Capabilities of the OPCUA DA Collector

The following table outlines the capabilities of the Historian OPCUA DA Collector.

Feature	Capability
Browse Source For Tags	Yes (on OPCUA servers that support browsing)
Browse Source For Tag Attributes	Yes
Polled Collection	Yes
Minimum Poll Interval	100 ms
Unsolicited Collection	Yes. If you are using an OPCUA DA collector with unsolicited data collection and the collector compression is disabled, new values must produce an exception. When the OPCUA DA collector performs unsolicited collection, the deadband percentage is determined by the collector deadband percent. You can only configure the collector deadband percent by enabling compression.
Timestamp Resolution	100ms
Accept Device Timestamps	Yes
Floating Point Data	Yes
Integer Data	Yes
String Data	Yes
Binary Data	Yes
Python Expression Tags	No

Note: You must set Time Assigned by field to Source if you have unsolicited tags getting data from an Historian OPCUA DA Collector.

Tag Attributes Available on Browse

The following table outlines the tag attributes available when browsing.

Attribute	Capability
Tag name	Yes
Source Address	Yes
Engineering Unit Description	Yes, varies by OPCUA Server Vendor.
Data Type	Yes. See Selecting Data Types.
Hi Engineering Units	Yes, varies by OPCUA Server Vendor.
Lo Engineering Units	Yes, varies by OPCUA Server Vendor.
Hi Scale	Yes
Lo Scale	Yes
Is Array Tag	No

Note: While some of these attributes are queried on a browse, they are not shown in the browse interface. These attributes are used when adding a tag, but you will not be able to see whether or not all attributes come from the server.

Selecting Data Types

The following table lists the data types recommended for use with Historian.

OPCUA Data Type	Recommended Data Type in Historian
I1 - 16 bit signed integer	Single Integer
I4 - 32 bit signed integer	Double Integer
R4 - 32 bit float	Single Float
R8 - 64 bit double float	Double Float
UI2 - 16 bit unsigned single integer	Unsigned Single Integer
UI4 - 32 bit unsigned double integer	Unsigned Double Integer
UI8 - 64 bit unsigned quad integer	Unsigned Quad Integer
I8 - 64 bit quad integer	Quad Integer
BSTR	Variable String
BOOL	Boolean
I1 - 8 bit single integer	Byte

Note: The Historian OPCUA Collector requests data from the OPCUA DA server in the native data type. Then the Historian OPCUA DA collector converts the received value to a Historian Data Type before sending it to the Historian database.

OPCUA Group Creation

To increase performance, it is recommended that you limit the number of OPCUA groups created by the Historian system. To do this, consider grouping Historian tags (collected by the Historian OPCUA DA Collector) using the least amount of collection intervals possible.