nonzero final value of triggered, buffered AO

[sshoham]

Hi,

I use buffered AO to output a waveform on 4 output channels (PCI-6711), and would like the AO to stay at a fixed state which is non-zero after the buffer is done. The analog output is triggered on the rising edge of PFI pin 7, and is set up using a cascade of VIs: AO config - AO write - Trigger Config - AO Write - AO Wait- AO clear. The output always goes to zero after the waveform is output, irrespective of the initial state, irrespective of the last sample, and including after I removed AO clear. The only way I have to return to the desired state is adding an additional 'Single update' afterwards, but this takes ~100ms to kick in, while the waveforms I'm working with are submillisecond.
Thanks for any ideas.

[JustinBritten]

Greetings,

Actually, I am surprised to hear what you are telling me, because our boards latch the last analog output value. The only time this won't happen is if your buffer is of the wrong size. I have linked a KnowledgeBase article that explains what may be going on here.

Analog Output Returns to Zero Volts After a Buffered Operation in LabVIEW
http://digital.ni.com/public.nsf/websearch/C887A5060A2C3EEF86256628004FC86B?OpenDocument

Regards,
Justin Britten

Applications Engineer
National Instruments