| 摘要 |
The interface circuit of the present invention is composed to provide: changeover switch 24 that switches between a connection state in which pull-up resistor 23 is connected to input terminal 22 and a connection state in which pull-down resistor 23 is so connected; and microcomputer 26 that discriminates whether it is sink input or source input by discriminating the switch connection state of this changeover switch 24. Moreover, the interface circuit is composed to switch between a signal output state that outputs a signal that is an inversion of the input signal and a signal output state that outputs the input signal as it stands, based on the above discrimination result by this microcomputer 26. |
