Patent ID: 7428251
Filing Date: 2008-09-23
Classification: G08C,H04Q

Abstract:
1. A control and supervisory signal transmission system including a plurality of controlled devices, each including a controlled unit and a sensor unit which supervises said controlled unit, said control and supervisory signal transmission system transmitting a control signal to said controlled unit and transmitting a supervisory signal from said sensor unit through a data signal line common to said plurality of controlled devices, said control and supervisory signal transmission system comprising: an intermediate station being connected to said data signal line and transmitting a supervisory signal sent from a given controlled device to a controlled device associated with said given controlled device as a control signal; and a plurality of child stations being associated with said plurality of controlled devices and being connected to said data signal line and the associated controlled devices, wherein said intermediate station comprises: timing generating means for generating a predetermined timing signal that is in synchronization with a clock having predetermined periodicity; an intermediate-station input unit to extract a supervisory signal superimposed on a serial pulse voltage signal transmitted through said data signal line, in every cycle of said clock, under the control of said predetermined timing signal; and an intermediated-station output unit to obtain said supervisory signal as said control signal, to superimpose said control signal on said serial pulse voltage signal according to each data value of said control signal in every cycle of said clock, and to output a resulting signal onto said data signal line in the same cycle in which said supervisory signal has been extracted, under the control of said predetermined timing signal, wherein each of said plurality of child stations comprises: a child-station input unit to generate a supervisory data signal according to a value from said sensor unit associated with the child station and to superimpose said supervisory data signal on a predetermined position of said serial pulse voltage signal as a data value of said supervisory signal, under the control of said predetermined timing signal; and a child-station output unit to extract data values of said control signal from said serial pulse voltage signal and to supply data corresponding to the child station from among the data values to said controlled unit associated with the child-station output unit, in every cycle of said clock, under the control of said predetermined timing signal.