The Research And Development Of An Intelligent Water-level Meter

Water-level meter is generally used in the automatic supervision and control system of water conservancy, rock oil, chemical industry, metallurgy, electric power etc. Based on the abundant experience of domestic and abroad intelligent meters, the meter presented in the paper is designed via advanced microchip, which integrates the functions such as data collection and storage, display and remote communication and can be used in various fluid level and strobe opening scale measurements.According to the request of this subject, we have developed the system hardware and software for the slave device and the inspection software running on the PC. In this paper all of the followings is illustrated detailedly, such as the research on the principles of measurement and its realization, Three means of water-level measurement that are separately based on photo electricity coder, pressure sensor and potentiometer; Selection of the microchip, We choose an advanced integrated SOC(System on Chip) microchip C8051F021 as the main controller; Realization of signal sampling, processing and its conversion in the MCU; Application of highprecision 16 bits ADC CMOS chip--AD7705 in our system, designing its interface with themicrochip and relevant program; Using a trickle charge timekeeping chip DS1302 in the system which can provide time norm and designing of its i/o interface and program; Additionally, a 4~ 20mA current output channel to provide system check-up using AD421. In the system, AD421, AD7705 and the microchip compose SPI bus; To communicate with the master PC, here we use two ways which are separately RS232 and RS485; Moreover, there are alarm unit, keyboard unit, power supply inspection unit and voltage norm providing unit in the system. Based on the hardware, we have finished software in the slave device and supervision software on the master PC. With all of the above, this water-level meter has satisfied all the request of system, settled many problems ever existed in the previous ones and attained high preciseness as a good meter.