counting falling edge on pci 6281

[VPS]

I have an analogue signal consisting of pulses of 5V (reference level 5V, pulses to 0V) which occur randomly.
I read this signal in using a pci 6281 NI card. This works fine.

Now I would like to count the number of pulses for a given time (e.g. number of falling edges). According to what I read in the manual it should be possible to configure the system such that one can start a counter (arm it) and then ask the counter from time to time what the current number of pulses is.
So the question is rather simple: what is the best configuration to do this? Should I use a different input (instead of analoge input)? Can I use the simple 'count events or time.vi' or should I use more advanced counter vi's?

Thanks for any suggestion.

[Nick_CH]

Dear Steven,

The best way to count events (falling or rising edge), it is to use the counter functionality. The device NI-6281 provides two counters.
That means
    for the Software: see the examples under. Find Examples -> Hardware Input and Ouput -> DAQmx -> Counter Measurements -> Count Digital Events
    for the Hardware: you need to connect you signal to the input ctr0/source

PS: Counter level is based on the TTL technologies

Best regards
Nick_CH

www.ni.com/gettingstarted