03-06-2025 06:48 AM
i have a NI 9208 as one of 8 other c's on the cDAQ 9189 - all the other are working fine with similar labview code, but for the NI 9208 (16*AI) it takes 4 seconds!!
i have tried with another physical NI 9208 with similar result
can someone help me out: why so slow?
03-06-2025 03:55 PM
Do you know you can specify channel lists in DAQmx channel control instead of creating this array of channels?
Based on the datasheet, it may be operating in high resolution mode, and since it is scanned architecture, the number of channels directly increase the overall acquisition time.
Assuming, 52ms conversion time x 16 channels = 832ms just for conversion, and there may be settling time in between channel switching.
03-07-2025 03:16 AM
thank you for the answer. i tried what you suggest - and it gave faster read, but that way i get only one channel:
how to get all the 16 channels?
also, I think the problem is somewhere else as i have several AO's with, granted, only 8 channels each and a DO with 32 channels and all running fine - i enclose the vi for your scrutiny
you also suggest that its set to high resulution - but i could not find a place to change to high-speed. where?
03-07-2025 05:04 AM
You only specified ai7. You should specify ai0:15 to select all channels.
Refer to the following links to your questions.
NI-DAQmx Syntax for Specifying Physical Channel Strings
What is the Maximum Sampling Rate per Channel in my Module?
Enable High-Speed or High-Resolution Mode for C Series Modules
03-10-2025 09:35 AM
thanks again for reply - however, i have tried it all with no difference. in the clip i went back to the array as input as there was no luck with the suggested solution. it still runs with a 4s freq. and the other ones that you can see parts of runs very fast
now it looks like the red-marked.
did i place the property-thing correctly?