| 摘要 |
PURPOSE:To obtain a data transmission system between a handset and a telephone set being decreased the number of signal lines in a curl cord as much as possible, by transmitting input telephone number information through one signal line in both ways. CONSTITUTION:Signal lines 3-5 are used for control signal transission in a data transmission direction, transmission data synchronizing signal transmission, and data transmission respectively and are contained in a curl cord. When telephone number information is inputted to a handset-side microprocessor 2a through a keyboard 2h, the microprocessor converts the information into serial data, which is transmitted to a telephone-side microprocessor 1a through a signal line 5. The information is further sent back to the handset side through the signal line 5 to be displayed on a digit display device 2g as input telephone number information. |
