OPC Specific Properties

OPC Specific Properties

PropID	Description
1	“Item Canonical DataType” The data type of the item as stored on the OPC server. This property is also exposed in the CanonicalDataType property of the daitem object.
2	“Item Value” The value that was last obtained from the OPC server for the item. This property is the same as the Value property of the daitem object. Querying this property behaves like a read operation from the device.
3	“Item Quality” The quality of the item's Value property. This property is the same as the Quality property of the daitem object. Querying this property behaves like a read operation from the device.
4	“Item Timestamp” The time that the Value and Quality was obtained by the device (if this is available) or the time the server updated or validated the Value and Quality in its cache. This property is the same as the TimeStamp property of the daitem object. Querying this property behaves like a read operation from the device.
5	“Item Access Rights” The ability of the server to read or write data to this item.
6	“Server Scan Rate” Represents the fastest rate at which the server could obtain data from the underlying data source. The accuracy of this value could be affected by system load and other factors, and is not a guaranteed rate.
7-99	Reserved for future use

Related Topics

• OPC DA Server Item Properties
• OPC Item Property Set
• OPC Recommended Properties