Attaching Grounded 10V Analog Input to TBX 1303

[CGATMIT]

I am attempting to attach a 10V grounded analog source to the input of our TBX 1303. The TBX is attached to an SCXI-1100, then to an SCXI-1000 and a desktop based PCI-6024E. When I configure the channel on the Measurement and Automation Explorer I am only offered a differential mode option. If I attach the device in this way to the board I get interference on all of the other signals on the board, even when the device is not on (i.e- a differential of 0V across its output terminals). I have conducted continuity checks and attached other signals to the wire being used and there does not appear to be any problem in the conductor. Most of the other signals on this board are low voltage thermocouples. Is there a way I can wire this device to this board? We do have other grounded devices outputting 10V signals with no trouble at all. I am not sure what would be different about this device. I have read the online information on this site but an not sure how to wire this device without wiring it to the common ground on the board as stated.

[Salvador_Santolucito]

Hi,

I would first check out the field wiring and noise tutorial:
http://zone.ni.com/devzone/conceptd.nsf/webmain/01f147e156a1be15862568650057df15?OpenDocument

There may be some information in there that can help you sort this out.

So the other 10v signals can be connected to the exact same analog input channel and give no noise? Is the signal that causes the noise at the same ground as your other signals? Is it a high current source? What is different about it?

Try some of the things mentioned in the tutorial, that may help.

-Sal

[CGATMIT]

Thanks Sal,
I have looked over the tutorial before and gave it another read today. My signal source is ground referenced and I did plug it into the same ground as the other ground referenced sources just to be sure that wasn't the problem. I also used a 9V battery across the wire to my TBX board and got a suitable response, so that should elimate the possibility of some short in the wire itself.
There might be an impedance incompatibility here however I'm not sure how to determine/measure that. The source is an older model detector interface. It recieves a signal from a UV Flourescense (Sulfur Dioxide) meter and conditions it. There is a digital output on it and analog output channels on the back of the device for 0-10V or 4-10mA. I have these wired to the TBX using shielded cable. Is there a chance my cable is not of sufficient gauge?
Thanks,
Mike

[CGATMIT]

Problem solved! An internal ground wire was not connected in the signal generator. Once it was reattached everything worked fine. Thanks to Sal for the assist....