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How Do I Set a Trigger Delay on a Frame Grabber?


I have a frame grabber with trigger inputs. I would like to have the frame grabber delay the triggered event after the trigger has been received. The help for the IMAQ Configure Trigger3 VI says the delay is only supported on the Smart Camera. How can I configure a delay on my frame grabber?

There is no direct way to configure a delay on a frame grabber with the IMAQ Configure Trigger3 VI. This feature is only available on the Smart Camera. However there is a workaround that will give you the same functionality. The IMAQ Generate Pulse3 VI will allow you to include a delay. Using this VI as an intermediate step, you can achieve trigger delay functionality by following the steps below:
  1. Place an IMAQ Generate Pulse3 VI onto the block diagram.
  2. Configure the IMAQ Generate Pulse3 VI to have a delay. This can be found as an input of the Pulse Parameters.
  3. Configure the IMAQ Generate Pulse3 VI to output its pulse on an unused RTSI line and make any other desired configuration changes to the IMAQ Generate Pulse3 VI.
  4. Place an IMAQ Configure Trigger3 VI onto the block diagram. 
  5. Configure the IMAQ Configure Trigger3 VI to wait for a trigger on the same RTSI line that the IMAQ Generate Pulse3 VI is outputting to.
  6. Make any other desired configuration changes to the IMAQ Configure Trigger3 VI. 
  7. This configuration should allow for a trigger delay to now be incorporated.
The screen shot below is an example of how you might need to configure the IMAQ Generate Pulse3 VI and the IMAQ Configure Trigger3 VI. The exact configuration will depend on the setup you have.
Note: There is no physical wiring needed, this will all be done on the card automatically. The frame grabber will generate the pulse and watch for it on the same RTSI line.

Related Links:
KnowledgeBase 4ND8LHZY: Triggered Grab Works In MAX but Times Out in LabVIEW
KnowledgeBase 491KCVP9: Creating Trigger Pulses on Control Lines of IMAQ Framegrabbers
Developer Zone: Factors to Consider when Triggering
Developer Zone: How to Trigger Each Line on a Line Scan Camera


Report Date: 12/29/2008
Last Updated: 12/06/2013
Document ID: 4SSAUK6T

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