We're using a PCI-6289 for a variety of DAQ applications. We're using both Connectors 0 and 1 along with SCB-68s for terminal blocks. I started noticing some strange behavior on the flow controller devices controlled by our digital out setup. We're using 8 channels (Port 0 lines 0-7) of the digital output as on/off control for the devices. I looked into the issues we were having and lines 0 and 1 were outputting strange values. All measurements I'll describe were made at the terminal block. While channels 2-7 had approximately 0 or 5 V outputs depending on the on/off setting, pins 0 and 1 were switching from about 1.3 to about 3.5. I swapped cables to test for a bad internal connection in the cable and got the same behavior. I also switched terminal blocks, and still got the same behavior. I also tested the behavior of the pins with the flow controller disconnected from the pin, and found no difference. Finally, with both the device we're controlling on pin 0 and the cable disconnected, I tested for continuity between the line 0 pin and all other pins on the terminal block to check if my wiring was giving a short somewhere. There were no connections between that (pin 52) and any other pins. This seems to me to isolate the problem to the DAQ card as opposed to the flow controller or the terminal block/cable.
Finally, I tested the output using multiple methods(DAQ Assistant and MAX) to ensure it wasn't something I did wrong in software.
It isn't the end of the world since we have more than enough digital outs on the card, but I want to see if there's any other troubleshooting or testing I could do on this, or whether I should just give those two lines up as busted and use different outputs.
Message Edited by JRanalli on 01-14-2010 11:17 AM
