Accelerate data acquisition

[franckfischer]

How can I accelerate data acquisition with FP-AI-100 ; I wanted several values on a 5 seconds period but the while loop is so slow what I only get 2...Is there a solution ? Is Read.vi the only way to gather datas ?

[Aaron_G]

Franck,

Depending upon the network module that is in use with the FP-AI-100, and assuming that there are no other modules on the bank, you should be able to read all 8 channels of data from the FP-AI-100 (with well written code) at 80 to 90 Hz. Actually, with ethernet modules you should be able to read faster than that, but the above rate is how fast you will be getting new data rather than stale data.

There are two types of "read VI's"; FP Read.vi and FP Advise.vi. The basic difference is that FP Read.vi is synchronous and FP Advise.vi is asynchronous. Based upon your previous questions and code, I recommend you stick with using the FP Read.vi as FP Advise.vi can be a bit more tricky to use.

Regards,
Aaron

[franckfischer]

Aaron,

As I said in another question, I want to do tasks in parallel ; I use write.vis in a first loop and monitor one channel of FP-AI-100 in the second. Problem is tasks can't be executed perfectly at the same time, the first loop gets the second slowly ; When the first one ends, then the seconds go on much more fast.

Regards,
Franck.

[Aaron_G]

Franck,

I can tell you the upper limits of performance (which is in my previous email) but it is always possible and much easier to program non-optimally in ways that restrict performance. Having looked at your code for your other posting, there are numerous things that can be done to improve performance.
Something that is brought to mind as I think back to your original program, you may need to add a small (1ms) delay to your loops. I do not recall if your program had them or not, but a while loop with no delay timer in it, will hog the processor and other parts of the program, other programs, or the OS may not get the processing power that they need. Make sure that you have a Wait Until Next Millisecond Multiple.vi in each while loop that r
uns more than once.

Regards,
Aaron