Data acquisition is the process of measuring an electrical or physical phenomenon such as load, pressure, torque, voltage, current, temperature, pressure, or sound with a computer. A Data acquisition system consists of sensors, measurement hardware, and a computer with programmable software. Compared to traditional measurement systems, PC-based Data acquisition systems exploit the processing power, productivity, display, and connectivity capabilities of industry-standard computers providing a more powerful, flexible, and cost-effective measurement solution.
A Data Acquisition System is comprised of three parts; an I/O sub-system, a host computer and the controlling software. However, some systems, such as the Power DNA Cube running a standalone Linux application combine the I/O sub-system and the host CPU in the same package. These systems are often referred to as embedded DAQ systems.
Standard systems with a separate host computer and I/O system require a method to communicate with each other. The most common Data Acquisition System interfaces are the PCI bus, PXI bus, Ethernet, USB and Serial I/O. However there are systems based on many other architectures including GPIB, CAN bus, Fire wire (IEEE-1394), PCI Express as well as many legacy bus architectures including VME, Multi Bus, ISA bus, NU Bus and many more.
Function of data acquisition system:
Data acquisition and conversion systems are used to acquire analog signals from one or more sources and convert these signals into digital form for analysis or transmission by end devices such as digital computers, recorders, or communications networks. The analog signal inputs to data acquisition systems are most often generated from sensors and transducers which convert real-world parameters such as pressure, temperature, stress or strain, flow, etc., into equivalent electrical signals. The electrically equivalent signals are then converted by the data acquisition system and are then utilized by the end devices in digital form. The ability of the electronic system to preserve signal accuracy and integrity is the main measure of the quality of the system.