Steam Net Simulation with Real Control System

Abstract: This master thesis has been conducted for Solvina. Solvina is a firm in Gothenburg, which among other things simulates steam nets for the paper process industry. Doing this Solvina has had to simulate not only the steam net itself, but also to simulate the control system. The purpose of this master thesis was to try to build an interface between the controller and the simulated process so that the simulated steam net could be controlled by the real control system. The process is modelled in Dymola/Modelica. The control system is built in Siemens process control system called Simatic PCS 7 and runs on a PC. The simulated process and the control system run on the same PC and the communication between the process and the control system is a communication between two applications running on the same operative system, which is Windows NT. The two applications communicate with each other by reading from and writing to a common file. The simulated process in Dymola calls a C++ function that reads the control signals from the file and writes the process values to the file, every sampling time. A J++ program communicates with the control system and writes the control signals to the file and reads the process values from the file, every sampling time. The communication is synchronized and the applications access the file using mutual exclusion.