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US 6,909,923 B2Granted
Safety communication on a single backplane
AssigneeRockwell Automation Technologies, Inc.
InventorsDavid A. Vasko, Joseph Lenner
Life of this patent
Estimating the term…
Abstract
Safety level error detection comparable to that provided by redundant wired safety relays is obtained on a backplane of a programmable logic controller or the like by a combination of error detection methods that in sum provide the requisite level of error detection required without necessitating a particular hardware requirement or duplicative message transmissions.
Claims30
A backplane system for interconnecting components of an industrial controller for safety operation comprising:
- (a) a backplane having at least one conductor for conducting data as digital messages;
- (b) at least two industrial controller components having connectors allowing connection of the industrial components to the conductor of the backplane for the communication of messages thereon;
- (c) a safety protocol means enforcing a communications protocol on messages communicated over the backplane among industrial controller components to provide an error indication upon any of:
- (i) loss of a message transmitted from one component to a second component;
- (ii) corruption of a message transmitted from one component to a second component;
- and
- (iii) misdirection of a message transmitted from one component, intended for a second component, to a third component;
- (d) the safety protocol means places the industrial controller in a predetermined safety state upon a predetermined error indication.
5 more elements
A backplane system for interconnecting components of an industrial controller for safety operation comprising:
- (a) an input component providing redundant input signals on a first and second dedicated wire conductor;
- (b) an output component receiving redundant output signals on a first and second dedicated wire conductor;
- (d) a backplane having at least one conductor for conducting data as digital messages;
- (e) at least two industrial controller components having connectors allowing connection of the industrial components to the conductor of the backplane and having terminals connectable to receive the redundant signals of the input and output devices on the dedicated wire conductors and to communicate between the input and output devices using at least one message for each set of redundant signals;
- and
- (f) a safety protocol means enforcing a communications protocol on messages communicated over the backplane among industrial controller components to provide an error rate in the transmission of messages between the input device and output device using the backplane no greater than the error rate obtained by direct connection of the dedicated wire conductors of the input and output components directly between the input and output components.
3 more elements
A backplane system for interconnecting components of an industrial controller for safety operation comprising:
- (a) a switch providing redundant contacts connectable to wires;
- (b) an output device providing redundant inputs connectable to wires;
- (c) a backplane having at least one conductor for conducting data as digital messages;
- (d) at least two industrial controller components having connectors allowing connection of the industrial components to the conductor of the backplane and having terminals connectable to wires of the switch and output device, the industrial controller components providing an interface between the terminals and the backplane allowing for the communication of a signal from the switch to a first industrial controller component through the backplane to a second industrial controller component to the output device;
- and
- (e) a safety protocol means enforcing a communications protocol on messages communicated over the backplane among industrial controller components to provide an error rate in the transmission of messages between the switch and output device using the backplane no greater than the error rate obtained by direct wire connection between the switch and output device.
3 more elements
A method of interconnecting components of an industrial controller for safety operation comprising the steps of:
- (a) communicating messages over a backplane having at least one conductor for conducting data as digital messages between at least two industrial controller components having connectors allowing connection of the industrial components to the conductor of the backplane for the communication of messages;
- (b) enforcing a safety protocol in the transmission of the messages to provide an error indication upon any of:
- (i) loss of a message transmitted from one component to a second component;
- (ii) corruption of a message transmitted from one component to a second component;
- and
- (iii) misdirection of a message transmitted from one component, intended for a second component, to a third component;
- and
- (c) placing the industrial controller in a predetermined safety state upon a predetermined error indication.
5 more elements
A method of interconnecting components of an industrial controller for safety operation including an input component providing redundant input signals on a first and second dedicated wire conductor;
- an output component receiving redundant output signals on a first and second dedicated wire conductor;
- a backplane having at least one conductor for conducting data as digital messages;
- and
- at least two industrial controller components having connectors allowing connection of the industrial components to the conductor of the backplane and having terminals connectable to receive the redundant signals of the input and output devices on the dedicated wire conductors and to communicate between the input and output devices using at least one message for each set of redundant signals;
- comprising the steps of:
- enforcing a safety protocol on messages communicated over the backplane among industrial controller components to provide an error rate in the transmission of messages between the input device and output device using the backplane no greater than the error rate obtained by direct connection of the dedicated wire conductors of the input and output components directly between the input and output components.
3 more elements
A method of interconnecting components of an industrial controller for safety operation including:
- a switch providing redundant contacts connectable to wires;
- an output device providing redundant inputs connectable to wires;
- a backplane having at least one conductor for conducting data as digital messages;
- at least two industrial controller components having connectors allowing connection of the industrial components to the conductor of the backplane and having terminals connectable to wires of the switch and output device, the industrial controller components providing an interface between the terminals and the backplane allowing for the communication of a signal from the switch to a first industrial controller component through the backplane to a second industrial controller component to the output device;
- the method comprising the steps of:
- enforcing a safety protocol on messages communicated over the backplane among industrial controller components to provide an error rate in the transmission of messages between the switch and output device using the backplane no greater than the error rate obtained by direct wire connection between the switch and output device.
3 more elements
Dependencies are inferred from the claim text.