Continuous testing as a strategy of improving the PLC software development cycles

An appropriate simulation environment for testing real-time software applications, especially PLC (programmable logic controller) programs, is in demand for many reasons. One of the them might be found in the altered conditions of cooperation (teamwork, teleworking, etc.) under which PLC software projects have to be carried out. Most areas of automation engineering lack largely formalizable procedures, in particular within the specification and testing phase, and almost no tools are available for the development of real-time software. The consequence is that PLC programs are usually not developed before the facility to be controlled is installed, and putting it into operation is often the only test. This results in unacceptable waste of time during the installation phase, unacceptable high risks, and unacceptable high costs of the outcome. The availability of simulation tools including real-time hardware and software platforms open interesting perspectives pertaining to an integrated approach of analysis and design of PLC programs and the corresponding testing environments.