System overview   
1.26  EST3 Installation and Service Manual 
Signature series devices 
The Signature series family consists of intelligent smoke and 
heat detectors, bases, input/output modules, and ancillary 
devices. The EST3 network supports Signature series devices 
using several models of the Signature Driver Controller module. 
Up to 125 detectors and 125 modules can be connected to the 
Signature Data Circuit on these modules. 
The Signature series smoke and heat detectors contain their own 
microprocessors. This allows the devices to make alarm 
decisions based on the information gathered by the sensing 
elements incorporated in the device. Signature series detectors 
can be installed in any of four detector bases: 
•  The Standard Base provides wiring terminals for connection 
to a remote LED. 
•  The Relay Base provides a detector activated, pilot-duty dry 
contact relay used to control external appliances. 
•  The Sounder Base incorporates a sounder horn that can be 
controlled by the detector, by a special Signature module, by 
the control panel, or by programmed rules 
•  The Isolator Base protects the Signature Data Circuit from 
wiring shorts. 
Signature modules interface and support the operation of 
initiating devices, conventional 2-wire smoke and heat detectors, 
manual pull-stations, strobes, bells, etc. The actual functions of 
each Signature module is determined by a personality code 
downloaded to the module through the System Definition Utility 
(SDU) program. 
Signature series manual pull-stations (1-stage and 2-stage) 
feature an integral Signature module that monitors the station. 
One-stage stations are monitored by a single input module that 
sends an alarm signal to the loop controller when the station is 
activated. Two-stage stations are monitored by a dual input 
module which sends two independent alarm events to the control 
panel; one when the pull-switch is activated, and the second 
when the key switch is activated. 
Alarm sensitivity setting 
Alarm sensitivity refers to the primary threshold (expressed in 
percent smoke obscuration) at which the smoke detector will go 
into alarm. The alarm sensitivity setting for smoke detectors can 
be set to one of five sensitivity levels. When smoke detectors 
having both ionization and photoelectric elements are used, the 
sensitivity setting applies to both elements. Reduced sensitivity 
settings are used to reduce the occurrence of nuisance alarms.