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Home >> BMW >> 2004 >> 745Li >> Repair and Diagnosis (Single Page) >> Electrical >> Body Electrical >> Body Electronics III - Overview >> Introduction to Advanced Body Electronics >> byteflight >> Function >> Transmitter/Receiver Module (SE)
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Transmitter/Receiver Module (SE)

The transmitter/receiver module is a module that can convert electrical signals into optical signals and transmit them via optical fibers. Every satellite has an electrical-optical transmitter/receiver module.

Fig 1: Identifying Intelligent Star Coupler
G03390684Courtesy of BMW OF NORTH AMERICA, INC.

The transmitter/receiver modules are connected individually via the byteflight to the Intelligent Star Coupler in the SIM. The SIM also contains a transmitter/receiver module for each satellite.

Fig 2: Identifying Transmitter/Receiver Modules (SE)
G03390685Courtesy of BMW OF NORTH AMERICA, INC.

All information transmitted across the byteflight is in the form of data telegrams sent by means of light pulses. The transmitter/ receiver modules in the SIM receive the light pulses from the various satellites. The Intelligent Star Coupler sends the data telegrams to all satellites. Data transmission is possible in both directions.

Fig 3: Intelligent Byteflight Transmissions
G03390686Courtesy of BMW OF NORTH AMERICA, INC.

The transmitter/receiver (SE) module contains the LED for the driver circuit and the receiver amplifier for converting the optical signals into digital signals. It also has an integral transmission quality monitoring circuit.

If one of the following faults occurs on one of the fiber-optic cables, the satellite concerned is shut down: 

The permissible degree of attenuation is stored within the system. If the attenuation exceeds the specified maximum level, one of the following faults may be the cause: