The Research Of Smart Transducer Based On Foundation Fieldbus

A smart multi-parameter fieldbus transducer based on FF protocol is developed, in order to reduce the gap between the international leading level and our own in instrumentation products.A two-processor architecture is designed as the overall scheme of the fieldbus transducer developed. The development and implementation of the scheme is comprised of two parts, the development of fieldbus round card and the implementation of device card. The main work of the first part is development of round card user applications (viz. Function Block) via FF Fieldbus developing kits produced by NI company. The design of device card is divided into two components: hardware and software. In the hardware design, sensors and chips are selected. Then the circuit is designed according to the low power-consumed principle. The functional routines such as A/D conversion, data processing, display with LCD and serial communication are programmed in the software design. The signals from the sensing elements of differential pressure, pressure and temperatureare conditioned and computed by the device card. The data processed are passed to the round card. Information is transferred between the two cards via serial communication. Then the round card accomplishes communication to the fieldbus. By means of that the smart transducer realizes the basic functions of fieldbus device.A creative way of how to develop a fieldbus device is brought up through the transducer research. The conclusions are valuable and practical to the development and production of the fieldbus devices.