NI 9425 Count pulses ?

[ive1]

Hi, I have successfully configured NI 9425 and want to know if there is a posibility off counting number of pulses in known time? Thanks, Ive1

[Simon-P]

Greetings, Ive1;

I have looked around a bit, and a starting point such as the example "Digital - SW - Timed Input" might be a good starting point. Since the acquisition will be software timed, the pulse's length will be important; pulses that are too fast will be problematic to count through software. 

Starting with the example, adding some logic into the loop that will add a number to an indicator after the boolean (connected to the read) is read might be your best bet.

By the way, the example is for the latest version of the drivers; for an older version, the example is split into two, named "Read Dig Chan" and "Read Dig Port".

Cordially,

Simon Perez

Applications Engineer

National Instrument

[ive1]

Hi,

looking at pulse length; should a minimum width of 5 ms be ok?

Thanks for your reply!

[Simon-P]

Greetings, ive1;

I'm not quite sure just what the minimum would need to be; however, 5ms seems to be a bit fast. I would say to try it with a known pulse, however, and seeing how accurate you can get it to be. Still, there will probably be some loss due to jitter since it is counting through software.

Codrially,

Simon Perez

Applications Engineer

National Instruments