Configuring Hardware and Communication Connections STEP 7.pdf

Configuring Central Racks
2.4.1 Rules for Connecting Expansion Racks (SIMATIC 400)
If you connect expansion racks (SIMATIC 400) to an interface module (send IM) of
the central rack, then the following characteristics for the send IM and the receive
IM must match:
• Power transfer (with/without)
• Type of link (centralized/distributed)
• Communication bus transmission (with/without interrupt transmission).
2.4.2 Arranging the Expansion Rack (SIMATIC 400)
Procedure
1. Select the appropriate (expansion) racks from the "Hardware Catalog" window.
2. Drag the racks to the station window one by one.
3. If you wish to change the number of the rack:
Double-click the second row of the rack in the upper half of the station window.
You can change the number in the "General" tab for the rack.
4. Assign modules to the racks.
Important: To permit the racks to be connected to each other, the interface
modules must be inserted in all racks.
5. For S7-400 only: make the connections between the interface modules in the
racks:
- Double-click on the send IM.
- Select the "Connect" tab
This tab shows all racks that are not connected (racks with inserted receive
IMs).
- Select the individual racks and use the "Connect" button to connect them
to the required interface of the send IM (C1 or C2).
Connection lines then show how the racks are connected together.
2.4.3 Special Case: When the Central Rack Has More Than One CPU
If you wish to extend the configuration which consists of the segmented rack CR2
(S7-400) or a multicomputing configuration with racks you must adhere to the
following order:
1. Configure the central rack (for example, CR2) with the send IM.
2. Only insert Receive IMs in the expansion racks.
3. Remove the connections between the interface modules (IMs) as described
above.
Only then can you insert modules in the expansion racks. Reason: Because the
address space exists more than once for multiple CPUs, the expansion rack must
first be assigned to an address space (= a CPU).
Configuring Hardware and Communication Connections with STEP 7
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