Telephone exchange metering system

Disclosed is an automatic telephone metering system for use with private automatic branch exchanges (PABX) in connection with direct distance dialed (DDD), wide area telephone service (WATS), and extended area service (EAS). The system records usage information in the form of the trunk number, the line or extension number, the called number, date, time of call start and duration of call. That usage information is acquired by a sampling system which samples the trunk lines of the exchange during the signaling portion of call placement. The trunk lines, when sampled, are analyzed by receivers assigned by a central processing unit to busy trunks. Each of the trunks has a trunk address (TA) and each receiver has a receiver address (RA). The receivers are associatd with trunks by sample addresses (SA). A memory for storing the usage information for each busy trunk is addressed by the trunk address.