READ_INPUT_STREAM

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Reads raw samples from the specified task or virtual channels. Raw samples constitute the internal representation of samples in a device, read directly from the device or buffer without scaling or reordering. This block determines a Vector of appropriate size and data type based on your device specifications. **Compatibility:** Compatible with National Instruments devices that utilize NI-DAQmx. 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 read from. read_all : bool If True, reads all available samples in the buffer. If False, reads the number of samples specified in `number_of_samples_per_channel` (default is False). number_of_samples_per_channel : int The number of samples per channel to read (default is 1000). Returns: out : Vector Returns data in an interleaved or non-interleaved 1D array, depending on the raw ordering of the device. Refer to your device documentation for more information.

Python Code

from flojoy import flojoy, DataContainer, Vector, DeviceConnectionManager
from typing import Optional


@flojoy(deps={"nidaqmx": "0.9.0"})
def READ_INPUT_STREAM(
    task_name: str,
    read_all: bool = False,
    number_of_samples_per_channel: int = 1000,
    default: Optional[DataContainer] = None,
) -> Vector:
    """Reads raw samples from the specified task or virtual channels.

    Raw samples constitute the internal representation of samples in a device, read directly from the device or buffer without scaling or reordering.
    This block determines a Vector of appropriate size and data type based on your device specifications.

    **Compatibility:**
    Compatible with National Instruments devices that utilize NI-DAQmx.

    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 read from.
    read_all : bool, optional
        If True, reads all available samples in the buffer. If False, reads the number of samples specified in `number_of_samples_per_channel` (default is False).
    number_of_samples_per_channel : int, optional
        The number of samples per channel to read (default is 1000).

    Returns
    -------
    Vector
        Returns data in an interleaved or non-interleaved 1D array, depending on the raw ordering of the device. Refer to your device documentation for more information.
    """

    task = DeviceConnectionManager.get_connection(task_name).get_handle()
    raw_data = (
        task.in_stream.readall()
        if read_all
        else task.in_stream.read(
            number_of_samples_per_channel=number_of_samples_per_channel
        )
    )
    return Vector(raw_data)

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Example App

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Download this Flojoy App

This app shows how to use input stream blocks for with National Instruments Compact DAQ module.

Blocks used:

• CREATE_TASK_ANALOG_INPUT_CURRENT
• CONFIG_INPUT_STREAM
• READ_INPUT_STREAM
• READ_INPUT_STREAM_INTO_BUFFER
• 2x LINE
• PRINT_DATACONTAINER
• TEXT_VIEW
• TIMER
• LOOP

The blocks were connected as shown, and the app was run. The result displayed the first 100 samples from an analog module in the first plot and constantly updated the second plot with the latest data from the device buffer.