EP0196911A2
Expired / Lapsed
EP
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Local area networks
Assignee: Honeywell Inc
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Filing: 1986-04-01
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Granted: —
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Expires: 2006-04-01
Abstract
Abstract In a local area network having a plurality of nodes and utilizing a token passing scheme for communicating between nodes, each node has an interface apparatus which operates independently of a processor associated with said node. The present invention provides for diagnosing and/or recovering a first (remote) node from a second (supervisor or master) node. The first node includes means for monitoring for a message frame addressed to it. If such a message frame is a special function frame, and the node is in an off-line mode, the type of special function frame is determined and the command specified by the type of special function frame is performed. The operation of the first node then returns to the mode of waiting to receive a message frame addressed to it.
Inventors
- 👤 Tony J. Kozlik
- 👤 Bruce J. Landini
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 21:51
CPC Classifications
H; H04; H04L; H04L43/00; H04L43/08; H04L43/0805; H04L43/0817; H04L12/00; H04L12/28; H04L12/40; H04L12/40169; H04L12/40176; H04L12/40195; H04L12/407; H04L12/417; Y; Y10; Y10S; Y10S370/00; Y10S370/908
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
120 words
A local area network having a plurality of nodes and utilizing a token passing scheme for communicating betwen nodes, each node having an interface apparatus which operates independently of a processor associated with said node, characterized by means for diagnosing a first node from a second (remote) node, comprising: first means for monitoring for a message frame addressed to the first node and determining if the message frame is a special function frame; and second means which, if the message frame is determined to be a special function frame, sets the node to an off-line mode, determines the nature of special function frame and performs the command specified thereby, and returns to the mode of monitoring for a message frame.
Claim 2
Dependent Claim
120 words
A local area network having a plurality of nodes and utilizing a token passing scheme for communicating betwen nodes, each node having an interface apparatus which operates independently of a processor associated with said node, characterized by means for diagnosing a first node from a second (remote) node, comprising: first means for monitoring for a message frame addressed to the first node and determining if the message frame is a special function frame; and second means which, if the message frame is determined to be a special function frame, sets the node to an off-line mode, determines the nature of special function frame and performs the command specified thereby, and returns to the mode of monitoring for a message frame.
Claim 3
Dependent Claim
83 words
Apparatus according to Claim 1, characterized in that the second means comprises means for: a) reading information specified, if the nature of the special function frame is a read command wherein the information to be read is specified; b) issuing a control signal to abort the current processing of the processor associated with the node if the nature of the special function frame is an abort command; and c) queuing an acknowledgement frame message to be subsequently transmitted to the second (remote) node.
Claim 4
Dependent Claim
55 words
Apparatus according to Claim 2, characterized in that the second means further comprises means for: a) issuing a reset control signal to the node if the nature of the special function frame is a reset command; and b) waiting a predetermined amount of time to allow the reset control signal to propagate through the node.
Claim 5
Dependent Claim
65 words
Apparatus according to either of Claims 2 and 3 characterized in that the means for issuing a control signal to abort the current processing comprises means for: a) issuing a high priority, non-inhibitable interrupt to the processor associated with the node, the interrupt causing the processor to suspend operation; and b) queuing a time out frame message to be subsequently transmitted to said first node.
Claim 6
Dependent Claim
133 words
Apparatus according to any previous claim, characterized in that the first means further comprise means for: a) determining whether the message frame is a token pass frame, such that if the message frame is not a token pass frame the message frame is processed as a normal transmission message frame, and otherwise proceeding to step (b); b) determining if a return special function frame is queued, to transmit the return special function frame if it is queued, and then proceeding to step (d); c) determining if the node is in the off-line mode, to transmit available information frames if the node is not in the off-line mode, and otherwise proceeding to step (e); d) passing the token to a successor node; and ---e) returning to the mode of monitoring for a message frame.
References Cited (Backward Citations)
No citation records indexed.
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