Failure And Replacement Of Components During Operation; Failure And Replacement Of A Cpu - Siemens SIMATIC S7-400H System Manual

Failure and replacement of components during operation

13.2 Failure and replacement of components during operation
13.2 Failure and replacement of components during operation
Which components can be replaced?
The following components can be replaced during operation:
● Central units (e.g. CPU 417–4H)
● Power supply modules (e.g. PS 405 and PS 407)
● Signal and function modules
● Communication modules
● Synchronization modules and fiber-optic cables
● Interface modules (e.g. IM 460 and IM 461)
13.2.1

Failure and replacement of a CPU

Complete replacement of the CPU is not always necessary. If only load memory fails, it is
enough to replace the corresponding memory module. Both cases are described below.
Starting situation for replacement of the CPU
Failure
The S7-400H is in redundant mode and a CPU
fails.
Requirements for replacement
The module replacement described below is possible only if the "new" CPU
● has the same operating system version as the failed CPU and
● if it is equipped with the same load memory as the failed CPU.
186
NOTICE
New CPUs are always shipped with the latest operating system version. If this differs
from the version of the operating system of the remaining CPU, you will have to equip
the new CPU with the same version of the operating system. Either create an operating
system update card for the new CPU and use this to load the operating system on the
CPU or load the required operating system in HW Config with "PLC -> Update Firmware",
see section Updating the firmware without a memory card (Page 61).
How does the system react?
Partner CPU switches to single mode.
•
The partner CPU reports the event in the
•
diagnostics buffer and in OB 72.
System Manual, 09/2007, A5E00267695-03
S7-400H