Hi, I have a problem to use that DAQPad as pulled-low mode rather than pulled-high mode.Basically that DAQPad-6508 has a front panel switch to change the power-up state selection for 96 channels. But jumperd the switch to pulled-low mode to use 96 channels, both DI and DO will not work properly. DI does not get any state change, and DO works like pulled-high mode. Insted jumperd to pulled-high mode, both DI and DO work fine at this time. Why the pulled-low mode does not work properly? Is there any difference between line connection as to the mode selection?
Yes, there is a switch that should set all the lines to either high or low in the power-up state. The switch uses a 100 k resistor pulled up to either 5 VDC or GND. Are you using the Measurement & Automation Explorer Test Panel for the DAQPad-6508 to verify the power-up state as well as a multimeter? You can try to manually pull high or low lines using the instructions on page 3-9 of the DAQPad-6507/6508 User Manual to see if that gives the correct response. The manual is located at the http://www.ni.com/manuals pages.
Geneva L. Applications Engineering National Instruments http://www.ni.com/ask