Multifunction DAQ
PXI-6254 Multiple Counter Output Different Frequencies
- last edited on by
Content Cleaner
Hi,
Id like to create a single task which contains three different CO Pulse Freq channels across two DAQ boards, all at different frequencies, with finite sampling. After a little searching, I found this article:
https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000000P8kmSAC&l=en-US
Case 3 seems to suggest that I cannot do this. Is it true that I cannot have two finite-sampled counter output pulse frequency at different rates on one PXI-6254 (32 AI M Series multifunction board)?
If that's the case, I guess I will have to switch to continuous sampling mode, but I'd really like all three of these pulse trains to have a specfic number of ticks.
Here's some code I was working on to create the channels. I got stuck when I came to configuring the timing. I can't find a way to select a specific channel in the task within the DAQmx Timing property node. Maybe that's because you can't do this...
- last edited on by
Content Cleaner
Hello,
This is because a finite counter task requires two counters and the PXI-6254 only has two counters.
How Many Counters Does Each Type of Counter Input or Output Task Take?
What this means is that you will only be able to do one finite counter task on the PXI-6254. With the introduction of the X Series DAQ devices (63XX cards), you could do 4 seperate finite counter output tasks. X Series devices have 4 advanced counters that can perform finite counter outputs with a single counter. The NI PXIe-6363 has similar specs to the 6254 and has 4 advanced counters.
How fast is the pulse train that you are producing and what duty cycle? Below is a post that talks about something similar:
What Steve suggests is to use the DIO lines and use the counter as the sample clock then perform a finite DIO task. This might be a way to do what you are asking.
