The Development Of PROFIBUS-PA Bus Pressure Gauges And The Research Of Key Techniques

Rapid development in industrial automation technology leads to further application ofintelligent devices in field bus control system, therefore PROFIBUS-PA, as a member ofPROFIBUS, has a great advantage in the process control. In this paper, a PROFIBUS-PAbus pressure meter has been developed based on deep research of PROFIBUS-PAtechnology. The development of PROFIBUS-PA bus pressure meter makes a major advanceon PA research in China and considerable practical engineering value.PROFIBUS-PA bus pressure meter has the virtue of good accuracy, low-powerconsumption and safety compared with traditional pressure meter. This paper firstintroduces PA technology, and then describes the design of PA pressure meter in detail,including microprocessor, sensor, A/D converter, temperature measurer, LCD display unit,and PA communicator, following by demonstrating the program initialization file, the PAcommunication, device description of GSD and EDD files, and applying anti-interferencein hardware and software.This paper proposes various key technologies like nonlinear correction, temperaturecompensation, circuit safety, and PA profile.The calculation of temperature and pressuresensor output as variables with output pressure signal from quadratic polynomialreconstruction sensor by least square measurement has accomplished nonlinear correction,temperature compensation and improving system accuracy. In order to meetthe requirement of intrinsic safety,system uses SIM1-2modulation and demodulation chipfor security. Design and debug the circuit and solve bus power supply of SIM1-2afterfurther study of the SIM1-2. At the same time,find the chip burning is caused byself-excited oscillation of SIM1-2peripheral circuit due to measurement or false operation;discuss the rules of PA profile and present selection method of compact module pressuremeter, And corresponding rules are established for pressure meter.An experimental environment is established to test bus power supply andcommunication protocol of pressure meter. After meet the certification test conditions, toapply for the ID number of the equipment, test conformance and interoperability ininstrumentation technology and economic institute PROFIBUS-PA testing laboratory.Aseries of experiments turn out that PROFIBUS-PA pressure meter successfully passed the certification test profile version3.02.