A drive control system has: a plurality of drive control devices; and an upper-level control device to which each of the drive control devices is connected in parallel with each other via a common signal line. The upper-level control device transmits a common information acquirement request signal to each of the drive control devices. Upon receiving the information acquirement request signal, each of the drive control devices determines transmission start timing for a response signal based on transmission sequence information indicating its transmission sequence and a length of the response signal such that the response signal does not temporally overlap with a response signal being transmitted from another drive control device to the upper-level control device. Each of the drive control devices transmits the response signal to the upper-level control device via the signal line at its transmission starting timing.