Numerical control system with two separated daisy-chain bus systems for the connection to servo amplifiers and position encoders

摘要

A numerical control system with shortened communication paths to lower a cost of the system is presented. A plurality of servo amplifiers (A1-A4) for respectively controlling a plurality of servomotors (M1-M4) are arranged separately from a numerical controller (1). Pulse encoders (P1-P4) for detecting positions/velocities of the servomotors are connected to the numerical controller by optical cables (3) forming a first serial communication path in a daisy chain, via a branch unit (4). The servo amplifiers for driving the servomotors are connected to the numerical controller by optical cables in a second daisy chain (2), via the branch unit. Since the communication path (3) for transmitting signals from the pulse encoders connects the pulse encoders (P1-P4) and the numerical controller (1) without the servo amplifiers (A1-A4) intervened in between, the communication path is not elongated even in a case of the servo amplifiers are located remote from the servomotors, to construct the system with a low cost.