Rockwell Automation 1775-MX_S4A,D17756.3.1 User Manual PLC-3 BACKUP CONC(OR.DU1 - Manual (Page 37)

Installing a Backup System
Chapter 2
2-22
If you designate another I/O channel for use as a backup communication
channel, replace the references to I/O channel 1 with the actual I/O channel
used in the following procedure.
1. Connect one end of a 1770-CD twinaxial cable to the I/O channel 1
terminals on the terminal swing arm of a scanner module in the
backup processor.
2. For 1775-S4A, -SR scanner modules, install a 1770-XT terminator to
the I/O channel 1 terminals in the backup processor as shown in
Figure 2.16. For 1775-S5 and -SR5 scanner modules, select a
terminator by using the internal switches as shown in Figure 2.17.
3. Connect the other end of the 1770-CD twinaxial cable to the I/O
channel 1 terminals on the terminal swing arm of the corresponding
scanner module in the primary processor.
4. For 1775-S4A, -SR scanner modules, install a 1770-XT terminator to
the I/O channel 1 terminals in the primary processor as shown in
Figure 2.16. For 1775-S5 and -SR5 scanner modules, select a
terminator by using the internal switches as shown in Figure 2.17.
5. Using the LIST function, configure I/O channel 1 for backup
communication in both the primary and backup processors.
Important: Use numbers 81 through 89 for the resident and partner
numbers.
CAUTION: To guard against damage to equipment, make sure
that you configure each channel in the backup system with the
same resident and partner numbers, when using multiple backup
communication channels. If you use a different resident or
partner number on different channels of the same processor,
both processors may shut down if the backup cable breaks.