EKE-Trainnet

IEC 61375-1 standard’s WTB train bus interface

Cable redundancy supporting MAU IEC 821 VMEbus interface for mapping

server module

The WTB module of the Coach Computer implements the WTB Link Layer functions of the IEC 61375-1 Train Communications Network standard. It provides the Mapping Server (located on the CPU-module) with all the necessary primitives for accessing the Wire Train Bus.

The WTB module supports the cable redundancy as specified in the IEC 61375-1 standard. The Sub D-9 type cable connectors are located in front of the module while the communication to the CPU module goes via the VME back plane bus.

The WTB module is realised through highly efficient combination of a dedicated micro-processor and FPGA-logic. In addition to strict compliance to the IEC 61375-1 standard, the WTB module has the capability of carrying out enhanced diagnostics functions, like monitoring the bit error ratios between individual train coaches for recognising againg physical connections. To handle incompatible cabling or extremely harsh operating conditions, the WTB module is able to act as a bus repeater by completely re-generating the data stream towards both extremities.

Intelligent repeater management is included in the WTB module’s system software to support the selection of an optimal num-ber of concurrently enabled repeaters on the train bus, thus allowing the network timing to retain undegraded specifications. The WTB module is able to provide applications with timing synchronization when a Macro Period finishes.

and uses TCN standard’s Sub D-9 type connectors. In the basic module, the bus redundancy is integrated in a single bus connector, separate connectors for the redundant bus are available as an option. The bus interface sustains fritting current. Fritting current source is available as an option.

VMEbus interface. The module has static RAM accessible from both the local CPU and the VMEbus interface. The TCN standard’s docking principle for WTB process data is supported. A separate memory area is reserved for message data and maintenance messages as well for Remote Procedure Call type access to the Link Layer primitives.

DIMENSIONS: 4 TE × 3 U × 160 mm (W x H x D)

INPUT POWER: 5 VDC ± 5% (1,0 A max, 0,5 A typ)

MTBF: 500 000 h (25°C)

TEMPERATURE RANGE: Operational -40°C…+70°C

Data Rate: 250 kbit/s, 500 kbit/s or 1.0 Mbit/s

MAU: Transformer isolation. Combined bus

connectors, individual bus connectors

as option.

Redundancy support, cable shields

grounded internally. Bus repeter function

available. Fritting source available as option.

Interface: A24 Slave with D08(EO)/D16

256 kB DPRAM for process and

message data.