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ATTACH_ANALOG_INPUT_VOLTAGE

Attach channel(s) to a task to measure voltage. **Compatibility:** Compatible with National Instruments devices that utilize NI-DAQmx. Tested on a simulated NI-9229 module. This block is designed for use with Windows and Linux systems due to NI driver availability. Ensure you have installed the NI-DAQmx runtime from https://www.ni.com/en/support/downloads/drivers/download.ni-daq-mx.html. Params: task_name : str The name of the task to attach the channel(s) to. cDAQ_start_channel : NIDAQmxDevice The device and channel to read from. cDAQ_end_channel : NIDAQmxDevice To read from only one channel, set this to the same as `cDAQ_start_channel`. To read from multiple channels, set this to the last channel you want to read from. min_val : float Specifies in **units** the minimum value you expect to measure (default is -5.00). max_val : float Specifies in **units** the maximum value you expect to measure (default is 5.00). units : Literal The units to use to return voltage measurements (default is "VOLTS"). Returns: out : Optional[DataContainer] This block does not return any meaningful data; it is designed for creating a task to measure voltage.
Python Code
from flojoy import flojoy, DataContainer, NIDAQmxDevice, DeviceConnectionManager
from typing import Optional, Literal
import nidaqmx


@flojoy(deps={"nidaqmx": "0.9.0"})
def ATTACH_ANALOG_INPUT_VOLTAGE(
    task_name: str,
    cDAQ_start_channel: NIDAQmxDevice,
    cDAQ_end_channel: NIDAQmxDevice,
    min_val: float = -5.00,
    max_val: float = 5.00,
    units: Literal["VOLTS"] = "VOLTS",
    default: Optional[DataContainer] = None,
) -> Optional[DataContainer]:
    """Attach channel(s) to a task to measure voltage.

    **Compatibility:**
    Compatible with National Instruments devices that utilize NI-DAQmx. Tested on a simulated NI-9229 module.

    This block is designed for use with Windows and Linux systems due to NI driver availability. Ensure you have installed the NI-DAQmx runtime from https://www.ni.com/en/support/downloads/drivers/download.ni-daq-mx.html.

    Parameters
    ----------
    task_name : str
        The name of the task to attach the channel(s) to.
    cDAQ_start_channel : NIDAQmxDevice
        The device and channel to read from.
    cDAQ_end_channel : NIDAQmxDevice
        To read from only one channel, set this to the same as `cDAQ_start_channel`. To read from multiple channels, set this to the last channel you want to read from.
    min_val : float, optional
        Specifies in **units** the minimum value you expect to measure (default is -5.00).
    max_val : float, optional
        Specifies in **units** the maximum value you expect to measure (default is 5.00).
    units : Literal, optional
        The units to use to return voltage measurements (default is "VOLTS").

    Returns
    -------
    Optional[DataContainer]
        This block does not return any meaningful data; it is designed for creating a task to measure voltage.
    """
    # Check if task already exists
    task = DeviceConnectionManager.get_connection(task_name).get_handle()

    # Attach the requested channel(s) to the task
    name, address = cDAQ_start_channel.get_id().split("/")
    if cDAQ_end_channel:
        _, address_end = cDAQ_end_channel.get_id().split("/")
        address = f"{address}:{address_end[2:]}"
    physical_channels = f"{name}/{address}"

    units = (
        nidaqmx.constants.VoltageUnits.VOLTS
    )  # TODO: Support TEDS info associated with the channel and custom scale

    task.ai_channels.add_ai_voltage_chan(
        physical_channels, min_val=min_val, max_val=max_val, units=units
    )

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Example

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React Flow mini map

This app shows how to use a thermocouple and voltage input blocks for with National Instruments Compact DAQ modules.

Blocks used:

  • CREATE_TASK_ANALOG_INPUT_THERMOCOUPLE
  • CREATE_TASK_ANALOG_INPUT_VOLTAGE
  • CONFIG_TASK_SAMPLE_CLOCK_TIMINGS
  • TASK_WAIT_UNTIL_DONE
  • 2x READ_TASK
  • 2x LINE

The blocks were connected as shown, and the app was run. The result displayed the first 100 samples taken from the two devicesโ€™ buffer for multiple channels. The app ensures that the operation is complete for the thermocouple task before stopping it.