Abstract
The evolution of the Internet has led to a great influence on the software industry and the development of companies. Recently, networked control systems are widely adopted in industry because of the big facilities provided for plant control. Also, accessing the local control systems and remote telemetry units (RTUs) remotely became a primary requirement. Therefore, this paper presents a method for connecting a PLC (Programmable Logic Controller) to a server and hence to the internet for the sake of remotely access. The work starts with building a local network for interconnecting a PLC with its Ethernet extension, an HMI (Human Machine Interface) touch screen, a supervisory PC, a smartphone, and a hub/switch. After that, the PC is connected to the internet and the server program is updated to get a global network that can be accessed via the internet worldwide without the need for public (real) IP. A web site is designed and used through the PC to reach the PLC system. The HMI touch screen is programmed with SoMachine software provided by Schneider Electric. An Android application is also developed with Java and published in google play of Android smartphones in order to add another means for controlling the PLC control system. PID (Proportional-Derivative-Integral) control algorithm is designed as a function block for home temperature control. The home temperature control is adopted just as a case study to prove the work of the overall control system.
