Title:
有線放送システム
Document Type and Number:
Japanese Patent JP4170489
Kind Code:
B2
Abstract:
In a proposed cable broadcasting system in which a command signal transmitted from a center equipment to a transmission line for setting an operation mode of a tap device on the transmission line, the command signal can be transmitted without fail even when an instantaneous power failure occurs because of thunderbolt and the like. The center equipment transmits a command signal with a retransmission number indicating the number of transmission plural times at intervals of a time longer than the duration time of the instantaneous power failure. The tap device determines whether the new received data of the command signal is a command to the tap device itself by using the address of the received data. When the command is for itself, it is determined whether the command (received command) coincides with the command previously used for setting the operation mode. When they do not coincide with each other, the operation mode is set in response to the received command. To the contrary, when they coincide with each other, the retransmission number given to each command is compared. When the retransmission number of the received command is equal to or smaller than the previous number, the operation mode is set in response to the received command.
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Inventors:
Eiji Shibata
Application Number:
JP42899A
Publication Date:
October 22, 2008
Filing Date:
January 05, 1999
Export Citation:
Assignee:
Maspro Denkoh Co., Ltd.
International Classes:
H04H20/12; H04H20/28; H04H20/76; H04H60/13; H04H60/37; H04N5/00; H04N7/10; H04N21/6338; H04N21/647
Domestic Patent References:
| JP851615A | ||||
| JP61186044A |
Attorney, Agent or Firm:
Tsutomu Adachi
Toshihiro Tanaka
Toshihiro Tanaka