Is it possible to capture/catch a 100 ms pulse by usb6008?

[colinzhang]

Hi,

Is it possbile to catch a 100 ms pulse (peak value is about 2~3V) by usb6008? The detailed signal is attached picture, the signal that acquired by USB6008 under differential mode, 1000 sample rate.

Yes, the max sample rate is enough for 100ms pluse signal. But now the problem is how to catch/capture this signal that appears only one time.

I find that USB6008 has one PFI that can use to trigger. But this trigger just supports digital type, even so, i also try to trig to start acquiring signal by this PFI. But still fail to achieve goal.

Anyway, no need very High precision measurement about this pulse, detection of pulse is enough here.

At final, as the topic " is it possible" , or any other suggestion? please advice, thanks. 

[johnsold · Accepted solution]

Colin,

You can certainly capture such a pulse. If you set the AI for continuous sampling at 100 Hz or faster, then read all available samples about 5-10 times per second, you will capture the pulse. For a signal as clean as shown in your image, just do an Array Max & Min on each group of samples. When Max > ~1 V, then you found the pulse. The index and the sampling period can give you the time of the pulse. Occasionally you will capture part of the pulse in one Read and the remainder of the pulse in the next Read. Dependingon your application, you may need to add a bit of logic to handle that situation.

Lynn

[colinzhang]

Thanks, Lynn.

Even i know this is not very good, but i also don't have any other option.