when pc powers down Daq card turns on all Dio's

[Audi]

My application is a Labview front-screen using Daq card and GPIB to control Radiation Experiments. Recently during a power down situation the Daq card drove all my outputs high thus opening 4 Radiation Shutters

[RIO-Todd]

All of our E Series multifunction DAQ devices have pull-up resistors on the digital lines. Therefore, on power-up the state of the digital lines will be pulled high. This is probably what is happening in your case. If you want the value of the digital outputs to be low when they are not actively being driven, you can add a resistor between the digital lines and digital ground (pull-down resistor). The document linked below describes how to do this. I hope this helps.

Setting the Default State of Digital Lines on E Series DAQ Boards
http://digital.ni.com/public.nsf/websearch/B4FED0C879BD155F862569ED00142DC7?OpenDocument
Regards,

Todd D.
NI Applications Engineer