I have a question, I'm using a NI compactDAQ for trending a couple of 4..20mA signals. I'm connecting the measuring points directly into the transmitter loop.
The problem I have with the NI compactDAQ card NI 9219 ( which uses a shunt to measure m amps) is that if I switch of the trending the loop get interrupted and the PLC doesn't see the transmitter.
So I'm looking for something to measure the mA with out breaking the loop during measuring.
thanks,
