Why does my HSDIO board drive all lines high during initialization?

[bmihura]

I've got two NI PCI-6541 boards that execute the following LabVIEW pseudo-code.

for i = 0 to 1
{
   Execute these VIs:
   niHSDIO Init Generation Session.vi
   niHSDIO Assign Dynamic Channels.vi
   niHSDIO Configure Sample Clock.vi
   niHSDIO Export Signal.vi
   niHSDIO Configure Generation Mode.vi
   niHSDIO Export Signal.vi
   niHSDIO Configure Generation Repeat.vi

   Set these properties:
   ExportedSampClk.Mode
   SampClk.Impedance
   RefClk.Impedance
   SampClk.Rate

   Execute these VIs:
   niHSDIO Write Named Waveform (1D U32).vi
   niHSDIO Write Script.vi
   niHSDIO Get Session Reference.vi
}

Execute these VIs:
niTClk Configure For Homogeneous Triggers.vi
niTClk Synchronize.vi
niTClk Initiate.vi

********************************

For some reason, the first VI called (niHSDIO Init Generation Session.vi) sets all my DIO board's outputs to high. They are not set correctly until the last VI (niTClk Initiate.vi) is run.

How do I make this not happen?

[David S.]

Hi bmihura -

Have you tried calling niHSDIO Reset Device or setting the "reset instrument" input on the niHSDIO Init Generation Session VI to TRUE?   I believe this will tri-state the lines for you.