Measuring difference between fall times of two pulses on different lines.

[GNS]

hi,
I m using two trigger pulses on two different channels/lines for data acquisition. I m using SCXI 1530 Module. I need to measure the difference beween the fall times of the pulses. Pulses are of very short duration. Plz suggest some solution. One can mail me directly on gorakh@neometrixtechnology.com
one more doubt i m having. can't SCXI 1530 mudule work with DC signals...? plz. write back soon. It's urgent.
Regards
GNS

[RIO-Todd]

You could use the SCXI-1530 to acquire the two triggering signals and then within software determine the difference between the fall times.

For example, if you are acquiring the signals at 1 KHz then there will be a 1 ms. time interval between each sample you acquire. If there were 300 samples between the falling edges of both signals, that would correlate to 0.3 seconds. Therefore, you could acquire both signals and then use the array of data along with the timing information to determine the time between falling edges of both signals.

Each channel on the SCXI-1530 has a 0.2 Hz highpass filter designed to block the DC offset of IC piezoelectric based tranducers and so DC will not come through on the SCXI-1530.

The SCXI-1530 was designed specifically for IC
piezoelectric accelerometers and microphones and so if you are just wanting to look at an analog signal, I would suggest to look into another SCXI module. The SCXI-1102 is an example of a 32-input module that can accept DC signals (linked below).

SCXI-1102
http://sine.ni.com/apps/we/nioc.vp?cid=1654〈=US

I hope this helps.

Regards,

Todd D.
NI Applications Engineer