Abstract: A numerical controller and a servomotor control system, capable of axis control required in case of a communication failure in the control of servomotors driven by servo amplifiers connected to a plurality of serial buses. The numerical controller has a plurality of serial buses to which the numerical controller and a plurality of servo amplifiers are daisy-chain-connected and controls servomotors connected individually to the servo amplifiers. The device comprises a plurality of communication control circuits for detecting respective communication failures of the serial buses and selecting means for selecting whether or not to notify the other communication control circuits of a communication failure, if any, of any one of the communication control circuits detected thereby.

Abstract: An error decoding circuit comprises a syndrome computing circuit for computing a syndrome on a receive data, an error detecting circuit for detecting an error based on the syndrome, an error pattern computing circuit for computing an error pattern based on the syndrome, and an inverting circuit for performing an error correction of a receive data based on the computed error pattern. Only when there is an error in the receive data, based on the detection result of the error detecting circuit, a request signal for extension of a bus cycle is outputted to a bus master. On the other hand, if there is no error in the receive data, an inputted data is outputted to a data bus without correction. By so doing, the high speed operation of the data bus is executed.

Abstract: A data table stored in a numerical controller associates motors controlled by the numerical controller with information from sensors used by the motors. When the numerical controller is turned on, the contents of the data table are sent from the numerical control section to the motor control section. The motor control section controls each motor by using information from the sensors associated with the motor in the data table.

Abstract: In a servo control system, a numerical control device and at least one servo amplifier are connected to each other with a serial bus to control a servo motor connected to the servo amplifier. In this system, data transfer systems of at least two types for the serial bus are set, and a data transfer system is selected by a parameter set in the numerical control device.

Abstract: A distribution board includes wiring and connectors removably attaching a plurality of I/O units. These I/O units include transmitter-receiver units. When the I/O units are attached to one or more of the connectors on the distribution board, the attached I/O units and the wiring provided on the distribution board are connected to one another.

Abstract: A numerically controlled machine tool which requires fewer signal lines between a machine control console and a numerical control unit. Switch matrixes (1, 2, . . . n) have matrix elements (S111, S112, . . . ) disposed thereto in a matrix shape. Common signals (COM1, COM2, . . . COMj) are supplied to the common lines COM of the switch matrixes (1, 2, . . . n). Output data signals (DAT11, DAT12, . . . DAT2l) are supplied from data lines (DAT1, DAT2) of the switch matrixes (1, 2, . . . n). In the same way, input data signals (DATn1, DATn2, . . . DATnm) are supplied from data lines (DATn) of the switch matrixes (1, 2, . . . n). With this arrangement, unnecessary common lines are reduced by providing the common lines COM with the switch matrixes (1, 2, . . . n).