Patent ID: 6570928
Filing Date: 2003-05-27
Classification: H04H,H04L,H04N

Abstract:
A cable broadcasting system provided witha center equipment including a broadcasting equipment for transmitting a broadcasting signal to a transmission line, and a transmission equipment for producing and transmitting to said transmission line a command signal for setting an operation mode of an electronic device provided on said transmission line, a power supply device for supplying said transmission line with power signals for operating electronic devices disposed on said transmission line with electricity, and a plural electronic devices disposed dispersedly on said transmission line, for executing processing of signal transmission for a broadcasting signal passing through said transmission line, provided with a receiving circuit for receiving the command signal transmitted from said center equipment to said transmission line, a control circuit for setting the operation mode of the electronic device in response to the command signal when the command signal received at said receiving circuit is a command signal to said electronic device, and a power source circuit for taking in said power signals from said transmission line and converting said power signals to a voltage for operation to supply each said built-in circuit with electricity, wherein said transmission equipment of said center equipment is provided with a transmission data producing means for producing a transmission data including an identification data for identifying an electronic device when said electronic device whose operation mode is to be set is designated from the outside and a command data for indicating command content, a transmission data outputting means for giving the transmission data produced by said transmission data producing means a number data indicating the transmission number and outputting the transmission data having been given with said number data plural times at predetermined time intervals, and a transmission means for converting a transmission data outputted from said transmission data outputting means to a command signal and transmitting said command signal to said transmission line, and said control circuit of said electronic device is provided with a command signal identifying means for determining whether the command signal received at said receiving circuit is for said electronic device, based on said identification data constituting said command signal, a command content determining means for determining whether the command data constituting said command signal coincides with the previously received command signal for said electronic device, when said command signal is determined to be for said electronic device by said command signal determining means, a transmission number determining means for determining whether a number data given to the new received command signal is larger than a number data given to the previously received command signal to said electronic device, when said command signal is determined to coincide with the previously received signal, and an operation mode setting means which does not carry out setting of the operation mode based on the new received command signal when said number data given to the new received command signal is determined to be larger than the number data given to the previously received command signal by said transmission number determining means, and carries out setting of the operation mode in response to the new received command signal when said number data given to the new received command signal is equal to or smaller than the number data given to the previously received command signal and when said command data is determined to be different from the previously received command data by said command content determining means.