To prevent erroneous reception of a data in a reception side when data transmission is started from the condition where the data is not transmitted, in the data transmission using Manchester code between an encoder for detecting position information for a rotating machine or the like and a controller for conducting position and speed control of the rotating machine using the position information.
A transmission circuit for adding a data frame for stand-by of reception just in front of a transmitted normal data frame comprising the Manchester code, and a reception circuit for starting a reception operation for the normal data frame when the data frame for the stand-by of the reception is detected are provided in each of the encoder and the controller.
KAMEDA AKISHI
YAMAZAKI KOICHI
KISHIBE TARO
