Configuring External Triggering with RTSI for NI Frame Grabber in LabVIEW

Updated Aug 3, 2023

Reported In


  • PCI-1409
  • PCI-1422
  • PCI-1424
  • PCIe-1427
  • PCI-1428
  • PCIe-1429
  • PCIe-1430
  • PCIe-1433
  • PCIe-1473
  • PCIe-1437


  • LabVIEW



Issue Details

  • I have a National Instruments Camera Link Frame Grabber that I would like to trigger through RTSI from an external hardware, such as a NI PXIe, PCI, or USB DAQ device. How do I configure this in LabVIEW?
  • Is there an example LabVIEW VI on how to read from a Camera Link camera with an external trigger source? I'm using the PCIe-1430. 


Use the NI-IMAQ function IMAQ Configure before IMAQ Grab to configure the frame grabber to look for a hardware trigger. 
  1. Set the Type input to RTSI
  2. Set the Line Number to be the DAQ trigger line on which the trigger will be output
  3. Set the Frame timeout and Action inputs appropriately based on your intended behavior

For example, in the image below, the IMAQ Configure is configured to look for a trigger on PXI_Trig0. Each trigger will cause a new buffer to be acquired. 
More triggering examples with NI-IMAQ API can be found in LabVIEW's NI Example Finder. For example:
  • Hardware Input and Output >> Vision-Acquisition >> NI-IMAQ >> ...
  1. Signal Input and Output >> HL Triggered Ring (Express).vi
  2. Low-Level >> LL Triggered

Additional Information

For PXI trigger lines, the RTSI line numbers map one-to-one. For example, RTSI line 0 maps to PXI_Trig0, RTSI line 1 maps to PXI_Trig1, etc. 

When using this triggering method, make sure the camera is set to free run mode. This ensures that only the frame grabber is triggered, rather than both the camera and frame grabber. If both devices are triggered, you may see slower image acquisition.