MVB and TRDP at a glance
MVB and TRDP are used for train communication, but they use different network technologies. Connecting them requires a gateway that maps the agreed application data between the two sides.
| Aspect | MVB | TRDP |
|---|---|---|
| Full name | Multifunction Vehicle Bus | Train Real-time Data Protocol |
| Communication | Vehicle bus | Protocol over IP-based Ethernet networks |
| Standards reference | IEC 61375-3-1 | IEC 61375-2-3 |
| Integration task | Identify bus interfaces and source/destination signals | Define datasets, addressing and communication timing |
What is MVB?
Multifunction Vehicle Bus (MVB) is part of the IEC 61375 Train Communication Network family. It connects onboard equipment so controllers and subsystems can exchange process and diagnostic information.
When selecting an MVB interface or gateway, check the physical interface, device role, supported data services and redundancy against the existing network. These capabilities vary by product and configuration.
Reference: IEC 61375-3-1: Multifunction Vehicle Bus
What is TRDP?
Train Real-time Data Protocol (TRDP) is a railway communication protocol defined in IEC 61375-2-3. It carries process data and message data over IP-based Ethernet networks. Process data supports regular operational updates; message data supports exchanges that are initiated when needed.
A TRDP communication module gives host electronics access to this network. A protocol converter also translates the application's data between TRDP and another interface, such as MVB, CAN or serial.
Reference: IEC 61375-2-3: TCN communication profile
What does an MVB-to-TRDP gateway do?
A gateway receives data from one network, applies a configured mapping and makes it available on the other. This can support a refurbishment project that retains existing MVB equipment while introducing Ethernet-based subsystems.
For example, a subsystem status value must arrive with the correct meaning, units and validity on the receiving side. Converting a frame alone does not define that application behavior.
- Map signal identifiers, data types, byte order, units and scaling.
- Define source and destination addresses and datasets.
- Agree update intervals, timeouts and handling of invalid or missing values.
- Record configuration ownership and version information.
Match the module to the interface
Use an MVB gateway for an MVB connection. For SPI, CAN, serial, UDP or TCP/IP equipment, select a module that explicitly supports the required conversion. Confirm the necessary communication services, host interface and configuration tools.
Specify redundancy and safety-related communication requirements separately. They depend on the complete application and selected configuration, rather than the protocol name alone.
Check the complete data path
Check the mapping from the source equipment through the gateway to the receiving application. Include startup, normal updates, communication loss and recovery. Confirm that values, timing and diagnostic information meet the project's interface requirements.
Keep the mapping file, firmware version and results together so the installed configuration can be reproduced during maintenance.