dOPC Client Toolkit Help file
TdOPCItem Class
dOPCIntf.TdOPCItemData
    dOPC.TdOPCItem
C++
public: class TdOPCItem : public TdOPCItemData;
C#
public class TdOPCItem : TdOPCItemData;
Visual Basic
Public Class TdOPCItem
Inherits TdOPCItemData

dOPC

class for an OPCItem 

TdOPCItem represents a connection to a data source within the server.

Associated with each item is a Value, Quality and TimeStamp.

TdOPCItem Constructors 
Description 
This is Create, a member of class TdOPCItem. 
TdOPCItem Methods 
Description 
IsGoodQuality returns True if the Quality of the value is good, otherwise False
IsReadAble returns True if the value is readable, otherwise False
IsWriteAble returns True if the value is writeable, otherwise False
OPCCommand executes the passed Command on the server. 
QualityAsString returns the Quality as a human readable string. 
ValueStr returns the latest Value as a string. 
WriteAsync performs an asynchronous write of the passed values to the server. 
WriteSync performs a synchronous write of the passed values to the server. 
TdOPCItemData Properties 
Description 
AccessPath contains the complete path of the item (e.g. Branch1.Branch2.Item1). 
AccessRights contains the access rights of the item. 
CanonicalDatatype contains the native data type of the item. 
This is ChangeCount, a member of class TdOPCItemData. 
ClientHandle contains a value associated with the item. 
Data 
Data 
Data is not used by TdOPCItemData
 
EUInfo contains the Engineering Units information of the item. 
EUType contains the type of Engineering Units (EU) information of the item (if any) contained in the property EUInfo
GUIItems contains a list of all controls (e.g. TEdits) connected to the item. 
IsActive contains the state of the data acquisition for this item. 
ItemID contains the unique identifier for the item. 
LastError contains the code for the last occurred OPC error. 
Parent contains a reference to the parent TdOPCGroup object. 
Quality contains the latest quality read from the server. 
RequestType contains the data type which the item's return value will have. 
 
ServerHandle contains the assigned server handle for the item. 
Tag 
Tag has no predefined meaning. 
TimeStamp contains the latest timestamp read from the server. 
Value contains the latest value read from the server. 
WantQuality contains the quality that should be written in the WriteAsync and WriteSync methods. 
WantTimeStamp contains the timestamp that should be written in the WriteAsync and WriteSync methods. 
WantValue contains the value that should be written in the WriteAsync and WriteSync methods. 
What do you think about this topic? Send feedback!
Copyright © 2001-2014 Kassl GmbH (http://www.kassl.de). All rights reserved.