| 摘要 |
PURPOSE: To simplify the whole of a system by interlocking the level adjustment of the digital amplitude value before A/D conversion, by which the level for D/A conversion after summing synthesis of respective digital amplitude values is set to a desired state, and the level adjustment of the analog amplitude value after D/A conversion with each other. CONSTITUTION: Multiplication means 14 which multiply plural digital amplitude values by respective coefficients, an adding means 16 which adds plural digital amplitude values multiplied by coefficients in multiplication means 14, and a conversion means 18 which converts the digital amplitude value added by the adding means 16 to an analog amplitude value are provided. A control means 20 is provided which changes only the converted analog amplitude value in accordance with control information in the case of the the level, which is designated by control information for level designation, equal to or lower than a prescribed value and changes only the digital amplitude value in accordance with control information in the case of the level lower than the prescribed value. |
