| 摘要 |
PROBLEM TO BE SOLVED: To precisely detect an electrical connection failure between a module main body and a terminal block.SOLUTION: In an I/O module 10, a voltage detection section 13 supplies a weak current from one end of the return signal channel on each of the plural return signal channels formed between a terminal block 11 and the same being interposed by a connector CN to detect both-end voltages VA, VB and VC of the return signal channels. A failure alarm section 37 compares each of these both-end voltages to a threshold voltage and determines as an electrical connection failure when the both-end voltage is higher than the threshold voltage; based on a logical product of the determination result, determines a heavy failure has occurred representing a heavy electrical connection failure and displays a heavy failure alarm on a monitor 33 to prompt to stop the control on a field device connected to the I/O module; determines a slight electrical connection failure has occurred based on a logical sum of the determination results and displays a slight failure alarm on a monitor 33 to prompt to perform maintenance service on the I/O module. |
