The Kepco Series SN 488 and SN 500 Digital Programmers make it possible to control the output of a suitable power supply by means of digital input signals. The SN Programmer is used as the interface between a digital data bus and the d-c power supply to be programmed. The SN programmers accept digital data from the data bus and convert this data to an analog voltage output, which serves as the control signal input for the d-c power supply (See Fig. 1-2). In response to the control signal, the d-c power supply is programmed to the magnitude initially commanded by the data bus controller.