I have a simple setup - Motion detector sends a signal which sets off the remote chime when a car pulls into the driveway.

Eagle Eye Outdoor Motion Sensor - MS14A
Transceiver Module - TM751
Remote Chime - SC546A

The motion detector is installed on a tree branch 12 feet high facing down into a driveway. I get false alarms sometimes during the day and also no alarms sometimes during the night when a car pulls into the driveway.

Can anyone suggest how I should diagnose this?

Thanks...RN

Two things come to mind regarding the daytime alarms. One is movement of the branch it's mounted on, the other is movement of other branches in the tree.

Deane

Deane,

Good point, I'll see if this happens more on windy days. Sometimes several days can go by without a single false alarm. Could sunlight fading in and out of clouds also cause a temperature change and thus setting off the unit?

Are there less sensitive X10 Motion Detector units available?

Thanks...Rohit

Things to consider:

1. Trees (and branches) move, these are living things and the seasons, weather, and time of day all effect them.

2. Cats, birds, squirrels and other rodents climb in and around trees.

3. Motion detectors should be mounted in as stable a location as possable, a wall is better than a branch.

4. Perhaps the motion detector does not need to face down, have you tried other locations / positions?

I have seen temp changes cause my motion detector to trigger false signals. I find it more often when the sun is low in the sky when it seems to have more of an effect on the unit. I can't keep it completly shaded where it currently is, but the problem is only for a short time.

I see a lot of complaining about false triggers with these sensors. Most of the time it is the fact that people do not realize what kind of "viewing" range these things have. I had one in a position to monitor the driveway and was receiving a lot of false triggers, I finally realized that it was "seeing" my neighbors driveway also more that 80 feet away!
I solved most of my problem by mounting the sensor about 8 feet high on a cheepie web cam mount that allowed me to tilt it down to lower the field of view and adjust it left and right to achieve only the coverage I needed.
Plants and sudden temp changes will trigger these things, so consider that when aiming.
A lot of trial and error but that is why I consider it a "hobby" :)