Error -200022 for cDAQ-9174 with Three NI-9237 Modules

[nikede]

I am trying to run a simple code to read three channels from each of the three modules. I am using the LabVIEW express VI as shown in the image below. 

When I run the code with the two task as shown in the image the code runs fine. As soon as I add a third task (using the express VI), I receive error-200022. This error switches from task to task each time I run the code. 

Is there a way to manually code around the Express VI to run 3 or 4 simultaneous tasks? 

[Brian.D]

Hello,

Are these tasks analog inputs? Please refer to the following document regarding the error: https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000000P7gKSAS&l=en-US

I recommend ensuring that your tasks do not share any channels. Otherwise, the following link provides some information on how many tasks can concurrently run on your chassis: https://www.ni.com/en/support/documentation/supplemental/18/number-of-concurrent-tasks-on-a-compactd...

Do you have any tasks running in NI-MAX?

[nikede]

Hi Brian, 

Yes, these tasks are all analog inputs. 

I have checked all of the channels and have ensured that none share the same channels. They are each pulling 3 channels from a separate module. 

In total, I would only be running 3 tasks, which is less than the limit on the chassis (the eventual goal would be 4), each reading 3 channels from the modules. I believe this should be able to function properly. 

There are not any tasks running in NI-MAX.

Thanks for the help, 

Nikki

[even-And]

Have you tried Channel Expansion?

It might be worth considering migrating off the DAQ Assistant VIs to the DAQmx functions. The DAQ Assistant is a wrapper for the DAQmx functions and is great for quick simple measurements. But trouble can arise when you try to run multiple DAQ Assistant VIs. 

[JÞB]

The cDAQ 4 slot chassis can only have 2 AI Tasks.  BUT, there is no reason why you cannon have 1 TASK using channels from all three AI modules.