Rockwell Automation 1775-MX_S4A,D17756.3.1 User Manual PLC-3 BACKUP CONC(OR.DU1 - Manual (Page 12)

Choosing a Backup Configuration
Chapter 1
1-5
How MX Backup Works
Figure 1.3 shows the implementation of MX backup. The scanner modules
still control I/O communication channels but the memory communication
modules handle data transfers between the primary and backup processors.
Figure 1.3
MX Backup Configuration
CH1
SCANNER
MODULE #1
SCANNER
MODULE #1
B/U
CH1
CH2
CH3
CH4
B/U
CH1
CH2
CH3
CH4
PRIMARY PROCESSOR BACKUP PROCESSOR
I/O COMMUNICATION
PEERĆTOĆPEER
COMMUNICATION
I/O COMMUNICATION
CH2
CH3
TO/FROM
I/O
MEMORY
COMMUNICATION
MODULE
MEMORY
COMMUNICATION
MODULE
B/U
XMTG
RCVG
B/U
XMTG
RCVG
BACKUP COMMUNICATION
INTERCONNECT CABLE
TO/FROM
OTHER
PEERĆTOĆPEER
CHANNELS
10973ĆI