| 摘要 |
PURPOSE:To eliminate the need for using a jumper wire and a special connector, by providing an automatic bypass circuit for making a device selecting signal bypass to a subordinate device at the time of removal, and detaching the bypass circuit at the time of installation. CONSTITUTION:A device selecting signal 4 which has been sent out of a central processor 1 is inputted to an input/output device. In this case, when a power source of a device 2 is turned on, a contact S2 in an internal selecting circuit 12 is closed, and a relay contact 10 in an automatic bypass circuit 8 is opened, therefore, the signal 4 is inputted to the circuit 12. When the circuit 12 goes wrong, the power source of the device 2 is cut in order to remove the circuit 12. At this time point, a power source supply to the circuit 8 is cut and the contact 10 becomes a closed state, and the signal 4 is bypassed automatically to the input/output device 3. The circuit 8 is provided in other place physically from the circuit 12, therefore, even if the circuit 12 is removed in this state, the device selecting signal is not cut but transmitted to a subordinate input/ output device. |
