I'm hoping that someone can help me with this problem. I have installed a photoelectric beam sensor and I've connected the "normally open" contacts to a DS12A RF door sensor. So, when the beam is in "light off" state, the circuit is closed and the DS12A sends "normal". When the beam is in "light on" state, the circuit opens and the DS12A sends "alert".
This setup works ok in the "light off" state in which the circuit is closed. When the device goes to "light on" and the relay circuit is open, the DS12A goes wild and starts sending a continuous stream of "alert" and "normal" indications. These are sent until the photo beam sensor is unplugged or else goes back into "light off" condition. I've tried this with 2 different DS12A devices, and both reacted the same.
When the photo beam relay is in the open state, I can measure 3V AC across the leads, and I'm assuming that this is some form of noise that the DS12A is reacting to. I believe that the sensing current used by the DS12A is at around 3V, so it makes sense that it would react to this current.
I would guess that there's a way to filter this relay circuit using resistors and/or diodes, but I don't know how to do it. I would appreciate some advice on how to get this to work.