Data transfer, function - GF82.00-P-2000AB

MODELS 215, 220 as of 1.9.03 

Data transfer in the MOST bus 

The audio gateway control unit (N93/1) makes it possible to provide all the data on the CAN interior compartment to each respective component. It acts as an interface (gateway). To this end signals arriving at the audio gateway control unit (N93/1) are converted such that they can be sent by the MOST to the CAN interior compartment and vice versa. It acts as the clock generator, with which data sections (data frames) are sent to the bus system. A data frame here consists of 2 subframes.

The sequence of several data frames then contains the entire data required for operation of the components in the MOST ring.

Light pulses are converted into electrical signals and back again by means of the optical transmitter and receiver diodes, which are integrated into every MOST component.

The components can then receive or transmit the electrical signals. Source data (music and language) and control data (CD selection and muting during incoming telephone calls) are transmitted. The source data are sent synchronously, such as, for example on a music CD, as blocks in subframes. By contrast, the control data are transferred asynchronously. They are split up, distributed using several subframes and transmitted.

The control data are provided with an address (Code), which indicates for which components the information is intended in the MOST ring.

Data arriving at the components are combined to form individual data packages and can then be edited. A data frame can thus contain the most varied of information (source and control data of all the components in the MOST ring).

The transmitting and receiving units are switched off when they are not required, in order to lower the quiescent current (sleep mode). They are switched off immediately after the operating unit is turned off or after the transmitter key is removed (A8/1).

With a new optical information transmission start, the bus system can be activated with the help of the "ON" switch (ON/OFF) of the operating module or by turning the transmitter key (A8/1) to "terminal 15R ON", provided that the system was not shut off before the transmitter key (A8/1) was removed. This activation occurs by means of an electrical signal in the wake-up line, triggered by the audio gateway control unit (N93/1).

If a telephone is integrated and the transmitter key inserted, a wake-up can also be triggered in the event of an incoming call.

Irrespective of whether information is intended for a component at the start, the processed light pulse reenters the bus at full intensity.