| 摘要 |
PURPOSE:To improve the reliability of data transmission, by turning back output data of an output circuit connected to a remote input/output bus and collating turned-back data with output data. CONSTITUTION:Input data from an industrial process is transmitted to a central processing device through an input circuit 40, a remote I/O bus 32, and a transmitting/receiving part 22. Output data based on this input from the central processing device 10 is supplied to an output circuit 50 through the transmitting/ receiving part 22 and the bus 32. The output circuit 50 outputs its output to the industrial process and turns it back to the bus 32 through an output turning- back circuit 50'. A remote processor 24 collates turned back output data with output data and reports the result to the central processing device 10. Thus, it is self-diagnosed whether operations of the remote input/output device and the output circuit are normal or not to improve the reliability of data transmission. |
