pci1200 digital input output

[dries]

Hi,I'm a student using labview 6.1 for the first time. I use the digital input/output lines of a pci 1200 card. I use 8 digital input lines placed in one sequence, and 7 digital output lines placed in another sequence. The VI can read the input lines but the output lines give a voltage of 0.5 Volts instead of 5 VOLTS, how can I solve this problem?

[RIO-Todd]

What are you writing to the digital output lines in LabVIEW? Writing a Boolean value of False to a digital line will write a TTL logic low voltage and writing a Boolean value of True to a digital line will write a TTL logic high voltage. Make sure you are writing a true Boolean value to the lines you want to output 5 V.

Also, make sure you are not loading down the digital outputs. The digital lines can source 13 mA of current. If you are connecting a small resistance load across the digital outputs, you might be loading down the digital ouputs. I hope this helps.

Regards,

Todd D.
Applications Engineer
National Instruments