Omron SYSMAC C500 Installation Manual page 32

Assembly
24
tional Backplane. First, though, we have to mount an I/O Control Unit to the
leftmost slot of the CPU Rack.
I/O Control Unit
Now we can use a cable to connect the CPU Rack to another Backplane.
This Backplane has a Power Supply and I/O Units mounted to it, but it has no
CPU of its own. The additional Backplane must also have an I/O Interface
Unit mounted to its leftmost position. This configuration of additional Back-
plane, Power Supply, I/O Units, and I/O Interface Unit is called an Expansion
I/O Rack.
I/O Interface Unit
The CPU Rack and Expansion I/O Rack shown above are connected by a
cable. Remember that this whole configuration is still referred to as one PC.
It is possible to keep adding Expansion I/O Racks in this way until the maxi-
mum number of I/O points for the system is reached. Each Expansion I/O
Rack needs an I/O Interface Unit.
CPU Rack
Expansion I/O Rack
Section 3