TP1 lines can be extended into TP1 areas. Maximum 15 TP1 lines can be combined into one TP1 area. The base for a TP1 area is its main line. A TP1 area main line is limited to one TP1 line segment, which shall NOT be extended by means of TP1/TP1 couplers. In order to connect a TP1 line to a TP1 area main line, a TP1/TP1 coupler is to be used. The TP1 area main line is to be connected to the primary side of this TP1/TP1 coupler, which in this context is called a 'Line Coupler'. The TP1 lines that are connected to the secondary sides of the TP1/TP1 coupler are not limited to one TP1 line segment.
Area capacity = [capacity main line] + [capacity line] x 15
- the capacity taken by the 15 TP1/TP1 couplers from the main line (primary side) is 15 x 1 = 15 devices
- per TP line:
- the capacity taken by the TP1/TP1 coupler for the connection with the main line (secondary side) is 1 device
- the capacity taken by the 3 TP1/TP1 couplers from the line (primary side + secondary side) is 3 x 2 = 6 devices
This brings the total capacity of an TP1 area to: [ 64 - 15 ] + [ (4 x 64) - 1 - 6 ] x 15 = 3784 devices.