Description

The data communications network is split-up into five separate communication rings:

1. a wide area network (WAN – Primary); (WAN - Primary)

2. a wide area Network (WAN - Secondary)

3. a wide area network (WAN - Secondary); (LAN)

4. an internal area network (IAN); and(IAN)

5. a fixed telecommunications network (FTN).(FTN)

The WAN normally consists of a primary and secondary link, but certain applications may only need a primary link with redundant ring switches.

As the name suggests, the local area network (LAN) covers a small local area. This network is used to connect the control and display system to the central interlocking unit at the control centre, and to connect with the diagnostics and maintenance system and related remote terminals.

The internal area network is the network which connects the components of the 2oo2 redundant central interlocking unit with the watch-dog circuit and communications with the outside world. The network is contained within the central interlocking unit module in the control cabinets at the control centre.

The fixed telecommunications network provides a switched Ethernet network between the interlocking location and all of the FTN access points for the object controllers connected to the interlocking. This allows the use of Ethernet through fibre-optics, copper cable or wireless connection from the FTN access point so that the IP network is extended to a gateway in each signalling location which contains object controllers. Within the signalling location, each object controller has its own Ethernet connection and IP address.

Technical specs