S, and HS wipers advance into the wire banks to the
a simplified schematic diagram of the four 10- by
desired position (fig. 6-35).
10-wire banks and the XX-X wire banks in the normal.
Principles of Linefinding
When one wiper of the XY switch is in a given position
in its 10- by 10-wire bank, the other three wipers are
Linefinding is actually the process used to
in the same position in their respective 10- by 10-wire
connect one telephone line station to another. Since all
banks. As the switch steps a certain number of steps
the line stations will not be in use at the same time, it
in the X direction (fig. 6-35), the XX-X wipers
would be impractical to have a switch for each line
advance the same number of steps into the XX-X wire
station. Therefore, to reduce system complexity and
banks. As the switch steps in the Y direction, the T, R,
Figure 6-34.--Four wire banks and associated wipers shown in the X2 position.
Figure 6-35.--Four wire banks and associated wipers shown in position 26.