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Posted 25 March 2012 - 08:01 PM
Posted 26 March 2012 - 12:04 AM
The EOL Resistor at the switch allows for sensing of the circuit open or shorted. Do not put the resistor at the control. It is a waste of a good resistor. In that case program the zone definition as Normally Closed and remove the resistor instead of placing it at the control.
Normally closed zones with no resistor have better noise immunity than EOL wired zones. What you loose with no EOL Resistor is the ability to detect the wires shorted together between the control and the switch. The alarm triggers when the zone circuit is opened with a normally closed zone definition.
If you measure the zone input terminals with a voltmeter on an M1 you will see:
Zone Open: 12 to 13.8 volts DC, must be greater than 9 volts DC.
Zone Shorted: 0 volts DC, must be less than 4 volts DC.
EOL Resistor in place: 4 to 9 volts DC, normally about 7 volts.
Posted 26 March 2012 - 02:51 AM
It's rare that EOL resistors are used in residential settings anyways. Of course they're ideal, but rarely used.
Posted 28 March 2012 - 07:45 PM
Posted 28 March 2012 - 08:02 PM
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