/// <summary>Reads opc-items via an synchronous read</summary>
/// <param name="OPCDataSrc">determines the source, the data have to be read (cache or device)</param>
/// <param name="itemServerHandles">the serverhandles of the opc-items to be read</param>
/// <param name="theGroup">the group in which the opc-items are hosted</param>
/// <returns> itemstates, returned form the opc-server </returns>
public OPCITEMSTATE[] readSync(OpcRcw.Da.OPCDATASOURCE OPCDataSrc,
int[] itemServerHandles, out int[] errors)
{
if (m_disposed)
{
throw new NullReferenceException("This object has been disposed!");
}
IntPtr pItemStates = IntPtr.Zero;
IntPtr pErrors = IntPtr.Zero;
int NumItems = itemServerHandles.Length;
OPCITEMSTATE[] result = new OPCITEMSTATE[NumItems];
string ErrorStr = "";
try
{
// Usually reading from CACHE is more efficient
// AND the underlying device has to do less communication work.
// BUT, you must have an active ITEM and GROUP, so that the opc server
// will update the data by itself; otherwise you'll get quality OUT_OF_SERVICE
m_OPCSyncIO.Read(OPCDataSrc, //OPCDATASOURCE.OPC_DS_DEVICE or OPCDATASOURCE.OPC_DS_CACHE,
NumItems,
itemServerHandles,
out pItemStates,
out pErrors);
if (pItemStates == IntPtr.Zero)
{
throw new ArgumentNullException("EXT_OPC_RDSYNC_ITEMSTATES");
}
if (pErrors == IntPtr.Zero)
{
throw new ArgumentNullException("EXT_OPC_RDSYNC_ERRORS");
}
//Evaluate return ErrorCodes to exclude possible Errors
errors = new int[NumItems];
Marshal.Copy(pErrors, errors, 0, NumItems);
IntPtr pos = pItemStates;
// Now get the read values and check errors
for (int dwCount = 0; dwCount < NumItems; dwCount++)
{
result[dwCount] = (OPCITEMSTATE)Marshal.PtrToStructure(pos, typeof(OPCITEMSTATE));
if (errors[dwCount] != 0)
{
m_OPCServer.GetErrorString(errors[dwCount], m_LocaleID, out ErrorStr);
System.Diagnostics.Debug.WriteLine(ErrorStr);
}
pos = (IntPtr)(pos.ToInt32() + Marshal.SizeOf(typeof(OPCITEMSTATE)));
}
if (ErrorStr != "")
{
throw new Exception(ErrorStr);
}
// Free allocated COM-ressouces
Marshal.FreeCoTaskMem(pItemStates);
Marshal.FreeCoTaskMem(pErrors);
}
catch (Exception)
{
// Free allocated COM-ressouces
Marshal.FreeCoTaskMem(pItemStates);
Marshal.FreeCoTaskMem(pErrors);
// just forward it
throw;
}
return(result);
}
/*------------------------------------------------------
* Execute SyncRead
*
* (ret) True OK
* False NG
* ------------------------------------------------------*/
public bool SyncRead(OpcRcw.Da.OPCDATASOURCE DataSource, int[] ServerHd, object[] Values, OpcRcw.Da.FILETIME[] TimeStamps, short[] Qualities)
{
int iItemCount = ServerHd.Length;
IOPCSyncIO OPCSyncIO;
IOPCSyncIO2 OPCSyncIO2;
IntPtr ppItemVal;
IntPtr ppErrors;
IntPtr posItem;
int[] Errors = new int[iItemCount];
OPCITEMSTATE ItemState;
int i;
try
{
switch (m_OpcdaVer)
{
case DEF_OPCDA.VER_30:
OPCSyncIO2 = (IOPCSyncIO2)m_OPCGroup2;
OPCSyncIO2.Read(DataSource, iItemCount, ServerHd, out ppItemVal, out ppErrors);
Marshal.Copy(ppErrors, Errors, 0, iItemCount);
posItem = ppItemVal;
for (i = 0; i < iItemCount; i++)
{
ItemState = (OPCITEMSTATE)Marshal.PtrToStructure(posItem, typeof(OPCITEMSTATE));
if (Errors[i] == 0)
{
Values[i] = ItemState.vDataValue;
TimeStamps[i] = ItemState.ftTimeStamp;
Qualities[i] = ItemState.wQuality;
}
Marshal.DestroyStructure(posItem, typeof(OPCITEMSTATE)); // 05/02/08 Release memory
//posItem = new IntPtr(posItem.ToInt32() + Marshal.SizeOf(typeof(OPCITEMSTATE))); // 1.0.0.5 10/06/21 Kishimoto Fixed for Memory Leak
posItem = (IntPtr)(posItem.ToInt32() + Marshal.SizeOf(typeof(OpcRcw.Da.OPCITEMSTATE))); // 1.0.0.5 10/06/21 Kishimoto Fixed for Memory Leak
}
Marshal.FreeCoTaskMem(ppItemVal);
Marshal.FreeCoTaskMem(ppErrors);
break;
case DEF_OPCDA.VER_10:
case DEF_OPCDA.VER_20:
default:
OPCSyncIO = (IOPCSyncIO)m_OPCGroup;
OPCSyncIO.Read(DataSource, iItemCount, ServerHd, out ppItemVal, out ppErrors);
Marshal.Copy(ppErrors, Errors, 0, iItemCount);
posItem = ppItemVal;
for (i = 0; i < iItemCount; i++)
{
ItemState = (OPCITEMSTATE)Marshal.PtrToStructure(posItem, typeof(OPCITEMSTATE));
if (Errors[i] == 0)
{
Values[i] = ItemState.vDataValue;
TimeStamps[i] = ItemState.ftTimeStamp;
Qualities[i] = ItemState.wQuality;
}
Marshal.DestroyStructure(posItem, typeof(OPCITEMSTATE)); // 05/02/08 Release memory
//posItem = new IntPtr(posItem.ToInt32() + Marshal.SizeOf(typeof(OPCITEMSTATE))); // 1.0.0.5 10/06/21 Kishimoto Fixed for Memory Leak
posItem = (IntPtr)(posItem.ToInt32() + Marshal.SizeOf(typeof(OpcRcw.Da.OPCITEMSTATE))); // 1.0.0.5 10/06/21 Kishimoto Fixed for Memory Leak
}
Marshal.FreeCoTaskMem(ppItemVal);
Marshal.FreeCoTaskMem(ppErrors);
break;
}
}
catch (Exception exc)
{
MessageBox.Show(exc.ToString(), "SyncRead");
return(false);
}
// erase Errors
System.GC.Collect(); //04/12/29 Revised Memory Leak
return(true);
}