Get time of execution of counter measurements

[BruceAmmons]

Okay, I was talking about buffered edge counting originally.  Use the timebase as the source to the counter, and buffer a value each time a rising or falling edge occurs.

Bruce

[homunculus87]

Hello Bruce.

Thanks for your suggestions, but I already mentioned this method in the link I provided in my first post and I am looking for a more elegant solution.

[homunculus87]

Hello Kevin Price,

thanks, I have to admit, that the trick with the cumulative sum is quite elegant and simple, but my co-worker tells me that semi-period measurement lacks a trigger option (in LV 7.1) , which is vital so synchronize the measurements. I'll check if there is a (start/stop) triggering possible, but currently I have no access to the lab.

[Kevin_Price]

From what I both remember and have somewhat verified with just a li'l bit of searching, E-series boards like the 6036e don't support triggered counter measurements.  I'm pretty sure that's a hardware limitation.   You might also run into trouble trying to run 2 simultaneous buffered counting tasks because that board only has 1 DMA channel available for data transfer.  The other task would have to use interrupts.

I must admit, I don't know what it is you need to synchronize with the counter measurement via trigger.  There *may* be a somewhat more complicated way to do it using one of your high speed digital boards, but I don't have personal experience to vouch for it.

I would highly recommend that you consider buying a newer data acq board that will let you put this app together with a lot less grief.  Probably an M-series board so you can get a PCI version as a drop-in replacement for the 6036e.  The newer counters in the M-series boards support an "arm start" trigger for counter input tasks and also have 2 DMA channels available for counters.  They'll let you get your measurements either via 1 semi-period task and a cumulative sum or 2 edge-counting tasks which produce edge times directly.  I myself would opt for the 1 counter solution so I could use the other counter to produce the tick clock.  (On the semi-period measurement counter, the external signal is used as the "gate" and the tick clock is used as the "source.")

There's other ways but one's probably enough, eh?

-Kevin P