| 摘要 |
PURPOSE:To minimize inconvenience produced from the generation of failure, by monitoring the operating state of a terminal device continuously and detecting the failure generated in the terminal device earlier. CONSTITUTION:Data are transmitted from a main controller 1 to data lines D0- Dn, a device designating data to be selected is transmitted to device designation lines N0-Nm, and a low-level control signal is transmitted on a control signal line 5. A terminal controller 2 selected by the device designating data, that is, the controller 2 to which an output signal is transmitted from a selection circuit 4, transmits data D0-Dn-1 to a terminal device 11, a timing circuit 8 is operated and a high-level output is generated from an NAND gate 9. An input data to a register 3 is checked at a check circuit 6. When the data is normal, a start signal is generated from an AND gate 10, and while the operating state of the terminal devices is checked at a check circuit 14, it is monitored at a monitor circuit. |
