Abstract: A programmable controller according to the present invention is for reinforcing the function of a programmable machine controller (PMC) of a numerical control unit (CNC) incorporating a minicomputer. In order to achieve high-speed processing of a PMC ladder program which implements auxiliary control functions for machining inclusive of tool-change control, control of the rotational speed of a spindle and workpiece-change control, the programmable controller is provided with an electrically rewritable programmable read-only memory (EEPROM) (6), and a random-access memory (RAM) (7) to which program data is transferred from the EEPROM (6), and the arrangement is such that the contents of the EEPROM (6) are rewritten before the data transfer.

Abstract: A system for carrying out reference point return in a numerical control device is provided, including a deceleration dog having a short length and arranged at a machine table, a deceleration limit switch operated by the deceleration dog, for generating a deceleration start signal, and a time setting device (6) for setting a deceleration time, starting with a generation of the deceleration start signal and ending with a generation of a deceleration end signal, and a slow-speed travel time. A reference point return processing device (5) starts a deceleration of the machine table in response to the deceleration start signal, and stops the machine table at a first electrical grid point reached by the machine table after the slow-speed travel time has elapsed after the passing of the deceleration time.

Abstract: An NC unit processing method executes numerical control processing based on a numerical control program and sequence control processing based on a sequence program at predetermined times on a time-sharing basis. The processing method first stores a location of a sequence program to be executed next in a predetermined storage area in response to a first timer interrupt (IRQ.sub.n+1) generated during execution of the sequence program. Input/output processing based on an input/output program is then executed, followed by numerical control processing based on the numerical control program in response to a second timer interrupt (IRQ.sub.n) generated during execution of the input/output processing. When the numerical control program ends, the execution location of the sequence program is referred to, and sequence program processing is executed from this location until the first timer interrupt (IRQ.sub.n) is once again generated.

Abstract: An axis feedrate output system for CNC equipment which controls the position of a machining table in each axis by effecting feedrate control in accordance with a residual error between a position command and detected positional information in each axis. A current feedrate of the machining table in each axis is derived from the residual error, and a current actual feedrate of the machining table is synthesized using the current feedrate for the respective axes an output which represents the current actual feedrate of the machining table in the form of a ratio to a predetermined maximum feedrate is generated. An error register stores the residual error (servo error) between the position command for each axis from an MPU in the CNC equipment and the positional information detected by a position sensor and provides a feedrate command for effecting feedrate control.

Abstract: A data transfer system transfers, bit by bit, serial data sent from first equipment (10) to predetermined bits of a predetermined address in a RAM (300) of second equipment (30). Each bit of the serial data sent from the first equipment (10) is transferred to a predetermined bit of a predetermined address of the RAM (300) in the second equipment (20) upon each occurrence of a clock pulse which is delivered from the first equipment (10) in synchronism with each bit data. The data transfer system includes a counter (206) which is incremented by the clock pulses and an address generator (210) which responds to the output of the counter (206) to generate an address of the RAM (300).