PURPOSE: To make it unnecessary to multiplex a highway for service and a highway for tone, by providing a time switch on the highway for tone and switching the output of this time switch and information on the highway for service by a selector.
CONSTITUTION: Information on a highway 3 for tone is replaced with tone information, which should be transmitted to the same channel as a channel of a highway 3 for service to which the tone should be transmitted, by a switch control memory 11, and this tone information is outputted completely synchronously with information on the highway 2 for service. From a selector circuit 12, information of the highway 2 for service is normally outputted but information on the highway for tone is outputted for the input from a select signal line 13. Consequently, the select signal is transmitted at the timing synchronous with the channel of the highway 2 for service, to which the tone should be transmitted, from the switch control memory 11 to output information on the highway 3 for tone only to this channel.
| JPS6315556 | CONTROLLING SYSTEM FOR SENDING DIAL TONE |
| JPH0231554 | TONE GENERATOR USING MEMORY |
| WO/1982/001635 | IMPROVEMENTS IN OR RELATING TO LINE INTERFACE CIRCUITS |
MAEDA TOSHIYUKI
KUWABAYASHI JIYUNICHI
HASEGAWA SHINGO
OKI ELECTRIC IND CO LTD