Automatic detection of designated controller in a distributed control system using a web client

A system comprising:

• a process;
• a client device comprising a web-based human-machine interface (HMI);
• and
• a distributed control system in networked communication with the client device and the process, wherein the distributed control system is configured to control the process and comprises:
• a plurality of controllers, each comprising a processor, each of the plurality of controllers being configured to:
• receive data from the process from an input/output module,
• provide the data from the process to the web-based HMI of the client device when acting as a designated controller, and
• implement a control algorithm that affects the process when acting as the designated controller;
• and
• a designated controller selection logic hardware module, comprising a processor configured to execute designated controller selection logic, the designated controller selection logic configured to detect an interruption in communication between a previous designated controller and the web-based client, poll each of the plurality of controllers for a response, and select a current designated controller as the controller that responds first to the polling;
• wherein the client device is configured to automatically establish communication with the current designated controller to obtain data from the process.

A tangible, non-transitory, computer-readable medium having instructions encoded thereon, wherein the instructions comprise:

• machine-readable code for determining whether communication between a designated controller and a web-based client is interrupted, wherein the designated controller was previously selected as the designated controller from plurality of controllers of a redundant-controller control system and the designated controller is configured to:
• provide process data from an input/output module to a human-machine interface (HMI) client, and
• implement a control algorithm that affects a result in the redundant-controller control system;
• machine-readable code to poll each of the plurality of controllers for a response upon determining communication between the designated controller and the web-based client is interrupted;
• machine-readable code to identify which of the plurality of controllers responds first to the polling;
• machine-readable code to select the controller that responded first as a new designated controller.