/// <summary>
/// Reads an item property from an XML stream.
/// </summary>
private void ReadProperty(XmlTextReader reader)
{
// look up the property id.
PropertyDescription property = null;
if (reader.MoveToAttribute(PROPERTY_ID))
{
try
{
property = PropertyDescription.Find(new PropertyID(((int)System.Convert.ToInt32(reader.Value))));
}
catch
{
property = null;
}
}
// ignore invalid properties.
if (property == null)
{
return;
}
// read value.
object value = ReadValue(reader, property.Type);
switch (property.ID.Code)
{
case QUALITY: { m_quality = (Quality)value; break; }
case TIMESTAMP: { m_timestamp = (DateTime)value; break; }
case ACCESSRIGHTS: { m_accessRights = (accessRights)value; break; }
case SCANRATE: { m_scanRate = (float)value; break; }
case EUTYPE: { m_euType = (euType)((int)value + 1); break; }
case EUINFO: { m_euInfo = (string[])value; break; }
case HIGHEU: { m_maxValue = (double)value; break; }
case LOWEU: { m_minValue = (double)value; break; }
default:
{
m_properties[property.ID] = value;
break;
}
}
}
private void Browse(ItemIdentifier itemID, OPCBROWSETYPE dwBrowseFilterType, string szFilterCriteria, short vtDataTypeFilter, int dwAccessRightsFilter, ArrayList hits)
{
BrowseFilters filters = new BrowseFilters {
MaxElementsReturned = 0,
BrowseFilter = browseFilter.all,
ElementNameFilter = (dwBrowseFilterType != OPCBROWSETYPE.OPC_FLAT) ? szFilterCriteria : "",
VendorFilter = null,
ReturnAllProperties = false
};
filters.PropertyIDs = new PropertyID[] { Property.DATATYPE, Property.ACCESSRIGHTS };
filters.ReturnPropertyValues = true;
BrowseElement[] elementArray = null;
try
{
Opc.Da.BrowsePosition position = null;
elementArray = this.m_server.Browse(itemID, filters, out position);
if (position != null)
{
position.Dispose();
position = null;
}
}
catch
{
throw new ExternalException("BrowseOPCItemIDs", -2147467259);
}
foreach (BrowseElement element in elementArray)
{
if (dwBrowseFilterType == OPCBROWSETYPE.OPC_FLAT)
{
if (element.HasChildren)
{
this.Browse(new ItemIdentifier(element.ItemName), dwBrowseFilterType, szFilterCriteria, vtDataTypeFilter, dwAccessRightsFilter, hits);
}
}
else
{
if (dwBrowseFilterType == OPCBROWSETYPE.OPC_BRANCH)
{
if (element.HasChildren)
{
goto Label_00F9;
}
continue;
}
if ((dwBrowseFilterType == OPCBROWSETYPE.OPC_LEAF) && element.HasChildren)
{
continue;
}
}
Label_00F9:
if (element.IsItem)
{
if (vtDataTypeFilter != 0)
{
short type = (short)OpcCom.Interop.GetType((System.Type)element.Properties[0].Value);
if (type != vtDataTypeFilter)
{
continue;
}
}
if (dwAccessRightsFilter != 0)
{
accessRights rights = (accessRights)element.Properties[1].Value;
if (((dwAccessRightsFilter == 1) && (rights == accessRights.writable)) || ((dwAccessRightsFilter == 2) && (rights == accessRights.readable)))
{
continue;
}
}
}
if (dwBrowseFilterType != OPCBROWSETYPE.OPC_FLAT)
{
hits.Add(element.Name);
}
else if (element.IsItem && ((szFilterCriteria.Length == 0) || Opc.Convert.Match(element.ItemName, szFilterCriteria, true)))
{
hits.Add(element.ItemName);
}
}
}
/// <summary>
/// Checks if the specified property is valid for the specifed access type.
/// </summary>
private ResultID ValidatePropertyID(PropertyID propertyID, accessRights accessRequired)
{
switch (propertyID.Code)
{
// check access rights for value properties.
case VALUE:
case QUALITY:
case TIMESTAMP:
{
if (m_accessRights != accessRights.readWritable && m_accessRights != accessRequired)
{
switch (accessRequired)
{
case accessRights.readable: { return(ResultID.Da.E_WRITEONLY); }
case accessRights.writable: { return(ResultID.Da.E_READONLY); }
}
}
break;
}
// no checks required for intrinsic properties.
case DATATYPE:
case ACCESSRIGHTS:
case SCANRATE:
case EUTYPE:
case EUINFO:
{
break;
}
// eu limits only valid for analog items.
case HIGHEU:
case LOWEU:
{
if (m_euType != euType.analog)
{
return(ResultID.Da.E_INVALID_PID);
}
break;
}
// data type limits properties are always read only.
case MINIMUM_VALUE:
case MAXIMUM_VALUE:
case VALUE_PRECISION:
{
if (accessRequired == accessRights.writable)
{
return(ResultID.Da.E_READONLY);
}
break;
}
// lookup any addition property.
default:
{
if (!m_properties.Contains(propertyID))
{
return(ResultID.Da.E_INVALID_PID);
}
break;
}
}
// property is valid.
return(ResultID.S_OK);
}
/// <summary>
/// Checks if the specified property is valid for the specifed access type.
/// </summary>
private ResultID ValidatePropertyID(PropertyID propertyID, accessRights accessRequired)
{
switch (propertyID.Code)
{
// check access rights for value properties.
case VALUE:
case QUALITY:
case TIMESTAMP:
{
if (m_accessRights != accessRights.readWritable && m_accessRights != accessRequired)
{
switch (accessRequired)
{
case accessRights.readable: { return ResultID.Da.E_WRITEONLY; }
case accessRights.writable: { return ResultID.Da.E_READONLY; }
}
}
break;
}
// no checks required for intrinsic properties.
case DATATYPE:
case ACCESSRIGHTS:
case SCANRATE:
case EUTYPE:
case EUINFO:
{
break;
}
// eu limits only valid for analog items.
case HIGHEU:
case LOWEU:
{
if (m_euType != euType.analog)
{
return ResultID.Da.E_INVALID_PID;
}
break;
}
// data type limits properties are always read only.
case MINIMUM_VALUE:
case MAXIMUM_VALUE:
case VALUE_PRECISION:
{
if (accessRequired == accessRights.writable)
{
return ResultID.Da.E_READONLY;
}
break;
}
// lookup any addition property.
default:
{
if (!m_properties.Contains(propertyID))
{
return ResultID.Da.E_INVALID_PID;
}
break;
}
}
// property is valid.
return ResultID.S_OK;
}
/// <summary>
/// Reads an item property from an XML stream.
/// </summary>
private void ReadProperty(XmlTextReader reader)
{
// look up the property id.
PropertyDescription property = null;
if (reader.MoveToAttribute(PROPERTY_ID))
{
try
{
property = PropertyDescription.Find(new PropertyID(((int)System.Convert.ToInt32(reader.Value))));
}
catch
{
property = null;
}
}
// ignore invalid properties.
if (property == null)
{
return;
}
// read value.
object value = ReadValue(reader, property.Type);
switch (property.ID.Code)
{
case QUALITY: { m_quality = (Quality)value; break; }
case TIMESTAMP: { m_timestamp = (DateTime)value; break; }
case ACCESSRIGHTS: { m_accessRights = (accessRights)value; break; }
case SCANRATE: { m_scanRate = (float)value; break; }
case EUTYPE: { m_euType = (euType)((int)value+1); break; }
case EUINFO: { m_euInfo = (string[])value; break; }
case HIGHEU: { m_maxValue = (double)value; break; }
case LOWEU: { m_minValue = (double)value; break; }
default:
{
m_properties[property.ID] = value;
break;
}
}
}
/// <summary>
/// Writes the value of the specified item property.
/// </summary>
public Opc.IdentifiedResult Write(
PropertyID propertyID,
Opc.Da.ItemValue value)
{
// initialize result and validate property.
IdentifiedResult result = new IdentifiedResult();
result.ItemName = m_itemID;
result.ItemPath = null;
result.ResultID = ValidatePropertyID(propertyID, accessRights.writable);
result.DiagnosticInfo = null;
// handle value writes.
if (propertyID == Property.VALUE)
{
// copy value.
m_value = Opc.Convert.Clone(value.Value);
// update quality if specified.
if (value.QualitySpecified)
{
m_quality = value.Quality;
}
// update timestamp if specified.
if (value.TimestampSpecified)
{
m_timestamp = value.Timestamp;
}
// return results.
return result;
}
// lookup property description.
PropertyDescription property = PropertyDescription.Find(propertyID);
if (property == null)
{
result.ResultID = ResultID.Da.E_INVALID_PID;
return result;
}
// check datatype.
if (!property.Type.IsInstanceOfType(value.Value))
{
result.ResultID = ResultID.Da.E_BADTYPE;
return result;
}
// write non-value
switch (propertyID.Code)
{
// standard properties.
case DATATYPE: { m_datatype = (System.Type)value.Value; return result; }
case QUALITY: { m_quality = (Quality)value.Value; return result; }
case TIMESTAMP: { m_timestamp = (DateTime)value.Value; return result; }
case ACCESSRIGHTS: { m_accessRights = (accessRights)value.Value; return result; }
case SCANRATE: { m_scanRate = (float)value.Value; return result; }
case EUTYPE: { m_euType = (euType)value.Value; return result; }
case EUINFO: { m_euInfo = (string[])Opc.Convert.Clone(value.Value); return result; }
case HIGHEU: { m_maxValue = (double)value.Value; return result; }
case LOWEU: { m_minValue = (double)value.Value; return result; }
// other defined properties.
default:
{
if (!m_properties.Contains(propertyID))
{
result.ResultID = ResultID.Da.E_INVALID_PID;
return result;
}
m_properties[propertyID] = Opc.Convert.Clone(value.Value);
break;
}
}
// write complete.
return result;
}
