Siemens SIMATIC S7-1500R/H Manual page 34

Note
MAINT LED of the two CPUs
The MAINT LEDs of both CPUs only go out when the following conditions are fulfilled:
• The CPUs are in the RUN-Redundant system state.
• No maintenance is demanded.
Note
LED displays in redundant operating state
In the RUN-Redundant system state, the LED displays on both CPUs are identical
(exception: you are performing an LED flash test on one CPU).
Meaning of LINK RX/TX LED
Each port of the X1, X2, X3 and X4 interfaces has a LINK RX/TX LED. The table below
shows the various LED patterns of the ports of the CPU 1517H-3 PN.
Table 4- 2 Meaning of LINK RX/TX LED
LINK TX/RX LED
Off
Flashes green
Illuminated green
LED flashes
yellow/green
CPU 1517H-3 PN (6ES7517-3HP00-0AB0)
Equipment Manual, 11/2019, A5E42011886-AB
There is no connection between the interface of the device and a communication partner.
No data is currently being sent/received via the interface.
There is no LINK connection.
The redundancy connections were interrupted.
The CPU performs an LED flash test.
There is a connection between the interface of the device and a communication partner.
The redundancy connections are OK.
Data is currently being received or sent by a communication partner via the interface of the
device.
Interrupts, diagnostics, error messages and system events
4.1 Status and error display of the CPU
Meaning
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