PURPOSE: To use a necessary number of an optional angle, as an output, by connecting an absolute type rotary encoder to a motor shaft, and converting an output of the encoder to address information.

CONSTITUTION: A gray code signal which is inputted from an encoder 7 is driven by a transistor T1 and drives a photocoupler 12. An output of the coupler 12 is converted to a binary code by using an exclusive OR 13, driven by a transistor T2 again and inputted to an address of a memory 14 such as an EP-ROM, etc. By outputting a memory data of this address, a conversion of a signal is executed, a necessary number for an optional angle can be used as an output, and its timing can also be changed easily, therefore, the control can be simplified.