Subdivided Cr - Siemens SIMATIC S7-400 Installation Manual

2.4

Subdivided CR

Characteristics
The "subdivided" characteristic relates to the configuration of the CR. In the
(non-divided) CR the I/O bus and communication bus are continuous and
interconnect all the slots; in the subdivided CR, however, the I/O bus and
communication bus consist of two segments each. The UR2-H rack used here
functions as two electrically isolated UR2 racks on the same rack profile.
A subdivided CR has the following important characteristics:
• The communication bus and I/O bus are subdivided into two segments with 9
slots each.
• Each segment represents a self-contained CR.
The following figure shows a divided CR with a divided I/O bus and communication
bus.
Automation System S7-400 Hardware and Installation
A5E00850741-01
Division I
1 2 3 4 5 6 7
1 2 3 4 5 6 7
I/O bus
Segment 1
Communication bus
Segment 1
Division II
8 9 1 2 3 4 5
8 9 1 2 3 4 5
I/O bus
Segment 2
Communication bus
Segment 2
Installing the S7-400
6 7 8 9
6 7 8 9
2-9