DAQ with Real Time (RT) Scan

[pgutie]

Hi everyone,

We currently working with multiple modules (9234, 9237, 9381) to acquire data from multiple sensors using LabVIEW 2019. While attempting this the 9234 and 9237 modules both run using DAQmx where as the 9381 module operates using RT scan. We have had significant issues getting all of three of these modules to have synchronization when it comes to start time. I am still relatively new with working with this software but I was wonder is it possible to use all of these modules in unison? There is not a large understanding if this is possible on my end or my colleagues but searching has not yielded a definitive yes or no answer. 

[mcduff · Accepted solution]

The 9234 and 9237 can be synchronized together using channel expansion, as long as you are using the same sampling rate for both modules. In channel expansion, there is a single task whose start may be triggerable. (I do not know if triggering is supported on these modules.) The other thing to realize is, both the 9234 and 9237 have a phase delay in the input due to the fact they are 24 bit DSA digitizers. This phase delay needs to accounted for and can make it look like your signals are not aligned.

I have no experience doing RT scans for the 9381. I know in the past, RT scans were quite slow and cumbersome. They were also quite limited in scope with respect to their capabilities.

If you need to really synchronize all three, you may/will have to bite the bullet and program all of them using the FPGA. You should be able to synchronize them in the FPGA, it's just a lot more work.

[pgutie]

Hello, Thank you for your reply on getting both the 9234 and 9237 modules synchronized. With the channel expansion that you recommended and the slight corrections made to our code we were able to get data that has never been this synced before. Currently we are looking into connecting the RT but I am thinking it will not work but thank you again. As far as using FPGA for this, no one in the lab I work at knows how to do that so we may result to using a different module all together.