107BOnline and diagnostic tools
14.1 Status LEDs
S7-1200 Programmable controller
634
System Manual, 11/2011, A5E02486680-05
Description
STOP/RUN
Yellow / Green
ERROR
Red
MAINT
Yellow
Defective hardware
On (yellow)
On
Off
LED test or defective CPU firmware
Flashing
(alternating yellow and green)
Flashing
Flashing
The CPU also provides two LEDs that indicate the status of the PROFINET communications.
Open the bottom terminal block cover to view the PROFINET LEDs.
●
Link (green) turns on to indicate a successful connection
●
Rx/Tx (yellow) turns on to indicate transmission activity
The CPU and each digital signal module (SM) provide an I/O Channel LED for each of the
digital inputs and outputs. The I/O Channel (green) turns on or off to indicate the state of the
individual input or output.
Status LEDs on an SM
In addition, each digital SM provides a DIAG LED that indicates the status of the module:
●
Green indicates that the module is operational
●
Red indicates that the module is defective or non-operational
Each analog SM provides an I/O Channel LED for each of the analog inputs and outputs.
●
Green indicates that the channel has been configured and is active
●
Red indicates an error condition of the individual analog input or output
In addition, each analog SM provides a DIAG LED that indicates the status of the module:
●
Green indicates that the module is operational
●
Red indicates that the module is defective or non-operational
The SM detects the presence or absence of power to the module (field-side power, if
required).
Table 14- 2 Status LEDs for a signal module (SM)
Description
DIAG
(Red / Green)
I/O Channel
(Red / Green)
Field-side power is off
Flashing red
Flashing red
Not configured or update in progress
Flashing green
Off
Module configured with no errors
On (green)
On (green)
Error condition
Flashing red
-
I/O error (with diagnostics enabled)
-
Flashing red
I/O error (with diagnostics disabled)
-
On (green)