The Design And Implementation Of Multi Channel Embedded Data Acquisition Device

The key rotary devices are the central unit of steel and chemical industrial enterprises. Itsrunning state and maintenance condition are most important for production and operation. Theon-line status supervisory systems are adopted to monitor and measure the operatingcondition of mechanical devices real time, and to prevent high risk state operation ofequipment and emergency accidents, which is helpful to safety operation of equipments andorganization scheduling of production. Data acquisition device is the core of the on-line statussupervisory systems because its performance directly determines the real time and accuracy ofthe systems.Data acquisition device can be used to measure the vibration, axial displacement,temperature and other parameters of key rotary devices, which are transmitted to server sidemonitoring station for fault early warning and diagnosis for monitoring software of the hostcomputer.According to the above information, a kind of multi-channel embedded data acquisitiondevice which can realize multi-sensor signal acquisition is designed in this paper. Weanalyzed the function of data acquisition device and the system structure from the systempoint of view. The common output signal types of sensor include voltage and current, whichcan be compatible with data acquisition device Then the types of signal are chosen by dataacquisition device, and the input analog signal is tuned by circuit, which can meet signalamplitude, frequency and other requirments of back-end circuit of the data acquisition device.The tuned sensor signal is transmitted to24-channel selection circuit of the data acquisitiondevice to perform channel selection, and then it is sent to A/D (analog-to-digital) convertercircuit to convert the analog signals to digital signals. Then the data are collected by the maincontroller of the system, and packed with TCP/IP protocol and uploaded to server via Ethernetwhen the data acquisition device receivers the collection command from server sidemonitoring station.The data acquisition device in this paper is mainly including the multi-channel plate,multi-channel data acquisition control board, backplane circuitry, power supply, etc. Thispaper discusses the design and implementation of a data acquisition device from three aspects.Firstly, a multi-channel plate is designed to perform functions such as the signal type selection,programmable amplifier and programmable filters. Then, main control board of dataacquisition is designed, and mainly fulfills choosing the input signal channels, analog-digitalconversion, and then data are collected, packed and transmitted to the server side monitoringstation by the embedded microprocessor. Finally, the backplane circuitry and the power supply of the data acquisition device are designed, where the backplane circuitry is used toperform connect function among channel board, main control board and power panel, andpower supply circuit can provide power to data acquisition device.