Siemens SIMATIC ET 200AL System Manual page 1109

Diagnostics in STEP 7
The diagnostics buffer of the CPU displays that the PROFINET ring is open.
The diagnostics in the project tree shows:
● Maintenance demanded in lower-level component in the S7-1500H system
● Maintenance demanded in lower-level components of PLC_1 and PLC_2
● Maintenance demanded in lower-level components of local modules of PLC_2
The diagnostics in the network view indicates errors at the affected port of the PROFINET
interfaces of PLC_2.
Figure 7-12 Diagnostics example: RUN-Redundant system state, open PROFINET ring
You can evaluate the diagnostics using the displays of the CPUs via the "Diagnostics" menu
as with standard CPUs. You can find additional information in the section Display of the CPU
(Page 27).
S7-1500H Example 2:
A synchronization module has been removed from a CPU of the redundant S7-1500H
system.
Evaluating diagnostics via X3 and X4 LEDs on the CPU
The X3 LED on PLC_2 CPU is not illuminated. This means:
● The redundancy connection on the synchronization module was interrupted at the H-Sync
interface X3.
or
● There is no synchronization module at the H-Sync interface X3.
Diagnostics
Function Manual, 11/2019, A5E03735838-AF
Diagnostics of the S7-1500R/H redundant system
7.4 Diagnostics in the RUN-Redundant system state
113