ASD-B2-0121-B-AC SERVO DRIVE .1KW 220S B2 6.THE ASD-B2-0121-B-AC SERVO DRIVE.The 1KW 220S B2 6 is a precise and economical servo drive designed for industrial automation. With its 0.1 kilowatt power rating and superior AC servo technology, it provides smooth motion control for a variety of motor types.