missing hardware triggers hdio? (PFI0)

[mdwuznik]

I'm using (or rather trying, for now) to utilise the HSDIO card for acquisition like follows:

Scripted generation according to scheme: (l1, wrtcfg1, wrtlat are 1000clock long waveforms)

script myscript

generate l1

repeat 10

generate wrtlat marker0(0)

generate wrtcfg1 marker0(0)

end repeat

end script

Marker0 is exported (properly) to PFI0. Same line is configured to run the data acquisition (multiple records, both Start and Advance Trig point to same PFI0 signal). For test purposes I'm doing that with SMA2164, where channel 6 (wvfm sent to DUT) is wired directly back to ch4 (wvfm received from DUT) to get rid of possible DUT influence. What worries me is that I seem to catch _half_ of the signals I generate, instead of all. The attached vi has two independent test loops, the timed generation one (every second, do the script above), which means generating 2xrepetitions (20 in the example above) trigger pulses on PFI0 (scope proves this assumption being right). However, the second loop - acquisition part (acq 20 records each iteration of the loop, timeout 10s) which should in principle run once per each generation loop iteration runs only every second time.

 I would be grateful for pointing my errors.

Michal

PS:Checked the bahaviour on two different setups, one with PCI 6562, second with PXI 6562. Both are missing triggers from PFI line (no difference which) in the presented scenario.

[Koza · Accepted solution]

Hello,

I've just read your message. In your case I would suggest using Initiate/Fetch combination rather than Read (Fetch is better when you need to acquire data and you wait for triggers). Also it is important to remember that first you should initialize acquire task and then generate task (in your case first trigger is generated after 10 ms what can be not enough for acquire task to start).

Please find example application that:
1. Initializes acquisition of 1s after a trigger from Marker 0 (PXI line 0)
2. Generates trigger (PXI line 0) and 1s of data
3. Generates 1s of zeroes
4. Generates trigger (PXI line 0) and 1s of data

Acquisition task should read data only from points 2. and 4.

Hope this helps,
Best regards,
Michal

[Keith.Shapiro]

Hi Michal,

Are you still having issues with this?

Thanks,

Keith Shapiro

National Instruments R&D

[mdwuznik]

Thank you both.

That was exactly Read/Initiate+Fetch issue. 

Sorry for not looking at the thread, I found the solution soon after writing, and forgot about writing after having gone code frenzy...

Regards

Michal

[Keith.Shapiro]

Glad to hear you've got things working.  Please let us know if you have any more issues.

Keith Shapiro

National Instruments R&D