PC-Based Data Acquisition using PCL-208

Abstract

DAQ (Data AcQuisition) is simply the process of bringing a real-world signal, such as avoltage, into the computer, for processing, analysis, storage or other data manipulation. A Physical phenomena represents the real-world signal you are trying to measure. In order to optimize the characteristics of a system in terms of performance, handling
capacity and cost, the relevant subsystem can be combined together. Analog data is generally acquired and transformed into the digital form for the purpose of processing, transmission and display. Rapid advances in Personal Computer (PC) hardware and software technologies have resulted in easy and efficient adoption of PCs in various precise measurement and complex control applications. A PC based measurement or control application requires conversion of real world analog signal into digital format and transfer of digitized data into the PC. A data
acquisition system that performs conversion of analog signal to digital data and the digital data to analog signal is interfaced to a pc to implement the functions of a measurement and control instrumentation applications. In this project we have used the electromagnetic sensor to acquire the data of a magnetic disk angular velocity, which we have got in mili volts range. This has been further transformed approximately into the range of 5 volt by using an operational amplifier of suitable gain (~30)and then rectified .We then transformed the analog voltage into digital by using ADC 0804 and the processing part is done by using ATMEL89c51.In the second phase we have used the data acquisition card PCL-208 and 207 to interface the amplified output to PC by the help TURBO C (C compiler).