Knowledge Base Nr: 00032 OPCClient.h - http://www.swe-kaiser.de

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OPC: übersichtliche C++ Wrapperklasse für OPC

  
// erlaubt das starten/stopen eines opc servers, das anlegen von gruppen und items,
// das synchrone und asynchrone lesen/schreiben von items.
// virtuelle funktionen für die ereignisbehandlung können überschrieben werden
// nachdem eine eigene klasse abgeleitet wurde.
// (es wird der OPC Client Toolkit von FactorySoft benötigt)

#if !defined(AFX_OPCCLIENT_H__90B262F7_1FEB_11D3_B382_0000E83A0185__INCLUDED_)
#define AFX_OPCCLIENT_H__90B262F7_1FEB_11D3_B382_0000E83A0185__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

class  CItem : public CObject
{
public:
  CItem() : m_bIsGood(FALSE) { }
  virtual ~CItem() { }

  CItem& operator= (const CItem& source)
  {
    if( this == &source )
      return *this;

    m_strName   = source.m_strName;
    m_varValue  = source.m_varValue;
    m_bIsGood   = source.m_bIsGood;
    m_timestamp = source.m_timestamp;

    return *this;
  }

  CString   m_strName;
  COleVariant m_varValue;
  BOOL    m_bIsGood;
  FILETIME  m_timestamp;
};

class OPCServer;
class OPCCallback;
class CAdviseSink;
class Item;
class CGroup;

#include <afxtempl.h>

typedef CTypedPtrList<CObList, Item*> ItemList;


class COPCClient : public CObject
{
private:
  OPCServer*      m_opcServer;     // the connected server

  //used for GetLastError()
  HRESULT     m_hr;
  CString     m_strLastError;

  // OPC 2.0  call back (one for all groups)
  OPCCallback*    m_callbackCP;

  // OPC 1.0 call back (one for all groups)
  CAdviseSink*    m_testSink;

  //the list of all items (for internal usage only!)
  ItemList  m_items;

  //the list of all groups (for internal usage only!)
  CObList   m_groups;

protected:
  CString GetErrorString(LPCTSTR description, HRESULT error, LPCTSTR addText = NULL);
  void    ReportError(LPCTSTR description, HRESULT error, LPCTSTR addText = NULL);

  Item* GetItemInfo(LPCSTR lpszGroupName, LPCSTR lpszItemName);
  CGroup* GetGroupInfo(LPCSTR lpszGroupName);

public:
  COPCClient();
  virtual ~COPCClient();

  BOOL Start(LPCOLESTR lpszProgID, LPCSTR lpszMachineName = NULL);  //f.e. L"OPC.SimaticNET"
  BOOL Stop();

  void GetLastError(CString& strError, HRESULT& hr) { strError = m_strLastError; hr = m_hr; }

  //the Siemens OPC server have problems with adding items to active groups
  //so the group is created as inactive and must be activated later
  //nRefreshRate returns the advised refresh rate
  BOOL AddGroup(LPCSTR lpszGroupName, DWORD& nRefreshRate, FLOAT deadband = 0.0);

  BOOL ActivateGroup(LPCSTR lpszGroupName, DWORD& nRefreshRate, FLOAT deadband, BOOL bActivate = TRUE);

  BOOL AddItem(LPCSTR lpszGroupName, CItem& cItem);

  BOOL WriteItem(LPCSTR lpszGroupName, CItem& cItem, BOOL bAsync = FALSE);
  BOOL WriteItems(LPCSTR lpszGroupName, int nItemCount, CItem cItems[], BOOL bAsync = FALSE);

  BOOL ReadItem(LPCSTR lpszGroupName, CItem& cItem, BOOL bFromDevice = FALSE);
  BOOL ReadItems(LPCSTR lpszGroupName, int nItemCount, CItem cItems[], BOOL bFromDevice = FALSE);

  //overwrite this method to receive changes
  virtual void OnValueChange(CItem& cItem);

  //overwrite this method to receive trace messages
  virtual void OnMessage(LPCSTR lpszMsg, HRESULT hr);
};

#endif // !defined(AFX_OPCCLIENT_H__90B262F7_1FEB_11D3_B382_0000E83A0185__INCLUDED_)