Individual signalling elements (signals, track circuits, points, level crossings) are identified by means of standard nomenclature. The trackside equipment, which generates the data for the signalling elements, may include solid-state interlocking (SSI) outputs, relay contacts, push buttons, levers and other indications.
In SOP's and ECS's, the first letter denotes the general kind of the element. Preceding letters denote the function of the element. This is not always the case, as some labels don't have the first letter.
Meaning of the first letter:
| Code
|
Meaning
|
| L
|
Level Crossing
|
| P
|
Points
|
| R
|
Route
|
| S
|
Signal
|
| T
|
Track Circuit
|
Signals
| Code
|
Meaning
|
| BR, R
|
Repeater signal
|
| RGE
|
Electric lamp illuminating danger aspect (Red)
|
| HGE
|
Electric lamp illuminating caution aspect (Yellow)
|
| DGE
|
Electric lamp illuminating clear aspect (Green)
|
| RGK
|
Electro-mechanical indicator, signal showing danger aspect (Red)
|
| HGK
|
Electro-mechanical indicator, signal showing caution aspect (Yellow)
|
| DGK, OFFK
|
Electro-mechanical indicator, signal showing clear aspect (Green)
|
| OFFG
|
Signal apparatus OFF, signal showing clear aspect (Green)
|
| LOSECK
|
Electro-mechanical indicator, Limit of Shunt
|
Points
| Code
|
Meaning
|
| GF
|
Ground Frame
|
| FK
|
Electro-mechanical indicator, Ground Frame points locally operated
|
| N
|
Normal position
|
| NK
|
Electro-mechanical indicator, normal position
|
| NWK
|
Electro-mechanical indicator, points operating apparatus in normal position
|
| R
|
Reverse position
|
| RK
|
Electro-mechanical indicator, reverse position
|
| RWK
|
Electro-mechanical indicator, points operating apparatus in reverse position
|
