H04Q5/00—Selecting arrangements wherein two or more subscriber stations are connected by the same line to the exchange
H04Q5/02—Selecting arrangements wherein two or more subscriber stations are connected by the same line to the exchange with direct connection for all subscribers, i.e. party-line systems
H04Q5/14—Signalling by pulses
H04Q5/16—Signalling by pulses by predetermined number of pulses