SPI Rack

The SPI rack driver is separated into two layers:

• QCoDeS driver: Instrument driver based on QCoDeS and the instrument’s native interface.

• Native interface: Instrument API that provides control over the instrument and is an extension of the spirack package.

QCoDeS driver

class qblox_instruments.SpiRack(*args: Any, **kwargs: Any)

Bases: SpiRack, Instrument

SPI rack driver class based on QCoDeS.

Example usage:

from qblox_instruments import SpiRack
from qblox_instruments.qcodes_drivers.spi_rack_modules import S4gModule

spi = SpiRack("my_spi_rack", "COM4")   # connects to an SPI rack on COM port 4
spi.add_spi_module(3, "D5a", "alice")  # adds an D5a module with address 3 named "alice"
spi.add_spi_module(2, "S4g", "bob")    # adds an S4g module with address 2 named "bob"
spi.add_spi_module(6, S4gModule)       # adds an S4g module with address 6 with the default name module6

spi.bob.dac0.current(10e-3)            # sets the current of output 1 of the S4g module named "bob" to 10 mA
spi.alice.dac6.voltage(-2)             # sets the voltage of output 7 of the D5a module named "alice" to -2 V

__init__(name: str, address: str, baud_rate: int = 9600, timeout: float = 1, is_dummy: bool = False)

Instantiates the driver object.

Parameters

• name (str) – Instrument name.

• address (str) – COM port used by SPI rack controller unit (e.g. “COM4”)

• baud_rate (int) – Baud rate

• timeout (float) – Data receive timeout in seconds

• is_dummy (bool) – If true, the SPI rack driver is operating in “dummy” mode for testing purposes.

add_spi_module(address: int, module_type: Union[SpiModuleBase, str], name: Optional[str] = None, **kwargs) → None

Add a module to the driver.

Parameters

• address (int) – Address that the module is set to (set internally on the module itself with a jumper).

• module_type (Union[str, SpiModuleBase]) – Either a str that is defined in _MODULES_MAP, or a reference to a class derived from SpiModuleBase.

• name (Optional[str]) – Optional name of the module. If no name is given or is None, a default name of “module{address}” is used.

Raises

ValueError – module_type is not a string or a subclass of SpiModuleBase

close() → None

Closes connection to hardware and closes the Instrument.

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

Print a standard message on initial connection to an instrument. Overridden from superclass to accommodate IEEE488.2 for IDN.

Parameters

• idn_param (str) – Name of parameter that returns ID dict. Default IDN.

• begin_time (Optional[float]) – time.time() when init started. Default is self._t0, set at start of Instrument.__init__.

class qblox_instruments.qcodes_drivers.spi_rack_modules.SpiModuleBase(parent, name: str, address: int, **kwargs)

Bases: SpiModuleBase, InstrumentChannel

Defines an abstract base class for SPI modules. All module drivers should inherit from this class.

This class defines no actual functionality but rather serves to provide a common interface shared among all modules.

Parameters

• parent – Reference to the SpiRack parent object. This is handled by the add_spi_module() function.

• name (str) – Name given to the InstrumentChannel.

• address (int) – Module number set on the hardware (set internally on the module itself with a jumper).

__init__(parent, name: str, address: int, **kwargs)

Defines an abstract base class for SPI modules. All module drivers should inherit from this class.

This class defines no actual functionality but rather serves to provide a common interface shared among all modules.

Parameters

• parent – Reference to the SpiRack parent object. This is handled by the add_spi_module() function.

• name (str) – Name given to the module.

• address (int) – Module number set on the hardware (set internally on the module itself with a jumper).

QCoDeS instrument parameters

QCoDeS parameters generated by SpiRack.

SPIRack.IDN

Please see QCoDeS for a description.

Properties

• value: Anything

SPIRack.temperature

Returns the temperature in the C1b module. Reads the temperature from the internal C1b temperature sensor. Accuracy is +- 0.5 degrees in 0-70 degree range.

Properties

• unit: C

• value: on

SPIRack.battery_voltages

Calculates the battery voltages from the ADC channel values. Returns: [VbatPlus, VbatMin]

Properties

• unit: V

• value: on

Native interface

class qblox_instruments.native.SpiRack(address: str, baud_rate: int = 9600, timeout: float = 1, is_dummy: bool = False)

Bases: object

SPI rack native interface class. This class relies on the spirack API.

__init__(address: str, baud_rate: int = 9600, timeout: float = 1, is_dummy: bool = False)

Instantiates the driver object.

Parameters

• address (str) – COM port used by SPI rack controller unit (e.g. “COM4”)

• baud_rate (int) – Baud rate

• timeout (float) – Data receive timeout in seconds

• is_dummy (bool) – If true, the SPI rack driver is operating in “dummy” mode for testing purposes.

add_spi_module(address: int, module_type: Union[SpiModuleBase, str], name: Optional[str] = None, **kwargs) → Tuple[str, SpiModuleBase]

Add a module to the driver and return module object.

Parameters

• address (int) – Address that the module is set to (set internally on the module itself with a jumper).

• module_type (Union[str, SpiModuleBase]) – Either a str that is defined in _MODULES_MAP, or a reference to a class derived from SpiModuleBase.

• name (Optional[str]) – Optional name of the module. If no name is given or is None, a default name of “module{address}” is used.

Returns

• str – Name

• SpiModuleBase – SPI module object

Raises

ValueError – module_type is not a string or a subclass of SpiModuleBase

get_idn() → Dict

Generates the IDN dict.

Returns

The QCoDeS style IDN dictionary. Currently only the firmware version is actually read from hardware.

Return type

dict

close() → None

Closes connection to hardware and closes the Instrument.

set_dacs_zero() → None

Calls the set_dacs_zero() function on all the modules, which in turn should cause all output values to be set to 0.

class qblox_instruments.native.spi_rack_modules.SpiModuleBase(parent, name: str, address: int, **kwargs)

Bases: object

Abstract SPI module base class.

__init__(parent, name: str, address: int, **kwargs)

Defines an abstract base class for SPI modules. All module drivers should inherit from this class.

This class defines no actual functionality but rather serves to provide a common interface shared among all modules.

Parameters

• parent – Reference to the SpiRack parent object. This is handled by the add_spi_module() function.

• name (str) – Name given to the module.

• address (int) – Module number set on the hardware (set internally on the module itself with a jumper).

abstract set_dacs_zero() → None

” Base method for set_dacs_zero. Should be overridden by subclass.

S4g QCoDeS driver

QCoDeS parameters generated by S4gModule.

class qblox_instruments.qcodes_drivers.spi_rack_modules.S4gModule(parent, name: str, address: int, reset_currents: bool = False, dac_names: Optional[List[str]] = None, is_dummy: bool = False)

Bases: S4gModule, InstrumentChannel

QCoDeS style instrument channel driver for the S4g SPI module.

NUMBER_OF_DACS = 4

__init__(parent, name: str, address: int, reset_currents: bool = False, dac_names: Optional[List[str]] = None, is_dummy: bool = False)

Instantiates the driver object. This is the object that should be instantiated by the add_spi_module() function.

Parameters

• parent – Reference to the SpiRack parent object. This is handled by the add_spi_module() function.

• name (str) – Name given to the InstrumentChannel.

• address (int) – Module number set on the hardware.

• reset_currents (bool) – If True, then reset all currents to zero and change the span to range_max_bi.

• dac_names (Optional[List[str]]) – List of all the names to use for the dac channels. If no list is given or is None, the default name “dac{i}” is used for the i-th dac channel.

• is_dummy (bool) – If true, do not connect to physical hardware, but use a dummy module.

Raises

ValueError – Length of the dac names list does not match the number of dacs.

set_dacs_zero() → None

Sets all currents of all outputs to 0.

S4g QCoDeS parameters

S4g.current

Sets the output current of the dac channel. Depending on the value of ramping_enabled, the output value is either achieved through slowly ramping, or instantaneously set.

Properties

• unit: A

• value: Numbers -0.04<=v<=0.04

S4g.span

Sets the max range of the DACs. Possible values: ‘range_max_uni’: 0 - 40 mA, ‘range_max_bi’: -40 - 40 mA, ‘range_min_bi’: -20 - 20 mA.

Properties

• value: Enum: {‘range_max_bi’, ‘range_min_bi’, ‘range_max_uni’}

S4g.ramp_rate

Limits the rate at which currents can be changed. The size of of steps is still limited by ramp_max_step.

Properties

• unit: A/s

• value: on

S4g.ramp_max_step

Sets the maximum step size for current ramping. The rate at which it ramps is set by ramp_rate.

Properties

• unit: A

• value: on

S4g.ramping_enabled

Turns ramping on or off. Toggling ramping_enabled changed the behavior of the setter for the current parameter. If enabled, ramping is done at a rate set by ramp_rate and in steps specified by ramp_max_step.

Properties

• value: Boolean

S4g.is_ramping

Returns whether the dac is currently in the process of ramping.

Properties

• value: on

S4g.stepsize

Returns the smallest current step allowed by the dac for the current settings.

Properties

• unit: A

• value: on

S4g.dac_channel

Returns the dac number of this channel.

Properties

• value: on

S4g native interface

class qblox_instruments.native.spi_rack_modules.S4gModule(parent, name: str, address: int, reset_currents: bool = False, dac_names: Optional[List[str]] = None, is_dummy: bool = False)

Bases: SpiModuleBase

Native driver for the S4g SPI module.

NUMBER_OF_DACS = 4

__init__(parent, name: str, address: int, reset_currents: bool = False, dac_names: Optional[List[str]] = None, is_dummy: bool = False)

Instantiates the driver object. This is the object that should be instantiated by the add_spi_module() function.

Parameters

• parent – Reference to the SpiRack parent object. This is handled by the add_spi_module() function.

• name (str) – Name given to the InstrumentChannel.

• address (int) – Module number set on the hardware.

• reset_currents (bool) – If True, then reset all currents to zero and change the span to range_max_bi.

• dac_names (Optional[List[str]]) – List of all the names to use for the dac channels. If no list is given or is None, the default name “dac{i}” is used for the i-th dac channel.

• is_dummy (bool) – If true, do not connect to physical hardware, but use dummy module.

Raises

ValueError – Length of the dac names list does not match the number of dacs.

set_dacs_zero() → None

Sets all currents of all outputs to 0.

D5a QCoDeS driver

QCoDeS parameters generated by D5aModule.

class qblox_instruments.qcodes_drivers.spi_rack_modules.D5aModule(parent, name: str, address: int, reset_voltages: bool = False, dac_names: Optional[List[str]] = None, is_dummy: bool = False)

Bases: D5aModule, InstrumentChannel

QCoDeS style instrument channel driver for the D5a SPI module.

NUMBER_OF_DACS = 16

__init__(parent, name: str, address: int, reset_voltages: bool = False, dac_names: Optional[List[str]] = None, is_dummy: bool = False)

Instantiates the driver object. This is the object that should be instantiated by the add_spi_module() function.

Parameters

• parent – Reference to the SpiRack parent object. This is handled by the add_spi_module() function.

• name (str) – Name given to the InstrumentChannel.

• address (int) – Module number set on the hardware.

• reset_voltages (bool) – If True, then reset all voltages to zero and change the span to range_max_bi.

• dac_names (Optional[List[str]]) – List of all the names to use for the dac channels. If no list is given or is None, the default name “dac{i}” is used for the i-th dac channel.

• is_dummy (bool) – If true, do not connect to physical hardware, but use a dummy module.

Raises

ValueError – Length of the dac names list does not match the number of dacs.

D5a QCoDeS parameters

D5a.voltage

Sets the output voltage of the dac channel. Depending on the value of ramping_enabled, the output value is either achieved through slowly ramping, or instantaneously set.

Properties

• unit: V

• value: Numbers -8.0<=v<=8.0

D5a.span

Sets the max range of the DACs. Possible values: ‘range_4V_uni’: 0 - 4 V, ‘range_8V_uni’: 0 - 8 V (only if non-standard 12 V power supply is present), ‘range_4V_bi’: -4 - 4 V, ‘range_8V_bi’: -8 - 8 V (only if non-standard 12 V power supply is present), ‘range_2V_bi’: -2 - 2 V.

Properties

• value: Enum: {‘range_8V_bi’, ‘range_4V_bi’, ‘range_4V_uni’, ‘range_8V_uni’, ‘range_2V_bi’}

D5a.ramp_rate

Limits the rate at which currents can be changed. The size of of steps is still limited by ramp_max_step.

Properties

• unit: V/s

• value: on

D5a.ramp_max_step

Sets the maximum step size for voltage ramping. The rate at which it ramps is set by ramp_rate.

Properties

• unit: V

• value: on

D5a.ramping_enabled

Turns ramping on or off. Toggling ramping_enabled changed the behavior of the setter for the current parameter. If enabled, ramping is done at a rate set by ramp_rate and in steps specified by ramp_max_step.

Properties

• value: Boolean

D5a.is_ramping

Returns whether the dac is currently in the process of ramping.

Properties

• value: on

D5a.stepsize

Returns the smallest current step allowed by the dac for the current settings.

Properties

• unit: V

• value: on

D5a.dac_channel

Returns the dac number of this channel.

Properties

• value: on

D5a native interface

class qblox_instruments.native.spi_rack_modules.D5aModule(parent, name: str, address: int, reset_voltages: bool = False, dac_names: Optional[List[str]] = None, is_dummy: bool = False)

Bases: SpiModuleBase

Native driver for the D5a SPI module.

NUMBER_OF_DACS = 16

__init__(parent, name: str, address: int, reset_voltages: bool = False, dac_names: Optional[List[str]] = None, is_dummy: bool = False)

Instantiates the driver object. This is the object that should be instantiated by the add_spi_module() function.

Parameters

• parent – Reference to the SpiRack parent object. This is handled by the add_spi_module() function.

• name (str) – Name given to the InstrumentChannel.

• address (int) – Module number set on the hardware.

• reset_voltages (bool) – If True, then reset all voltages to zero and change the span to range_max_bi.

• dac_names (Optional[List[str]]) – List of all the names to use for the dac channels. If no list is given or is None, the default name “dac{i}” is used for the i-th dac channel.

• is_dummy (bool) – If true, do not connect to physical hardware, but use dummy module.

Raises

ValueError – Length of the dac names list does not match the number of dacs.

set_dacs_zero() → None

Sets all voltages of all outputs to 0.