Input/output device with configuration, fault isolation and redundant fault assist functionality
AssigneeFisher-Rosemount Systems, Inc.
InventorsMichael D. Apel, Steve Dienstbier
Life of this patent
Estimating the term…
Abstract
A process control system is provided having a plurality of I/O devices in communication using a bus. A primary redundant I/O device and a secondary redundant I/O device are coupled to the bus, where the secondary redundant I/O device is programmed to detect a primary redundant I/O device fault. The secondary redundant I/O device, upon detecting the primary redundant I/O device fault, publishes a primary redundant I/O device fault message on the bus. The controller may deactivate the primary redundant I/O device and activate the secondary redundant I/O device responsive to the primary redundant I/O device fault message.
Claims12
A field device for use in a process control system, the process control system including an I/O device and a plurality of field devices in communication with the I/O device using a bus segment having at least one data line, the field device comprising:
- a field interface for communicatively linking the field device with the bus segment;
- and
- a field device processor coupled with the field interface for controlling operation of the field device including performing fault detection for the field device;
- wherein the field device processor is configured to;
- attempt to affect one or more of the at least one data line of the bus segment;
- use the field interface to take a reading of the one or more data lines of the bus segment to determine whether the field device processor affected the one or more data lines of the bus segment;
- detect a potential field device fault when the reading taken of the one or more data lines of the bus segment indicates that the field device processor did not affect the one or more data lines of the bus segment;
- and
- upon detection of the potential field device fault, sever the communication link provided by the field interface with the bus segment prior to concluding that the field device is faulty.
A method for severing communication between a field device and a bus segment in a process control system, the process control system including an I/O device and a plurality of field devices in communication with the I/O device using the bus segment, the method comprising:
- communicatively linking the field device with the bus segment using a field interface of the field device;
- and
- controlling operation of the field device with a field device processor coupled to the field interface, including performing fault detection for the field device by;
- attempting to affect one or more data lines of the bus segment;
- using the field interface to read the one or more data lines of the bus segment;
- determining, based on reading the one or more data lines of the bus segment, whether the field device processor affected the one or more data lines of the bus segment;
- detecting a potential field device fault when reading the one or more data lines of the bus segment indicates that the field device processor did not affect the one or more data lines of the bus segment;
- and
- severing the communication link with the bus segment upon detecting the potential field device fault prior to concluding that the field device is faulty.
A process control system comprising:
- a process controller;
- an I/O device communicatively coupled to the process controller;
- and
- a plurality of field devices in communication with the I/O device using a bus segment, each of one or more of the plurality of field devices comprising;
- a field interface for communicatively linking the field device with the bus segment;
- and
- a field device processor coupled with the field interface for controlling operation of the field device including performing fault detection for the field device;
- wherein the field device processor is configured to;
- attempt to affect one or more data lines of the bus segment;
- use the field interface to take a reading of the one or more data lines of the bus segment to determine whether the field device processor affected the one or more data lines of the bus segment;
- detect a potential field device fault when the reading taken of the one or more data lines of the bus segment indicates that the field device processor did not affect the one or more data lines of the bus segment;
- and
- upon detection of the potential field device fault, sever the communication link provided by the field interface with the bus segment prior to concluding that the field device is faulty.
Dependencies are inferred from the claim text.