NI9237 sample rates - what is the best way to avoid crashing?

[pbennion]

Hi everyone,

I'm developing a LabVIEW program for a test bench my student organization uses. We sample data from a variety of thermocouples, pressure transducers, and flow meters at 1000Hz and occasionally write data for short (<15min) experiments. We have a cDAQ-9178 with NI9401, 9205, and 9213 modules.

Recently, we added a few full-bridge load cells (with a previously unused NI9237 module), but the new DAQ Assistant eventually crashes with error code -200279, saying it can't keep up.

Playing around with the sample number and sample rate helps, but doesn't fix the issue - it will eventually crash. Is there anything different about NI9237 sampling practices compared to, say, NI9205?

I've attached a stripped-down version of my program - I removed everything that wasn't related to the data producer loop and the barest data processing in the consumer loop. The issue generally surfaces within a minute of pressing play.

Thanks,

-Peter

[crossrulz · Accepted solution]

Since you are in a cDAQ chassis, I am pretty sure you can just have all of your channels be in the same task/DAQ Assistant.  Try combining all of your channels into 1 configuration.

[pbennion]

Combining the three DAQ assistants works like a charm! I guess I always assumed you couldn't have multiple resources in a single assistant so I never tried it before.

I wonder why it was specifically the NI9237 that took issue with being in parallel, though.

Anyways, thanks for the advice!

-Peter

[crossrulz]

I think your issue was more on the number of sample clocks needed.  That is dictated by the chassis, not the modules.  So setting them all up to use the same sample clock actually saves resources.