Design and Development of Embedded Networked Wireless Digital Controller for Multiple Plants using Bit-Representation Data Formation
Kritapras Mee-im, Santi Nuratch, Wanchak Lenwari · 2019
This paper proposes some powerful techniques to design and development data packages used for multiple plants embedded wireless digital controller. The system performs data exchanging using master-slave topology, the common one in industrial automation systems. The master and slaves are implemented on low-cost IoT-supported 32-bit microcontroller. The Free-RTOS is used as real-time operating system. All drivers of the master and slave controllers are implemented using C language and mainly preforms bitwise operations to obtain the speed and efficiency of the code execution. The plants used in this research are brushed dc-motors driven by PWM-based bidirectional H-bridge drivers. There are four types of the data packages are proposed. The data packages are designed using bit-representation data formation techniques. The data package design technique requires only one byte for the package header. It can reduce numbers of bytes of data exchanged over network. To archive the real-time control and monitoring capabilities of the system, the WebSockets protocol is selected implemented in all devices, master, slaves and computer. In addition, the proposed system is also evaluated on other protocols, the HTTP and MQTT. The experimental results show that the proposed techniques, system design and data package design, can perform on all communication protocols, no package loss. Using the WebSockets as communication protocol can archive the real-time capability of the system. It means that the proposed system can be implemented in real-world applications, the industrial real-time control monitoring and control systems.