Rockwell Automation 1779-KP3R DATA HIGHWAY II - Manual (Page 32)

Installing the 1779-KP3
Communication Interface
Chapter 2
2Ć16
Figure 2.9
Backup Cabling Using the SA4 and KP3 Modules in Detail
S4A KP3
Backup A
Backup B
KP3 S4A
Backup A
Backup B
Pin 1 Backup
1775-CBB or
1779-CBC Cable
11009-I
1775-CBB or
1779-CBC Cable
1775-CBB Cable
Using an S4A or S5, an MX, and a KP3
You can provide backup PLC–3s by connecting the S4A (or S5) module
to the KP3 module in both the primary and backup PLC–3s. Then
connect each KP3 to the MX modules. Then connect the primary MX
module to the MX in the backup (figure 2.10). This method provides
faster switchover of communications between the primary and backup
PLC–3 processors.