)	Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a "valid" instrument.
load_metadata(metadata)	Load metadata into this classes metadata dictionary.
print_readable_snapshot([update, max_chars])	Prints a readable version of the snapshot.
record_instance(instance)	Record (a weak ref to) an instance in a class's instance list.
remove_instance(instance)	Remove a particular instance from the record.
set(param_name, value)	Shortcut for setting a parameter from its name and new value.
set_address(address)	Set the address for this instrument.
set_terminator(terminator)	Change the read terminator to use.
snapshot([update])	Decorate a snapshot dictionary with metadata.
snapshot_base([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).
validate_status([verbose])	Validate the values of all gettable parameters
write(cmd)	Write a command string with NO response to the hardware.
write_raw(cmd)	Low-level interface to visa_handle.write.

Attributes:

ancestors	Ancestors in the form of a list of InstrumentBase
delegate_attr_dicts	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	A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.
full_name	Full name of the instrument.
label	Nicely formatted label of the instrument.
name	Full name of the instrument
name_parts	A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.
omit_delegate_attrs	A list of attribute names (strings) to not delegate to any other dictionary or object.
parent	The parent instrument.
root_instrument	The topmost parent of this module.
short_name	Short name of the instrument.
visabackend
visa_handle	The VISA resource used by this instrument.
visalib
parameters	All the parameters supported by this instrument.
functions	All the functions supported by this instrument.
submodules	All the submodules of this instrument such as channel lists or logical groupings of parameters.
instrument_modules	All the InstrumentModule of this instrument Usually populated via add_submodule().
log
metadata

reset() → None

Reset the instrument. When the instrument is reset, it performs the following actions.

Returns the SourceMeter to the GPIB default conditions.

Cancels all pending commands.

Cancels all previously send *OPC and *OPC?

__del__() → None

Close the instrument and remove its instance record.

__getitem__(key: str) → 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.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

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[qcodes.parameters.parameter_base.ParameterBase] | None = 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: 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: tuple[qcodes.instrument.instrument_base.InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent 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.

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: float | None = 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: type | None = 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: type[T] | None = 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

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

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_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:

name – The name of the component to get.

Returns:

The component with the given name.

Raises:

KeyError – If the component does not exist.

get_idn() → dict[str, str | None]

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[T]

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.

property label: str

Nicely formatted label of the instrument.

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

Load metadata into this classes metadata dictionary.

Parameters:

metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]

A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: List[str] = []

A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase | None

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: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

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) → 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.

property short_name: str

Short name of the instrument.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → Dict[str, 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: bool | None = True, params_to_skip_update: Sequence[str] | None = 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.

visabackend: str = visabackend

visa_handle: pyvisa.resources.MessageBasedResource = visa_handle

The VISA resource used by this instrument.

visalib: str | None = visalib

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, 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().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: Dict[str, Any] = {}

class qcodes.instrument_drivers.Keithley.Keithley2450(name: str, address: str, **kwargs: Any)

Bases: VisaInstrument

The QCoDeS driver for the Keithley 2450 SMU

Attributes:

source	We have different source modules depending on the source function, which can be 'current' or 'voltage'
sense	We have different sense modules depending on the sense function, which can be 'current', 'voltage' or 'resistance'
ancestors	Ancestors in the form of a list of InstrumentBase
delegate_attr_dicts	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	A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.
full_name	Full name of the instrument.
label	Nicely formatted label of the instrument.
name	Full name of the instrument
name_parts	A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.
omit_delegate_attrs	A list of attribute names (strings) to not delegate to any other dictionary or object.
parent	The parent instrument.
root_instrument	The topmost parent of this module.
short_name	Short name of the instrument.
visabackend
visa_handle	The VISA resource used by this instrument.
visalib
parameters	All the parameters supported by this instrument.
functions	All the functions supported by this instrument.
submodules	All the submodules of this instrument such as channel lists or logical groupings of parameters.
instrument_modules	All the InstrumentModule of this instrument Usually populated via add_submodule().
log
metadata

Methods:

buffer(name[, size, style])
npts()	Get the number of points in the sweep axis
set_correct_language()	The correct communication protocol is SCPI, make sure this is set
abort()	This command stops all trigger model commands on the instrument.
initiate()	This command starts the trigger model.
wait()	This command postpones the execution of subsequent commands until all previous overlapped commands are finished.
clear_event_register()	This function clears event registers.
clear_event_log()	This command clears the event log.
reset()	Returns instrument to default settings, cancels all pending commands.
__del__()	Close the instrument and remove its instance record.
__getitem__(key)	Delegate instrument['name'] to parameter or function 'name'.
__getstate__()	Prevent pickling instruments, and give a nice error message.
__repr__()	Simplified repr giving just the class and name.
add_function(name, **kwargs)	Bind one Function to this instrument.
add_parameter(name[, parameter_class])	Bind one Parameter to this instrument.
add_submodule(name, submodule)	Bind one submodule to this instrument.
ask(cmd)	Write a command string to the hardware and return a response.
ask_raw(cmd)	Low-level interface to visa_handle.ask.
call(func_name, *args)	Shortcut for calling a function from its name.
close()	Disconnect and irreversibly tear down the instrument.
close_all()	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.
connect_message([idn_param, begin_time])	Print a standard message on initial connection to an instrument.
device_clear()	Clear the buffers of the device
exist(name[, instrument_class])	Check if an instrument with a given names exists (i.e.
find_instrument(name[, instrument_class])	Find an existing instrument by name.
get(param_name)	Shortcut for getting a parameter from its name.
get_component(full_name)	Recursively get a component of the instrument by full_name.
get_idn()	Parse a standard VISA *IDN? response into an ID dict.
instances()	Get all currently defined instances of this instrument class.
invalidate_cache()	Invalidate the cache of all parameters on the instrument.
is_valid(instr_instance)	Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a "valid" instrument.
load_metadata(metadata)	Load metadata into this classes metadata dictionary.
print_readable_snapshot([update, max_chars])	Prints a readable version of the snapshot.
record_instance(instance)	Record (a weak ref to) an instance in a class's instance list.
remove_instance(instance)	Remove a particular instance from the record.
set(param_name, value)	Shortcut for setting a parameter from its name and new value.
set_address(address)	Set the address for this instrument.
set_terminator(terminator)	Change the read terminator to use.
snapshot([update])	Decorate a snapshot dictionary with metadata.
snapshot_base([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).
validate_status([verbose])	Validate the values of all gettable parameters
write(cmd)	Write a command string with NO response to the hardware.
write_raw(cmd)	Low-level interface to visa_handle.write.

property source: Keithley2450Source

We have different source modules depending on the source function, which can be ‘current’ or ‘voltage’

Return the correct source module based on the source function

property sense: Keithley2450Sense

We have different sense modules depending on the sense function, which can be ‘current’, ‘voltage’ or ‘resistance’

Return the correct source module based on the sense function

buffer(name: str, size: int | None = None, style: str = '') → Keithley2450Buffer

npts() → int

Get the number of points in the sweep axis

set_correct_language() → None

The correct communication protocol is SCPI, make sure this is set

abort() → None

This command stops all trigger model commands on the instrument.

initiate() → None

This command starts the trigger model.

wait() → None

This command postpones the execution of subsequent commands until all previous overlapped commands are finished.

clear_event_register() → None

This function clears event registers.

clear_event_log() → None

This command clears the event log.

reset() → None

Returns instrument to default settings, cancels all pending commands.

__del__() → None

Close the instrument and remove its instance record.

__getitem__(key: str) → 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.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

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[qcodes.parameters.parameter_base.ParameterBase] | None = 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: 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: tuple[qcodes.instrument.instrument_base.InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent 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.

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: float | None = 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: type | None = 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: type[T] | None = 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

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

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_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:

name – The name of the component to get.

Returns:

The component with the given name.

Raises:

KeyError – If the component does not exist.

get_idn() → dict[str, str | None]

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[T]

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.

property label: str

Nicely formatted label of the instrument.

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

Load metadata into this classes metadata dictionary.

Parameters:

metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]

A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: List[str] = []

A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase | None

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: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

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) → 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.

property short_name: str

Short name of the instrument.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → Dict[str, 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: bool | None = True, params_to_skip_update: Sequence[str] | None = 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.

visabackend: str = visabackend

visa_handle: pyvisa.resources.MessageBasedResource = visa_handle

The VISA resource used by this instrument.

visalib: str | None = visalib

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, 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().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: Dict[str, Any] = {}

class qcodes.instrument_drivers.Keithley.Keithley2450Buffer(parent: Keithley2450, name: str, size: int | None = None, style: str = '')

Bases: InstrumentChannel

Treat the reading buffer as a submodule, similar to Sense and Source

Attributes:

default_buffer
buffer_elements
inverted_buffer_elements
available_elements
ancestors	Ancestors in the form of a list of InstrumentBase
delegate_attr_dicts	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	A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.
full_name	Full name of the instrument.
label	Nicely formatted label of the instrument.
name	Full name of the instrument
name_parts	A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.
omit_delegate_attrs	A list of attribute names (strings) to not delegate to any other dictionary or object.
parent	The parent instrument.
root_instrument	The topmost parent of this module.
short_name	Short name of the instrument.
parameters	All the parameters supported by this instrument.
functions	All the functions supported by this instrument.
submodules	All the submodules of this instrument such as channel lists or logical groupings of parameters.
instrument_modules	All the InstrumentModule of this instrument Usually populated via add_submodule().
log
metadata

Methods:

from_name_to_scpi(element_names)
from_scpi_to_name(element_scpis)
get_last_reading()	This method requests the latest reading from a reading buffer.
get_data(start_idx, end_idx[, readings_only])	This command returns specified data elements from reading buffer.
clear_buffer()	Clear the data in the buffer
trigger_start()	This method makes readings using the active measure function and stores them in a reading buffer.
delete()
__getitem__(key)	Delegate instrument['name'] to parameter or function 'name'.
__getstate__()	Prevent pickling instruments, and give a nice error message.
__repr__()	Custom repr to give parent information
add_function(name, **kwargs)	Bind one Function to this instrument.
add_parameter(name[, parameter_class])	Bind one Parameter to this instrument.
add_submodule(name, submodule)	Bind one submodule to this instrument.
ask(cmd)
ask_raw(cmd)
call(func_name, *args)	Shortcut for calling a function from its name.
get(param_name)	Shortcut for getting a parameter from its name.
get_component(full_name)	Recursively get a component of the instrument by full_name.
invalidate_cache()	Invalidate the cache of all parameters on the instrument.
load_metadata(metadata)	Load metadata into this classes metadata dictionary.
print_readable_snapshot([update, max_chars])	Prints a readable version of the snapshot.
set(param_name, value)	Shortcut for setting a parameter from its name and new value.
snapshot([update])	Decorate a snapshot dictionary with metadata.
snapshot_base([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).
validate_status([verbose])	Validate the values of all gettable parameters
write(cmd)
write_raw(cmd)

default_buffer = {'defbuffer1', 'defbuffer2'}

buffer_elements = {'date': 'DATE', 'fractional_seconds': 'FRACtional', 'measurement': 'READing', 'measurement_formatted': 'FORMatted', 'measurement_status': 'STATus', 'measurement_unit': 'UNIT', 'relative_time': 'RELative', 'seconds': 'SEConds', 'source_value': 'SOURce', 'source_value_formatted': 'SOURFORMatted', 'source_value_status': 'SOURSTATus', 'source_value_unit': 'SOURUNIT', 'time': 'TIME', 'timestamp': 'TSTamp'}

inverted_buffer_elements = {'DATE': 'date', 'FORMatted': 'measurement_formatted', 'FRACtional': 'fractional_seconds', 'READing': 'measurement', 'RELative': 'relative_time', 'SEConds': 'seconds', 'SOURFORMatted': 'source_value_formatted', 'SOURSTATus': 'source_value_status', 'SOURUNIT': 'source_value_unit', 'SOURce': 'source_value', 'STATus': 'measurement_status', 'TIME': 'time', 'TSTamp': 'timestamp', 'UNIT': 'measurement_unit'}

from_name_to_scpi(element_names: List[str]) → List[str]

from_scpi_to_name(element_scpis: List[str]) → List[str]

property available_elements: Set[str]

get_last_reading() → str

This method requests the latest reading from a reading buffer.

get_data(start_idx: int, end_idx: int, readings_only: bool = False) → List[Any]

This command returns specified data elements from reading buffer.

Parameters:

• start_idx – beginning index of the buffer to return

• end_idx – ending index of the buffer to return

• readings_only – a flag to temporarily disable the elements and output only the numerical readings

Returns:

data elements from the reading buffer

clear_buffer() → None

Clear the data in the buffer

trigger_start() → None

This method makes readings using the active measure function and stores them in a reading buffer.

delete() → None

__getitem__(key: str) → 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.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

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[qcodes.parameters.parameter_base.ParameterBase] | None = 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: 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: tuple[qcodes.instrument.instrument_base.InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent 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

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

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_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:

name – The name of the component to get.

Returns:

The component with the given name.

Raises:

KeyError – If the component does not exist.

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.

property label: str

Nicely formatted label of the instrument.

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

Load metadata into this classes metadata dictionary.

Parameters:

metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]

A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: List[str] = []

A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase

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: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

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.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → Dict[str, 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: bool | None = False, params_to_skip_update: Sequence[str] | None = 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, 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().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: Dict[str, Any] = {}

class qcodes.instrument_drivers.Keithley.Keithley2450Sense(parent: Keithley2450, name: str, proper_function: str)

Bases: InstrumentChannel

The sense module of the Keithley 2450 SMU.

Parameters:

• parent –

• name –

• proper_function – This can be one of either “current”, “voltage” or “resistance”. All parameters and methods in this submodule should only be accessible to the user if self.parent.sense_function.get() == self._proper_function. We ensure this through the ‘sense’ property on the main driver class which returns the proper submodule for any given function mode

Attributes:

function_modes
ancestors	Ancestors in the form of a list of InstrumentBase
delegate_attr_dicts	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	A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.
full_name	Full name of the instrument.
label	Nicely formatted label of the instrument.
name	Full name of the instrument
name_parts	A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.
omit_delegate_attrs	A list of attribute names (strings) to not delegate to any other dictionary or object.
parent	The parent instrument.
root_instrument	The topmost parent of this module.
short_name	Short name of the instrument.
parameters	All the parameters supported by this instrument.
functions	All the functions supported by this instrument.
submodules	All the submodules of this instrument such as channel lists or logical groupings of parameters.
instrument_modules	All the InstrumentModule of this instrument Usually populated via add_submodule().
log
metadata

Methods:

auto_zero_once()	This command causes the instrument to refresh the reference and zero measurements once.
clear_trace([buffer_name])	Clear the data buffer
__getitem__(key)	Delegate instrument['name'] to parameter or function 'name'.
__getstate__()	Prevent pickling instruments, and give a nice error message.
__repr__()	Custom repr to give parent information
add_function(name, **kwargs)	Bind one Function to this instrument.
add_parameter(name[, parameter_class])	Bind one Parameter to this instrument.
add_submodule(name, submodule)	Bind one submodule to this instrument.
ask(cmd)
ask_raw(cmd)
call(func_name, *args)	Shortcut for calling a function from its name.
get(param_name)	Shortcut for getting a parameter from its name.
get_component(full_name)	Recursively get a component of the instrument by full_name.
invalidate_cache()	Invalidate the cache of all parameters on the instrument.
load_metadata(metadata)	Load metadata into this classes metadata dictionary.
print_readable_snapshot([update, max_chars])	Prints a readable version of the snapshot.
set(param_name, value)	Shortcut for setting a parameter from its name and new value.
snapshot([update])	Decorate a snapshot dictionary with metadata.
snapshot_base([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).
validate_status([verbose])	Validate the values of all gettable parameters
write(cmd)
write_raw(cmd)

function_modes = {'current': {'name': '"CURR:DC"', 'range_vals': <Numbers 1e-08<=v<=1>, 'unit': 'A'}, 'resistance': {'name': '"RES"', 'range_vals': <Numbers 20<=v<=200000000.0>, 'unit': 'Ohm'}, 'voltage': {'name': '"VOLT:DC"', 'range_vals': <Numbers 0.02<=v<=200>, 'unit': 'V'}}

auto_zero_once() → None

This command causes the instrument to refresh the reference and zero measurements once.

clear_trace(buffer_name: str = 'defbuffer1') → None

Clear the data buffer

__getitem__(key: str) → 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.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

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[qcodes.parameters.parameter_base.ParameterBase] | None = 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: 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: tuple[qcodes.instrument.instrument_base.InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent 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

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

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_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:

name – The name of the component to get.

Returns:

The component with the given name.

Raises:

KeyError – If the component does not exist.

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.

property label: str

Nicely formatted label of the instrument.

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

Load metadata into this classes metadata dictionary.

Parameters:

metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]

A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: List[str] = []

A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase

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: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

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.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → Dict[str, 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: bool | None = False, params_to_skip_update: Sequence[str] | None = 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, 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().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: Dict[str, Any] = {}

class qcodes.instrument_drivers.Keithley.Keithley2450Source(parent: Keithley2450, name: str, proper_function: str)

Bases: InstrumentChannel

The source module of the Keithley 2450 SMU.

Parameters:

• parent –

• name –

• proper_function – This can be one of either “current” or “voltage” All parameters and methods in this submodule should only be accessible to the user if self.parent.source_function.get() == self._proper_function. We ensure this through the ‘source’ property on the main driver class which returns the proper submodule for any given function mode

Attributes:

function_modes
ancestors	Ancestors in the form of a list of InstrumentBase
delegate_attr_dicts	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	A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.
full_name	Full name of the instrument.
label	Nicely formatted label of the instrument.
name	Full name of the instrument
name_parts	A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.
omit_delegate_attrs	A list of attribute names (strings) to not delegate to any other dictionary or object.
parent	The parent instrument.
root_instrument	The topmost parent of this module.
short_name	Short name of the instrument.
parameters	All the parameters supported by this instrument.
functions	All the functions supported by this instrument.
submodules	All the submodules of this instrument such as channel lists or logical groupings of parameters.
instrument_modules	All the InstrumentModule of this instrument Usually populated via add_submodule().
log
metadata

Methods:

get_sweep_axis()
sweep_setup(start, stop, step_count[, ...])
sweep_start()	Start a sweep and return when the sweep has finished.
sweep_reset()
__getitem__(key)	Delegate instrument['name'] to parameter or function 'name'.
__getstate__()	Prevent pickling instruments, and give a nice error message.
__repr__()	Custom repr to give parent information
add_function(name, **kwargs)	Bind one Function to this instrument.
add_parameter(name[, parameter_class])	Bind one Parameter to this instrument.
add_submodule(name, submodule)	Bind one submodule to this instrument.
ask(cmd)
ask_raw(cmd)
call(func_name, *args)	Shortcut for calling a function from its name.
get(param_name)	Shortcut for getting a parameter from its name.
get_component(full_name)	Recursively get a component of the instrument by full_name.
invalidate_cache()	Invalidate the cache of all parameters on the instrument.
load_metadata(metadata)	Load metadata into this classes metadata dictionary.
print_readable_snapshot([update, max_chars])	Prints a readable version of the snapshot.
set(param_name, value)	Shortcut for setting a parameter from its name and new value.
snapshot([update])	Decorate a snapshot dictionary with metadata.
snapshot_base([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).
validate_status([verbose])	Validate the values of all gettable parameters
write(cmd)
write_raw(cmd)

function_modes = {'current': {'name': 'CURR', 'range_vals': <Numbers -1<=v<=1>, 'unit': 'A'}, 'voltage': {'name': 'VOLT', 'range_vals': <Numbers -200<=v<=200>, 'unit': 'V'}}

get_sweep_axis() → ndarray

sweep_setup(start: float, stop: float, step_count: int, delay: float = 0, sweep_count: int = 1, range_mode: str = 'AUTO', fail_abort: str = 'ON', dual: str = 'OFF', buffer_name: str = 'defbuffer1') → None

sweep_start() → None

Start a sweep and return when the sweep has finished. Note: This call is blocking

sweep_reset() → None

__getitem__(key: str) → 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.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

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[qcodes.parameters.parameter_base.ParameterBase] | None = 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: 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: tuple[qcodes.instrument.instrument_base.InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent 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

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

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_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:

name – The name of the component to get.

Returns:

The component with the given name.

Raises:

KeyError – If the component does not exist.

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.

property label: str

Nicely formatted label of the instrument.

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

Load metadata into this classes metadata dictionary.

Parameters:

metadata – Metadata to load.

property name: str

Full name of the instrument

This is equivalent to full_name() for backwards compatibility.

property name_parts: list[str]

A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.

omit_delegate_attrs: List[str] = []

A list of attribute names (strings) to not delegate to any other dictionary or object.

property parent: InstrumentBase

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: InstrumentBase

The topmost parent of this module.

For the root_instrument this is self.

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.

For an InstrumentModule this does not include any parent names.

snapshot(update: bool | None = False) → Dict[str, 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: bool | None = False, params_to_skip_update: Sequence[str] | None = 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, 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().

log: InstrumentLoggerAdapter = get_instrument_logger(self, __name__)

metadata: Dict[str, Any] = {}

class qcodes.instrument_drivers.Keithley.Keithley2600MeasurementStatus(value)

Bases: StrEnum

Keeps track of measurement status.

Attributes:

CURRENT_COMPLIANCE_ERROR
VOLTAGE_COMPLIANCE_ERROR
VOLTAGE_AND_CURRENT_COMPLIANCE_ERROR
NORMAL
COMPLIANCE_ERROR

CURRENT_COMPLIANCE_ERROR = 'Reached current compliance limit.'

VOLTAGE_COMPLIANCE_ERROR = 'Reached voltage compliance limit.'

VOLTAGE_AND_CURRENT_COMPLIANCE_ERROR = 'Reached both voltage and current compliance limits.'

NORMAL = 'No error occured.'

COMPLIANCE_ERROR = 'Reached compliance limit.'

qcodes.instrument_drivers.Keithley.Keithley26xx(*args, **kwargs)

All Keithley 26xx SMUs supported by QCoDeS.

alias of Union[Keithley2601B, Keithley2602A, Keithley2602B, Keithley2604B, Keithley2611B, Keithley2612B, Keithley2614B, Keithley2634B, Keithley2635B, Keithley2636B]

class qcodes.instrument_drivers.Keithley.Keithley2601B(name: str, address: str, **kwargs: Any)

Bases: Keithley2600

QCoDeS driver for the Keithley 2601B Source-Meter

Parameters:

• name – Name to use internally in QCoDeS

• address – VISA resource address

Methods:

__del__()	Close the instrument and remove its instance record.
__getitem__(key)	Delegate instrument['name'] to parameter or function 'name'.
__getstate__()	Prevent pickling instruments, and give a nice error message.
__repr__()	Simplified repr giving just the class and name.
add_function(name, **kwargs)	Bind one Function to this instrument.
add_parameter(name[, parameter_class])	Bind one Parameter to this instrument.
add_submodule(name, submodule)	Bind one submodule to this instrument.
ask(cmd)	Override of normal ask.
ask_raw(cmd)	Low-level interface to visa_handle.ask.
call(func_name, *args)	Shortcut for calling a function from its name.
close()	Disconnect and irreversibly tear down the instrument.
close_all()	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.
connect_message([idn_param, begin_time])	Print a standard message on initial connection to an instrument.
device_clear()	Clear the buffers of the device
display_clear()	This function clears the display, but also leaves it in user mode
display_normal()	Set the display to the default mode
exist(name[, instrument_class])	Check if an instrument with a given names exists (i.e.
exit_key()	Get back the normal screen after an error: send an EXIT key press event
find_instrument(name[, instrument_class])	Find an existing instrument by name.
get(param_name)	Shortcut for getting a parameter from its name.
get_component(full_name)	Recursively get a component of the instrument by full_name.
get_idn()	Parse a standard VISA *IDN? response into an ID dict.
instances()	Get all currently defined instances of this instrument class.
invalidate_cache()	Invalidate the cache of all parameters on the instrument.
is_valid(instr_instance)	Check if a given instance of an instrument is valid: if an instrument has been closed, its instance is not longer a "valid" instrument.
load_metadata(metadata)	Load metadata into this classes metadata dictionary.
print_readable_snapshot([update, max_chars])	Prints a readable version of the snapshot.
record_instance(instance)	Record (a weak ref to) an instance in a class's instance list.
remove_instance(instance)	Remove a particular instance from the record.
reset()	Reset instrument to factory defaults.
set(param_name, value)	Shortcut for setting a parameter from its name and new value.
set_address(address)	Set the address for this instrument.
set_terminator(terminator)	Change the read terminator to use.
snapshot([update])	Decorate a snapshot dictionary with metadata.
snapshot_base([update, params_to_skip_update])	State of the instrument as a JSON-compatible dict (everything that the custom JSON encoder class NumpyJSONEncoder supports).
validate_status([verbose])	Validate the values of all gettable parameters
write(cmd)	Write a command string with NO response to the hardware.
write_raw(cmd)	Low-level interface to visa_handle.write.

Attributes:

ancestors	Ancestors in the form of a list of InstrumentBase
delegate_attr_dicts	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	A list of names (strings) of objects which are (or will be) attributes of self, whose attributes should be passed through to self.
full_name	Full name of the instrument.
label	Nicely formatted label of the instrument.
name	Full name of the instrument
name_parts	A list of all the parts of the instrument name from root_instrument() to the current InstrumentModule.
omit_delegate_attrs	A list of attribute names (strings) to not delegate to any other dictionary or object.
parent	The parent instrument.
root_instrument	The topmost parent of this module.
short_name	Short name of the instrument.
visabackend
visa_handle	The VISA resource used by this instrument.
visalib
parameters	All the parameters supported by this instrument.
functions	All the functions supported by this instrument.
submodules	All the submodules of this instrument such as channel lists or logical groupings of parameters.
instrument_modules	All the InstrumentModule of this instrument Usually populated via add_submodule().
log
metadata

__del__() → None

Close the instrument and remove its instance record.

__getitem__(key: str) → 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.

Note

We do not recommend the usage of Function for any new driver. Function does not add any significant features over a method defined on the class.

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[qcodes.parameters.parameter_base.ParameterBase] | None = 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: 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: tuple[qcodes.instrument.instrument_base.InstrumentBase, ...]

Ancestors in the form of a list of InstrumentBase

The list starts with the current module then the parent and the parents parent until the root instrument is reached.

ask(cmd: str) → str

Override of normal ask. This is important, since queries to the instrument must be wrapped in ‘print()’

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.

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: float | None = 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

display_clear() → None

This function clears the display, but also leaves it in user mode

display_normal() → None

Set the display to the default mode

static exist(name: str, instrument_class: type | None = 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.

exit_key() → None

Get back the normal screen after an error: send an EXIT key press event

classmethod find_instrument(name: str, instrument_class: type[T] | None = 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

Full name of the instrument.

For an InstrumentModule this includes all parents separated by _

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_component(full_name: str) → MetadatableWithName

Recursively get a component of the instrument by full_name.

Parameters:

name – The name of the component to get.

Returns:

The component with the given name.

Raises:

KeyError<