Product specifications
Section 2 Installation Installing the PM86x/TP830 Processor Unit in Redundant Configuration
3BSE036351-510 A 91
5. Connect the RCU Link Cable TK851 to both CPUs. Note that in redundant 
CPU configuration, COM3 and the electrical ModuleBus on the baseplate can 
not be used.
6. Baseplates cable connections:
a. Connect the power leads to both CPUs and the power supervision signals 
from SS8xx to screw terminals SA and SB (see
 Figure 28 on page 83).
b. Connect the Control Network cables to CN1 (single bus connection) or 
CN1 + CN2 (redundant bus connection). The Control Network is 
connected to both CPUs.
c. Connect the Control Builder to COM4 with cable TK212 of the Primary 
CPU (if required for changing an IP address etc.). Otherwise connect the 
Control
 Builder to the Control Network.
7. Connect the optical ModuleBus to the optical contacts on the processor units 
(see
 Figure 2 on page 32 and Figure 40 on page 131). Information regarding 
optical cable selection and cable length is provided in the S800 I/O 
documentation.
Note that the RCU Link Cable TK851 must be used and can not be replaced by a 
similar cable. Using another cable will disable the identification of the CPUs in 
the CB and Operator Station. When running in single configuration the RCU 
Link Cable TK851 might temporarily be used to perform the function of a 
termination plug.
The CPU connected to the RCU Link Cable connector marked “UPPER” will be 
defined as “UPPER” in the Control Builder and Operator Station. The marking 
has no relevance to the physical placement of the CPUs. Any CPU can become 
the Primary CPU.
Both CPUs should be powered from the same supply (single or redundant). For 
redundant power supply, see
 Figure 46 on page 140. 
Connection to the optical ModuleBus is identical to that for the processor unit 
and for the FCI in S800 I/O (
Figure 55 on page 161).










