How fast can the A/D converter on the 7344 motion controller receive an analog signal from a UMI-7764 analog output

[mick 490]

How fast can the A/D converter on the 7344 motion controller receive an analog signal from a UMI-7764 analog input terminal.At present i am putting 10Hz through but the results i get on my graph are to close together to make sense i require up to 500HZ to be read and displayed on my graph in my program is this possible.Any help would be greatly appreciated

[Darren]

Mick,

From what I understand, the analog inputs on the 7344 are software-timed...that means that the A/D will return values as fast as your acquisition loop is running. I just ran a simple program on my computer to test the speed. I have a while loop with nothing but the ADC Read function, and its execution time is a fraction of a millisecond. Now this will slow down substantially as you put more functions in the loop. If you want to attempt to time the acquisition, you can try putting a "Wait" function in the loop...that way, if you have a 100 ms wait within the loop, your Motion ADC rate will be roughly 10 Hz, although software latencies may cause this to fluctuate while your program is running. If you need a precise sample rate, you will need an analog in
put device with a scan clock...I suggest you look at National Instruments' low-cost E Series DAQ devices if this is an avenue you need to pursue.

Also, I recommend that whenever you have Motion-related questions in the future that you post to the "Motion" forum instead of the "LabVIEW General" forum.

Good luck,
Darren