Exporting multiple markers in arbitrary waveform mode

[gregoryng]

I am using the example Fgen Arb Waveform Marker.vi (from the LV2011 examples) as the basis for generating markers and exporting them to PFI0 and PFI1 on a PXI-5422. 

I have added a 2nd property node call after the first to configure marker1.  The program runs without error but only generates marker0.  It seems that if I configure the Active Channel as "marker1" or "marker2" or "marker3" or "marker4", the property node has no effect.  I would expect that subsequent calls should configure additional markers.

I have used script mode to configure more markers with my signal generator as well, but I'm trying to understand how things work in arbitrary waveform mode for some legacy code.

[Carl_W]

Hi,

The manual for the 5422 calls out that only one marker can be placed per segment and marker position must be placed at an integer multiple of four samples. This could be your problem.

http://www.ni.com/pdf/manuals/371400d.pdf

[kirsch]

If you want to output four markers, then you will need to use script mode. The necessary script would be very simple.

[gregoryng]

Thanks for your research into this matter, Carl (and all my other questions), and for your reply, Marcos.  Marcos's reply has answered the root of my question.

With respect to the number of markers supported, let me share my experience and see if this is intended:

I don't get any errors when attempting to configure only one marker, named one of marker1, marker2, or marker3, in Arbitrary Waveform mode, but these property node calls have no visible effect. No marker is exported.  If I attempt to configure "marker4", then I get an error, "Unknown channel or repeated capability name.  marker4" (that seems reasonable).  Is it on purpose that there's no warning/error for trying to configure marker1-marker3 in arbitrary waveform mode, or am I not seeing a side effect of what I did?

Yes, I have used script mode to make 4 markers.  Just for anyone's reference (not really relevant to my question now that Marco has confirmed what is required), here's a script that fires one marker every 32 generations and fires two other markers each generation.

script myScript0
repeat forever
    wait until scripttrigger0
    Generate wfmChirp marker0(2200,2600) marker1(2000,2800) marker2(0,200)
    repeat 31
        wait until scripttrigger0
       Generate wfmChirp marker1(2000,2800) marker2(0,200)
    end repeat
end repeat
end script

So just to summarize, the things that I think confused me the most before/during this thread were:

1. lack of error/warning feedback when configuring marker1-marker3 in arb waveform mode

2. the blanket "one marker per segment" statement seems inaccurate given arb script mode

3. arb script mode isn't mentioned in the PXI-5422 or PXI-5421 hardware specifications

[kirsch · Accepted solution]

So just to summarize, the things that I think confused me the most before/during this thread were:

1. lack of error/warning feedback when configuring marker1-marker3 in arb waveform mode

2. the blanket "one marker per segment" statement seems inaccurate given arb script mode

3. arb script mode isn't mentioned in the PXI-5422 or PXI-5421 hardware specifications

1. The board supports 4 markers, numbered 0 - 3. So when you configure those, you don't get an error. When you configure marker4 you get an error because it does not exist.

2. I think you are right, that statement applies to Arbitrary Waveform Mode, not to Script Mode.

3. That is probably another documentation problem. Script Mode was not supported when the 5421/5422 first came out, so my guess is that when support for it was added, the documentation was not updated.

Good luck, 

Marcos (not Marco 🙂 )