Use Case

Get attributes of a device parameter


OPC Client has the UI windows for displaying the device details information.

The UI window displays parameter names, its’ engineering units and values (if the parameter is readable).

When OPC Client displays the value of a parameter, the value is displayed according to the “display format“, which is described in the DD.

If the OPC Client also has the parameter-write-function and if the parameter is writable, an UI-element for writing the value to a parameter is displayed.


Mass Configuration


Topology and device node are available in OPC UA Server

Device is connected to the OPC UA Server.

OPC Client gets the parameter list of a device from OPC Server.

To display the parameter name and its value, OPC Client tries to get the detail information of each parameter.

Post conditions

On the OPC client, user can see the parameter names, and can see the detail information for each parameter.

Detail Information of parameter:

the data type, the label name, the minimum value, the maximum value, the engineering units, writable, readable, the enumeration list, the display format, the edit format.


Engineer, Expert, Observer, Plant Asset Manager


Whenever a user needs the attributes of parameters for further access.






OPC Client requests to get the attributes of a parameter of a device to OPC Server.


OPC Server gets the attributes of the parameter which is specified by OPC Client from the device DTM.


OPC Client displays the parameter name to use the label name, and the engineering units.


Step 1, The specified parameter does not exist in the device.



To use the attributes of a device parameter which is gotten by this use case, OPC Client can work as follows.

[For read parameter]

OPC Client can recognize a parameter is readable or not, and then OPC Client gets the value of the parameter via OPC Server from the device.

OPC Client displays the corresponding label with the value if the data type of a parameter is the enumeration, otherwise (if the data type is not the enumeration) OPC Client displays the value according to the “display format“.

[For write parameter]

OPC Client can recognize a parameter is writable or not, and then OPC Client can check the entered value whether the data type, and the minimum value and the maximum value of the entered value are correct or not when user tries to write a value to a parameter.

Open Issues