AD/DA Converters:   AD/DA Converters is a device that converts a continuous physical quantity (usually voltage) to a digital number that represents the quantity's amplitude. Simply put: changes analog voltage to ones and zeros.  Converters can be just A/D (Analog to Digital), D/A (Digital to Analog) and both.  They can also range from a minimum of 2 Channels up to 16 Channels in most cases.