Can I trigger the read of a buffer period measurement with a external signal (PFI line) with my 6602 card? How can I do it?

[enmollo]

I am doing a buffered period measurement with a 6602 card, Labview real time. I want to measure the period of 6 rising edges of a TTL, but I want to do it exactly when an edge comes on other external signal (of course slowler than the previous one), that is to say that I want an external start trigger. Can anybody help me? I have hardly searched at the web and I have not found an example of code of what I am looking for.
Another question:
After reading the buffer, how does my program know that the data has been refreshed in a continuous measurement? I attach two VIs I am trying to make work and a quite explanatory bmp of what I
want to do.
Thanks.

[Filipe A.]

Hello;

I can't think of any way to accomplish that task. Once the counters have only two input pins, and both are in use when one configures the counter to do buffered measurements, there isn't a way to trigger that operation in hardware.

I'm not sure if I understood your second question, however, the buffered operation on a counter is hardware controlled, meaning that a pulse on its gate input triggers the transfer of the count value from the counter register to the PC memory buffer. That is therefore a continuous measurement.

Regards
Filipe A.
Applications Engineer
National Instruments