Generating and external trigger in P2P setup including FlexRIO and 5673

[AndyBrown]

I have a setup where data that I generate in a FlexRIO is streamed over a P2P link to an RFSG (PXIe-5673e) for generation.  The pattern that I'm creating includes occasional impulses of very short duration that I would like to be able to measure and verify using an external instrument.  I know I can add a DIO module to the front of the FlexRIO to generate this trigger event but I was hoping to avoid this.  Is there a way on the 5673 that I can route a signal from one of the PXI_Trig lines on the backplane directly to the PFI line on the front?  That way I could use the FlexRIO to signal on the PXI_Trig line and have the output show up for external use on the PFI line.

[Timothy_S]

Andy,

If I'm understanding your question correctly, you're trying to route a FlexRIO generated trigger that is being sent to the 5673 by way of a PXI-Trig line, and then want to route that through the 5673 to a front-accessible PFI line? This is for usage with an external instrument that will be doing measurements on the signal being generated by the 5673? Is there any frequency in which you would need to trigger the external instrument, or is that mostly just when the generation begins/ends?

The easiest way to get specific signals out of the 5673 is to take a look using the niRFSG Export Signal VI/Function. This allows certain triggers ( Start, Script, Marker, Started, Done, etc ) to be exported to PFI (or PXI_Trig) lines, so if you can sync the external instrument up with one of those events, then it would be pretty straight-forward to get that working. The only other idea I could have with this is try try using the DAQmx Connect Terminals VI/Function to attempt a direct route from the PXI_Trig line to the PFI line in question. I'm not sure without checking hardware if that route is available or if the connection can be made, but it is a possibility. I'll have to try and get the hardware together to test that, but let me know if you have any success with either of the above methods.

[AndyBrown]

Timothy:

Thanks for the response.  Your assumption is correct, I'm trying to find a way to signal an event that occurs in the FlexRIO out to an external line.  I'm hoping that I can use one of the PFI lines on the RFSG and will not have to add a DIO FlexRIO adapter module.

The events are not predictable and do not line up with start, done, marker event, etc.  So the standard ways of generating a trigger with the RFSG will not work.

I will look into the DAQmx Connect Terminals VI/Function to see if that provides me the necessary functionality.

Andy

[Timothy_S]

Andy,

With that being the case, trying to use the connect terminal functionality is likely the best bet. I'll keep working on getting that tested here as well so let me know if you have any updates from your end.

[AndyBrown]

Timothy:

I've tried your recommendation.  I was encouraged that it did not throw an error but when I connected the PFI0 line to a scope I did not see any output.  Not sure if I needed to do anything else with the RFSG driver.  The attached project contains the Host/FPGA files and the FPGA bitfile.  Any additional suggestions would be appreciated.

Andy

[Timothy_S]

Andy,

After taking a brief look through your code, you've got things setup in the general fashion I would use for the connect terminals function. When you were testing this, what were your Source and Destination terminals set to, and what was the intended signal that you were going to be pushing from one terminal to another. When testing that functionality, I would try to start with a consistent or constant signal (sample/reference clock, constant output, etc) that you can easily read from without taking any timing issues in to account. Let me know how you had the functions setup and I may be able to help direct you from there. There aren't any other real ways to get specific trigger signals through the RFSG in this manner, so we should start by testing the functionality with known signals and move forward from there.