<![CDATA[The use of conventional measuring instruments in DC motor experiment activities at the laboratory requires a high degree of manual reading precision and has been unable to present integrated information within a unified monitoring platform. This study aims to design and construct an HMI-based electrical parameter monitoring system for DC motor experiments at the Energy Conversion Laboratory of Politeknik Negeri Manado. The developed system integrates a PZEM-017 DC sensor as the measurement device, an Omron CP1E PLC as the central data processor, and an HMI touchscreen as the user visualization medium. RS485 communication with the Modbus RTU protocol is employed between the PZEM-017 sensor and the PLC via the CP1W-CIF11 module, while RS232 via the CP1W-CIF01 module interconnects the PLC with the HMI. The DC motor is supplied with 165 V DC from a variable DC power supply, and loading is performed using one, two, and three indicator lamps, with the three-lamp condition serving as the principal measurement scenario at the DC motor terminals. The monitored electrical parameters encompass voltage, current, and power, all displayed in real-time on the HMI screen. Experimental results demonstrated that the average measurement error for voltage was 0.31%, current was 1.37%, and power was 0.52% relative to a reference digital multimeter. The average HMI response time recorded was 127 ms. This monitoring system is expected to enhance the effectiveness of DC motor practicum activities and support the development of automation-based laboratory facilities.]]>
