Selecting Pin Function

The digital pattern instrument provides multiple capabilities in one instrument. Use the niDigital Select Function VI, the SelectedFunction .NET enumeration, or the niDigital_SelectFunction C function to programmatically set the pin function to one of the following options.

  • Digital
  • PPMU
  • Off
  • Disconnect
Selected Function Description Usage
Digital The pin is connected to the driver, comparator, and active load functions. The PPMU is not sourcing but can make voltage measurements. When you change the selected function to Digital, the state of the digital pin driver returns to the last digital state on the line.
Note You must be in Digital mode to use the frequency counter.

To control the state of the digital pin driver through software, use the following:

  • niDigital Write Static VI
  • DigitalPinSet.WriteStatic .NET method
  • niDigital_WriteStatic C function

To control the state of the digital pin driver through a pattern, use the following:

  • niDigital Burst Pattern VI
  • DigitalPatternControl.BurstPattern .NET method
  • niDigital_BurstPattern C function

To automatically switch the selected function of the pins in the pattern burst to Digital, set the select digital function parameter of following to TRUE:

  • niDigital Burst Pattern VI
  • DigitalPatternControl.BurstPattern .NET method
  • niDigital_BurstPattern C function
PPMU The pin is connected to the PPMU. The driver, comparator, and active load are off while this function is selected.

To source a voltage or current, call the following:

  • niDigital PPMU Source VI
  • DigitalPpmu.Source .NET method
  • niDigital_PPMU_Source C function

The niDigital PPMU Source VI, the DigitalPpmu.Source .NET method, and the niDigital_PPMU_Source C function automatically switch the selected function to the PPMU state and start sourcing from the PPMU. Changing the selected function to Disconnect, Off, or Digital causes the PPMU to stop sourcing.

If you change the selected function to PPMU using the niDigital Select Function VI, the DigitalPinSet.SelectedFunction .NET property, or the niDigital_SelectFunction C function, the PPMU is initially not sourcing.

Note You can make PPMU voltage measurements using the niDigital PPMU Measure VI, the DigitalPpmu.Measure .NET method, or the niDigital_PPMU_Measure C function from within any selected function.
Off The pin is electrically connected, and the PPMU and digital pin driver are off while this function is selected. —
Disconnect The pin is electrically disconnected from instrument functions. Selecting this function causes the PPMU to stop sourcing prior to disconnecting the pin.
Notice In the disconnect state, some I/O protection and sensing circuitry remains exposed. Do not subject the instrument to voltages beyond its operating range.
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Defining Levels

Define levels for digital pins or digital pin groups in the levels file (.digilevels) with the Digital Pattern Editor or through a test program written in LabVIEW, C, or with Microsoft .NET technologies.

You can program levels on a per-pin or per-pin group basis. The levels apply to the pin or pin group for all currently enabled sites. You can also program levels on a per-channel basis. In this case, the level applies only to the specified single channel.

Refer to PXIe-6570 Specifications for valid level values.

Multisite Programming

The digital pattern instrument includes access to the following hardware resources for up to eight sites:

  • Source engine
  • Capture engine
  • History RAM
  • PPMU