Common mode voltage in NI 6250

[Rafi2003]

HI,

What is the limit for the common mode voltage when using differential inputs in NI6250?

IN my application the differential voltage is  few volts but with reference to ground, it is 80 volts.

Can it work?

Is this issue addressed anywhere?

Thanks

Rafi

[Steven_K. · Accepted solution]

Hi Rafi,

The 6250 is not able to handle such a large differential to ground. I've found the specification in the NI 625x Specifications.

Maximum working voltage for analog inputs

(signal + common mode) ................ ±11 V of AI GND

If you need to have that high of a common mode rejection you might considering looking at some of our CompactDAQ modules. For example the NI9205 has 250V continuous Channel to earth ground Isolation.