Digital I/O devices process digital signals (e.g., outputs from a controller) and output the results in digital format. A digital I/O module has both input and output functionality and is used for data acquisition. A digital I/O module includes on-off signals used in communication, user interface, or control. USB digital I/O can act as an alternative to acquisition and transmission of digital signals through PCI or ISA boards. It provides integrated signal conditioning, reduction in wiring/cabling requirements and ease of installation. A digital I/O board is a specially made device for automation and control of industrial equipment, and is usually used in machine vision and automation applications. A digital I/O card is a data acquisition card that has both digital inputs and outputs. Other digital I/O devices are commonly available.