Siemens SINAMICS G120 Function Manual page 191

Table 6- 4
LED BF display for CANopen
In addition to the signal states "on" and "off" there are three different flashing frequencies:
Table 6- 5
GREEN - single flash Bus state "Stopped"
RED - single flash
RED - double flash
Safety Integrated Function Manual, SINAMICS G120 and G120C
Function Manual, 01/2011, FW 4.4, A5E03052391B AB
Diagnostics of the safety functions
SAFE LED
YELLOW - on
YELLOW - slow
YELLOW - rapid
Communication diagnostics via CANopen
BF LED Explanation
GREEN - on Bus state "Operational"
GREEN - fast Bus state "Pre-Operational"
RED - on No bus
Alarm - limit reached
Error event in control (Error Control Event)
Meaning
One or more safety functions are enabled, but not active.
One or more safety functions are active; no safety function faults have
occurred.
The converter has detected a safety function fault and initiated a STOP
response.
Alarms, faults and system messages
6.1 Operating states indicated on LEDs
189