OPC UA tags

FactoryTalk Linx

OPC UA Connector acts as a proxy between one or more OPC UA Servers and a

FactoryTalk

application, providing OPC UA data as tags.

A tag refers to a unique identifier for a data item within the OPC UA Server application. Use tags to read and write Live Data values from and to the data source.

Data items in an OPC UA Server can contain data as a scalar value, an array of data values, and a structure.

FactoryTalk Linx

OPC UA Connector converts these data to tags in

FactoryTalk Live Data

, where each tag represents a single scalar value. Tags can also contain children, which can be a tag, a folder, or other OPC UA constructs. In

FactoryTalk Live Data Test Client

, a usable item is displayed as a tag or a folder. When a tag data item is below another tag,

FactoryTalk Live Data Test Client

presents the tag as both a data item and a folder. To distinguish the folder from the data value, the tag name is shown as the folder, and ¹ is appended to the tag name to indicate the value portion. If the value is an array, is appended to all the elements in the browser.

For example:

If MyTag
contains data and has children below it, the data appears as MyTag.Value
in the tag browser. When the tag is selected, is discarded from the tag name, making it appears as MyTag
in the application.

If MyTag
is an array of ten elements, each element appears as a single tag such as MyTag[0].Value
, MyTag[1].Value
, and so forth. When the tag is selected is discarded from the tag name, allowing the application to access array values as MyTag[0]
, MyTag[1]
, and so forth.

Previous versions of

FactoryTalk Linx

OPC

UA Connector use

@UA_Folder

to denote the folder aspect of a tag. This method has been deprecated and tags configured with previous versions of

FactoryTalk Linx

OPC UA Connector are compatible with the current and future versions of

FactoryTalk Linx

OPC UA Connector.

An extensive set of predefined

OPC