Technological and manufacturing processes are sources of the initial data for multichannel sensor systems. The data are received by a control system as random processes of parameter variations and in the form of random events.
Multichannel data acquisition systems are intended for the transformation of the initial parameters of processes and events (output signals from one or several sensors and transducers) into equivalent digital signals, suitable for further processing, transferring and input into a central computer, which controls the channeling data acquisition and forms data arrays for further display or its use in control systems. Modern data acquisition systems are able to handle practically all physical and chemical quantities, due to the wide variety of frequency–time-domain sensors and transducers.
Methods of data acquisition depend on solved tasks of control and measurement and directly influence the structure and functionalities of multichannel data acquisition systems.
A modern measurement and control sensor system could be set up in different ways. A central computer is connected to a number of input (sensors) and output (actuators) devices. In such systems, many frequency–time-domain sensors pick up information about process-related measurands.
Two traditional methods of data acquisition are widely used in modern automatic control and measuring systems. These are: