Using NI 9219 to count pulses

[Dick N]

I would like to use a NI 9219 analog input module to count pulses. Is this possible? If so, how is it done.

[GarPar]

Hi Dick-

     Counting pulses can be done with analog input, it just takes some programming logic to do it.  It is much easier to just do it with a counter, but it can be done.

     I actually wrote a simple piece of example code and loaded it to the LabVIEW Community page here.

     Hopefully this gets you started in the right direction!

Regards,

[John_P1]

Nice code Gary,

Just to add to the conversation... one caveat is that the 9219 has a max sample rate of 100Hz.  If your pulses are shorter than 10 ms (1/100Hz) then they might not be detected.

Best Regards,

[Dick N]

Thanks Gary and John for your help.

Since  posting the request I came across a code that uses two express VI's. The example VI is titled "Trigger Counter" and located in the Help section. It uses "Trigger and Gate" express VI and a "Statistics" express VI. By setting the trigger value at 2.7 volts, trigger on rising, and stop the trigger at 1 sample, a value is sent for each pulse. The statistics express VI accumulates the total pulses.

Anyhow it seems to work.

Yes, John, I found out the hard way of the sampling rate limitation on the 9219. We are using the 9291 in a wireless carrier. Is there another analog module that samples faster?

Dick N

[John_P1]

Hi Dick,

Here's a link to our Wireless DAQ Product Page for Analog Input:

http://sine.ni.com/nips/cds/view/p/lang/en/nid/206850 

Currently, there are a couple of options for faster modules that will work with the 9163 wireless carrier:

The 9205 or 9206 can sample at 250 kHz (divided by the number of channels you are using)

The 9215 can sample at 100 kHz per channel

The modules can be used with your existing 9163 carrier so you could just purchase the C Series module without the WLS carrier if you wanted to swap them out.

Best Regards,