NI 9239

[Nandagopal]

Hi all,

I am measuring the battery voltage using NI 9239 and cRIO and my measurements are all proper. if suddenly disconnect the battery, the voltage is not suddenly droping to zero. if i try to connect the pull down resistor, there is no common terminal in the module.

can someone tell wot needs to be done??

Thanks,

Nanda

[TCPlomp]

Remember a Voltage difference of 0 V means that the connections are linked. If you measure the voltage with a multimeter you will get overload and not zero.

The 9239 is a differential mode DAQ device, so the inputs are floating. To get what you want connect the signals with a high value resistor (10 MOhm), be ware this draws a small current from the system.

Ton

Message Edited by TonP on 10-20-2008 03:15 PM