hvl_ccb.dev.labjack.labjack

A LabJack T-series devices wrapper around the LabJack’s LJM Library; see https://labjack.com/ljm . The wrapper was originally developed and tested for a LabJack T7-PRO device.

Extra installation

To use this LabJack T-series devices wrapper:

1. install the hvl_ccb package with a labjack extra feature:

   $ pip install "hvl_ccb[labjack]"
   

   this will install the Python bindings for the library.

2. install the library - follow instruction in https://labjack.com/support/software/installers/ljm .

class LabJack(com, dev_config=None)

Bases: SingleCommDevice

LabJack Device.

This class is tested with a LabJack T7-Pro and should also work with T4 and T7 devices communicating through the LJM Library. Other or older hardware versions and variants of LabJack devices are not supported.

class AInRange(value=<no_arg>, names=None, module=None, qualname=None, type=None, start=1, boundary=None)

Bases: StrEnumBase

An enumeration.

ONE = 1.0

ONE_HUNDREDTH = 0.01

ONE_TENTH = 0.1

TEN = 10.0

property value: float

class BitLimit(value=<no_arg>, names=None, module=None, qualname=None, type=None, start=1, boundary=None)

Bases: IntEnum

Maximum integer values for clock settings

THIRTY_TWO_BIT = 4294967295

class CalMicroAmpere(value=<no_arg>, names=None, module=None, qualname=None, type=None, start=1, boundary=None)

Bases: Enum

Pre-defined microampere (uA) values for calibration current source query.

TEN = '10uA'

TWO_HUNDRED = '200uA'

class CjcType(value=<no_arg>, names=None, module=None, qualname=None, type=None, start=1, boundary=None)

Bases: NameEnum

CJC slope and offset

internal = (1, 0)

lm34 = (55.56, 255.37)

class ClockFrequency(value=<no_arg>, names=None, module=None, qualname=None, type=None, start=1, boundary=None)

Bases: IntEnum

Available clock frequencies, in Hz

FIVE_MHZ = 5000000

FORTY_MHZ = 40000000

MAXIMUM = 80000000

MINIMUM = 312500

TEN_MHZ = 10000000

TWELVE_HUNDRED_FIFTY_KHZ = 1250000

TWENTY_FIVE_HUNDRED_KHZ = 2500000

TWENTY_MHZ = 20000000

DIOChannel

alias of TSeriesDIOChannel

class DIOStatus(value=<no_arg>, names=None, module=None, qualname=None, type=None, start=1, boundary=None)

Bases: IntEnum

State of a digital I/O channel.

HIGH = 1

LOW = 0

class DeviceType(value=<no_arg>, names=None, module=None, qualname=None, type=None, start=1, boundary=None)

Bases: AutoNumberNameEnum

LabJack device types.

Can be also looked up by ambigious Product ID (p_id) or by instance name: `python LabJackDeviceType(4) is LabJackDeviceType('T4') `

ANY = 1

T4 = 2

T7 = 3

T7_PRO = 4

classmethod get_by_p_id(p_id: int) → DeviceType | list[DeviceType]

Get LabJack device type instance via LabJack product ID.

Note: Product ID is not unambiguous for LabJack devices.

Parameters:

p_id – Product ID of a LabJack device

Returns:

Instance or list of instances of LabJackDeviceType

Raises:

ValueError – when Product ID is unknown

class TemperatureUnit(value=<no_arg>, names=None, module=None, qualname=None, type=None, start=1, boundary=None)

Bases: NameEnum

Temperature unit (to be returned)

C = 1

F = 2

K = 0

class ThermocoupleType(value=<no_arg>, names=None, module=None, qualname=None, type=None, start=1, boundary=None)

Bases: NameEnum

Thermocouple type; NONE means disable thermocouple mode.

C = 30

E = 20

J = 21

K = 22

NONE = 0

PT100 = 40

PT1000 = 42

PT500 = 41

R = 23

S = 25

T = 24

config_high_pulse(address: str | TSeriesDIOChannel, t_start: int | float, t_width: int | float, n_pulses: int = 1) → None

Configures one FIO channel to send a timed HIGH pulse. Configure multiple channels to send pulses with relative timing accuracy. Times have a maximum resolution of 1e-7 seconds @ 10 MHz. :param address: FIO channel: [T7] FIO0;2;3;4;5. [T4] FIO6;7. :raises LabJackError if address is not supported. :param t_start: pulse start time in seconds. :raises ValueError: if t_start is negative or would exceed the clock period. :param t_width: duration of high pulse, in seconds. :raises ValueError: if t_width is negative or would exceed the clock period. :param n_pulses: number of pulses to be sent; single pulse default. :raises TypeError if n_pulses is not of type int. :raises Value Error if n_pulses is negative or exceeds the 32bit limit.

static default_com_cls()

Get the class for the default communication protocol used with this device.

Returns:

the type of the standard communication protocol for this device

disable_pulses(*addresses: str | TSeriesDIOChannel | None) → None

Disable previously configured pulse channels. :param addresses: tuple of FIO addresses. All channels disabled if no argument is passed.

enable_clock(clock_enabled: bool) → None

Enable/disable LabJack clock to configure or send pulses. :param clock_enabled: True -> enable, False -> disable. :raises TypeError: if clock_enabled is not of type bool

get_ain(*channels: int) → float | Sequence[float]

Read currently measured value (voltage, resistance, …) from one or more of analog inputs.

Parameters:

channels – AIN number or numbers (0..254)

Returns:

the read value (voltage, resistance, …) as float`or `tuple of them in case multiple channels given

get_cal_current_source(name: str | CalMicroAmpere) → float

This function will return the calibration of the chosen current source, this ist not a measurement!

The value was stored during fabrication.

Parameters:

name – ‘200uA’ or ‘10uA’ current source

Returns:

calibration of the chosen current source in ampere

get_clock() → dict[str, int | float]

Return clock settings read from LabJack.

get_digital_input(address: str | TSeriesDIOChannel) → DIOStatus

Get the value of a digital input.

allowed names for T7 (Pro): FIO0 - FIO7, EIO0 - EIO 7, CIO0- CIO3, MIO0 - MIO2 :param address: name of the output -> ‘FIO0’ :return: HIGH when address DIO is high, and LOW when address DIO is low

get_product_id() → int

This function returns the product ID reported by the connected device.

Attention: returns 7 for both T7 and T7-Pro devices!

Returns:

integer product ID of the device

get_product_name(force_query_id=False) → str

This function will return the product name based on product ID reported by the device.

Attention: returns “T7” for both T7 and T7-Pro devices!

Parameters:

force_query_id – boolean flag to force get_product_id query to device instead of using cached device type from previous queries.

Returns:

device name string, compatible with LabJack.DeviceType

get_product_type(force_query_id: bool = False) → DeviceType

This function will return the device type based on reported device type and in case of unambiguity based on configuration of device’s communication protocol (e.g. for “T7” and “T7_PRO” devices), or, if not available first matching.

Parameters:

force_query_id – boolean flag to force get_product_id query to device instead of using cached device type from previous queries.

Returns:

DeviceType instance

Raises:

LabJackIdentifierDIOError – when read Product ID is unknown

get_sbus_rh(number: int) → float

Read the relative humidity value from a serial SBUS sensor.

Parameters:

number – port number (0..22)

Returns:

relative humidity in %RH

get_sbus_temp(number: int) → float

Read the temperature value from a serial SBUS sensor.

Parameters:

number – port number (0..22)

Returns:

temperature in Kelvin

get_serial_number() → int

Returns the serial number of the connected LabJack.

Returns:

Serial number.

read_resistance(channel: int) → float

Read resistance from specified channel.

Parameters:

channel – channel with resistor

Returns:

resistance value with 2 decimal places

read_thermocouple(pos_channel: int) → float

Read the temperature of a connected thermocouple.

Parameters:

pos_channel – is the AIN number of the positive pin

Returns:

temperature in specified unit

send_pulses(*addresses: str | TSeriesDIOChannel) → None

Sends pre-configured pulses for specified addresses. :param addresses: tuple of FIO addresses :raises LabJackError if an address has not been configured.

set_ain_differential(pos_channel: int, differential: bool) → None

Sets an analog input to differential mode or not. T7-specific: For base differential channels, positive must be even channel from 0-12 and negative must be positive+1. For extended channels 16-127, see Mux80 datasheet.

Parameters:

• pos_channel – is the AIN number (0..12)

• differential – True or False

Raises:

LabJackError – if parameters are unsupported

set_ain_range(channel: int, vrange: Real | AInRange) → None

Set the range of an analog input port.

Parameters:

• channel – is the AIN number (0..254)

• vrange – is the voltage range to be set

set_ain_resistance(channel: int, vrange: Real | AInRange, resolution: int) → None

Set the specified channel to resistance mode. It utilized the 200uA current source of the LabJack.

Parameters:

• channel – channel that should measure the resistance

• vrange – voltage range of the channel

• resolution – resolution index of the channel T4: 0-5, T7: 0-8, T7-Pro 0-12

set_ain_resolution(channel: int, resolution: int) → None

Set the resolution index of an analog input port.

Parameters:

• channel – is the AIN number (0..254)

• resolution – is the resolution index within 0…`get_product_type().ain_max_resolution` range; 0 will set the resolution index to default value.

set_ain_thermocouple(pos_channel: int, thermocouple: Union[None, str, ThermocoupleType], cjc_address: int = 60050, cjc_type: Union[str, CjcType] = <CjcType.internal: (1, 0)>, vrange: Union[Real, AInRange] = <AInRange.ONE_HUNDREDTH: '0.01'>, resolution: int = 10, unit: Union[str, TemperatureUnit] = <TemperatureUnit.K: 0>) → None

Set the analog input channel to thermocouple mode.

Parameters:

• pos_channel – is the analog input channel of the positive part of the differential pair

• thermocouple – None to disable thermocouple mode, or string specifying the thermocouple type

• cjc_address – modbus register address to read the CJC temperature

• cjc_type – determines cjc slope and offset, ‘internal’ or ‘lm34’

• vrange – measurement voltage range

• resolution – resolution index (T7-Pro: 0-12)

• unit – is the temperature unit to be returned (‘K’, ‘C’ or ‘F’)

Raises:

LabJackError – if parameters are unsupported

set_analog_output(channel: int, value: int | float) → None

Set the voltage of a analog output port

Parameters:

• channel – DAC channel number 1/0

• value – The output voltage value 0-5 Volts int/float

set_clock(clock_frequency: Number | ClockFrequency = 10000000, clock_period: Number = 1) → None

Configure LabJack clock for pulse out feature. :param clock_frequency: clock frequency in Hz; default 10 MHz for base 10. :raises ValueError: if clock_frequency is not allowed (see ClockFrequency). :param clock_period: clock roll time in seconds; default 1s, 0 for max. :raises ValueError: if clock_period exceeds the 32bit tick limit. Clock period determines pulse spacing when using multi-pulse settings. Ensure period exceeds maximum intended pulse end time.

set_digital_output(address: str, state: int | DIOStatus) → None

Set the value of a digital output.

Parameters:

• address – name of the output -> ‘FIO0’

• state – state of the output -> DIOStatus instance or corresponding int value

start() → None

Start the Device.

stop() → None

Stop the Device.

exception LabJackError

Bases: DeviceError

General Error for the LabJack device.

exception LabJackIdentifierDIOError

Bases: LabJackError

Error indicating a wrong DIO identifier