Description

• An object oriented OPC DA Client SDK/ToolKit written in C++, Both X86/X64 supported, implementing the OPC DA specification version 2.05A
• New Features (Compare with the original version)
  • Build with x64 project.
  • Build with MFC.
  • Multithread supported.
  • Connect to server with CLSID.(Hasn't tested)

Notes

Current master branch contains a huge bug fixes commit from PR#14, which might introduce some new bugs. If the master branch went wrong, you may check release 0.4.1 as a backup.

Basic Guide

• Install OPC Core Component x64 is NECESSARY if you want to build x64 project, I bundled the 3.0.105.1 version (seems more popular).
• You can test the Toolkit with MatrikonOPC Simulation Server.
  • You can get it free at offical site after reg.
  • Start OPC Simulation Server, then build project. Run the demo, input hostname, then input server ID, it should work.
  • If you were to commit a issue, you should give a code sample with the Simulation Server. Since this is the only env we can reproduce the error.
• I advice you to use hostname instead of IP address for reasons below.
  • If you want to access OPC by IP, you have to enable RemoteRegistry service in services.msc
  • Also , for UAC problem after Vista, your program must run as admin to avoid some issue.
• There is a convenience wrapper class that may help you connect local server easier.

Advanced Guide

• Multi - Thread Programing Guide
  • Call COPCCLint::initand COPCClinet::stop in every thread. There are two method to init, in one application, different thread could use different method.
    • You can call COPCClient::init(MULTITHREADED) to init thread OLE, then the COPCxxx created in the thread could be accessed from other thread that is also inited with MULTITHREADED.
    • You can call COPCClient::init() to init thread OLE, but all COPCxxx created in the thread can't be accessed from different thread.
  • Attention: If you are using anything related to MFC GUI, you MUST use COPCClient::init() in main thread (the UI thread) . (See MSDN) .

Detail & ChangeLog

• Date: 2021-10-10

  • Thanks for wolfgang.griech (wolfgang.griech@gmail.com), who contributed a huge bug fixes PR#14 that may fix many issues in this project.

• Date: 2017-07-07

  • Thanks for mzillgith, now the project can connect to remote server with CLSID.(It hasn't been tested)

• Date: 2017-04-13

  • Fix a string conversion bug which might lead stack overflow
  • Add a convenience class to connect local server in sync I/O mode

      // connect local server
      LocalSyncOPCCLient* client = new LocalSyncOPCCLient;
      client->Init();
      if (client->Connect("Matrikon.OPC.Simulation.1"))
      {
          // sync write and sync read
          client->WriteUint16("Bucket Brigade.UInt2", 998);
          std::cout << client->ReadUint16("Bucket Brigade.UInt2");
  
          // disconnect and stop
          client->DisConnect();
          client->Stop();
          delete client;
      }
  

  • You could rewrite or override the member function IsOPCConnectedPLC() to make connection more safety
  • You could rewrite or override the member function ItemNameFilter(std::string) to avoid adding useless items
  • Since there are too many Variant type, I only add three basic I/O functions as a guidence, it should help you to add what you need

• Date:2016-12-13

  • Thanks for Tom Loya's contribution, now the project can work in a multi-threaded environment. You should call COPCClient::init() and COPCClient::stop() in every thread.

• Date:2016-07-01

  • this std branch tries to move every ATL to STL.
  • the static .lib now works for MFC too.

• Date:2016-05-31

  • Modified from X86 Version OPC Client 0.4a by beharrell
  • Add some Hint info
  • X64 Version uses includes files form OPC Core Component 3.0.106.