Product specifications
Installing the PM86x/TP830 Processor Unit in Redundant Configuration Section 2 Installation
90 3BSE036351-510 A
Installing the PM86x/TP830 Processor Unit in Redundant 
Configuration
In redundant configuration two PM861/PM864/PM865/PM866 units are mounted 
onto two separate DIN-rails. If sufficient space is available, the units can be 
mounted onto the same DIN-rail
Use the following procedure to install the processor units along the DIN-rail:
1. Mount the processor units.
2. Mount the communication interfaces on the CEX-Bus to the left of the 
processor unit. If BC810s are used, the configuration of the segments should be 
considered. If no BC810s are used, the interfaces can be divided between the 
two CPUs in any preferred way.
3. Press the units gently together and make sure that the CEX-Bus is correctly 
connected, via the connectors on the baseplates.
4. If BC810s are used, connect the TK851 cable to the two BC810s (Figure 31 on 
page 100). If no BC810s are used, mount the CEX-Bus extension cable TK850 
to the units at farthest away from the processor units or, if no units are 
mounted, directly to the CEX-Bus on the processor unit. The CEX-Bus 
extension cable must be connected to both CPUs whether or not there are any 
other CEX-Bus units (
Figure 29 on page 93).
This topic does not apply to the installation of PM891 unit in redundant 
configuration. See 
Installing the PM891 Processor Unit in Redundant 
Configuration on page 94.
Note that in redundant CPU configuration, COM3 and the electrical ModuleBus 
on the baseplate can not be used.










