Siemens S7-400 installation manual Subdivided CR, Characteristics

Installing the S7-400

2.4Subdivided 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.

			Division I									Division II
1	2	3	4	5	6	7	8	9	1	2	3	4	5	6	7	8	9
1	2	3	4	5	6	7	8	9	1	2	3	4	5	6	7	8	9
				I/O bus									I/O bus
			Segment 1										Segment 2
	Communication bus										Communication bus
			Segment 1									Segment 2

Automation System S7-400	Hardware and Installation	2-9
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