Running parallel cDAQ-9174's

[chuggins1434]

I'm running two cDAQ-9174's and have come up with a way to get them to run without interfering with each other, but would like a second opinion (...or third or forth etc...) before I go too far down this path.  It seems to work fine, but if someone has a better idea about how to continuiously monitor 40-50 channels then I'm all ears.  VI attached for your pleasure.  Ignore the front end, I'm just trying to get the backend to work for now.

Thanks guys/gals!

Chad

[SerJames]

Hi Chad,

I believe your code would work but it seems like you are doing more than is necessary.

I would recommend looking at the Voltage- Continuous Input example (found in the Example Finder and at https://decibel.ni.com/content/docs/DOC-25105) for structuring your DAQmx channels. As it appears each chassis is writing to it's own table, you could just set up a duplicate chain and have both run their own tasks in the loop feeding to their associated table. On how to set this up, look at some of the synchronization examples we have posted and extrapolate from that data. A couple links I found on it could be found here

https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z0000019YMNSA2&l=en-US

https://www.ni.com/docs/en-US/bundle/ni-daqmx/page/multidevicetasks.html

There are definitely a number of examples to pull from.

Also, this is a little pickier, but from a setup standpoint you could pull out the entire channel configuration outside of the loop and set it up once, and then just perform the repeated read commands. This does have a performance improvement overall as you don't need to reset your channel every iteration of your loop, which is repeated redundant work. If you are unfamiliar with the different steps of the DAQ tasks, there is some excellent documentation on how each step works found here:

https://www.ni.com/en/support/documentation/supplemental/06/learn-10-functions-in-ni-daqmx-and-handl...

Hopefully these get you some good data points for reference.

Cheers!