17
Document 15949 Rev. E 4/12/95 P/N 15949:E
Isolated-Redundant Circuit
By flanking each communications loop device with a pair of ISO-X fault isolator modules,
each device is protected from short circuit faults that may occur on other devices. For
example, a fault on Zone 2 will not effect Zones 1 and 3. The isolator modules on either side
of Zone 2 will open the loop. Zone 1 will still operate from power on loop out and Zone 3 will
operate from loop return. Since the system will no longer be able to communicate with Zone
2, a trouble signal(s) will be generated for that device.
This circuit is a variation of the redundant circuit, therefore, no T-tapping or branching is
allowed. The ratings and characteristics are the same as for the redundant circuit.
Figure 3-8: Isolated-Redundant Communications Loop
+ - + -
AIM-200
Loop
Out
commloop3
Loop
Return
M500XJ
Isolator Module
Protected
Premises
Area "3"
Protected Premises Area "2"
M500XJ
Isolator Module
M500XJ
Isolator Module
M500XJ
Isolator Module
Protected
Premises
Area "1"
ISO-X
ISO-X
ISO-X
ISO-X
Technical Manuals Online! - http://www.tech-man.com