This research is a continuation of several previous researches to make a power measuring instrument to support research in the laboratory. One result of these previous researches is the "Microcontroller-based Digital Wattmeter". This instrument can measure the values of electrical quantities in the grid such as the frequency of the voltage, True RMS of voltage and current, power and power factor.
In this research, we add a data-logger on Digital Wattmeter so that the instrument can send all data to the computer ten times per second. We have also made a special software on the computer to receive the data. Data stored on the array in integer format. A special algorithm will make a chart of the value of the frequency of the voltage, RMS voltage, RMS current, power and power factor on a computer screen. This software can save and print data in numerical and graphical formats.
This software has been able to work properly. The results of software testing have proven that this software can be used easily, and this microcontroller-based system is ready to be used to support some researches in the laboratory.