The paper introduces the method concerning resolving the remote waste water measurement and management issues occurring in each workshop of China Petrochemical Co.Ltd Wuhan Branch through network communication. The 940 Intrinsically Safe Flow Meter is to measure the wastewater and the flow meter signal is transferred to the workshops by serial passive transceiver. The flow meter possesses the function of real time response, remote management and data access ability with installing the port server in workshops. Data acquisition, analysis, save and LAN inner release of wastewater data could meet the requirements of the plant network system. The essay illustrates the features, structure, work principle of the system, and especially focusing on the passive isolation telemetering network communication based on MODBUS communication protocol. The system has been confirmed to be stable during the operation for two years and the system has achieved the good reputation from the clients.