From Friday, April 19th (11:00 PM CDT) through Saturday, April 20th (2:00 PM CDT), 2024, ni.com will undergo system upgrades that may result in temporary service interruption.

We appreciate your patience as we improve our online experience.

Counter/Timer

cancel
Showing results for 
Search instead for 
Did you mean: 

6218 only one of two counters works

All-

    I am using the two counters on my USB 6218 simultaneously.  Counter 0 works, while counter 1 does not for the standard input.  When I switch counter 1 to the timebase, it counts the timebase fine.  When I switch it back to the standard pin (PFI3, I believe), it does not count my pulses.  However, this same pulse source counts fine on counter 0 on its standard pin.  Any suggestions?  It worked fine, but now I have changed computers (and no longer have access to the old one).  LV 2013, daqmx15.?.?  J

0 Kudos
Message 1 of 3
(2,125 Views)

I'm not sure I understand 100%.  Here's what I think I've gathered:

1. Both counters are doing edge counting

2. There's some kind of external pulse source.  (Or sources?).  It's wired into the default source input for Ctr 0 (PFI8, according to MAX pinouts for a simulated M-series device).

3. It's unclear what, if anything, is physically wired to Ctr 1's default source input (PFI3 according to MAX).

4. Ctr 0 counts successfully, Ctr 1 doesn't.

5. When you configure Ctr 1 to use an internal timebase as its source signal for counting edges, then it *does* count fine.

 

If I've got that right, then the next thing I'd do is configure Ctr 1 to count edges on the signal that Ctr 0 is also counting.  That's allowed, 2 tasks can both count edges sourced from the same PFI pin.

 

If that works, I'd suspect there's a conflict or oversight between the physical wiring in place for Ctr 1's pulses and the task configuration settings that define what Ctr 1 should count.  Maybe the signal is wired to a pin *adjacent* to PFI3 or something like that.

 

 

-Kevin P

CAUTION! New LabVIEW adopters -- it's too late for me, but you *can* save yourself. The new subscription policy for LabVIEW puts NI's hand in your wallet for the rest of your working life. Are you sure you're *that* dedicated to LabVIEW? (Summary of my reasons in this post, part of a voluminous thread of mostly complaints starting here).
0 Kudos
Message 2 of 3
(2,111 Views)

Kevin,

    Thanks so much for your reply.  It seems that the whole incident was precipitated by a flaky cable.  You may now berate me for ineffective troubleshooting.  J

0 Kudos
Message 3 of 3
(2,096 Views)