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Redundancy Communications Module
The Redundancy Communications Module (RCM), catalog number IC697RCM711, provides a communications path for sharing data between the two CPUs in the redundant system. In a synchronized system, I/O data is controlled by one unit (the active unit) but is shared between both units (active and backup units). The RCM provides the communications path between the two units. An RCM must be configured in both the Primary PLC and the Secondary PLC. The RCM must reside in rack 0 and there can be no empty slot between the RCM and the CPU (there can be other modules).
RCM Features
The following figure shows the features of the RCM module.
OK
LOCAL READY LOCAL ACTIVE REMOTE READY REMOTE ACTIVE
REDUNDANCY
COMMUNICATIONS
MODULE
a47004
RCM 711
BOARD OK
LOCAL SYSTEM
READY
LOCAL SYSTEM
ACTIVE
REMOTE SYSTEM READY
REMOTE SYSTEM ACTIVE
ON = TRUE DEPRESS 1 SEC. TO SWITCH ACTIVE CPU (MIN 10 SECS BETWEEN SWITCHES)
MODULE FUNCTION
REDUNDANCY COMMUNICA TIONS MODULE.
HIGH SPEED INTERFACE BETWEEN HOT. STANDBY REDUNDANCY SUPPORTED CPUs.
CONNECT TO END
OF EXPANSION BUS
EXPANSION
PORT IN (TOWARDS CPU)
TO BEM711
OR BEM713
(USE TERMINATED CABLE CBL811 OR CBL826)
50 FT. MAXIMUM
CABLE LENGTH FROM BEM 713 TO TO RCM711
UNUSED PORT
DO NOT INSTALL
CABLE OR
TERMINATOR
MODULE IC697RCM711
LABEL:
44A726758±136R02
Figure 5. Redundancy Communications Module - IC697RCM711
Chapter 2 System Components | 19 |