Patent ID: 9397763
Filing Date: 2016-07-19
CPC Classification: H04B,H04Q

Claim Text:
1. A method for detecting abnormality of an input signal in a control/monitoring signal transmission system in which a master station is connected with a plurality of slave stations via a common data signal line, and transmission of data is performed according to a transmission synchronization scheme, the method comprising: determining, by the slave station, occurrence of an abnormal state when data corresponding to a signal level of an input part is larger than a lower limit threshold value and smaller than an upper limit threshold value, wherein the lower limit threshold value and the upper limit threshold value are updated based on data transmitted from the master station; detecting, by the slave station, a low sensitivity state of a signal of the input part based on the determination result of the abnormal state; and superimposing data indicating the low sensitivity state, data corresponding to the signal level of the input part and data indicating a number of determinations of the abnormal state on a management data region in a transmission signal to be transmitted to the common data signal line by the slave station, the management data region being different from a control/monitoring data region comprising data of a control data signal and data of a monitoring data signal.