Siemens SINUMERIK MCU1720 Equipment Manual page 28

Description
4.2 Operator control and display elements
Name Function
SD Activity
LED
(directly on
the card slot)
Meaning of the RUN/STOP, ERROR and MAINT PLC-LEDs
RUN/STOP LED
LED off
LED off
LED lights up green
LED lights up green
LED lights up green
LED lights up green
LED lights up yellow
LED lights up yellow
LED lights up yellow
LED flashes yellow
LED flashes
yellow/green
28
Status
LED off
LED flashes yellow
ERROR LED
LED off
LED flashes red
LED off
LED flashes red
LED off LED lights up yellow
LED off
LED flashes yellow
LED off
LED flashes yellow
LED off
LED flashes red LED flashes yellow
LED off
LED off
Meaning
SD card not inserted or inactive.
Active access to SD card
MAINT LED
Supply voltage at the CPU not present or too low.
LED off
An error has occurred.
LED off
The CPU is in the RUN operating state.
LED off
Diagnostic event pending.
LED off
A plant maintenance request is pending.
The affected hardware must be validated/replaced
within a short interval.
Active force job
PROFIenergy pause
A plant maintenance requirement is pending.
The affected hardware must be validated/replaced
within a foreseeable interval.
Configuration faulty
Firmware update completed successfully.
CPU is in STOP operating state.
LED off
The program on the SIMATIC Memory Card cau‐
ses a fault.
CPU defective
CPU performs internal activities during STOP, e.g.
ramp-up after STOP.
LED off
Downloading the user program from the SIMATIC
Memory Card
Startup (transition from RUN → STOP)
LED off
Meaning
Equipment Manual, 09/2019, A5E47437728B AB
MCU 1720