| 摘要 |
<p>PURPOSE:To simplify input processing by inputting the signal for confirming that the switching operation of an input signal is finished when one of a control signal and a diagnostic signal is switched and inputted selectively. CONSTITUTION:When a sensor provided with a failure diagnosis is connected to an I/O device, a switch 11 is closed previously. Thus, when an input signal switching signal inputted through an FF 6 becomes L-level, the output of an inverter 74 becomes H-level, and the output of the multiplexer 3 is switched to diagnostic output. Simultaneously, the output of the inverter 75 becomes H-level, and a counter 78 is operated. A shift register 7 operated by a clock is connected to the counter 78, and after the lapse of prescribed time, a confirming signal is outputted through a buffer 79. This prescribed time is the time required for operation that the multiplexer 3 is operated after the input switching signal is inputted and the output is switched perfectly from the control signal to the diagnosis signal.</p> |
