Siemens SIMATIC ET 200AL System Manual page 217

Interrupts, error messages, diagnostics and system alarms
5.1 Status and error displays
LED P1 LINK, LED P2 LINK
Table 5- 2 Status displays of the LEDs P1 LINK and P2 LINK
LEDs
P1 LINK P2 LINK
Off
On
Flashes
LED ET-CON1, LED ET-CON2
Table 5- 3 Status displays of the LEDs ET-CON1 and ET-CON2
LEDs
ET-CON1 ET-CON2
Off
On
28
Meaning
There is no connection between the
PROFINET interface of your PROFINET
device and a communication partner (e.g.,
IO controller).
There is no connection between the
PROFINET interface of your PROFINET
device and a communication partner (e.g.,
IO controller).
The "Node flash test" is run (the RUN,
ERROR and MAINT LEDs also flash).
Meaning
There are no I/O modules available at the
respective ET-Connection or the modules
do not have supply voltage.
A communications connection to at least
one IO module at the corresponding ET-
Connection is available.
Solution
Check whether the bus cable to the switch
or IO controller is disconnected.
-
-
Solution
Check the wiring for the ET-Connection or
the supply voltage for the I/O module.
-
Interface module IM 157-1 PN (6ES7157-1AB00-0AB0)
Manual, 12/2016, A5E32347036-AD