pxi-6527 digital I/O ports not working

[jgriff]

I have been unable to get my two PXI-6527's to work.

In MAX, my devices are recognized, they pass self-test, and I can set the output high or low on a specific port and line on the PXI-6527 using the test panel. When I take a measurement at that line, say from -5.7 to +5.7 (port 5, line 7), I am not reading any voltage. I tried the same thing using one of the digital output LabView examples, without any luck. I've tried several different ports and lines on both PXI-6527 cards.

When I measure from the 'GND' pin to the '+5V' pin, I do read 5V on my multimeter.

I have several other DAQ devices with digital I/O on them  (PXI-6025E's, PXI-6704, PXI-6221), and I am successful at setting output voltages on the digital I/O lines.

Is there anything I need to do to set my PXI-6527 cards up to output digital signals.

[ManLongAtNI · Accepted solution]

Hi Jake,

The output channels of a 6527 device are solid-state relays containing an LED and two MOSFETs connected together to form a bidirectional switch. The output channels won't output a 5 V TTL signal without providing an external source. Using the +5 V line from the 6527 device allows you to use it as a TTL-level output device with non-isolated power. Refer to sections 3-10, 3-11 of the 6527 User Manual as a reference for the above information.

Thank you for choosing National Instruments.

Regards,

Glenn

Applications Engineer

National Instruments