Function

The D2B interface for permanently installed telephone (A59) is switched on and off by the discrete "wake-up" line. It reacts to the descending edge (in the off state the level is at "high") and the duration of the "wake-up" signal.

Control data received from the D2B bus is relayed on by the D2B interface for permanently installed telephone (A59) with the aid of discrete data buses to the CTEL transmitter/receiver (A35); the D2B interface for permanently installed telephone (A59) switches the CTEL transmitter/receiver (A35) on or off upon request from the COMAND operating, display and control module (A40/3) and transfers the functions to be performed (e.g. dialing a number). In the other direction the data (caller's voice, control data) from the CTEL transmitter/receiver (A35) is transferred from the D2B interface for permanently installed telephone (A59) in a corresponding D2B format to the COMAND operating, display and control module (A40/3) for further processing.

Relay of traffic message channel (TMC) traffic messages (only with dynamic guidance (code 815)):
The TMC traffic messages are received by the CTEL transmitter receiver (A35) and transferred to the D2B interface for permanently installed telephone (A59). Here the data is converted and relayed on to the traffic data recorder (A2/43) via the CAN (telephone) bus.