| 摘要 |
PURPOSE:To eliminate the need for an analog input section and also other backup device even when the titled input/output device is replaced because of a fault by using an input current signal as an output current signal as it is in the automatic mode. CONSTITUTION:When mode changeover switches 24, 25 are selected to the automatic mode, that is, when the both are thrown to the position of a fixed contact A, the switch 24 is opened, the switch 25 short-circuits an output of an analog output section 18 and suppress its output, then a current signal inputted externally to current input terminals 6, 7 of a terminal board 2 is fed to current output terminals 10, 11 of the terminal board 2 via a diode 21 and a connection wire 22 and outputted externally without any modification. Since no current flows to the inside of a main body unit 3 via input terminals 8, 9 or output terminals 12, 13 of the terminal board 4 in this case, even if a fault takes place in the unit and the unit 3 is drawn, the current output is not stopped. |
