A numerical controller is equipped with an access unit configured to access variables included within a machining program at a time of analyzing the machining program, a look-ahead determining unit configured to determine whether or not the variables accessed by the access unit were accessed during look-ahead of the machining program, a specific variable determining unit configured to determine whether or not the variables determined to have been accessed during look-ahead by the look-ahead determining unit are specific variables, and an output unit configured to output at least one of numbers of the specific variables accessed during look-ahead and a time of accessing the specific variables during look-ahead, in the event that the variables accessed during look-ahead are determined to be the specific variables by the specific variable determining unit.

A numerically controlled production system is connected to a numerical controller, which includes a control program with successive program sets, and a look-ahead module which determines therefrom for successive clock-cycle points a movement profile with guidance variables for a movement axis prior to a movement. Subject to a condition, the control program includes program branching with multiple alternative control program sections, and determines which of the alternative control program sections is to be additionally executed subject to the condition. The look-ahead module calculates and stores an alternative movement profile for each alternative control program section prior to an additional movement, and holds the alternative movement profile available for the conditional program branching in order to carry out the additional movement.

A numerical controller determines whether or not block prefetching from a program is sufficient based on whether at least one block subsequent to a predetermined reference block, which exists after a running block of the program and is needed to execute the reference block, has been prefetched or not. If the determination result is that prefetching is not sufficient, block prefetching from the program is performed.

A numerical controller includes a look-ahead unit configured to look ahead a block in the program into a buffer, a remaining block determination unit configured to determine whether retraction of a tool is needed or return of the tool is needed based on an amount of the block looked ahead in the buffer, a tool operation control unit configured to control retraction and return of the tool when the remaining block determination unit determines that retraction of the tool is needed, a block division unit configured to divide a block to divide at a position apart from both ends of the block according to a command from the tool operation control unit, and a tool path generation unit configured to generate a tool retraction path and a tool return path and insert the generated paths into a divided position in the block divided by the block division unit.

A numerically controlled production system is connected to a numerical controller, which includes a control program with successive program sets, and a look-ahead module which determines therefrom for successive clock-cycle points a movement profile with guidance variables for a movement axis prior to a movement. Subject to a condition, the control program includes program branching with multiple alternative control program sections, and determines which of the alternative control program sections is to be additionally executed subject to the condition. The look-ahead module calculates and stores an alternative movement profile for each alternative control program section prior to an additional movement, and holds the alternative movement profile available for the conditional program branching in order to carry out the additional movement.

A numerical controller determines whether or not block prefetching from a program is sufficient based on whether at least one block subsequent to a predetermined reference block, which exists after a running block of the program and is needed to execute the reference block, has been prefetched or not. If the determination result is that prefetching is not sufficient, block prefetching from the program is performed.

A processing executing unit of a control device is configured to set the number of blocks to be read indicating the number of blocks to be read from a storage unit per unit time and a fan rotational speed of a fan motor in accordance with the amount of allowable machining error or a feed rate of a table that is inputted by an operator, and further configured to read a machining program from the storage unit block by block at the set number of blocks to be read and cause a fan control unit to perform a process to drive the fan motor at the set fan rotational speed.

To provide a numerical controller that can detect a position in a machining program at which a speed control abnormality is likely to occur due to an insufficient look-ahead blocks that are used to determine an acceleration/deceleration operation, and start a look-ahead processing function from the position in parallel with looking ahead at the machining program from the start of the machining program. A numerical controller includes a program execution unit that executes a machining program, a program look-ahead unit that simultaneously looks ahead at the machining program from different blocks in the machining program in parallel with execution of the machining program and that includes a first program look-ahead unit and a second program look-ahead unit, and a look-ahead allocation unit that divides a storage unit into at least a first region and a second region and instructs the first program look-ahead unit to perform a look-ahead action of storing look-ahead blocks in the first region and instructs the second program look-ahead unit to perform a look-ahead action of storing look-ahead blocks in the second region.

To provide a numerical controller that can detect the position at which the look-ahead blocks used to determine an acceleration/deceleration operation is insufficient in a machining program in order to stabilize feed rate, cutting speed and other factors. A numerical controller includes a program execution unit that executes a machining program, a program look-ahead unit that looks ahead at the machining program in parallel with execution of the machining program, a look-ahead blocks calculation unit that calculates a look-ahead blocks, which is the difference between a first sequence number that is the number of a block being executed by the program execution unit and a second sequence number that is the number of a block that is looked ahead by the program look-ahead unit while the machining program is being executed, and an exhaustion block detection unit that detects an exhaustion block, which is a block at which the look-ahead blocks falls below a prescribed value.

To provide a numerical controller that can detect the position at which the look-ahead blocks used to determine an acceleration/deceleration operation is insufficient in a machining program in order to stabilize feed rate, cutting speed and other factors. A numerical controller includes a program execution unit that executes a machining program, a program look-ahead unit that looks ahead at the machining program in parallel with execution of the machining program, a theoretical value calculation unit that calculates theoretical values per block in processing time for the machining program from the feed rate of the machine tool and lengths of minute straight lines that make up the machining path followed by the machine tool, a measured value calculation unit that calculates actually measured values per block in the look-ahead time taken by the program look-ahead unit and the processing time for the machining program while the machining program is being executed, and an abnormal block detection unit that detects an abnormal block that is a block at which the result of subtracting the total of the theoretical values from the total of the actually measured values is more than a prescribed value.