Configuring Hardware and Communication Connections STEP 7.pdf

When Is a Rack "Compatible"?
Basics of Configuring Hardware with STEP 7
A rack of a SIMATIC 400 station can be exchanged for another rack only if the
basic rules listed below are adhered to. If one or more of the basic rules are not
adhered to, STEP 7 does not permit an exchange and terminates the procedure
with an error message that provides information on the cause of the termination.
• A segmented rack (CR2) cannot be exchanged for a non-segmented rack (for
example, UR1) and vice versa.
• You must be able to insert all modules of the rack to be exchanged into the new
rack; that is, no slot rules must be violated when the modules are inserted into
the new rack.
Example 1: An attempt to replace a UR1 rack that has a CPU with an ER1
expansion rack is not permitted. Inserting a CPU in the ER1 violates a slot rule - no
CPUs can be inserted in an ER1.
Example 2: An attempt to replace a segmented central rack in an S7-400 station
(CR2) with a Universal rack (for example, UR1) is not permitted. The slots of the
modules from two segments cannot be assigned uniquely to the slots in a different,
non-segmented rack, and vice versa. A CR2 rack therefore can be replaced only
by a CR2 rack with a different order number, for example, to make it possible to
insert redundant power supply modules without having to enter the rest of the
configuration again.
When Is a C7 control System "Compatible"?
A C7 control system contains integrated modules (CPU and I/O) and can be
exchanged for another one if the following rules are adhered to:
• For each slot (row in the configuration table) of the new C7 control system, the
corresponding slot in the old C7 control system meets the following conditions:
- Has no modules
- Has an identical or exchangeable module (also applies to the CPU)
• The new C7 control system has just as many or more integrated modules as the
old C7 control system.
When Is a DP Slave "Compatible"?
If DP slaves can be exchanged, then they can only be exchanged within the same
family, for example, within the ET 200M family. DP slaves can also be displayed in
NetPro; however, they can only be exchanged in the Configuring Hardware
application.
The same basic rules for exchange apply to modular DP slaves as apply to racks:
the number of inserted modules must have a place in the new DP slave and the
functionality of the old DP slave must also be provided by the new DP slave.
If functions that are used by more than one station were configured, such as direct
data exchange between DP slaves, you must provide this configuration to the new
DP slave.
Configuring Hardware and Communication Connections with STEP 7
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