A control system includes a programmable logic control section controlling operation of a machine and a numerical control section controlling relative motion between a tool of the machine and a work piece. A method, performed in the control system, includes: evaluating an input signal, received by the programmable logic control section, in relation to a first condition, wherein the input signal includes information about a state of the tool or of a subtractive process performed via interaction of the tool and the work piece; and in response to the input signal satisfying the first condition, providing the information to the numerical control section. The state may for example be tool breakage, tool wear or wrong cutting data. An operator of the machine may for example specify via programs in the numerical control section how the machine is to respond to such states.

A method for determining process sequences from individual process data (21), which occur repeatedly in successive process steps, have a variable value (22) and a constant reference content (23), is described, wherein, for successive process steps, the process data (21) are assigned to unique existing object data records with value (28) or object data records with value (28) that are to be newly created using their detected value (22) and using their reference content (23). In order to record process data with high integrity and to be able to determine process sequences, it is proposed that the object data records with value (28) are linked to object data records without value (30, 33) via object relation data records (29, 32) according to their reference content (23), wherein the existing object data records (28) are linked to a process step data record assigned to the respective process step via a process input data record and the newly created object data records (30, 33) and object relation data records (29, 32) are linked to the process step data record via a process output data record.

A method for manufacturing a machine component includes determining a track of a cutting edge and feeding the cutting edge along the track. The determining a track includes calculating a coordinate (X(t), Y(t), Z(t)) of a first end portion of the cutting edge in accordance with X(t)=(R.sub.sh(t)cos (t)X.sub.chip(t)), Y(t)=(R.sub.sh(t)sin (t)Y.sub.chip(t)), and Z(t)=(Z.sub.sh(t)Z.sub.chip(t)), where a variable t assumes (N+1) values not smaller than 0 and not greater than 1. (t) represents an angle formed by a straight line connecting a point of cutting projected on an XY plane and an origin of the XY plane to each other with respect to an X axis, and (t) satisfies a condition $\tan \left(t\right)=\frac{\tan .Math.\tan {}_s-\tan .Math.\sqrt{{\tan }^2+{\tan }^2-{\tan }^2{}_s}}{\tan }$

An operation management system configured to acquire measured values of a workpiece from a numerical controller which controls a machine tool to measure the workpiece is provided with a measurement macro receiving unit configured to read a measurement macro for controlling the measurement from the numerical controller, a measurement macro analysis unit configured to analyze the measurement macro to identify the name of a measurement result variable loaded with the measured values, and a measurement result read-out unit configured to read out the value of the measurement result variable from the numerical controller. The operation management system easily acquires the result of the workpiece measurement from the numerical controller.

A method for manufacturing a machine component includes determining a track of a cutting edge and feeding the cutting edge along the track. The determining a track includes calculating a coordinate (X(t), Y(t), Z(t)) of a first end portion of the cutting edge in accordance with X(t)=(R.sub.sh(t)cos (t)X.sub.chip(t)), Y(t)=(R.sub.sh(t)sin (t)Y.sub.chip(t)), and Z(t)=(Z.sub.sh(t)Z.sub.chip(t)), where a variable t assumes (N+1) values not smaller than 0 and not greater than 1. (t) represents an angle formed by a straight line connecting a point of cutting projected on an XY plane and an origin of the XY plane to each other with respect to an X axis, and (t) satisfies a condition

[00001]$\tan .Math..Math.\left(t\right)=\frac{\tan .Math..Math..Math.\tan .Math..Math.{}_s-\tan .Math..Math..Math.\sqrt{{\tan }^2.Math.+{\tan }^2.Math.-{\tan }^2.Math.{}_s}}{\tan .Math..Math..Math.\tan .Math..Math.{}_s+\tan .Math..Math..Math.\sqrt{{\tan }^2.Math.+{\tan }^2.Math.-{\tan }^2.Math.{}_s}}.$

A control system includes a programmable logic control section controlling operation of a machine and a numerical control section controlling relative motion between a tool of the machine and a work piece. A method, performed in the control system, includes: evaluating an input signal, received by the programmable logic control section, in relation to a first condition, wherein the input signal includes information about a state of the tool or of a subtractive process performed via interaction of the tool and the work piece; and in response to the input signal satisfying the first condition, providing the information to the numerical control section. The state may for example be tool breakage, tool wear or wrong cutting data. An operator of the machine may for example specify via programs in the numerical control section how the machine is to respond to such states.

A numerical controller for controlling a machine tool for machining a work on the basis of an NC program for execution including a variable includes NC program reading unit, NC program analyzing unit, and a variable value table sequentially holding a variable value assigned to a variable at time of execution of a predetermined unit of program read by the NC program reading unit, and the NC program analyzing unit includes a character string for variable-check creating unit for replacing a character string included in an instruction affected by the variable in the predetermined unit of program with a character string for variable-check on the basis of the predetermined unit of the program read by the NC program reading unit and the variable value obtained from the variable value table and an NC program for variable-check writing unit.

An operation management system configured to acquire measured values of a workpiece from a numerical controller which controls a machine tool to measure the workpiece is provided with a measurement macro receiving unit configured to read a measurement macro for controlling the measurement from the numerical controller, a measurement macro analysis unit configured to analyze the measurement macro to identify the name of a measurement result variable loaded with the measured values, and a measurement result read-out unit configured to read out the value of the measurement result variable from the numerical controller. The operation management system easily acquires the result of the workpiece measurement from the numerical controller.