Numerical control system using I/O unit for time measurement

摘要

In a numerical control system in which a numerical controller and an I/O unit perform serial data communication through a communication line, a counter of the I/O unit starts time measurement with an input signal from an in-machine measurement device as a trigger and stops counting at the start of transmission of DI data. The I/O unit transmits a flag indicative of input of the input signal as a trigger and a value in the stopped counter to the numerical controller. Based on a time value measured by a timer and the counter value, the numerical controller calculates the time of input of the input signal.

主权项

1. A numerical control system, which comprises a numerical controller and one or more I/O units connected to the numerical controller and transfers input and output signals between the numerical controller and the I/O units through serial communication,
wherein the I/O unit starts sending back to the numerical controller in the serial communication on receiving data from the numerical controller, and each of the I/O units comprising: a time measurement section configured to start time measurement with an input signal as a trigger; and a serial communication section configured to transmit a flag indicative of input of the input signal and a measured value of the time measurement section at the start of sending back by the I/O unit to the numerical controller, the numerical controller comprising: an acquisition section configured to acquire the flag and the measured value input through the serial communication; a timer configured to measure time; and an input time calculation section configured to calculate the time of input of the input signal based on the time measured by the timer and the measured value acquired by the acquisition section.