Table of Contents
Advertisement
4.4.2
LED displays
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
LED flashes
yellow/green
NCU 1750
Equipment Manual, 10/2023, A5E45627807B AH
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
LED flashes red
LED flashes yellow
4.4 Operator control and display elements
MAINT LED
Supply voltage at the PLC not present or too low.
LED off
An error has occurred.
LED off
The PLC 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.
The PLC is in the STOP operating state.
LED off
The program from the internal PLC memory causes
an error.
PLC defective
The PLC performs internal activities during STOP,
e.g. ramp-up after STOP.
LED off
Loading the user program from the internal PLC
memory.
Startup (transition from RUN → STOP)
LED off
Startup (booting the PLC)
Test the LEDs during startup, insert a module.
LED flash test
Description
Meaning
37
Advertisement
Table of Contents
