"AT&T Home Security System - Wire a Wireless KeyPad to a Magnetic Reed Switch"

 By Ron Stultz

28 Dec 2011

Summary: attach one wire of the normally closed (NC) magnetic reed switch to the wireless keypad back plate "green" terminal and the other wire from the reed switch to the "black" terminal AND change 3 dipswitches.

Background:

Both the AT&T home security system model 8440 and 8420 wireless keypads can be wired to a magnetic reed switch.

This is most commonly done on the most used home entry door.

Wiring the reed switch:

Magnetic reed switch must be of the normally closed (NC) type.

One wire of the reed switch is connected to the terminal marked "Green" on the wireless keypad back plate and the other reed switch wire to the terminal marked "Black."

Dipswitch settings:

Make sure on the device id set of dipswitches that with a magnetic reed switch attached you have dipswitch 6 "off", 7 "off" and 8 "on"

If you want to use a wireless keypad without a reed switch attached, 6 is "on", 7 is "off" and 8 is "on".