Filter Attributes Supported on Historian OPC HDA
Historian OPC HDA Server supports filtering on the following attributes:
- OPC_HDA_ITEM_ID
- OPC_HDA_DESCRIPTION
- OPC_HDA_DATA_TYPE
- OPC_HDA_ENGINEERING_UNITS
The following table provides the correspondence between OPC HDA attributes and Historian tag attributes, and shows the supported operators:
| Historian OPC HDA Attribute | Supported Operators | Historian Property Type |
|---|---|---|
| OPCHDA_DATA_TYPE | OPC_HDA_EQUAL_TO | Data Type |
| OPCHDA_DESCRIPTION | OPC_HDA_EQUAL_TO | Tag Description |
| OPCHDA_ENG_UNITS | OPC_HDA_EQUAL_TO | Engineering Units |
| OPCHDA_ITEMID | OPC_HDA_EQUAL_TO | Item ID |
Important: OPC HDA Server filter strings are case sensitive.
Historian HDA Server supports filtering on OPC_HDA_ARCHIVING attribute, but the filtering on OPC_HDA_ ARCHIVING attribute should not be used by the clients, since the OPC_HDA_ARCHIVING attribute value is always true. You can refer to the log file to trace a history of communication events dealt with by the Historian OPC HDA Server. You can also turn on the debug mode to more know more details in the log file. If an invalid filter is passed by a HDA Client, then the Historian HDA Server returns all the available items in the address space.
Tip:
- The wildcard character (*) will return all the tags.
- The wildcard (key*) will return tags which begins with key.
- The wildcard (key) returns an exact tag name.