Digital IO 6552 output '-1Volt' instead of '0Volt'

[HaD]

Hello, My question is very simple.
Im configuring the 6552 to be 5V family, and after that when im request 'Low' it output -1.2 volt instead of 0 volt.

I also tried to configure the low voltge manually, and i get the same result. the low is stuck on -1 volt.

why is that. im working with this card more than 2 years, and only now i chekced the real voltages in scope. i dont know when this problem started.

Thanks

[Aaron_W.]

HaD,

Thanks for posting on the NI Forums. You should be seeing 0 Volts when passing a logic low. Are you seeing this -1.2 volt low on all of your channels? Do you still see the -1.2 voltage if you are not using the 5 V family? Could you also tell me what connector block you are using with the 6552 to measure the signal? Also, I know this is a simple thing, but could you make sure you are measuring the voltage difference between the GND of the channel and the DIO line. 

I tried this with a PXI-6551 and I was able see the 0 V 'low' and a 3.3 V high (on 3.3 V logic family) and a 5 V high (on 5 V logic family). I would recommend checking to see if all the DIO pins are at this -1.2 V level when low. Thanks!

[Aaron_W.]

HaD,

I forgot a couple other questions that could help us get to the bottom of this problem. How long has it been since you have calibrated your 6552 card? Could you also tell me what happens if you make your programmable logic low level around 2 Volts or something large. How exactly are you testing this logic low level? Is this with a program that you are running? Would it be possible for you to use Measurement Automation Explorer and use the Test Panels for the PXI-6552 to do static generation as this is how I was able to test the PXI-6552. Thanks!