04611274 is referenced by 48 patents and cites 8 patents.

This disclosure is directed to a data transmission system via the power supply line wherein it is characterized in that; it effectively controls branching terminal units connected to the CPU via the power supply line, by transmitting a high frequency AC signal that is mixed into the AC commercial frequency via the power supply line, while it normally surveilles the actual status of terminal units during normal operations. According to this system as a preferred embodiment of the present invention, after sampling data via the poling, a specific AC commercial frequency cyclic period can be allocated in order to properly transmit any emergency data between terminal units via a contention, and as a result, even in the slow-speed transmission line, not only any change of condition occurring in the terminal units can quickly be sent to the central processing unit, but all the control signals from the central processing unit can also be sent to respective terminal units without being held for waiting.

Title
Data transmission system via power supply line
Application Number
6/518450
Publication Number
4611274
Application Date
July 29, 1983
Publication Date
September 9, 1986
Inventor
Hidehiko Tanaka
Tenri
JP
Masahiro Ise
Kashihara
JP
Katsuyuki Machino
Nara
JP
Agent
Birch Stewart Kolasch & Birch
Assignee
Sharp Kabushiki Kaisha
JP
IPC
H04Q 9/00
H04J 3/16
H04J 3/02
G06F 13/38
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