Logical control of an electronic crosspoint PABX

Recently completed, after 15 months´ work by members of Automatic Electric Laboratories, Inc., is a new electronic telephone switching system which will accommodate 100 local subscribers and 20 trunks emanating from an electromechanical exchange.1 Ten of the trunks are PBX (private branch exchange) trunks and ten are 2-way dial trunks. Four operator lines have been established, not only as intermediate terminations for the PBX trunks, but also to provide special services for local subscribers. A 6-position meet-me conference facility is reinforced by a progressive or chain conference feature. Provisions have been made for trunk transfer, trunk restriction, night service, and operator intercept on unequipped lines.2