Could I ask our signalling experts what a 'module' is. It's one of these that apparently failed this evening.
And are these modules 'cheap Chinese crap' as I heard it described by a member of GWR▸ staff?
The signalling in that area is an upgraded version of the original 1992
BR▸ Solid State Interlocking (
SSI▸ ). The interlocking is triplicated in a 'two out of three configuration' (i.e. it requires two of the three to agree before giving an output) and is located at the Thames Valley Signalling Centre (
TVSC» ) at Didcot. The interlocking is connected to the trackside equipment by means of two diverse data links using a pair of Long Distance Terminals (
LDT▸ ). At the local site the remote data links are connected to the local data links via duplicated Data Link Modules (DLM). The actual signals and points are interfaced to by a Trackside Functional Module (
TFM▸ ) which although a single unit has two independent processors built into it, one connected to each separate data link. In theory no single failure should close down the whole system. All of this equipment is of British manufacture although the firms that make it are French (Alstom) and German (Siemens).
Hope thats not too technical?
Oh dear just realised thats a lot more acronyms/abbreviations for CfN......