Siemens Simatic S7-1500 Manual page 117

Meaning of LINK RX/TX LED
Each port has a LINK RX/TX LED. The table below shows the various "LED scenarios" of
the CPU ports.
Table 6- 2 Meaning of the LED
LINK TX/RX LED
LED off
LED flashes green
LED lit green
LED flickers yellow
CPU 1512C-1 PN (6ES7512-1CK00-0AB0)
Manual, 09/2016, A5E35306440-AB
There is no Ethernet connection between the PROFINET interface of the PROFINET device
and the communication partner.
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 de-
vice and a communication partner.
Data is currently being received from or sent to a communications partner on Ethernet via
the PROFINET interface of the PROFINET device.
Interrupts/diagnostics alarms
6.1 Status and error displays
Meaning
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