04-21-2014 02:45 PM
Hi!
Device: 5672
Problem: I need to generate marker events with predefined period. Generation is performed in continuous mode from large file. So, after each N samples I need to create marker event on PFI out. I suppose that I can do it with scrpt like this:
script myScript
Repeat forever
generate myWfm subset (0, ?) marker0 (?) // i don't know what subset range must be here
end repeat
end script
But I don't understand what range I must set for subset and marker paramerters. IF I set a subset range from 0 to N samples, on second peroid I need set range from N to N+N and so on. How I can do it with script?
Thanks.
04-24-2014 12:24 PM
Instead of doing subsets, just do the whole waveform. You can issue a marker at multiple locations:
generate wfm marker0 (0,32,64,96,128)
Of course, this doesn't work out perfectly if:
1) (desired marker period / sample rate) is not an integer
2) waveform duration in seconds / desired marker period is not an integer
If #1 is not met, it may work for you to issue the marker at the nearest sample. This introduces jitter in the marker period.
If #2 is not met, what you want is (for example) markers at locations (0,32,64,...) the first time the waveform is played, but at locations (4,36,70,...) the second time, (8, 40, 74, ...) the third time, etc. You could work around this by writing multiple copies of the waveform to the device. Concatenate the waveform with itself until the total number of samples is a multiple of the desired marker period. In this example repeating the waveform 8 times would do the trick.
Hope this helps. I'm guessing you meet both #1 and #2, and you were just missing info on issuing multiple markers.