Measure time until I get a signal?

[gusse]

Hello,

I'm quite new here, and I feel stupid about asking this question, but  I have been trying now for a couple of days to make a VI that measure times until I get a signal in. I'm testing a timers accuracy, so when it turns on the power the VI should show me the time elapsed.

I'm just fighting with different kind of loops, but can't get any sense from it.

/gusse

[conzemic]

Hi.

What kind of a signal is available? Since you post in 'counter/timers', let's assume it is some kind of 5V logical signal, which you can set to high als long as your timer runs.

Then, what you need is a simple tick count which is controlled by a gate. Use MAX to set-up a counting task. When choosing the counter, you will be shown which lines to hook up to. Measurment then is
'When Gate is high, count ticks till gate is low.'

Accuracy and time depends on the tick source. On a dedicated counter card such as 6602, 80 Mhz is available, hence 1/80 000 000 s is duration of one tick. Uncertainty in counting results mostly from the gate not knowing, when a tick comes by as it opens and shuts. So this gives a max error of 2 ticks. Other (probably main) source is signal quality, i.e. slew rate of your logical gate signal.

Does that help already? If not, please ask further.

Michael