State machine function block with user-definable actions on a transition between states

A method of operating a state machine function block (SMFB) associated with a process plant, the SMFB executed by a controller and implementing a state machine having a transition table and a current state, the method comprising:

• receiving, by the controller from a first function block associated with the process plant, an input for the state machine, the input indicative of a condition within the process plant;
• identifying, by the controller from the transition table based on the current state and the input, a next state, a transition-out action associated with the current state, and a transition-in action associated with the next state, wherein the transition-in action and the transition-out action are identified from transition action data that is associated with an input/state pair of the transition table, wherein the input/state pair (i) is displayed, by a display device, with the transition action data in a graphical user interface, and (ii) corresponds to the input for the state machine and the current state;
• retrieving, from a database, a first set of executable logic associated with the transition-out action;
• executing, by the controller, the first set of executable logic to cause at least one of a first field device of the process plant and a workstation of the process plant to perform a first function associated with the transition-out action;
• after executing the first set of executable logic:
• retrieving, from the database, a second set of executable logic associated with the transition-in action, and
• executing, by the controller, the second set of executable logic to cause performance of a second function associated with the transition-in action;
• after executing the second set of executable logic, setting, by the controller, the current state of the state machine to the next state;
• and
• upon setting the current state of the state machine, providing, by the controller, a function block output to a second function block for use in controlling a second field device of the process plant, wherein the function block output is based on the current state of the state machine.