State logic
Encyclopedia
A state logic control system is a programming method created for PLC
s.
A state logic control system uses a state transition diagram
as a model of reality, thus using the fundamentals of finite-state machine theory as the basis of a programming language
. State logic enables users to model the application they are trying to control by using a hierarchy that consists of Tasks, subdivided by States which are described by Statements.
'Tasks' are a description of a sequential activity of the model. The machines, applications or processes being modelled by state logic will usually contain more than one 'task', representing several different and possibly parallel activities. Each of these activities will contain a given number of 'states'. As in finite-state machine theory, only one 'state' will be active at a time, and certain inputs and outputs will cause the transition between different states.
Given that PLCs usually control systems which are easily represented by a state transition diagram, the use of a very high-level programming language
such as state logic greatly helps the PLC programmer in making intuitive control programs.
Programmable logic controller
A programmable logic controller or programmable controller is a digital computer used for automation of electromechanical processes, such as control of machinery on factory assembly lines, amusement rides, or light fixtures. PLCs are used in many industries and machines...
s.
A state logic control system uses a state transition diagram
State diagram
A state diagram is a type of diagram used in computer science and related fields to describe the behavior of systems. State diagrams require that the system described is composed of a finite number of states; sometimes, this is indeed the case, while at other times this is a reasonable abstraction...
as a model of reality, thus using the fundamentals of finite-state machine theory as the basis of a programming language
Programming language
A programming language is an artificial language designed to communicate instructions to a machine, particularly a computer. Programming languages can be used to create programs that control the behavior of a machine and/or to express algorithms precisely....
. State logic enables users to model the application they are trying to control by using a hierarchy that consists of Tasks, subdivided by States which are described by Statements.
'Tasks' are a description of a sequential activity of the model. The machines, applications or processes being modelled by state logic will usually contain more than one 'task', representing several different and possibly parallel activities. Each of these activities will contain a given number of 'states'. As in finite-state machine theory, only one 'state' will be active at a time, and certain inputs and outputs will cause the transition between different states.
Given that PLCs usually control systems which are easily represented by a state transition diagram, the use of a very high-level programming language
Very high-level programming language
A very high-level programming language is a programming language with a very high level of abstraction, used primarily as a professional programmer productivity tool....
such as state logic greatly helps the PLC programmer in making intuitive control programs.