New Alarm-clock Equipment WA 490.

In 1969, the first completely automatic alarm-clock equipment WA 49 was brought into service in public telephone exchanges. A new generation of alarm-clock equipment WA 490 was developed in Switzerland to assure future requirements. The order carrying capacity of each alarm-clock rack was increased from 560 to 1500. The equipment is of modular construction and can be extended to a maximum of 20 racks. The operational trial was successfully completed with the first equipment in Zurich. The concept and construction of the new alarm-clock equipment WA 490 are outlined.