Failure And Replacement Of Bus Components - Siemens SIMATIC PCS 7 Function Manual

Component Replacement and Plant Changes
5.1

Failure and replacement of bus components

5.1.1 Replacement of SIMATIC components in runtime
Continuous operation
A crucial factor for continuous operation of fault-tolerant process control systems is the
replacement of faulty or failed components in runtime. Replacement of defective components
is only possible if fault-tolerant components are used. The redundant components continue to
operate and supply the function until the replacement is made. The system is no longer fault-
tolerant in this condition.
Which components can be replaced in central controllers?
The following components in a redundantly configured automation system can be replaced in
runtime:
● Central processing units (e.g., CPU 417-4H)
● Power supply modules (e.g., PS 405, PS 407)
● Communication modules
● Synchronization modules and fiber-optic cables
● Interface modules (e.g., IM 460, IM 461)
Which components of the distributed I/O can be replaced?
The following components in a redundantly configured distributed I/O system can be replaced
in runtime:
● DP master (CPU or CP in the AS)
● DP slaves (for example, ET 200M, ET 200iSP)
● Redundant interface modules (for example, IM 153-2 and IM 152-1)
● Input/output modules
● PROFIBUS DP cables
Additional information
You can find detailed, step-by-step instructions on the procedure for replacing components in
runtime in the manual
The following table is an overview of the descriptions:
Fault-tolerant Process Control Systems (V8.0)
Function Manual, 03/2012, A5E02779471-02
Automation System S7-400H; Fault-tolerant Systems.
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