measuringing time difference between two signals

[temlihemli@gmail.com]

Hi
I've have a pci 6024e and lv8.0 and wants to measure the time between
two signal goes high. I am planning to use the 24 bit, 20 MHz counter.
So far I have managed to measure the period of one of the signals,
using the "measure buffered semi-period" example, but only up to 200
kHz. So can anyone help me with how to set up the counter such that it
starts on the edge of the first signal and the value of the counter is
read out on the egde of the second signal?

Jeppe Holm

[Joe_H]

If you are using daqmx you can use the trigger VI to set this up.

[Ken_Tobler]

Hello!

The example "Meas Two Edges Separation.vi" can only be used with M Series cards (62xx) or the 6010.

For your 6024 you can do this:
- Use the example "Gen Dig Pulse Train-Continous-Pause Trigger.vi" to create a Pulse Train on counter 0 (f.e. with 100kHz) only when the first signal is on HIGH (you connect the first signal on the gate of counter 0, PFI9)

- Use the example "Count Digital Events-Pause Trig.vi" to count on counter 1 only the events when the second signal is LOW. The Counter Output of counter 0 must be connected to Counter 1 Source and the second signal should be connected to Counter 1 Gate (PFI4).

So the first counter will generate a pulse train at a known frequency (f.e. 100kHz) only when the first signal is HIGH, this signal goes to the second counter which count every rising edges only when then second Signal is LOW. So you can find out the time difference between the two signals.

I hope it was enough clear.

Have a nice day

Ken

[Norbert_B]

Jeppe,

am i correct if i see two different lines with TTL-signals in your application?
The solution could be quite different, depending on the settings of each line:
a) Is it always the same line which goes "high" first?
b) Is the first line still "high" when the second gets "high"?
c) Are the signals continuous?
So we need more infos for finding an acceptable way to solve the issue.

Norbert B.