SPC processors and multiplexers are small, box-shaped units that transmit data from precision measuring tools to a personal computer. Multiplexers have one or many connection ports for data output cables that are connected to tools. Portable printers (mini-processors) are connected to measuring tools and print a paper record of measurements and data. SPC software programs require a license to use. Licenses are obtained in the form of a disc, drive, or downloaded. These software programs provide insight into accuracy, error, efficiency, and potential trouble spots in addition to normal record keeping and data logging. These units are commonly used in light and heavy manufacturing industries as well as other industries where constant monitoring and measuring is necessary.