| 摘要 |
PURPOSE: To reduce the entire cost of the system by sending a data message to a center computer via a telephone interface. CONSTITUTION: A telephone interface 16 uses a modular connector to connect easily the tele-link system to a telephone line. A hook switch is provided and it is an FCC warrant relay, which makes connection or disconnection to/from the telephone line under the control of a microcomputer 26. A line isolator isolates electrically the tele-link circuit from the telephone line stipulated by the FCC regulation part 68 to provide a DC load required to keep the connection to a switch device in an office where equipments by a telephone company is in use mainly. Furthermore, the line state monitor makes a command to the microcomputer when the telephone line is busy. Thus, the entire system cost is reduced. |
