Numerical control system for a machine tool with a tool dimension

Abstract

A numerical control system is provided wherein numerical controllers associated with machine tools are respectively coupled to auxiliary controllers communicating with a host computer. Each auxiliary controller has a memory for storing revision values which respectively correspond to primary and spare tools being stored in a tool magazine of the associated machine tool. When a spare tool is attached to a tool spindle of the associated machine tool in place of a primary tool, each auxiliary controller reads out a corresponding revision value from the memory and transfers it to the associated numerical controller. Thus, a corresponding one of tool dimension compensation values being stored in a memory of the associated numerical controller is revised or modified by the revision value transferred thereto so as to adapt itself for the spare tool being used on the tool spindle. Further, when the primary tool is taken out from the tool magazine and a secondary spare tool is set up therein instead, the host computer reads out from its memory a revision value corresponding to the secondary spare tool and transfers it to the auxiliary controller. This revision value is stored in the memory of the auxiliary controller for later transfer to the associated numerical controller in connection with the use of the secondary spare tool on the tool spindle.