DE20100645U1 - Bus system - Google Patents

Description

Bus systems, especially two-wire systems such as CAN systems, are known to have advantages in their design. By inserting controllers, functional modules are created that fulfil tasks. The reduction in cables is advantageous, particularly with two-wire connections, whereby, for example, a ring-shaped, star-shaped or cascadable data system with standardised connection points can be provided.

The controllers are communication elements for data exchange via the serial, parallel or other data bus and between the real existing and functioning control elements in the user systems. Generated signals are decoded or processed in the controllers. By creating application-specific, interconnected via the bus system,

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communicating functional units (controllers) the entire system becomes operational.

Such a functional unit or controller is required for each switching function/application. This represents a corresponding amount of effort and also means that subsequent retrofitting is very complex, complicated and risky because the entire system has to be modified by using an additional controller.

The present invention eliminates these disadvantages. With the features specified in claim 1, the bus system is easy to expand and adapt to different requirements. All that is required is that the at least one expansion controller is suitably connected and programmed. The rest of the bus system remains unchanged, particularly with regard to the programs and bus protocols present in the controllers connected from the outset.

The subclaim contains an advantageous embodiment.
If there are functional modules (controllers) in a system that provide the required functions, switching states and signals in a similar way or form, these are adapted and used accordingly and prepared for the required application. If signals are to be fed to the system, this can be done by manipulating the signals of the controller using existing states. This enables the system to communicate with the bus system without having to connect directly to it. The system is particularly suitable for hierarchical and

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functions with the same priority. The optimal use for the functional module is for pure slave system functions.

Advantages are:

With this principle all necessary functions are fulfilled.
The existing bus system will not be subjected to any additional electrical or temporal load.

No additional functional module (controller) is required for communication with the bus system. This makes the system economical and increases reliability.

The system is largely independent of the software, the software versions and the transmission protocols.
No initialization is necessary during commissioning.
The functional safety (reliability) of the overall system is significantly increased.

Even information transfer to the bus system is possible by manipulating the basic controller function.

Troubleshooting or checking is easily possible for simply trained personnel, since the functional units can be checked individually.

The invention is essentially designed in such a way that the signals are adapted and manipulated in the supply lines from the controller to the actuators (information output) and from the sensors (information input modules). This can be done using commercially available connectors, insulation displacement technology or solder connections. A wireless transmission technology can also be used.

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if used. The contact can advantageously be made in a control unit that simultaneously fulfills the function of the control task.

The bus system can be expanded without changing the software. With constant, changeable or modified software states, increased functional reliability is achieved or promoted.

The invention is explained in more detail below using an embodiment with reference to the drawings.

Fig. 1 is a schematic representation of a section of a bus system and

Fig. 2 is a schematic representation of a section of a bus system according to the prior art.

As can be seen from Fig. 2, in a bus system according to the state of the art, which has, for example, a two-wire bus B with an additional supply line for an operating voltage U _B , each microcontroller //C ₁ , i.e. also any subsequently connected expansion controller //C _{2 ,} must be connected separately to the two-wire bus B. For example, the microcontroller //C ₁ connected to the bus B from the outset controls rear lamps LA1 to LA6 of a motor vehicle, whereby, for example, if a lamp fails, another lamp takes over its function - for example, a rear light can be switched to a flashing mode.

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Bus B can be used to control displays for the driver in the dashboard area.

To operate trailer lighting with lamps LA10 to LA14, an extension controller //C ₂ can be connected to bus B. Since the extension controller //C ₂ can now also communicate via the bus
, the transmission protocols on the bus must be adapted accordingly, so that the other Controller//C ₁ connected to the bus from the outset must also be reprogrammed. This can result in considerable effort.

In the inventive solution shown in Fig. 1, however, the extension controller //C ₂ is not connected directly to the bus B, but indirectly via the microcontroller //C ₁ which is connected to the bus B from the outset, and is only connected to the bus supply line to supply the operating voltage U _B. Signal inputs E1 to E6 and outputs A1, A2 are connected by means of established connections to connecting lines of the controller //C ₁ which is connected to the bus B from the outset, which lead to or come from actuators, for example the lamps LA1 to LA8 or their control stages, to sensors and/or other control units. A wireless connection is also possible. The extension controller //C ₂ is also provided with control connections which are used, for example, to control trailer lamps LAA1 to LAA5 or the like.

The expansion controller //C ₂ is now programmed to receive, process and output the signals received or output via the connecting lines and connections E1 to E6, A1, A2. It can

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communicates with the micro-controller //C ₁ , which is connected to the bus B from the outset, and via this with the other participants connected to the bus B, so that reprogramming of the other participants, including the micro-controller //C _1, is not necessary.

Other expansion controllers can also be connected and adapted accordingly. The proposed solution is not only applicable to a field bus in the form of a CAN bus, as is usually used in motor vehicles, but also to other bus systems. Other bus systems, such as parallel, star-shaped or cascadable bus systems, can also be considered.

Claims (2)

1. Bus system with at least one bus (B) and functional units connected to it, including controllers (µC ₁ , µC ₂ ), characterized in that at least one extension controller (µC ₂ ) is connected indirectly via a controller (µC ₁ ) connected to the bus (B) from the outset via its connecting lines with connections (E1 to E6, A1, A2) leading to actuators (LA1 to LA8), sensors and/or other control units or coming from them, or wirelessly, and that further actuators (LAA1 to LAA5), sensors and/or other control units are connected via the extension controller (µC ₂ ). 2. Bus system according to claim 1, characterized in that the expansion controller (µC ₂ ) is adapted by programming to detect, process and output signals supplied or output via the connections, which are compatible with the signals present on the connecting lines of the controller (µC ₁ ) connected to the bus (B) from the outset.