Smoke Alarm User Manual

Installation, Operation and Maintenance Manual
Issue 1 Page 2-1
February 2001
2 SYSTEM FUNCTIONAL DESCRIPTION
2.1 General
The following paragraphs provide a functional description of the overall operation of the system, as well
as functional descriptions of the major components that together make up the High Sensitivity Smoke
Detection (HSSD) system.
2.2 Overall Functional Description
The High Sensitivity Smoke Detection system comprises a number of major components. Figures 2.1 to
2.2, show how these components are interconnected. These Figures also show the options available for
configuring the system depending on the application in which it is to be used. The options available are
connecting the Detector via an Intelligent Interface. The system will support up to 127 Detectors. Each
Detector contains the following items:
termination board
detector head
fan module
Display module (optional)
This system is designed to provide high sensitivity smoke detection for an area up to 2000 sq-m (20,000
sq.ft). Smoke detection is accomplished by using a fan, mounted in the Detector, to draw in air from a
protected area through sampling pipe network back to the detector where the air is analysed for the
presence of smoke. The sensitivity of the Detector is programmable over a wide range to meet virtually
any application. In addition, an “Ultra” version of the detector is available with even higher sensitivity,
exclusively for clean room applications.
A three-colour light emitting diode (LED) mounted in the fascia plate of the Detector provides a visual
indication of the current status of the system. Current system conditions are indicated by this LED as
follows:
Continuous Green Normal
Flashing Green Auto Setup
Continuous Yellow Fault/Isolate
Flashing Red Pre-Alarm
Continuous Red Alarm
System status data collated on the termination board is transmitted via an RS-485 serial communications
link to the Display Module. The Display Module is an optional user interface which provides a display on
a back-lit mono LCD. The display provides a visual indication of the system status, smoke level, alarm
and trouble conditions of the Detector. By use of the control keys (4 cursor and 1 enter) an operator is
capable of viewing the information via a password protected menu function. The system status is also
indicated by a three colour LED providing the same functionality as described above.
Connections to a PC via an RS-232 network allow site-specific settings such as pre-alarm and alarm
levels to be loaded into a non-volatile RAM fitted on the termination board. The termination board
connects to the RS-485 network at an address set on a 7 way DIL switch. The Intelligent Interface
Module (IIM) is an optional user interface which serves as a communications controller, networking up to
127 termination boards. The IIM is linked via the RS-232 to a computer, running LaserNET version 3.0
software, situated on site. Alternatively, the IIM can be connected via a modem to a computer, which is
located at a remote site. Connection of the PC to the termination boards allows the system to be
configured and monitored from either a local or remote location. The IIM can also be programmed to dial
out to a remote PC should any alarm or trouble condition occur.