Research On Isolated Multi-Channel Data Acquisition And Control Equipment

Accurately data acquisition is the precondition of analyzing process, getting processstate information, and achieving accurate field control. As the continuouslydevelopment of industrial modernization, parallel signal processing has become moreand more popular in the fields of data acquisition and control. Meanwhile, there ishigher and higher requirement of temporal logic for collecting data and of equipmentcontrollability. Although high-performance parallel data acquisition and controlequipment plays a significant role in the current science research and productionprocess, majority of similar equipment in market still has following shortcomings:1) The number of signal sampling channels is limited, generally less than eightchannels,2) Cannot provide the good signal isolation between acquisition channels,unable to overcome input signal interference,3) Limited to the intensity of input signal,it is difficult to realize data acquisition of weak signals.In this thesis after analyzing and referring to the traditional data acquisition devices,according to practical field needs, a design scheme of the isolated multi-channel dataacquisition and control equipment is presented, which follows the design principles ofoperational, reliable and affordable. The lower computer hardware make use of51series microprocessor, CPLD and high-speed optocoupler, the upper computerinterface operational program based on Labview as the development platformseparately. All the software and hardware are developed on the method of modulardesign. This research equipment can realize data acquisition of state variables andanalog threshold comparison result for64-channel isolated parallel input signals. Theequipment also has capability of variable gains on weak signals for data acquisition, ofintelligent control on the precision of response time, comparator thresholds and otherparameters and of file saving of the collecting data.Through the experiments with input man-made signal and control signals of theactual industrial device, complete the function test and analysis of research equipment.The result is consistent with actual data. The test result shows off the equipmentperformance is reliable and stable, with a friendly user interface, which can perfectlymeet the isolated multi-channel data acquisition and control demand at moderate cost.