LabVIEW

Multi Device Syncronous Acquisition with Multi sample pattern match start trigger - rubber duck

Hello,

I am trying to set up a measurement where I need to find the time it takes for a signal to pass through a UUT. I am unable to re-configure much/of the wiring since this is a post deployment test on a station already configured to test another piece of equipment, so I'm trying to do this without changing the connections that are already setup. My basic plan is to run the stimulus signal to the input of the UUT and to the output connection of the UUT where the two HSDIO 6545 cards connect to the fixture. This way the stimulus applied at the UUT output will travel through the fixture/wiring and arrive at the HSDIO before the stimulus applied to the UUT Input. The difference in time between when the two signals arrive at the HSDIO cards should give me the time it takes for the signal to pass through the UUT.

The UUT has two digital output channels that are read by two different HSDIO 6545 cards, one card per channel. I am only able to route the stim signal applied to the output side of the UUT to one of the two DIO cards. This means that to check the UUT channel that the stim signal is not routed through I need to trigger both cards to start acquisition at the same time based off one DIO input on one card. After reviewing some of the HSDIO multi device examples i came up with the attached VI to try and accomplish a synchronous acquisition on two HSDIO cards triggered by one DIO line on one card.

Could someone please take a look at what I've done and make sure I'm doing this correctly? I have posted some questions in the code on the block diagram also while trying to outline how I think this is working. My concern is that though it might run and seem to work, I'm not actually getting the data as accurately as I think/hope to and just want to make sure this is correct.

I saved this for 18 but encountered some errors, so am attaching both the 18 and 20 versions.

Thank you