Machine tool control system having means for ignoring invalid command signals

Claim 1

IN A MACHINE CONTROL SYSTEM THE CODE READER FOR READING IN THE SEQUENCE WORDS OF CODED INFORMATION REPRESENTING DATA OF A MACHINE OPERATION INCLUDING THE OPERATION OF MOVING A TOOL RELATIVE TO A WORKPIECE, STORAGE MEANS TO REGISTER IN SEQUENCE CODED DATA TO BE PERFORMED BY THE MACHINE, PERMUTATION RESPONSIVE MEANS FOR PROVIDING DIFFERENT OUTPUTS IN RESPONSE TO EACH DIFFERENT WORD, CIRCUIT MEANS COUPLED TO THE OUTPUT OF SAID PERMUTATION RESPONSIVE MEANS TO PROVIDE AS VALID INDICATION FOR CERTAIN OF SAID OUTPUTS TO BE ACCEPTED BY THE MACHINE AN INVALID INDICATION IN RESPONSE TO OTHER OF SAID TO BE IGNORED, SWITCHING MEANS SEPARATE FROM SAID PERMUTATION RESPONSIVE MEANS FOR CONNECTING SAID CODE READER TO SAID STORAGE INDEPENDENTLY OF SAID PERMUTATION RESPONSIVE MEANS FOR SETTING AT LEAST PART OF SAID STORAGE MEANS FROM SAID CODE READER IN ACCORDANCE WITH THE WORDS BEING READ BY SAID CODE READER, FIRST CONTROL MEANS RESPONSIVE TO SAID CIRCUIT MEANS FOR ACTUATING SAID SWITCHING MEANS TO SET SAID STORAGE MEANS FROM SAID CODE READER INCLUDING SAID SECOND CONTROL MEANS RESPONSIVE TO SAID VALID INDICATION AND SECOND CONTROL MEANS RESPONSIVE TO SAID VALID INDICATION TO EFFECT AN INDEXING OF SAID CODE READER TO READ THE NEXT WORD.