Supplementary information
15.4 Configuring with STEP 7
CPU 410-5H Process Automation
System Manual, 09/2014, A5E31622160-AB
237
15.4
Configuring with STEP 7
15.4.1
Rules for arranging fault-tolerant station components
The are additional rules for a fault-tolerant station, in addition to the rules that generally apply
to the arrangement of modules in the S7-400:
●
Insert the CPUs into the same slots.
●
Redundantly used external DP master interfaces or communication modules must be
inserted in the same slots in each case.
●
Insert an external DP master interface for redundant DP master systems only in the
central controllers and not in the expansion units.
●
Redundantly used CPUs must be identical, which means they must have the same article
number, product version and firmware version. It is not the marking on the front side that
is decisive for the product version, but the revision of the "Hardware" component
("Module status" dialog mask) to be read using STEP 7.
●
Redundantly used other modules must be identical, which means they must have the
same article number, product version and - if available - firmware version.
Layout rules
●
A fault-tolerant station may contain up to 20 expansion units.
●
Assign racks with even numbers only to central controller 0, and racks with odd numbers
only to central controller 1.
●
FMs and CPs can be operated only in racks 0 through 6.
●
Pay attention to the rack numbers for operation of CPs for fault-tolerant communication in
expansion units:
The numbers must be directly sequential and begin with the even number, e.g., rack
numbers 2 and 3, but not rack numbers 3 and 4.
●
A rack number is also assigned for DP master no. 9 onwards if the central controller
contains DP master modules. The number of possible expansion units is reduced as a
result.
Compliance with the rules is monitored automatically by STEP 7 and considered accordingly
during configuration.
