NI-4351 TBX-68T digital I/O

[Greg N]

Hello,

I am attempting to use the digital I/O pins on the TBX-68T (using NI-4351) to generate output signals.  All seems fine until I close the application I'm using (custom C code, using NI-provided examples) at which time the digital I/O go to 1.7V.  I would really like these digital signals to go to gnd when not actively being used.  A pulldown resistor did not seem to do the trick.

Thanks,

Greg N

[KatieC]

Greg, 

What values have you tried with the pull-down resistor? Per this KB, you can use a resistor to pull the power-on state to a logic low; for this device, a logic low is less than .8V. Would that be sufficient for your application, or do you really need it to be 0V?

How are you closing your task/program in your code? Are you resetting the device then closing or just closing? One thought I had was to write an output low then close without resetting.

Could you please tell me what functions you are calling to close your program? That will help me in assisting you. Thanks!

Katie