Mains
Primary
Power Supply
LTC 8910
Primary CPU
LTC 8917
Relay Board
Backup
Power Supply
LTC 8910
Backup CPU
Primary Controller
Primary LAN
Keyboards 1-8
Alarm
Biphase
Console
Comm 3
Comm 4
Switch Control
Relay Contacts
Backup Controller
Backup LAN
Figure 6.1: Automatic switchover and Data Mirroring functions then unavailable.
LTC 8901 Series CPU Design Features
The LTC 8901 CPU was designed to withstand failure of a CPU board or power supply with no
loss of functionality or data. A diagram of the CPU bay is shown below. The bay contains two
identical sets of power supplies and CPU boards (primary and backup). The communication
ports for external devices, such as keyboards and alarm units, can be switched to either CPU.
The LTC 8943/95 System Controller PC monitors the operation of the CPUs through the
Primary Controller and Backup Controller ports. Under normal conditions, the external devices
are connected to the primary CPU. If the primary CPU or power supply fails, this is detected
by the LTC 8943/95 System Controller PC, which then switches the communication ports to
the backup CPU using the Switch Control input.
LTC 8943/95 System Controller PC Functions
The System Controller uses a rack-mount, industrial grade PC to provide several important
features in redundant LTC 8900 system configurations. The System Supervisor software that
runs on this PC provides user interface and control functions for the CPU selection and Data
Mirroring features. The System Controller data connections are shown in , page 32. The
System Controller uses the Primary Controller and Backup Controller ports on the LTC 8901
Series bay to communicate with the primary and backup CPUs. If a failure is detected, the
System Controller sends a signal on the Switch Control port of the LTC 8901 Series to cause
the switch to the backup controller. The System Controller then disables the LAN port
connected to the primary CPU and enables the LAN port connected to the backup CPU.
6.1.2
6.1.3
32
en | Hardware Installation Procedure for Redundant System Configuration Utilizing LTC
8901 Series CPU
LTC 8900 Series
2015.01 | 10.6 |
Installation Manual
Bosch Security Systems, Inc.
