NI-6704 is outputting the rails

[Terry_ALE]

I have an NI PCI-6704 and while it's current outputs seem to be working fine, the voltage outputs are consistently outputing more than the rails at about 14.1 Volts DC.  I alter the limits and change the output value, but the output doesn't change.

This issue occurs both in MAX and LabVIEW (Express and regular VIs).  I am using LabVIEW 8.5, NI-DAQmx 8.6.0f6, and MAX 4.3.0.49152 in Windows 2000 SP4.  We have created and run LV applications using the current output with no problems.  It is with the Voltage Analog Output that I get this issue.

Thanks for any help!

[Broken_Arrow]

It sounds like you are connected to a current output on both channels, either physically or software-wise:

I'm sure you are using the proper "V" or "I" type output pins, but be sure to check your wiring.

The other thing is, when you setup the Analog Output task, do you have the channels configured appropriately as Voltage and Current? See attached.

[Terry_ALE]

Thanks for the quick response.

The LabVIEW side of things seems to be configured correctly.  I also tried the same thing with the board's Test Panels in MAX which yielded the same results.

Hardware-wise, we are reading the output across channels 34 AO 0 (V) and 68 AO GND 0/16.  We tried this with no load and with a resistive load of 10kOhms.

[Broken_Arrow]

Well, the 14V is troubling. You may have taken out the buffer on the output with a load that had high voltage on it (?). There's only one DAC (yep for V and I) so since your I is working, the DAC is probably OK. You're doing everthing right. Try different channels, even different CH/GND combos. Maybe NI will chime in.

[ColeTrain]

Terry,

It sounds like this card may need to be repaired.  The best option would be to call on in and troubleshoot this card with an Applications Engineer.  You can call 1-800-531-5066 and just let them know that you have a possible RMA.