CONTROL SYSTEM OF FORECAST TONE REPRESENTING ELAPSE OF TALKING HOUR AND MINUTE

摘要

PURPOSE:To transmit a forecast tone by allowing a cell processing control section of a private branch of exchange to reference a caller class memory and a called party number class memory and starting a forecast tone control section only when the both can transmit the forecast tone to apply the titled system to an exchange where data lines and public telephone circuits exist in mixture. CONSTITUTION:An extension subscriber 1 and a trunk 3 are connected to an exchange switch 2 and when dialing of the subscriber 1 is finished, a call processing control section 4 controls the switch 2 and connects the trunk 3 to the subscriber 1. A caller class memory 6 storing forecast tone transmission propriety information corresponding to the caller extension and a called party class memory 7 storing forecast transmission propriety information corresponding to the called party number are connected to the control section 4. Then the memory 6 is referenced depending on the allocated position of the subscriber 1 at exchange connection and the dial information references the memory 7. In referencing the memories 6, 7, the forecast tone control section 5 is started only when the talking hour minute elapse forecast tone is transmitted and a forecast tone is transmitted to the trunk 3 at the elapse of a prescribed time.