US 5,629,941 A · Multiplex transmission system

Abstract

The object of this invention is to provide a multiplex transmission system which can effectively reduce the traffic amount associated with digital information on a communication line and can improve the efficiency of digital information transmission during a period after the beginning of activation of each of a plurality of communication nodes connected to the communication line until the communication nodes are set in a normal operation state. The multiplex transmission system includes a communication line (11) for transmitting multiplexed digital information, and a plurality of communication nodes (12A, 12B, 12C) each of which incorporates an arithmetic processing unit, and performs an information output operation for outputting digital information onto the communication line (11), and an information fetching operation for selectively fetching digital information from the communication line (11). Upon activation of the plurality of communication nodes (12A, 12B, 12C), a communication node, which is set in a normal operation state earliest, of the plurality of communication nodes (12A, 12B, 12C) outputs digital activation information, and the remaining nodes are shifted to the normal operation state in accordance with the digital activation information.

Claims25

Dependent claims

A multiplex transmission system to which a plurality of communication nodes are connected via a multiplex transmission path, and in which each of said plurality of communication nodes comprises a control unit for, when a communication state is normal, controlling transmission of a communication frame having its own predetermined data via said multiplex transmission path and selective reception of a communication frame transmitted from another communication node,

each of said plurality of communication nodes comprising:
detection means for detecting if the communication state of its own communication node is normal;
means for, when the communication state of the communication node is not normal, setting the communication state of its own node as a first communication state, and prohibiting transmission and reception of the communication frame during a predetermined first period after detection of the communication state;
means for setting the communication state of its own node as a second communication state, and prohibiting transmission of the communication frame but permitting reception of the communication frame during a predetermined second period after the end of the first period;
and
means for, when a predetermined communication frame transmitted from another communication node is received On the Second communication state, permitting transmission of the communication frame of its own node, while is still being in the second communication state, before the end of the second period.

3 more elements

each of said plurality of communication nodes comprising:
detection means for detecting if the communication state of its own communication node is normal;
means for, when the communication state of the communication node is not normal, setting the communication state of its own node as a first communication state, and prohibiting transmission and reception of the communication frame during a predetermined first period after detection of the first communication state;
and
means for setting the communication state of its own node as a second communication state, and prohibiting transmission of the communication frame but permitting reception of the communication frame during a predetermined second period after the end of the first period,
wherein the communication node, in which the second period ends earliest and transmission of the communication frame is permitted, of said plurality of communication nodes transmits a predetermined communication frame from its own node via said multiplex transmission path.

3 more elements

A multiplex transmission apparatus which transmits a communication frame having its own predetermined data via a multiplex transmission path, and selectively receives a communication frame transmitted from a transmitting side of another multiplex transmission apparatus, comprising:

detection means for detecting a predetermined condition;
means for, when the predetermined condition is detected, setting a communication state of its own as a first communication state, and prohibiting transmission and reception of the communication frame during a predetermined first period;
means for setting the communication state of its own as a second communication state, and prohibiting transmission of the communication frame but permitting reception of the communication frame during a predetermined second period after the end of the first period;
means for, when a predetermined communication frame is received on the second communication state, permitting transmission of the communication frame before an elapse of the second period, and for when the second period has elapsed without receiving the predetermined communication frame, permitting transmission of its own communication frame;
and
means for, when the second period has elapsed, transmitting the predetermined communication frame.

3 more elements

Dependencies are inferred from the claim text.

Multiplex transmission system

Life of this patent

Multiplex transmission system

Life of this patent

Abstract

Claims25