Research And Design Of Digital Communication System For Mixed-Mode Interface Sensors

For a large testing system,in order to facilitate system maintenance,it needs to reduce the number of system bus,simplify wiring and save more system space,because of numerous sensors.If the sensors in the testing system has the ability of self recognition and self calibration,it can bring great convenience to the connection and maintenance,and dramatically improve the connection efficiency.Therefore,the National Institute of Standards and Technology(NIST) and the Institute of Electrical and Electronic Engineers(IEEE) establish the IEEE1451 series standard for the general sensor communication interface in September 1993.The sensor interface standard has an important significance for developing news sensor and reforming the troditional sensors.IEEE1451 series standard is composed of IEEE1541.0~IEEE1451.6 seven substandards. IEEE1451.4 standard defines a mixed-mode interface for traditional analog sensors,including mixed-mode interface sensor model, transducer electronic data sheet(TEDS) and two types of mixed-mode interface. IEEE1451.4 sensor's communication is based on the 1-Wire bus technology.It takes a single line responsible for the control signal and data transmission and to provide current to equipment.The communication in the 1-Wire bus is bidirectional.The 1-Wire bus has the ability of taking multiple 1-Wire equipment.The DS2430A is a typical 256 bits 1-Wire EEPROM.It can be used to store the TEDS information of the mixed-mode interface sensor and communicate with the computer.A digital communication system for mixed-mode interface sensors is researched and designed.It is in the basis of IEEE1451.4 standard and 1-Wire bus technology,taking the traditional IEPE accelerometer for example.The 1-Wire storage device DS2430A is embeded in the traditional IEPE acceleration sensor in the digital communication system.The DS9097U-E25, that is an adapter of DALLAS company special for the 1-Wire serial interface,is used to achieve the connection between the DS2430A and the computer RS232 port.The TEDS information's read-write operation is implemented in the LabVIEW platform.Thus,a traditional analog sensor has the ability to recognize and calibrate itself.