Siemens SIMATIC S7-1500R/H Equipment Manual page 32

Interrupts, diagnostics, error messages and system events
5.1 Status and error display of the CPU
Meaning of the RUN/STOP, ERROR and MAINT LEDs
CPU 1517H‑3 PN has the following LEDs for displaying the current operating state and
diagnostics status.
NOTE
LED patterns of the S7-1500H redundant system
Note that it is not always possible to:
• Determine the state of the CPU from the signal pattern of individual LEDs
• Determine the state of the other CPU from the signal pattern of a CPU
The "Meaning" column only shows a possible typical cause.
To investigate the cause of the signal pattern, use the diagnostic buffer and its display via:
• STEP 7
• HMI devices
• Displays of the CPUs
The following table shows the meaning of the various color combinations for the RUN/STOP,
ERROR and MAINT LEDs.
Table 5-1 Meaning of the LEDs
RUN/STOP LED
LED off
LED flashes
yellow/green
LED lit yellow
LED flashes yellow
LED lit yellow
LED lit yellow
LED flashes
yellow/green
LED flashes yellow
1) If there is not enough storage space on a SIMATIC Memory Card or on both SIMATIC Memory Cards in RUN-Redundant, the
write function is aborted and the redundant system continues operation with the original configuration. The redundant
system will remain in the RUN-Redundant system state.
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ERROR LED
LED off
LED flashes red LED flashes yellow
LED off LED lit yellow
LED off LED lit yellow
LED flashes red LED flashes yellow
LED off
LED flashes yellow
LED off LED lit yellow
LED off
MAINT LED
Missing or insufficient supply voltage on the CPU.
LED off
Startup (CPU booting)
Test of LEDs during startup, inserting a module.
LED flashing test
CPU is in operating state STOP.
Completion of system initialization
CPU executes internal activities in an operating
state ≠ RUN-Redundant.
CPU defective
Firmware update using SIMATIC Memory Card has
failed.
Firmware update successfully completed.
The primary CPU is in STARTUP operating state.
The backup CPU is in SYNCUP operating state.
The CPU performs a warm restart.
LED off
Meaning
CPU 1517H-3 PN (6ES7517-3HP00-0AB0)
Equipment Manual, 11/2022, A5E42011886-AD