For the purpose to analyze the way to acquire PLC Data based on OPC Techniques and Ethernet, the PLC communication techniques and the OPC techniques based on Ethernet are introduced at first. And then the system framework for PLC data acquisition based on the OPC server is established. Finally, the structure of the data acquisition system about NC machine and the way to acquire PLC data from NC machine are introduced.

The purpose of this article is to realize the automatic on-line measurement of work coordinate system using Renishaw probe on the NC machine. We examined the application of Renishaw probe，and we use evolutionary analysis of the typical case to measure the coordinate system of the workpiece, and develops the parameter program. Besides, we experimented with the method based on Fanuc-18i.The related data is recorded in the course of the experiment, and we analyzes the error finally.