Siemens SIMATIC ET 200AL, System Manual

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Diagnostics and maintenance
4.6 Extended maintenance concept
PROFINET with STEP 7
Function Manual, 05/2021, A5E03444486-AL
95
Example: Maintenance demanded for a PROFINET cable
The following graphic illustrates how diagnostics information is exchanged when the
transmission quality on the optical cable decreases due to ageing, for example. In this
example, the scenario is considered after a maintenance required has already been
diagnosed.
Num-
ber
Description
① The system reserve of the fiber-optic cable drops below 0 dB.
② Both the ET 200S PN FO and the switch send the maintenance demanded alarm to the IO
controller.
③ Based on the interrupts, the IO controller detects the maintenance demanded from the switch
and from the IO device. The module information data is updated in the IO controller and the
corresponding error OBs are called. Note: To be able to start the error OBs in the IO controller,
the "Call the user program if communication errors occur" property must be selected in STEP 7
for the relevant IO controller.
④ In STEP 7 (on the programming device/PC), the maintenance demanded message is indicated
on the IO device and at the switch by a yellow wrench symbol.
⑤ STEP 7 can also read out detailed information directly from the switch.
Figure 4-13 Maintenance demanded for a PROFINET cable