BNC-2110 and RSE and NRSE signals

[EdDickens]

I have a customer that is using a BNC-2110 with a DAQCard 6062E. Two of the signals we are scanning have a range of 10 to -10 volts. Looking at the manual for the 2110, the card should be in differential mode and you can select either a floating or grounded referenced signal. I always understood diff mode to be for small signal less that 1 volt. Is it acceptable to measure the 10 volt signal with the card in dif mode, or will this cause problems of any kind? If not, can the 2110 be used with the 6062E set for RSE or NRSE?

Thanks
Ed

[mhaag]

Using differential for larger signals, like the +-10 V in your application, is perfectly acceptable and is done quite often. I believe that the 1V limitation that you are thinking of is the general rule that says you should not use RSE for anything less than 1V; however, differential will work fine for signals below and above 1V. For the BNC-2110, we recommend using it in differential mode as it has built in biased-resistors that can be enabled depending on whether your signal source is floating or grounded. With this feature built into the 2110, there is really no reason to use RSE or NRSE since differential general provides the best signal to your DAQ card. The 2110 can be used in RSE or NRSE if desired but becomes a little trickier due to the way the channel
s are combined to provide differential connections through the BNC connectors. This option should only be explored if you need access to more than 8 channels on the board.

If you wish to read a little more on Differential, RSE, and NRSE input modes, check out the document linked to below:

http://zone.ni.com/devzone/conceptd.nsf/2d17d611efb58b22862567a9006ffe76/01f147e156a1be15862568650057df15?OpenDocument