Start-up behavior of the Bus Terminal Controller
When the Bus Terminal Controller is switched on it checks its state, configures the K-bus, creates a configuration list based on the connected Bus Terminals and starts its local PLC.
The I/O LEDs flash when the Bus Terminal Controller starts up. If the system is in an error-free state, the I/O LEDs should stop flashing after approx. 3-5 seconds. If the event of an error, then the LED that flashes will depend on the type of that error (see Diagnostic LEDs).

The Bus Terminal Controller indicates a faulty TwinCAT configuration (LEDs/display). In the Bus Terminal controllers of the BCxx50, BCxx20 and BXxxxx series, the display can also be read via the System Manager.
