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AI Reads are taking longer than what they should #53
Description
Steps to reproduce:
- Engine running at 10 ms.
- DAQmx module running at 100 ms. Configure rate to 100 ms as well. Added 8 AI channels or so.
- AI channels update at ~200 ms.
I think this is hapenning because the RelativeTo property being set to Most Recent Sample before each read. This causes the read to wait for the next acquired sample. If the intention was reading the last sample, the property offset has to be changed to -1 (check the RelativeTo Property help). Would it also be good moving this property nodes to init?
Activity
Added offset Read Property node and set it to -1. This causes we read…
becega commentedon May 20, 2019
@agomezni Having this offset at -1 is creating errors in modules running in a cdaq connected to a cRIO
Error -200277 occurred at an unidentified location
Possible reason(s):
Invalid combination of position and offset. The position and offset specified a sample prior to the first sample acquired (sample 0).
Make sure any negative read offset specified will select a valid sample when combined with the read position.
@aggieslaughter this was the cause of the error you were seeing
agomez08 commentedon May 20, 2019
Hi @becega @aggieslaughter
Might be that the last sample still doesn't exist when we are setting the property. Maybe adding a For Loop to retry that same operation a certain number of times until we know the first sample is there?
If possible, I'd suggest we come up with a solution that doesn't imply going to the previous version where we used 0 for the offset since this causes the engine to run late in all the iterations.
Thanks!