System and method for implementing safety instrumented systems in a fieldbus architecture
AssigneeFieldbus Foundation
InventorsDavid A. Glanzer, Joseph D. Duffy, Stephen B. Mitschke, John Carl Gabler, L Jonas F. Berge, Ram Ramachandran
Life of this patent
Estimating the term…
Abstract
An apparatus, system and process is provided for communicating safety-related data, over an open system, from a sender to a receiver. Safety-related components, including function blocks, flexible function blocks, resource blocks and transducer blocks, as well as, safety-related objects are provided. Also, an extended safety-related protocol provides for authenticating communications between safety-related components over an existing black channel, such as one using a fieldbus Architecture.
Claims20
An apparatus for operating in a block-oriented safety related open control system comprising:
- a memory, which includes at least one safety related component;
- a processor, operably connected to the memory, wherein the processor executes the safety related component based on a system schedule;
- a medium attachment unit, which translates input messages and output messages between the processor and a transmission medium using an extended safety-related protocol;
- and
- wherein the processor manages the system schedule, instructs a second apparatus when it can execute a second safety related component, and passes a token to the second apparatus when a time arises for executing the second safety related component.
A process for communicating safety related data obtained by a first device to a second device comprising:
- obtaining, using a first device, information useful ingenerating a first data sequence;
- generating the first data sequence using the obtained information;
- generating a first authenticator for the first data sequence;
- combining the first data sequence and the first authenticator;
- and
- communicating the combination to the second device.
A process for authenticating a received message, wherein the received message includes information pertaining to a safety related component, comprising:
- receiving a first data sequence;
- receiving a first authenticator related to the first data sequence;
- generating a second data sequence based upon the first data sequence;
- calculating a second authenticator based upon the second data sequence;
- comparing the first authenticator and the second authenticator;
- when the first authenticator and the second authenticator are not the same, rejecting the received message;
- and
- when the first authenticator and the second authenticator are the same,
- receiving a sequence number related to the first data sequence;
- obtaining an expected sequence number;
- and
- comparing the received sequence number to the expected sequence number;
- when the received sequence number and the expected sequence number are not the same, rejecting the message;
- and
- when the received sequence number and the expected sequence number are the same, accepting the message.
Dependencies are inferred from the claim text.