System and method for controlling redundant communication links in networked safety systems
First Claim
1. A method for maintaining communications on a safety system network connection, comprising:
- communicating a link integrity signal indicative of a communication state on a first network communication link;
generating a control signal having characteristics corresponding to the communication state of the first network communication link, wherein the control signal characteristics are indicative of a short circuit between any two or more conductors associated with any of the first and second network communication links;
controlling a communication link switch coupled to the first network communication link and one or more second network communication links in response to the control signal characteristics; and
switching from the first network communication link to one of the second network communication links at the communication link switch if the control signal characteristics indicate a failure affecting any one or more signals associated with the first network communication link.
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Accused Products
Abstract
A system, apparatus, and method for maintaining communication integrity in a safety system. A link integrity signal indicative of any short circuits or open circuits in a first communication link is communicated. A control signal having characteristics corresponding to the communication state of the first communication link is generated. A communication link switch is coupled to the first communication link and one or more second communication links; this link switch being controlled in response to the control signal characteristics. If the control signal characteristics indicate that a failure affecting any one or more signals associated with the first communication link has occurred, the connection is switched to one of the second communication links.
11 Citations
46 Claims
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1. A method for maintaining communications on a safety system network connection, comprising:
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communicating a link integrity signal indicative of a communication state on a first network communication link; generating a control signal having characteristics corresponding to the communication state of the first network communication link, wherein the control signal characteristics are indicative of a short circuit between any two or more conductors associated with any of the first and second network communication links; controlling a communication link switch coupled to the first network communication link and one or more second network communication links in response to the control signal characteristics; and switching from the first network communication link to one of the second network communication links at the communication link switch if the control signal characteristics indicate a failure affecting any one or more signals associated with the first network communication link. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A network interface for maintaining communication integrity with at least one central processor in a safety system, comprising:
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a communication link redundancy module including a controllable link switch for activating one of a plurality of selectable communication links between the communication link redundancy module and the central processor; a terminal server coupled to the link switch to communicate with the central processor via the currently-activated communication link, the terminal server comprising a link signal detector to monitor a link signal indicative of a communication state of the activated communication link and to generate a control signal in response thereto, wherein the communication state is indicative of a short circuit between any two or more conductors associated with the activated communication link; and an interface circuit coupled to the terminal server to receive the control signal, and to generate a command to the controllable link switch to select a different one of the plurality of selectable communication links when the control signal indicates a failure of any one or more signals associated with the currently-activated communication link. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36)
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37. A safety system, comprising:
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(a) one or more control panels, each control panel coupled to one or more safety devices to control and/or monitor the safety devices; (b) at least one central processing system to collect data from the one or more control panels; and (c) a network interface module coupled to the control panels and the central processing system to facilitate communication therebetween, the network interface module comprising; (i) a communication link redundancy module including a controllable link switch for activating one of a plurality of selectable communication links between the communication link redundancy module and the central processor; (ii) a terminal server coupled to the link switch to communicate with the central processor via the currently-activated communication link, the terminal server comprising a link signal detector to monitor a link signal indicative of a communication state of the activated communication link and to generate a control signal in response thereto, wherein the communication state is indicative of a short circuit between any two or more conductors associated with the activated communication link; and (iii) an interface circuit coupled to the terminal server to receive the control signal, and to generate a command to the controllable link switch to select a different one of the plurality of selectable communication links when the control signal indicates a failure of any one or more signals associated with the currently-activated communication link. - View Dependent Claims (38, 39, 40, 41)
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42. A network interface for maintaining communication integrity with at least one central processor in a safety system, comprising:
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means for monitoring a link integrity signal indicative of a communication state on a first network communication link; means for generating a control signal having characteristics corresponding to the communication state of the first network communication link as indicated by the monitored link integrity signal, wherein the communication state is indicative of a short circuit between any two or more conductors associated with the first communication link; a communication link switch coupled to the first network communication link and one or more second network communication links; and means for controlling the communication link switch, in response to the control signal characteristics, to select one of the second network communication links if the control signal characteristics indicate a failure affecting any one or more signals associated with the first network communication link.
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43. A network interface for maintaining communication integrity with at least one central processor in a safety system, comprising:
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a communication link redundancy module including a controllable link switch for activating one of a plurality of selectable communication links between the communication link redundancy module and the central processor; a terminal server coupled to the link switch to communicate with the central processor via the currently-activated communication link, the terminal server comprising a link signal detector to monitor a link signal indicative of a communication state of the activated communication link and to generate a control signal in response thereto; an interface circuit coupled to the terminal server to receive the control signal, and to generate a command to the controllable link switch to select a different one of the plurality of selectable communication links when the control signal indicates a failure of any one or more signals associated with the currently-activated communication link; and wherein the communication link redundancy module comprises control logic to demodulate the command from the interface circuit, and to control the controllable link switch in response to the demodulated command. - View Dependent Claims (44, 45, 46)
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Specification