I/O DEVICE AND CENTRALIZED MONITORING SYSTEM

摘要

PROBLEM TO BE SOLVED: To detect a faulty part and the cause of fault on a monitoring panel online. SOLUTION: An I/O device 2 is provided with a CPU 2a and memory 2c, and performs address management of each part unit on a monitoring panel 8 and online abnormality monitoring. Control instruction (e.g. lighting of a display device 4e) from a controller 1 is converted into subordinate data whose station number is a display unit 4 by the device 2 and then is transmitted. The CPU 2a sequentially transmits an abnormality monitoring signal to each unit 3 and 4 while the device 2 is not accessed, and decides the existence of abnormality from the response. A state (on/off) signal of a switch 3e of a switch unit 3 is sent to the device 2 through a transmission device 3b, converted into state data and sent to the controller 1. A CPU 3a performs self-diagnosis of a state of the switch 3e based on the content of memory 3c when its own unit is not accessed, and sends an abnormality detecting signal to the device 2 at the time of uncoincidence.