Siemens SIMATIC ET 200SP HA System Manual page 96

Displays and interrupts
10.1 Status and error displays
DIAG LED
Table 10-1
MT LED
Table 10-2
PWR LED
Table 10-3
96
Diagnostic display of the DIAG LED
LED DIAG
The backplane bus supply of the system is disrupted or switched off.
Off
The module is not parameterized.
Flashes
The module is parameterized. No diagnostic message is pending.
On
The module is parameterized. At least one diagnostic message is pending.
Flashes
Maintenance display of the MT LED
MT LED Meaning
Maintenance is not required.
Off
Maintenance is required, i.e. at least one maintenance event has occurred.
On
Status display of the PWR LED
PWR LED Meaning
The supply voltage L+ is missing.
Off
The supply voltage L+ is available.
On
Meaning
Modules for devices in a hazardous area
System Manual, 04/2021, A5E50165138-AA