How are switching systems are classified.In what way a stored program control is superior to hardwired control?

Answer 1

A stored program controlled system can have features and properties changed through programming...which can often be done in PBX systems remotely. Hardwired control requires physical changes to wiring, strapping, etcetera, which means it cannot be done remotely but needs to be done on site.

Using business telephone systems as an example: Until the 70's most business phone systems had their characteristics and features configured by physical wiring and electro mechanical switches (relays) and other components. It was not unusual for equipment rooms to be filled with racks of switching equipment. By the mid 70s as stored program controlled (specialised computerized) systems took over what had taken a full room of hardwired equipment could be held in a refrigerator sized cabinet...a few years later, in a cabinet the size of a 2 drawer file cabinet. Also the equipment did not need constant adjustments and cleaning.

Around 1980 I was a business phone system technician working out of a garage (work location where we stored our trucks and got supplies) with about 70 other technicians, and hardwired systems were rapidly being replaced. By 1986 there were only 2 or 3 technicians covering the same territory. Some were replaced by centralized remote techs maintaining systems via modem...but most had had their need vanish due to the efficiencies of configuring and maintaining the newer systems.