Marker and Matrix Configuration for Overseas AUTOVON Switching System

Two types of markers were designed for the overseas AUTOVON (Automatic Voice Network). The switch marker and matrix (comprised of 6-element crosspoints) are used to interconnect the various switching circuits provided in the office. The DSA (Dial Service Assistance) marker and matrix are used to connect DSA trunk circuits to operator position circuits. Each marker is a sequentially operating device with self-checking circuitry to detect internal failures which are recorded by a separate maintenance monitor circuit. Two markers are always provided in each section (switch or DSA), one marker active or on-line, and the other used as a standby unit. When trouble is detected, an allotter circuit transfers the traffic load to the standby unit.