9752 Installation Guide
1. Introduction
497098 Issue 3
Page 3
Elements of the IAS
An IAS comprises a control unit in a shielded case, with 1 to 4 separate
keypads and various detectors, transmitters and other devices connected to
programmable zones. If required, a keyswitch can be connected to the 4-wire
bus through a keyswitch interface.
Note: The keyswitch interface is no longer available for purchase, but is
supported in existing installations. Instead, zones can be programmed as
keyswitch zones.
Note: Only one keyswitch can be connected to the 4-wire bus through a
keyswitch interface. However, further keyswitches can be connected as
standard zones, programmed with the appropriate zone type.
Each control unit has zone connectors on its printed circuit board (PCB).
Separate expanders enable more zones to be connected: each hardwired
expander adds up to 8 wired zones and each radio expander adds up to 8 or
16 wirefree zones (depending on the model used).
The control unit has 8 zones as standard, expandable to a maximum of 32.
Figure 1 shows how these elements are connected. In this example, the
control unit (14) is directly connected to 6 detectors and 2 door contacts.
Further zones are then connected to it through a hardwired expander (9) and
a radio expander (4). There are 4 keypads (7 and 11) and a keyswitch (13) on
the bus.
