Digital to Analog converter (hardware) or a setting value for a device (software). The hardware is a unit which accepts a number from the control system (binary encoded) and converts it to a corresponding output voltage. Such a device is the complement of an A/D converter. In many instances the output is used to program the output of a power supply... Found on http://www-bdnew.fnal.gov/operations/accgloss/gloss.html#A