Numerical control system

Claim 1

A numerical control system for controlling the movement of a tool of a machine tool comprising: a. an input circuit receptive of signals having information content representative of discrete positions to which a tool of a machine tool is to be moved, said signals being grouped in sequential blocks wherein information content of said signals comprising each of said blocks represents a plurality of command numerical values representative of said positions to which said tool is to be moved referred to an equal number of reference axes and corresponding to indications if said command numerical values correspond to incremental commands or absolute commands and includes command direction information indicating directions in which said tool is to be moved, said input circuit developing output signals having the information content of the received signals; b. means for generating timing pulses; c. a pre-processing counter for developing a predetermined sequence of output signals in response to said timing pulses applied thereto and in response to a signal applied thereto indicating a block of said received signals were received by said input circuit; d. means for applying said timing pulses to said pre-processing counter; e. means for generating and applying to said pre-processing counter said signal indicating a block of said received signals were received by said input circuit; f. a gate circuit for developing gate signals in response to read command signals and operation command signals applied thereto; g. read circuit means receptive of said input circuit output signals for developing and applying said read command signals applied to said gate circuit; h. pre-processing command circuit means receptive of said preprocessing counter output signals for developing in response thereto said operation command signals and for applying said operation command signals to said gate circuit; i. an arithmetic operation circuit comprising a plurality of registers for storing position information of said tool referred to said reference axes and said command numerical values, said arithmetic operation circuit comprising means for simultaneously converting said command numerical values which are absolute commands into equivalent incremental commands and replacing said absolute commands stored in said registers with said equivalent incremental commands, and computing position information of a subsequent position of said tool from said position information stored in said registers and from said incremental commands and replacing said position information with said subsequent position information in response to said gate signals; j. means for applying said input circuit output signals and said gate signals to said arithmetic operation circuit; k. pulse distribution circuit means for developing and applying pulse distribution control signals to said gate circuit in response to said timing pulses and one of said pre-processing counter output signals applied thereto, said gate circuit developing and applying gate signals to said arithmetic operation circuit in response to said pulse distribution control signals, said arithmetic operation circuit applying said incremental commands to means for positioning said tool in response to said last-mentioned gate signals, said pulse distribution circuit means comprising means for developing and applying a signal to clear and reset said pre-processing counter after said incremental commands are applied to said means for positioning said tool; and l. means for applying said timing pulses and one of said preprocessing counter output signals to said pulse distribution circuit.