Gateways operate up to OSI layer 4—or even higher when required—giving them access not only to physical connections and addresses but also to message content, allowing interpretation of bits and classification of address, data, and redundancy bits. This capability supports improved system structuring in vehicles.

Use Cases for Gateways

Changing Bus Topology
The fundamental function of any gateway is to allow a change in bus topology. A basic CAN line topology can be split using a gateway. This is commonly used in commercial vehicles. For example, a CAN bus can be split to add new control inputs like a joystick for speed and direction, blinker switches, or ramp controls.

Range Extender
Even before intelligent programming, gateways can serve as range extenders. Signal degradation due to long cable lengths can be mitigated by mirroring messages, regenerating voltage levels, or dividing the bus into segments that support higher baud rates—thus improving data throughput.

Changing the Baud Rate
Gateways enable communication between nodes operating at different baud rates. This is essential when integrating ECUs—designed for 250 kbit/s—into systems running at 500 kbit/s, without the need for redesign or hardware replacement.

Editing Bus Messages
Gateways can access and modify individual objects within a message while maintaining data integrity. In vehicle customization, for instance, speed limiter parameters can be modified. Similarly, in special vehicles, a joystick’s ID can be changed to match that of a throttle pedal, enabling redundant control of motor functions.

Message Routing
Gateways can selectively route messages from one bus to another. In automotive use, this ensures that messages from a control unit reach the correct target components efficiently.

Firewall Functionality
With ID mask filtering, gateways act as firewalls—allowing only selected messages through. This reduces the processing load on microcontrollers by filtering out unnecessary data.

Cybersecurity
A possible application is also the implementation of cybersecurity requirements. In today’s connected world, securing systems and networks is crucial, especially with increasing regulatory demands such as UNECE R 155. MRS offers secure gateway solutions to protect your applications from unauthorized access and manipulation.

Changing Bus Systems
Gateways serve as translators between different communication protocols and bus systems. For instance, they can enable communication between a LIN-based rain-light sensor and a control unit operating on a CAN bus.

Building on the CAN standard, there are various higher-layer protocols such as CANopen and J1939. A gateway can convert messages between these, allowing, for example, data from a J1939 network to be interpreted within a CANopen environment.

Whether dealing with CAN, CANopen, CAN FD, SAE J1939, LIN, or serial buses, gateways provide the flexibility to adapt both protocol and system architecture.

MRS Gateway Products

MRS Electronic’s product portfolio includes gateways with configurations ranging from a single CAN and LIN interface to modules featuring five CAN interfaces. These compact devices offer a flexible number of analog and digital inputs and outputs; some variants also include PWM-capable outputs. Most models operate within a voltage range of 9 to 32 V. All gateway variants are freely programmable within the Applics Studio development environment, enabling easy integration and customization for specific applications.