Banner Signal Issue

[slijin]

So this year, we've decided to use Banner's QS18VN6D optical sensor to detect the presence of balls in our acquirer. Sadly, it doesn't work as of yet.

We know that the sensor itself works for two reasons
1 - the yellow light turns on and off in response to an object in front of the sensor
2 - when the oscilloscope is hooked up as per the included diagram*, it reads high and low values (the white lead is low by default; it turns high when something is in front of it)

However, the problem is that the signal bizarrely doesn't exist
1 - when a multimeter is hooked up to read the circuit as indicated*, the voltage across signal and ground is a constant 0
2 - the computer sees constant "TRUE", likely because of this^ problem.

When on the robot, the power supply is a 12V, 20A output from the PDB; the signal is hooked up to, obviously, the Digital Sidecar, by connecting the "sensor in" as seen here* to a Digital I/O.


*Sensor in would be the signal lead on the scope/pos lead on the meter, sensor out would be the ground leads on the scope and meter.

Does anyone have any ideas as to why this isn't working**? Thanks.

** On an afterthought, I just remembered that at one point, we accidentally hooked up the Digital I/O pin from the sensor to the 5V power instead of the signal (it is now appropriately plugged into the signal pins) - could this have fried the sensor, somehow? I doubt it, since the sensor operates up to 30V, but I'm just tossing it out there.