How Do I Enable the AI Hold Complete Signal?

Updated May 28, 2019

Reported In

Hardware

  • PCI-6024E
  • DAQCard-6024

Issue Details

  • I am migrating from Traditional NI-DAQ to NI-DAQmx and can't find the SCANCLK signal. Where is it?
  • Are AI Hold Complete Event and SCANCLK the same?
  • How do I set up SCANCLK in NI-DAQmx?

Solution

NI-DAQ 7.0 and later ships with two different drivers: Traditional NI-DAQ and NI-DAQmx. In Traditional NI-DAQ, the AI Hold Complete Signal is called the SCANCLK signal. 

Troubleshooting steps to access SCANCLK using NI-DAQmx:
  • Try using the DAQmx Export Signal Property Node in LabVIEW:
  1. Open the block diagram.
  2. Right click to open the Functions Palette.
  3. Navigate to Measurement I/O » NI DAQmx » Task Config/Ctrl » DAQmx Signals » Signal Node and place it on your block diagram.
  4. Click the selected property. From the menu that opens, select Select Property » Events » AI Hold Complete Event » Output Terminal.
  5. Right-click the property and select Create»Constant.
  6. Right-click the constant you created and select I/O Name Filtering. In the window that appears, check Include Advanced Terminals and click OK.
  7. From the constant's drop-down menu, select /Dev x/AIHoldComplete where x is your device number.
  8. Connect the task ID and error inputs and outputs of the property node to force the property node to execute before you start your task.
  • Try the DAQmx Export Signal VI in LabVIEW :
  1. Open the block diagram
  2. Right click to open the Functions Palette 
  3. Navigate to Measurement I/O » NI DAQmx » Task Config/Ctrl » DAQmx Signals » Export Signal and place it on your block diagram.
  4. Right-click the signal and select Create » Constant.
  5. From the constant's drop-down menu select AI Hold Complete Event.
  6. Right-click the output terminal and select Create » Constant.
  7. Right-click the constant you created and select I/O Name Filtering. In the window that appears, check Include Advanced Terminals and click OK.
  8. From the constant's drop-down menu, select /Dev x/AIHoldComplete where x is your device number.
  9. Connect the task ID and error inputs and outputs of the VI in your task.
  • Try using the DAQmxSetExportedAIHoldCmpltEventOutputTerm function to enable the signal in C.