Local area network special function frames
First Claim
1. In a local area network having a plurality of nodes (16) wherein the local area network utilizes a token passing scheme for communicating between nodes (16), each node (16) having an interface apparatus (32, 34) which operates independently of a processor (38) associated with said node (16), each node (16) being capable of operating in an on-line mode and an off-line mode, wherein a node (16) in the off-line mode is responsive to a message frame identified as a special function frame, the special function frame containing diagnostic-type commands which are to be performed by the node (16) in the off-line mode, and further wherein the node (16) in the off-line mode does not participate in normal communications of the local area network including the token passing or the receiving of information frames, a method of diagnosing and recovering a second node (16) from a first node (16), the method implemented by the second node (16) comprising the steps of:
- (a) waiting (101, 105,
110) to receive the message frame addressed to the second node (16);
(b) determining (115) if the message frame is a special function frame, and if the message frame is determined to be the special function frame;
(c) insuring (120, 125,
135) that the node is in an off-line mode;
(d) determining (130, 140, 150, 155, 160, 165, 170, 175, 180,
185) the type of special function frame to perform the command specified by the type of special function frame, the function performed being monitored and analyzed by the first node (16) to determine and diagnose fault conditions of the second node (16); and
(e) returning to the step of waiting of step (a).
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Accused Products
Abstract
In a local area network having a plurality of nodes, wherein the local area network utilizes a token passing scheme for communicating between nodes, each node has an interface apparatus which operates independently of a processor associated with the node. The node can be in an on-line mode or an off-line mode, wherein the node does not participate in token passing or receive information when in the off-line mode. A method of the present invention provides for diagnosing and/or recovering a second node from a first node, the method implemented by the second node includes the steps of waiting to receive a message frame addressed to the second node. If the message frame addressed to the second node is a special function frame, and if the second node is in the off-line mode, the type of special function frame is determined to perform the command specified by the type of special function frame. The operation of the second node then returns to the step of waiting to receive a message frame addressed to it.
139 Citations
5 Claims
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1. In a local area network having a plurality of nodes (16) wherein the local area network utilizes a token passing scheme for communicating between nodes (16), each node (16) having an interface apparatus (32, 34) which operates independently of a processor (38) associated with said node (16), each node (16) being capable of operating in an on-line mode and an off-line mode, wherein a node (16) in the off-line mode is responsive to a message frame identified as a special function frame, the special function frame containing diagnostic-type commands which are to be performed by the node (16) in the off-line mode, and further wherein the node (16) in the off-line mode does not participate in normal communications of the local area network including the token passing or the receiving of information frames, a method of diagnosing and recovering a second node (16) from a first node (16), the method implemented by the second node (16) comprising the steps of:
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(a) waiting (101, 105,
110) to receive the message frame addressed to the second node (16);(b) determining (115) if the message frame is a special function frame, and if the message frame is determined to be the special function frame; (c) insuring (120, 125,
135) that the node is in an off-line mode;(d) determining (130, 140, 150, 155, 160, 165, 170, 175, 180,
185) the type of special function frame to perform the command specified by the type of special function frame, the function performed being monitored and analyzed by the first node (16) to determine and diagnose fault conditions of the second node (16); and(e) returning to the step of waiting of step (a). - View Dependent Claims (2, 3, 4, 5)
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Specification