I have a 24V pressure switch that is loop powered. Here is the manual/datasheet. I'm trying to figure out how to read the sensor with an Arduino.
Obviously, the Arduino can't handle 24V, so I got some optocouplers (manual/datasheet)
This, however, didn't seem to work. When I measured voltage across ports #1 and #2 (from the schematic), it measured between ~13V and ~20V (when the sensor was engaged vs not-engaged).
I'm not really sure how to fix this. I tried using a voltage divider (instead of an optocoupler), but, in my ignorance, I burned up one of my small resisters.
Thanks for any help!