Triggering Devices

[boba206]

Hi,

I am using a PXIe system (PXIe-1092 chassis w/ PXIe-8881 controller) with a PXIe-5745 AWG (FlexRIO) and a NI 5742 AO attached to a PXIe-7976R FPGA FlexRIO Module.  I have configured the output waveform for both of these and have successfully been able to produce a waveform but now I want to synchronize them so that they output at the same time.  I am new to PXI and FlexRIO and have been trying to determine how to trigger the two modules.  I have read that there is a PXI trigger bus but I am having a hard time finding good examples that aren't using NI SYNC and DAQmx, which I think won't work with my devices.  There is this article talking about how I can use the PXI Star trigger with FlexRIO devices but I can't seem to find any examples.

https://www.ni.com/docs/en-US/bundle/flexrio/page/target5devicehelp/pxi_star_trigger_line.html

Any help is appreciated.

Thank you

[UMASO · Accepted solution]

Hello, how much tightly would you like to synchronize 5745 and 5742?  

There may be multiple ways to synchronize the two.  One of the simplest methods is to export start trigger from 5745 and route it to PXI trigger line.  

As shown in the picture below, Getting Started example of PXIe-5745 routes its start trigger to be exported.  

Route this to either of PXI trigger line 0~7.  How to route signals from Integrated IO versions of FlexRIO is documented as shown in the below picture.  

On the side of 5742, mofidy FPGA VI so that waveform generation starts at trigger timing which comes through the trigger line.  

Since 5742 is 1MSps, this method may satisfy the level of synchronization.  

Another method is to utilize Sync API which accomplishes tighter degrees of synchronization, but the version of Sync API for 5742 and 5745 are different and it may take a certain amount of efforts.