Error handling and diagnostics
EL6751
163
Version: 3.5
6
Error handling and diagnostics
6.1
EL6751 – LED description
Fig. 134: LEDs
LED behavior
The most important states of the terminal can be quickly diagnosed on the basis of the LEDs:
LED
Color
Meaning
RUN
green
This LED indicates the terminal's operating state:
off
State of the EtherCAT State Machine:
INIT
= initialization of the terminal;
BOOTSTRAP
= function for terminal firmware updates
Flashes at 2 Hz
State of the EtherCAT State Machine:
PREOP
= function for mailbox communication and different standard-settings set
Flashes at 1 Hz
State of the EtherCAT State Machine:
SAFEOP
= verification of the sync manager channels and the distributed clocks.
Outputs remain in safe state
on
State of the EtherCAT State Machine:
OP
= normal operating state; mailbox and process data
communication is possible
Err
red
off
All configured bus devices are error-free (box state = 0); TwinCAT task or process is running.
Flashes at 1 Hz
At least one box state is not equal to 0 (e.g. device not found, wrong configuration, device in
error state)
Flashes at 10 Hz
Configuration upload being carried out
on
CAN controller is BUS OFF. Physical CAN problem. Possible causes: e.g. missing termination
resistor, bus line too long, wrong baud rate, node address assigned twice, wiring error, short-
circuit.
Restart required
CPU er-
ror
red
on
EL6751 processor error
Flashes at 10 Hz
The EL6751 processor starts
