Patent ID: 7119505
Filing Date: 2006-10-10
Classification: G05B

Abstract:
1. A servo motor control system in which a numerical control device and at least one servo amplifier are connected to each other with a serial bus to control a servo motor connected to the servo amplifier, wherein: at least two types of data transfer systems are prepared for the serial bus, a data transfer system is selected by a parameter which has been set in the numerical control device; a plurality of servo motors are connected to the numerical control device with a serial bus by a daisy chain system, each servo amplifier includes means for measuring a frequency of signal change for a predetermined time in a received signal on the serial bus and discriminating a data transfer system on the basis of the measured frequency of signal change, and at least a servo amplifier except for a most downstream servo amplifier in the daisy chain system includes first and second connectors for the serial bus, discriminates a data transfer system of the serial bus in the first connector on the basis of a signal received by the first connector and said discriminating means, and determines a data transfer system of the second connector on the basis of the discrimination result so that a servo amplifier connected to an upstream or a downstream in the daisy chain system is adaptable to a plurality of data transfer systems.