Siemens SIMATIC NET S7-1200 Operating Instructions Manual page 19

The LEDs indicate the operating and communications status of the module according to the
following scheme:
Table 2- 4
(red / green)
flashing green
flashing red
SIMATIC CM 1243-5
Operating Instructions, 01/2023, C79000-G8976-C246-06
Display of the basic states of the module by the "DIAG" LED
DIAG Meaning
Power OFF
RUN without errors
green
• Startup
• STOP without errors
• No project data
• Firmware update
Problem / error
Comment
The individual states are signaled by the
RUN/STOP and ERROR LEDs (see below).
The individual states are signaled by the
RUN/STOP and ERROR LEDs (see below).
LEDs and connectors
2.2 LEDs
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