pxi-6541 continuous vs. software trigger

[dch2]

I'm trying to generate a set of triggers for various pieces of hardware using the PXI-6541 card.  I intend to eventually run this on a RT target, but in the meantime have been playing around with the code in normal labview. 

The following speak to my ignorance of the HSDIO vi's for which I haven't been able to find answers: 

1. When a waveform is generated using the software trigger (using niHSDIO Configure Trigger.vi), does the waveform need to be reloaded in order to be ready for the next software trigger? I was using the "niHSDIO Configure Generation Repeat.vi" and it seems that after the "niHSDIO Initiate.vi" is called the waveform will repeat continuously until I tell it to stop.  However, if I try to continuously software trigger (using "niHSDIO Send Software Edge Trigger.vi") after calling "niHSDIO Initiate.vi" it only triggers once.

2. Which would have greater stability and speed, running the same waveform in a continous loop mode or using a timed loop on the RT target and using a software trigger to tell the card to write the waveform?

3.  Assuming a reinitiation is required between uses of software triggers, is there a way to store the waveform on the card (using a named waveform, for example) so that I don't have to reload the waveform every time?  I would think this would be a time consuming process if done on every loop?

4.  Is there an easier, more obvious way of doing what I'm trying to do? 

Thanks,

Doug

[Doug_L._Bear]

Hey Doug,

To paraphrase your issue, you are trying to continually generate the same waveform on a software trigger being sent.  There is an example that demonstrates this that ships with LabVIEW and the HSDIO driver. In Help»Find Examples...»Hardware Input and output»Modular Instruments»HSDIO»Dynamic Generation»Non-Scripted»Dynamic Generations Software Start Trigger with initial State.vi

This will have to be modified slightly as currently it is configured for only one run.

With regard to clearing the stored waveforms, as long as you call Abort, the waveforms should stay on the card's memory, howeverif you call Close it will clear all reserved resources including memoy on the card.

Anything that you can run solely on the card will be more stable than running on an RT system with software triggers.  So for example something like scripting would be more stable than a timed loop RT setup.

[Doug_L._Bear]

http://zone.ni.com/devzone/cda/tut/p/id/7285

This article might be able to provide you some more information about scripting on an HSDIO card.