Daniel B. Cardinal
Highly productive manufacturing processes rely on standard, controller-based system applications. These applications must appeal to the technicians and engineers who will need to understand, interact, and support functioning programs whether they’re independent or interdependent programming strategies.
Control circuits will always appear chaotic to support personnel. This is especially true when manufacturers task them with supporting various applications from different machine suppliers. Understanding the number of circuits that designers use and the way they are configured can provide clarity to users.
Machine events are typically mechanism movements, standalone external processes, or special application executions, and the length of a movement bar represents the allotted time a mechanism has to travel between two physical positions.
A support-focused control system must have the ability to enable control system designers to model conveyor applications by providing an object-oriented chart design environment that can enhance the ability of support personnel to monitor and interact with a conveyor control application.
A trigger-first design strategy enables manufacturers to obtain structured and organized control applications from many independent machine and conveyor suppliers. This method creates a common path for designs to trigger applications while enabling a standard way to develop rule-, template-, and table-based control applications.
Inside Machines: To document speed transition points, designers remove the aspect of time and adopt sensor activation charts. These charts purposely convey an object’s station-specific movement information to control system designers. The bars found on sensor activation charts represent the length of actuators or the distance objects travel while not activating a sensor.
Control applications developed for conveyors often adopt operating modes specific to each area. Area modes are usually a local segment, zone, sector, or multistation conveyor process. Operating modes are specific to enabling the machine, process, or mechanism to cycle, while support modes are operational characteristics that enhance user interactions and enable overall station or process control modes.
Controller manufacturers have made significant enhancements to controller programming environments. Today, programmers are using generic tag names to describe ladder logic instructions, simplifying programming, and making it easier to convert design information to control programming. Link to other parts of the support-focused enterprise controls series below.
PLC programs do not behave like scripted language programs used by most computer applications. A basic understanding of control application fundamentals is crucial for designing an effective support-focused system. This section of the article provides strategists with the rudimentary knowledge needed to recognize programming instructions, terms, logic circuits, and more. Link to parts 1, 2, and 3, below.
Upper-level system applications rely on movement detection circuits to produce dependable triggers when objects enter, stop in position, and exit process stations. This is part 3 in a series on standardizing development of programmable logic controller (PLC) programming for controlling discrete manufacturing processes. See 5 ways to arm a sensing trigger. Link to part 1 and 2, below.