Direct Control of Process Equipment’s in a Distributed Control System

Abstract

Distributed control systems (DCS) are employed in complex process control systems for monitoring, supervision, setpoint control and direct equipment control. In this project we concentrate on direct equipment control using a general purpose data acquisition module. A software program with a graphical user interface (GUI) is designed using Visual Basic in .Net environment that involve three processes. Monitoring textboxes, setpoint spin controls and checkboxlbutton based direct equipment control is accomplished in the GUI design. Control signals from the GUI program are sent to the process equipments using an Advantech USB-4711A DAQ module. Signals from the DAQ module are optically isolated and ON/OFF signals are passed to the process equipments through relay interface. The proposed technique of using general purpose DAQ hardware as a control device is supposed to be new in the era of DCS. The system is tested in the laboratory and is found to work satisfactorily.