Reducing pre-filling for buffered analog output

[BertMcMahan]

I realize this is an ancient thread, but I found it via Google and wanted to help anyone else coming across this issue. I'm using a USB-6229 and am seeing the same issue, and I'm using standard LabVIEW 2016. Setting the DataXferReqCond to something other than "Less than Full" will work (i.e., if you read the value right after writing it the property node returns the correct value) but when you use a DAQmx Write, then re-read the property, it gets reset to "Less than Full".

You can try it with this sample VI from NI:

http://www.ni.com/tutorial/4402/en/

Read AO.DataXferReqCond immediately after the Analog Write, and it will be reset to the default value. I don't know if this is a known issue or not but I couldn't find it in a brief search. It's not a big deal for me as I can work around it for now- I just wanted to put a little more data out there for those like me who are trying to trace down a delay in their analog output.