tailieunhanh - Using Visual Basic As An OPC Client

Tài liệu tham khảo Using Visual Basic As An OPC Client | Using Visual Basic As An OPC Client John Weber President & Founder Software Toolbox, Inc. jweber@ website: Your OPC Server Copyright Software Toolbox, 1999,2000,2001 All Rights Reserved Worldwide. Software Toolbox is a registered trademark of Software Toolbox, Inc. Presentation Updated 3/2001 Agenda OPC - Review of the Basics OPC - Terminology OPC & VB 101 - Automation Wrapper & Object Model Building Your VB Client - Read data - 7 easy steps with code from start to finish Housekeeping Handles Handles Everywhere - how the server and client correlate the data each is managing in your program Writing Data Future ideas to consider New developments since original presentation in 10/99 Resources for future learning OPC - Review of the Basics OPC is based on the Microsoft Component Object Model (COM) OPC stands for OLE for Process Control OPC is managed by the independent OPC Foundation () There are over 200 member . | Using Visual Basic As An OPC Client John Weber President & Founder Software Toolbox, Inc. jweber@ website: Your OPC Server Copyright Software Toolbox, 1999,2000,2001 All Rights Reserved Worldwide. Software Toolbox is a registered trademark of Software Toolbox, Inc. Presentation Updated 3/2001 Agenda OPC - Review of the Basics OPC - Terminology OPC & VB 101 - Automation Wrapper & Object Model Building Your VB Client - Read data - 7 easy steps with code from start to finish Housekeeping Handles Handles Everywhere - how the server and client correlate the data each is managing in your program Writing Data Future ideas to consider New developments since original presentation in 10/99 Resources for future learning OPC - Review of the Basics OPC is based on the Microsoft Component Object Model (COM) OPC stands for OLE for Process Control OPC is managed by the independent OPC Foundation () There are over 200 member companies supporting the OPC specification OPC defines a standard method for connecting automation application software OPC and VB 101 - Terminology OPC Server - a piece of software supporting the OPC specification - an OPC Data Access Server is a driver that handles connectivity to PLCs or other automation hardware OPC Item - A single tag or data point managed by the OPC server - . one data point in a PLC OPC Group - a user defined grouping of OPC items. Created by the OPC client as a way of organizing data items around logical process areas or equipment. Collection - a grouping of objects of the same data type - for example, each OPC server has an OPC items collection containing one software object for each OPC item. OPC and VB 101 Visual Basic supports COM COM implementations from Visual Basic use what is called an “Automation” interface The OPC Foundation supplies the source code to an “Automation Wrapper” DLL - most OPC vendors provide a compiled version Automation .