Siemens SIMATIC S7-1500 Manual page 44

Interrupts, error messages, diagnostics and system alarms
4.1 Status and error display of the CPU
RUN/STOP LED
LED flashes
yellow/green
Meaning of LINK RX/TX LED
Each port has a LINK RX/TX LED. The table below shows the various "LED scenarios" of
the ports for the CPU 1518-4 PN/DP MFP.
Table 4- 2
LINK TX/RX LED
LED flashes green
LED flickers yellow
44
ERROR LED
LED flashes red LED flashes yellow
Meaning of the LEDs
There is no Ethernet connection between the PROFINET interface of the
PROFINET device and the communication partner.
LED off
No data is currently being sent/received via the PROFINET interface.
There is no LINK connection.
The "LED flashing test" is being performed.
There is an Ethernet connection between the PROFINET interface of your
PROFINET device and a communication partner.
LED lit green
Data is currently being received from or sent to a communications partner
on Ethernet via the PROFINET interface of the PROFINET device.
MAINT LED
Startup (CPU booting)
Test of LEDs during startup, inserting a module.
LED flashing test
CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)
Meaning
Meaning
Manual, 12/2017, A5E40882737-AA