| The application of a hydrological telemetering system is to automatically collect related data, monitor hydrological information,do analsis on a computer basis,grasp in a comprehensive manner a water regime development trend,release a flood disaster forcast in advance, delivery from top down a dispatch and command in case of a flood control so as to provide decision-making reference and information services for the prevention and reduction of flood disasters as well as the flood control management,guarantee the human life and people's property and minimize the loss in floods. Being the core of a hydrological telemetering system,the RTU (Remote Terminal Unit) plays an important role in many aspects such as informatization of water resources and hydropower flood control and disaster reduction for urban area and drainage basin rational use and development of water resources and management and dispatch of reserviors in a scientific and optimised way.Based on the analysis on the functional demands and the technical indicators, this paper illustrates an overall structural design for multifunctional RTU (Remote Terminal Unit). It mainly includes multi-channel communication access, multi-sensor access and storage & control. The Chapter 3 Multi-channel Communication and Multi-sensor Access proposes a design scheme of MSTP protocol, which is a kind of protocol for RTU data communicating with center station via VHF, Inmarsat-C, GSM, BDStar and PSTN. In the Chapter 3, the design of a multi-function sensor involves a mature sensor art in terms of water level, precipitation, discharge and weather that are connected with various accesses (4-20mA, RS485, SDI-12 and RS232) and different types of sensors (pressure, supersonic, float and bulb). The concept of front/rear double CPUs is adopted in the design of RTU. The front RTU requires a low consumption of power, mainly responsible for attendant, recording of number of rain, data acquisition by previous traditional sensors and energizing or power off with rear CPU. The rear CPU adopts a mode of power off once the operation completion, which needs a high capacity, fruitful functions and high speed processing, mainly responsible of handling all the activities beyond the responsible scope of front CPU including communication of multi-channel, data acquisition by means of new type sensor, storage and control. Since the Remote Terminal Unit is long–term used in the field dominantly under a non-attendant situation, this paper describes a special distinctive methodology incorporating double SSD, Solid State Disk, modular architectural design, redundant backup, prevention of computer crash and running out, electromagnetic compatibility, lightning protection, low power consumption so as to make sure that the RTU is capable of keeping a long time operation free of trouble under the terrible circumstances in the field.According to the design aforesaid, this paper gives the introduction of the sample product of YCZ-2000 RTU (the front CPU PIC16C73 from the Microchip Company of America and the rear CPU RCM2300 from Z-world company). This RTU incorporates many functions together: telemetering, storage, manual set data and communication, etc., showing a feature of three multi-s and three doubles (multi-channel communication, multi-sensor access and multi work system, double SSD, double CPU and double watchdog). This RTU has a standardized design with good adaptability in terms of technical indicators, function, device access, communication protocol, and interface standard. The creative highlight of this paper is double-solid storage and double-watchdog techniques, which improves the reliability of RTU and takes a lead in the same line of domestic products. This sample product has experienced the procedure of prototype test, and been proofed by actual practices in the large, medium and mini-type hydropower projects. The application of this kind of RTU has won wonderful social and economic benefits. |
PDF Full Text Request