Abstract: A library manager holds related program fragments, for example, control logic fragments and visualization program fragments sharing the same control variables, in library files. Multiple copies of control logic program fragments are instantiated to develop a control program and of the control variable tags for each copy of the control logic program fragments are renamed to prevent conflicts. At a later time, visualization program fragments related to the control logic program fragments are identified by their common origin in the library manger. The control variables of these visual program fragments may then be automatically renamed by using their library files as a guide. The library files may also hold related non-program information.

Abstract: A development tool for control programs for industrial controllers develops an area-model detailing equipment and phases of operation of the equipment of a controlled process. This area-model is used as a framework for integrating reusable program fragments together into a cohesive control program. The area-model provides a naming convention for otherwise conflicting variables of the reused control components that preserves the identity of the control variables for subsequent programming. The renaming convention may be tracked so that other program portions stored together with the control program fragments in a library of object templates may be interconnected through the same or other editing systems.