Abstract : This paper describes the composition, function, and design method of each functional module of a constant pressure water supply system based on PIE and frequency converter control. The developed computer monitoring software, through the communication function of the PIE, realizes remote monitoring of the water supply system, improving the automation level and management efficiency of the system. Keywords : Water supply; PIE; Frequency converter; Communication; Remote monitoring Traditional community water supply methods, such as constant speed pump pressurization and elevated water tank supply, generally suffer from low efficiency, high energy consumption, low automation, poor reliability, and heavy system maintenance workload. Based on the water demand of a school, this paper designs a fully automatic variable frequency constant pressure water supply system, which effectively solves the above problems. Utilizing the communication function of the PLC and the developed host computer monitoring software, remote monitoring of the water supply status can be effectively achieved. 1. Hardware Design of Constant Pressure Water Supply System The water consumption of a certain school exhibits a continuous low-flow variation pattern. The design employs a parallel water supply system with multiple pumps. This system consists of multiple pump units and a single frequency converter. The number of pumps in operation is adjusted according to water consumption, and water pressure is maintained across the entire flow range using a combination of continuous regulation by the frequency converter and staged regulation by the fixed-frequency pump. This system features energy saving, reliability, and convenient maintenance. A small-flow auxiliary pump is also included to maintain normal leakage and water pressure during off-peak hours or nighttime low flow periods. Reliable switching of the pump's cyclic operation mode is controlled by a Mitsubishi FX2N-32MR PLC. Constant pressure control of the water supply system is achieved through a closed-loop control system composed of a pressure transmitter, PID controller, and frequency converter. Combined with signals from water level detection and motor fault detection, the overall structure of the water supply system is shown in Figure 1. [b][align=center]For more details, please click: Design of Fully Automatic Variable Frequency Speed ​​Regulation Constant Pressure Water Supply and its Remote Monitoring System[/align][/b]