CASE tools and interactive process modeling accelerate the software development cycle for refined petroleum storage tank vapor recovery

A petroleum storage tank vapor recovery system is described. The project involves development of many different types of software for different platforms, including multiple programmable logic controller (PLC) code development. The CASE tool allows a structured and efficient approach to the project. It makes possible the design and is useful in the area of documentation. The potential of CASE tools in this application is not fully realized, because of the inherent limitations of the PLC utilizing structured programming. The modeling utilizes very simple electronic spreadsheets and commercial software packages to interface with the PLCs