In general, PC data acquisition is data acquisition from a board or card designed to interface with a personal computer. These boards can be configured to work in a wide variety of configurations including the installation in PCI, ISA or PCMCIA slots. Typical data acquisition products include analog I/O, analog output, digital I/O and serial communications boards that are designed to interface with the bus of a personal computer.
When a PC data acquisition board or card is installed in a personal computer, a wide variety of test automation, measurement, and control applications can be accomplished.
A PC data acquisition system can convert analog signals into a digital output form, which can be manipulated with software. Using software in conjunction with a personal computer, analog data can be displayed, logged, charted, graphed, or stored in memory as needed.
Stored data can later be used and compared with a set of established limits. Control decisions are made if the stored data is at the limit, above or below the limit. With repetitive measurement made by a PC data acquisition system, continuous monitoring and control can be performed.
Based on matching, meeting or exceeding the set limits, a digital control signal (in the form of a single-bit output signal) can be used to turn on or turn off a relay. This in turn can be used to turn on various control elements like fans, pumps, motors, etc.
Alternatively, based on the difference between an input and an established set point, a precise analog output signal can be generated. This signal can be used to provide a complete closed loop control patch, providing continuous control of a process.
