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Problems of PCI-6014 and PCI-1200 connection, strange voltages on PCI-6014

Hi there,

I am a newbie to NI cards and experience a very strange problem.
I use 2 different A I/O cards in 2 computers, the idea is to communicate between those two via voltage signals.
I just use the Measurement and Automation Explorer Test panels.

PC-1)
Win2000
PCI-1200 Card
NI-DAQ 6.9.3 installed


PC-2)
WinXP
PCI-6014 Card
NI-DAQ 7.3 installed


I connected the Inputs and Outputs with 2 terminal blocks and a 10 wirecable.

The problem is, that I obviously measure and create wrong voltages on the PC-2 side, while on the PC-1 side everything seems to be OK.

I used the Test Panels which come with the Measurement and Automation Explorer.

If I set e.g. 2V DC as Output on PC-1, I can measure with my voltage meter 2V DC on both terminal blocks as expected, however, PC 2 Testpanel shows 2.3V DC. In this direction I have a constant Offset of 0.3V over the complete range.


If I set 2V Output on PC-2, I measure with the voltage meter on the terminal blocks 1.8V, and PC-1 shows also 1.8V!
In this direction I have an offset which chages depending on the voltage.

-4 -> -3.4
-3 -> -2.5
-2 -> -1.6

etc.

I checked the grounding, also the PCs have the same potential.
I first thought it could be a compatibility problem, but PCI-6014 cards are not compatible with NI-DAQ 6.9.3 therefore I cannot use the same versions.

I this a knoen problem?
Are there any self checks?
Might the PCI-6014 card be defective?
Any other ideas?

Any help is greatly appreciated,
Markus
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Hi Markus,

It sounds as though you are having problems with your PCI-6014. The difference in software versions shouldn't be an issue at all, so don't worry about that too much. If you try to output a voltage with the PCI-6014 and you are reading a voltage that is off by as much as half a volt depending on which voltage you choose, it definitely sounds like a problem with the actual card. This is backed up by the fact that you are reading that same voltage on the multimeter as well.

You can definitely test this by trying to replace the PCI-6014 with a different DAQ card to see if you get the same results. My guess is that you will see the correct readings on both sides if the card is replaced.

It sounds as though your board needs to be repaired or recalibrated. You can give us a call at 1-866-275-6964(866-ASK-MYNI) and we will be more than happy to get that set up for you. If you have any more questions or concerns, please feel free to post them in here and I will get back to you.

Regards,
Matthew Slaughter
Applications Engineer
National Instruments

LabVIEW Integration Engineer with experience in LabVIEW Real-Time, LabVIEW FPGA, DAQ, Machine Vision, as well as C/C++. CLAD, working on CLD and CLA.
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