FACILITY SUPERVISORY METHOD AND FACILITY SUPERVISORY SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a facility supervisory system that can relieve a communication load so as to reduce a communication scan time.;SOLUTION: A supervisory device 3 transmits an effective request message to obtain data transmission only when data being a supervisory object are changed to a controller 2, when data designated by the effective request message is changed, the controller 2 transmits a data change message including the data to the supervisory device 3 and the supervisory device 3 acquires data from the received data change message.;COPYRIGHT: (C)2002,JPO