Failure And Replacement Of A Synchronization Module Or Fiber-Optic Cable - Siemens SIMATIC S7-400H System Manual

Failure and replacement of components during operation
16.2 Failure and replacement of components during operation
16.2.5

Failure and replacement of a synchronization module or fiber-optic cable

In this section, you will see three different error scenarios:
● Failure of a synchronization module or fiber-optic cable
● Successive failure of both synchronization modules or fiber-optic cables
● Simultaneous failure of both synchronization modules or fiber-optic cables
The CPU indicates by means of LEDs and diagnostics whether the lower or upper redundant
link has failed. After the defective parts (fiber-optic cable or synchronization module) have
been replaced, LEDs IFM1F and IFM2F must go out.
Starting situation
Failure
Failure of a fiber-optic cable or synchronization
module:
The S7-400H is in redundant system mode and a
fiber-optic cable or synchronization module fails.
See also chapter Synchronization modules for
S7–400H (Page 341).
Procedure
Follow the steps below to replace a synchronization module or fiber-optic cable:
Step
1
2
3
4
5
272
What has to be done?
First, check the fiber-optic cable.
Start the reserve CPU (for example, STOP-
RUN or Start using the programming device).
Remove the faulty synchronization module
from the reserve CPU.
Insert the new synchronization module in the
reserve CPU.
Plug in the fiber-optic cable connections of
the synchronization modules.
How does the system react?
The master CPU reports the event in the

diagnostic buffer and with OB 72 of OB 82.
The reserve CPU changes to ERROR-

SEARCH mode for some minutes. If the error
is eliminated during this time, the reserve
CPU switches to redundant system mode,
otherwise it switches to STOP.
The LED Link1 OK or Link2 OK on the

synchronization module is lit.
How does the system react?
–
The following responses are possible:
1. CPU changes to RUN mode.
2. CPU changes to STOP mode. In this
case continue at step 3.
–
–
The LED Link1 OK or Link2 OK on the

synchronization module goes out.
Both CPUs report the event in the

diagnostic buffer
System Manual, 03/2012, A5E00267695-11
S7-400H