Process control network with redundant field devices and buses

A process control system that performs process control functions within a process in a distributed manner including:

• a communication bus that performs a communication process function in the process;
• a plurality of devices communicatively linked over the communication bus, wherein each of the devices performs a different process function within the process;
• a pair of redundant elements including a primary redundant element and a secondary redundant element that are adapted to perform the same process function within the process;
• and
• a controller coupled to the pair of redundant elements to detect a failure of one of the redundant elements and to operationally connect the other of the redundant elements in the process control system upon detection of the failure of the one of the redundant elements;
• wherein the primary redundant element comprises the communication bus and the secondary redundant element comprises a further communication bus.

A process control system that performs process control functions within a process in a distributed manner including:

• a communication bus that performs a communication process function in the process;
• a plurality of devices communicatively linked over the communication bus, wherein each of the devices performs a different process function within the process;
• a pair of redundant elements including a primary redundant element and a secondary redundant element that are adapted to perform the same process function within the process;
• and
• a controller coupled to the pair of redundant elements to detect a failure of one of the redundant elements and to operationally connect the other of the redundant elements in the process control system upon detection of the failure of the one of the redundant elements;
• wherein the primary redundant element comprises a first function block that performs a particular process function and the secondary redundant element comprises a second function block that performs the particular process function.

A process control system that performs process control functions within a process in a distributed manner including:

• a communication bus that performs a communication process function in the process;
• a plurality of devices communicatively linked over the communication bus, wherein each of the devices performs a different process function within the process;
• a pair of redundant elements including a primary redundant element and a secondary redundant element that are adapted to perform the same process function within the process;
• and
• a controller coupled to the pair of redundant elements to detect a failure of one of the redundant elements and to operationally connect the other of the redundant elements in the process control system upon detection of the failure of the one of the redundant elements;
• wherein the primary redundant element comprises a loop including the communication bus connected to one of the devices and the secondary redundant element comprises a redundant loop including a redundant communication bus connected to a redundant device.

A process control system that performs process control functions within a process in a distributed manner including:

• a communication bus that performs a communication process function in the process;
• a plurality of devices communicatively linked over the communication bus, wherein each of the devices performs a different process function within the process;
• a pair of redundant elements including a primary redundant element and a secondary redundant element that are adapted to perform the same process function within the process;
• a controller coupled to the pair of redundant elements to detect a failure of one of the redundant elements and to operationally connect the other of the redundant elements in the process control system upon detection of the failure of the one of the redundant elements;
• and
• a control logic operating in a functional element associated with the pair of redundant elements, the control logic adapted to detect an operational status of one of the redundant elements and to communicate the operational status to the controller.

A process control system that performs process control functions within a process in a distributed manner including:

• a communication bus that performs a communication process function in the process;
• a plurality of devices communicatively linked over the communication bus, wherein each of the devices performs a different process function within the process;
• a pair of redundant elements including a primary redundant element and a secondary redundant element that are adapted to perform the same process function within the process;
• and
• a controller coupled to the pair of redundant elements to detect a failure of one of the redundant elements and to operationally connect the other of the redundant elements in the process control system upon detection of the failure of the one of the redundant elements;
• wherein the controller includes a detector that detects the termination of communications from one of the pair of redundant elements to detect the failure of the one of the pair of redundant elements.

A process control system comprising:

• a loop controller including a control logic implementing a two-wire, two-way, loop-powered digital communication protocol;
• a redundant pair of two-way communication busses coupled to the loop controller including a primary communication bus and a redundant communication bus;
• and
• a plurality of devices coupled to the redundant pair of two-way communication busses;
• wherein the controller is adapted to detect a failure associated with one of the redundant pair of busses and to operationally connect the other of the redundant pair of busses in the process control system upon detection of the failure of the one of the redundant pair of busses.

A process control system comprising:

• a loop controller including a control logic implementing a two-wire, two-way, loop-powered digital communication protocol;
• a two-way communication loop coupled to the loop controller;
• and
• a redundant pair of functional elements including a primary functional element coupled to the communication loop and a redundant functional element coupled to the communication loop;
• wherein the loop controller is adapted to detect a failure associated with one of the redundant pair of functional elements via the two-way communication loop and to operationally connect the other of the functional elements in the process control system upon detection of the failure of the one of the functional elements.

A method of configuring a process control system that performs process control functions in a process in a distributed manner, the method including the steps of:

• providing a communication bus that performs a communication process function in the process control system;
• communicatively connecting a plurality of devices over the communication bus such that each of the devices performs a different process function within the process;
• using a pair of redundant elements including a primary redundant element and a secondary redundant element within the process to perform the same process function;
• and
• using the communication bus to detect a failure of one of the redundant elements;
• and
• operationally connecting the other of the redundant elements in the process control system in response to the failure of the one of the redundant elements.

A method of configuring a process control system that performs process control functions in a process in a distributed manner, the method including the steps of:

• providing a communication bus that performs a communication process function in the process control system;
• communicatively connecting a plurality of devices over the communication bus such that each of the devices performs a different process function within the process;
• using a pair of redundant elements including a primary redundant element and a secondary redundant element within the process to perform the same process function;
• and
• detecting a failure of one of the redundant elements;
• and
• operationally connecting the other of the redundant elements in the process control system in response to the failure of the one of the redundant elements;
• wherein the primary redundant element comprises a first function block that performs a particular process function and the secondary redundant element comprises a second function block that performs the particular process function and further including the step of alternatively communicatively coupling either the first or the second function block within a process control loop of the process.