Wiring previous-year banner sensors

[Cjmovie]

Hello,

We are trying to wire a banner reflective infrared sensor from previous years (among other, non-banner sensors). We are having some trouble getting the signal from these devices.

For instance, on the banner device: We have the device powered properly (the status light is green, and the orange NC/NO light correctly turns on and off as proper). I was able to find wiring information in posts from previous years on these forums.

However, when trying to get a signal from the device, we have a problem. Regardless of whether we use the NC or NO signal line, we are reading 0 on our digital input. On the analog input, we read voltages very close to 0 at all times. This happens with both sensor devices.

When tested with a multimeter, the voltage correctly switches between low and high (for one sensor, 0 and 12V, for the banner, 0 and 3ish). We only get this signal, however, when comparing the signal line to a positive line on the robot - not ground. When comparing to ground, we always receive a 0V signal.

I seem to recall that the digital sidecar compares all voltages to ground, which would be why we are having our trouble. However, I am unsure of how to wire these devices such that they will work properly - even the banner sensor, which was included in the KOP in previous years (legality of its use isn't a big deal, it's mainly being used for data collection at this point).

I have looked up also information on PNP vs NPN sensors, and although I understand the theory, am unable to grasp a way of forming the system to meet our needs.

Any information on the proper wiring of these devices would be greatly appreciated.

Thanks,
CJ