OBJECT-ORIENTED PROGRAMMING METHODOLOGIES FOR HIGH PERFOMANCE LOW COST HMI/PLC SYSTEMS

This paper examines the use of an object–oriented programming methodology to develop PLC and HMI control system configurations. Additionally, it will address the use of database-driven tools and how they be used to configure, manage, and automate object-oriented software programming. An overview is provided for building reusable object libraries; using IEC 1131 object programming for PLCs allows these libraries to be applied to multiple vendor platforms.The following diagram demonstrated the application of Object programming for a typical 2-pump lead/lag sequence:The benefits of using object-based programming techniques will be examined as they pertain to the following:Reduced cost of implementationReduced time for developmentStandardizationReduced startup and debugging timeReduced training costsReduced O&M costsReduced support costs on delivered systemsHow data-base driven development tools can be used to automate much of the HMI/PLC configuration will be demonstrated. These data-base driven tools utilize templates for the object models, which in-turn then provides the framework for generating the object tags, tag attributes and coordinated addressing between the HMI/PLC. This data-base tool and how it can be used to manage an integrated HMI/PLC system is shown in the following figure: