MODBUS is a serial communication protocol use in industry, which developed by Modicon in 1979. The most common usage of the MODBUS communication protocol is the Programmable Logic Controllers (PLC). The aim of this study is to develop a system for acquiring and analyze measured values from the power measuring device and display them on C# developed GUI. The main objective is to develop an algorithm for MODBUS RTU communication protocol for data acquisition process. In this study, a single power measuring device was used with the aid of MODBUS RTU and RS-485 communication protocols, and data shown in the device was visualized on the C# developed GUI application and analyze them according to the user’s requirement. Data acquisitions from the holding registers were made by using the MODBUS Function Code three. The test results were observed and verified accuracy by performing several trials. Data was collected from the power measuring device which was attached to the industrial soft starter panel of a milling machine. Voltage, Current, Total Harmonic Distortion and Power Factor for each phase were retrieved to the C# devolved computer application and verify results with the real-time data of the power measuring device.

Keywords : MODBUS, RTU, C#, Serial Port Communication, Microcontroller, PLC, RS-485, GUI, Remote Monitoring