| 摘要 |
1517639 Automatic exchange systems, data transmission ING C OLIVETTI & C SpA 9 Sept 1976 [30 Sept 1975] 37441/76 Heading H4K A data terminal is connected to the power supply and initialized upon detection in a switch on control unit of ringing signals on a telephone line. The program controlled terminal 1 is coupled to a remote terminal 2 over a telephone line 17. The terminal has a console switch 10 which can be set to a position TLA to set the terminal to incoming calls. The state of the switch is stored in register in a program and data RAM 6. When the switch 10 is set to this position, logic in a switch control unit 4 is primed to respond to ringing signals, and in reponse thereto connects the power supply 5 of the terminal to the mains VAC, thereby initiating reading from a location in a ROM or PROM 8 the identity of the perpheral unit which stores the initialization program, the latter being transferred to the RAM 6. The peripheral to be used is specified in the ROM or PROM by the manufacturer. In a mode in which an operator is present the terminal may be arranged to display a LOAD request upon detection of a call requesting the operator to specify the peripheral to be used. A fault program which may be entered if for example the operator does not make a permitted response and an arrangement to cause switch off and no further response to incoming calls in the event of a low voltage supply are described. Data is received at the maximum rate that can be carried by the line and the terminal remains active after termination of the connection until printing or processing of the received data is complete. The terminal then returns to standby condition ready for the next call. |
