Hello everyone.
We're having a problem with our ENET-9205 DAQ device. We have a system (a testbed) with approx. 20 sensors (RTD's, pressure transmitters, torque, speed, etc.) and a VSD powering a single 75 kW motor. The problem is, once the VSD is turned on, we get a lot of noise on our measurements(+-5%), even when the motor is not running and the VSD is drawing approx. 0.5Amps/Phase. Once we start the motor things get even uglier. The VSD is located approx. 3 meters from the testbed, so as far as I know this should be enough not to cause any significant noise. We even tried powering the electronics from a different grid section in the factory, separated by two sets of transformers, still no good. I'm fully aware I can do software filtering (a LPF with a cut-off frequency of 30 Hz performs somewhat better) but does anyone have any idea what's causing the havoc?
One more thing, some sections of cables going from sensors to DAQ device are not shielded, but as I said before they are 3-4 meters away from the VSD. Does anyone think this might actually be the problem.
Thanx in advance!
