Real-Time Data Acquisition And Controlling System Of Organophosphorus In Seawater Based On PIC Microprocessor

In this paper, a real-time multi-channel signal acquisition system for monitoring the organophosphorus in seawater is introduced, including the scheme, design of the system and experimental results.This system works as a virtual instrument. The hardcore controlling the DAQ is PIC microprocessor. Adopting CPLD to switch valves and pumps is easy, stabile and flexible. A preprocessing circuit is designed for analog signal transformation because of large inner impedance of biosensor and bipolar signal. LPF and short circuit ring is used to decrease interference. Microprocessor communicates with supervisory computer through RS232 serial port.Data is processed by the software installed in supervisory computer, which is programmed by LabWindows/CVI. Users can control the system through the visual instrument interface in supervisory computer.The experimental results show that the system can meet the requirement in the stability, accuracy and automation. Now this system has been put into commission.This data acquisition system has good performance and expansibility. It can be used for other kinds of analog signal.