Design and Engineering Application of Water Leakage Monitoring System for Hydropower Station Computer Room Based on Modbus RTU Protocol Conversion

To address the water-leakage risks in the computer room of hydropower stations, a distributed water-leakage monitoring system based on the resistance measurement principle is proposed. At the sensing layer, conductive-rubber sensing cables together with Leaksense ATL700 locating modules provide continuous coverage; the equivalent circuit model of the detection loop is consistent with the positioning method implemented in the device, where the leak distance equals the loop resistance divided by the cable resistance per unit length. At the data layer, an RS-485 bus and an SJ30 protocol converter bridge the Modbus RTU field bus to the existing supervisory platform. Grounding optimization combined with parameter tuning suppresses false alarms caused by electrostatic interference, and an interval mapping model between physical floor tiles and logical meter readings, together with a proved uniqueness condition, realizes low-cost precise positioning. Field application and simulated leakage tests show that the positioning error is within ±0.3 m, which agrees with the device accuracy specification of 2% of the cable length, and the average fault-locating time drops from 20 min to less than 5 min.