Hi,
I am trying to wire-up a PNP retroreflective sensor to an NI DAQ-6211. I am using the DAQ Assistant Express VI using the Frequency counter for the RPM.
I am powering the sensor with 24 V dc and the sensor has two options on the outputs NO and NC. I am using the NO option i.e. when the reflector is inline with the sensor then there is a positive edge. The NO sensor wire is wired to PFI0, stepped down with a voltage divider to 4 V. The NC wire is put to DGND together with the cable shield wire.
When it is wired up in this configuration the reading as a counter and RPM is stable. However, when the system is installed in the application it produces fluctuations in the reading. It seems like it is interference from a ground loop. But have tried everything possible.
Can you please help with the setup, if this correct and also why the readout values would be instable. Any help in way would be helpful.
Thank you.
