METHOD OF SENSING ABNORMAL STATE AND CONTROLLING OF RS485 COMMUNICATION SYSTEM CAPABLE OF SMOOTHLY AND NORMALLY PERFORMING A FUNCTION OF AN OPTICAL CONVERTER

摘要

PURPOSE: A method of sensing abnormal state and controlling of rs485 communication system is provided to conveniently sense an abnormal state of RS385 optical communication system in which an optical converter is connected to a ring mode.;CONSTITUTION: A frequency of an optical signal which is inputted from one optical converter is sensed(S420). It is determined whether an optical signal with a first frequency is inputted during a first period(S430). If an optical signal with the first frequency is inputted during the first period, an optical signal with a second frequency during a second period after passing through the first period is transmitted(S440). The optical converter converts an electrical signal of RS485 optical communication protocol which is received from a communication terminal into an optical signal. The optical converter converts an optical signal into an electrical signal.;COPYRIGHT KIPO 2012