With the help of a neat diagram explain a step by step switching system.

Configuration of a step by step switching system:

A step by step switching system may be constructed by using two motion selectors or uni-selectors uni-selectors or a combination of both. Here the wiper contacts of such selectors move in direct response to dialled pulses or another signal like off hook by the subscriber telephone. This wiper steps forward through one contact at a time and moves through as various contacts (takes as several steps) as the no of dialled pulses received or as needed to satisfy specific signalling conditions. Therefore the name step by step switching is specified to this method.