Siemens SIMATIC S7-400H - Failure and Replacement of an Input;Output or Function Module

Failure and Replacement of Components During Operation
10-6
Automation System S7-400H Fault-tolerant Systems
A5E00068197-07
10.1.3 Failure and Replacement of an Input/Output or Function Module
Initial situation
Failure How Does the System React?
The S7-400H is in redundant system mode
and an input/output or function module fails.
• Both CPUs report the event in the
diagnostics buffer and via appropriate
OBs.
Procedure
To replace signal and function modules (central or remote), perform the following
steps:
Step What Has To Be Done? How Does the System React?
1 Disconnect the wiring. • Call OB 82 if the module
concerned is
diagnosis-interruptible and
diagnostics interrupts are released
via the configuration.
– Call OB 122 if you are
accessing the module by direct
access
– Call OB 85 if you are accessing
the module by means of the
process image
2 Extract the failed module (in RUN
mode).
• Both CPUs process the
insert/remove-module interrupt
OB 83 in synchronism.
3 Insert the new module. • Both CPUs process the
insert/remove-module interrupt
OB 83 in synchronism.
• Parameters are assigned
automatically to the module by the
CPU concerned and the module is
addressed again.
4 Connect the wiring. Call OB 82 if the module concerned is
diagnosis-interruptible and diagnostics
interrupts are released via the
configuration.