BMW Motorrad Single-Wire-System (SWS)--simply perfect for sensible functions in the on-board network.
Introducing the R 1200 GS early in 2004, BMW Motorrad also presented its Single-Wire-System, a highly advanced, all-new system networking electrical and electronic components in the motorcycle. Combining sophisticated electronics with CAN-bus technology (Controller Area Network), this innovative on-board network offers a much wider range of functions than conventional on-board networks, while at the same time significantly reducing the number and intricacy of cables required.
In this network, information is conveyed through just one single wire (hence the name). And to ensure absolute security in a fully redundant system, the configuration comes with two wires for appropriate back-up.
The most significant benefits of this intelligent combination of electrics and electronics are the reduction of weight on both the wiring harness and the components used, a high level of robustness, and comprehensive diagnostic abilities. A further advantage is the easy integration of electronic accessories into the network, simple updates serving to flexibly extend and enhance the system whenever required.
The basic principle is to integrate all control units through just one single wire to provide a common network transmitting all signals regardless of their subsequent function. Hence, this network comprises all information at all times for all the components integrated into the system. The signals are then allocated to the right address at specific junction points, going straight from there to the appropriate electronic control units responsible for specific power-consuming items. There the information is processed and the appropriate functions are activated.
This eliminates the elaborate and complicated process of wiring each individual function through a separate line, which also reduces the potential sources of error inevitable in a conventional on-board network due to the large number of lines and connectors. And this, obviously, is crucial to a high standard of all-round reliability.
Communication network and central diagnosis.
With all control units forming one common communication system, the exchange of data is simple and efficient. Diagnosis of the overall system is equally simple and comprehensive, and can be performed at one central point, the electronic "brain" filtering out insignificant data and interference signals within defined tolerance limits. This makes the system largely immune to interference such as electromagnetic noise.
Including the anti-theft warning system and ABS, a total of five control units communicate with one another in the new K 1200 S. The instrument cluster also performs the functions of a control unit, and the BMS-K digital engine electronic control unit is responsible not only for engine management as described in the foregoing, but also for the transmission of data to the diagnostic system. The Central Electronic System (CES), finally, masterminds the non-engine-specific electrical functions.
On-board network without conventional fuses.
The entire on-board network operates without any conventional, melt-down fuses, the CES reliably switching off the function involved in the event of a short-circuit or malfunction. It then saves information on defects registered for centralised diagnosis, ensuring that each defect can be located quickly and directly. The big advantage of this electronic control function is that CES automatically re-activates the appropriate function each time the motorcycle is re-started, thus checking itself whether the defect is still there. Possible failure of a signal path, finally, will not affect the other functions, keeping the entire system reliable and failure-proof.
The control units also serve as relays, only the starter still being activated by a conventional relay. A compact alternator developing 580 W at 42 Amps supplies the electrical system on the K 1200 S. The maintenance-free battery has a capacity of 14 Amp/hours.
Electronic immobiliser--anti-theft security of the highest standard. The K 1200 S comes as standard with an electronic immobiliser. Controlled via a transponder in the key to the ignition, this sophisticated system offers anti-theft security of the highest standard fully equal to the security in a BMW car.
As soon as the rider inserts the key into the ignition lock and switches on the ignition, a chip in the key communicates with the Digital Motor Electronics via the ring aerial integrated in the ignition lock. Incorporating the electronic immobiliser algorithms, DME then initiates a challenge response process (the engine control unit activates a random "challenge" and the ring aerial/key reply by an appropriate "response" in order to identify themselves) and triggers an exchange of data between the coded chip and the electronic immobiliser, with the data exchanged changing each time the engine is to be started. Whenever the response from the ring aerial fits the challenge presented, the engine control unit will release the ignition and fuel injection and the rider can start the engine. This technology is currently the best and most secure immobiliser technology available.
New instrument cluster in digital technology.
The new on-board electronic system of the K 1200 S allows the introduction of a highly advanced, fully digitalised, extra-light instrument cluster comprising the speedometer, rev counter and an information display referred to as the Info-Flatscreen. The Info-Flatscreen provides ongoing information on coolant temperature, the level of fuel in the tank, the time, and the gear currently in mesh.
If the motorcycle is fitted additionally with ESA Electronic Suspension Adjustment, the Info-Flatscreen provides additional information on the current set-up of the suspension. The overall mileage of the motorcycle, trip mileage and - once the fuel tank has dropped to the reserve level - remaining mileage on the fuel left in the tank are also available on request by the rider. Any deficiencies in the system, finally, are presented by appropriate signals in the display.
The entire instrument cluster is masterminded by a photoelectric cell and is automatically illuminated at dusk.
All the motorcycle's switches and manual controls are of the latest generation introduced for the first time on the R 1200 GS. The particular fortes of these switches and controls are a high level of function, clear design, and easy accessibility. The basic arrangement of switches and BMW's typical logic in controlling the direction indicators have been maintained.
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