NI-HSDIO Express (Generation) VI

NI Digital Waveform Generator/Analyzer

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NI-HSDIO Express (Generation) VI

Acquires a digital waveform from a National Instruments digital waveform generators/analyzer.

Dialog Box Options
Block Diagram Inputs
Block Diagram Outputs

Dialog Box Options

ParameterDescription
ConfigurationContains the following options:
  • Device—Specifies the device to use for the generation. This ring control lists all devices installed on this computer which can be used by this Express VI. If you reopen the NI-HSDIO Express (Generation) configuration page and the current device is dimmed, you can no longer select it.
  • Generation Mode—You can select one of the following modes:
    • Finite—Configures the device to generate a single waveform once. In this generation mode, the Express VI waits until the waveform generation is complete or Max time expires before exiting.
    • Start Continuous—Configures the device to generate the same waveform continuously until it is stopped or a new waveform is downloaded. In this generation mode, the Express VI returns without waiting for the waveform generation to complete.
    • Stop Continuous—Configures the Express VI to stop a generation previously started by an instance of this Express VI configured in Start continuous generation mode. This VI stops the device and releases all device resources used by the generation.
  • Channels—Displays the channels currently configured to acquire data.
    • Modify—Click Modify to launch the Select Channels dialog box.
  • Timing—Contains the following options:
    • Extract rate from waveform—Specifies whether this Express VI configures the device sample rate using the value in the waveform at the data input terminal or the sample rate stored in the waveform file.

      Checked: Uses the sample rate stored in the waveform file at the data input terminal.

      Unchecked: Uses the sample rate specified in rate.

    • Rate (Hz)—Specifies the Sample clock frequency for the generation.

      Units: Samples per second (S/s)

  • Generation Data—Contains the following options:
    • Data Source—Specifies whether the Express VI retrieves the data to generate from an .hws (Hierarchical Waveform Storage) file. Otherwise, data must be wired to the data input terminal.
    • Path—If Read from file is checked, use this control to specify the .hws file containing the data to generate.
VoltageContains the following options:
  • Data Voltage—Contains the following options:
    • Logic family—Specifies the voltage levels used in the generation data channels through one of the predefined logic families.
    • Custom levels—Specifies whether you configure custom high and low voltage levels for the data channels. This feature is not supported on all devices.
      • Data high—Specifies the voltage generated by the data channels when they are driving a logic high level.

        Units: volts (V)

      • Data low—Specifies the voltage generated by the data channels when they are driving a logic low level.

        Units: volts (V)

  • Trigger Line Voltage—Contains the following options:
    • Logic family—Specifies whether you configure the voltage levels for the trigger channel using one of the predefined voltage families for this device.
    • Custom levels—Specifies whether you configure custom high and low voltage levels for the trigger channel. This feature is not supported on all devices.
      • Trigger high—Specifies the voltage high level for the trigger channel. This feature is not supported on all devices.

        Units: volts (V)

      • Trigger low—Specifies the voltage low level for the trigger channel. This feature is not supported on all devices.

        Units: volts (V)
TriggerContains the following options:
  • Trigger type—Specifies the Start trigger type for the generation. If this control is set to None, the generation starts as soon as you run this VI. If this control is set to Digital edge, the following options are visible:
    • Trigger source—Specifies the input terminal for the trigger signal.
    • Digital edge—Specifies whether to trigger on a rising or falling edge of the trigger signal.
  • Max time (s)—Specifies how long to allow the VI to complete the finite generation before returning a timeout error. This control is only available in the Finite generation mode.

    Units: Seconds (s)
Advanced TimingConfigures options used less frequently for timing. Contains the following:
  • Clock Configuration—Contains the following options:
    • Sample clock source—Specifies the Sample clock source.
    • Reference clock source—Specifies the PLL reference clock source. The device phase-locks the Sample clock to the Reference clock signal to prevent the Sample clock from drifting relative to the Reference clock.
    • Sample clock output terminal—Specifies which terminal, if any, the device should use to export the Sample clock signal.
  • Data Position—Specifies which edge of the Sample clock signal is used to time the generation. You can also configure the device to generate data at a configurable delay past each rising edge of the Sample clock.
  • Data delay—Specifies the delay after the Sample clock rising edge when the device generates a new data sample. Data delay is expressed as a fraction of the clock period.
  • Initial state—Specifies the state of the data channels between the time the device is configured and the first data sample is generated. This configuration option is only useful if you configure a Start trigger for the generation. Set this control to Hold last value if you are not using a Start trigger.
  • Idle state—Specifies the state of the data channels at the end of the generation or after you stop the generation.

Block Diagram Inputs

ParameterDescription
dataContains the digital waveform to generate. data does not exist when you select the Read from File option in the NI-HSDIO Express (Generation) configuration page.
closeDetermines whether the instrument session remains open when the Express VI finishes execution. Use this parameter for loop optimization by setting it to FALSE on all iterations other than the last iteration. close is TRUE by default.
Note  This input is not intended to be used to share the session between Express VIs. If you have a loop containing multiple Express VIs that use the same device, you must wire in TRUE for this input.
max timeSpecifies the timeout value for the generation.
error inDescribes error conditions that occur before this Express VI runs.

Block Diagram Outputs

ParameterDescription
error outContains error information. If error in indicates that an error occurred before this Express VI ran, error out contains the same error information. Otherwise, it describes the error status that this Express VI produces.

This Express VI uses the functionality of the following VIs and functions:

niHSDIO Init Generation Session
niHSDIO Assign Dynamic Channels
niHSDIO Configure Sample Clock
niHSDIO Configure Voltage
niHSDIO Configure Generation Repeat
niHSDIO Export Signal
niHSDIO Property Node
niHSDIO Configure Data Position
niHSDIO Configure Data Position Delay
niHSDIO Configure Trigger
niHSDIO Write Named Waveform
niHSDIO Initiate
niHSDIO Wait Until Done
niHSDIO Abort
niHSDIO Close

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