DSC Motion Sensor Trips Before Recessed Door Sensor

ioguy

New Member
I have a relatively new DSC install that I noticed an issue with.  When coming home yesterday (Armed - Away), the motion sensor tripped (set off the alarm & siren) prior to the door opening signal (so there was no Opening Delay).
 
The sensor points right at the door (about 10' away) and must have picked up my arm as the door opened.  The door switch is a recessed style which doesn't open on the magnetic contact until the door is about 1.5-2' open.
 
I don't really want to move the motion sensor - any DSC programming options I could use to combat this?
 

RAL

Senior Member
It's possible that the motion detector didn't pick up your arm, but rather saw a blast of colder outside air as the door cracked open.

I'm not an expert on this DSC panel, and the install manual isn't crystal clear on how zone type 05 behaves when it says "Once armed, this zone will act like an interior type zone [04]. 
 
Type 04 is really an interior follower type, in that if the entry door contact is triggered first and then the motion detector triggers, it will not trigger an alarm right away, but will "follow" the entry delay, giving you time to  disarm.  Hopefully zone type 05 picks up that characteristic, too. 
 
So one thing to try to prove this out would be to change the configuration to type 04 and see if it makes any difference.  If it does not, then the problem is as you say, that the motion detector is indeed triggering before the magnetic contact. 
 
In that case, I think you have two choices.  One is to relocate the motion detector so that it can't see the door.  The other would be to mask off part of the motion detector lens so that it doesn't see the door. 
 
In general, it's a bad idea to point a motion detector at a door that is used as an entry/exit door because it can cause these sorts of problems. 
 
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