Hi:
Have you tried testing the lines in Measurement & Automation Explorer? To test the ports in Measurement & Automation Explorer, expand devices and interfaces; right click on the PCI-6534 and select test panels.
You can use pin 1 which supplies constant 5V to test the ports:
port 0(Lines 0:7) -> pins 10,44,45,12,13,47,48,15.
Also try writing to the lines and see if that works. If it does not work in Measurement & Automation, the card might be bad. So its good place to check first.
Regards,
Bharat Sandhu
Applications Engineering
National Instruments
Penny