Warning

Features currently under evaluation may be modified in the next version without prior notice. If you are using these beta features, we welcome your feedback and experience. Your input is crucial to refining and improving these features before their official release. Please share your thoughts and experiences with us, and contribute to the evaluation process.

OPC-DA

Capabilities

Capability	Support	Comment
OPC-UA protocol		See OPC-UA
Connection monitoring state with a OPC-DA server		See Server monitoring connection state
Reading value by subscription from OPC-DA server		See Reading values using subscription
Writing value from OPC-DA server		See Writing values

Supported types

Concept

Overview

OnSphere allows you to easily read (Reading values using subscription) and write (Writing values) data on a OPC-DA server. The status of connection between OnSphere and the OPC-DA server is also monitored.

Here are the possible connection parameters for an OPC DA server :

OnSphere Type transformation

Opc Da Type	OnSphere Type
BSTR	TEXT
BOOL	BOOLEAN
I1	TEXT
I2	NUMBER
I4	NUMBER
UI1	NUMBER
UI2	NUMBER
UI4	NUMBER
R4	DECIMAL
R8	DECIMAL

Note

If a type is not in the above table it is not officially supported but it does not mean it won’t work.

Connect

Here are the possible connection parameters for an OPC DA Server :

Field	Description	Support	Usage
classId	The class Id of the OPC DA Server		Tells which application to connect to on the Windows machine
progId	The programme Id of the OPC DA Server		Tells which application to connect to on the Windows machine
domain	The domain of the Windows machine you are trying to reach
passwordProvider	The OPC DA Server password
host	The host of the OPC DA Server

Note

It is recommended to use classId if possible. If the classId and the progId are provided the classId has priority.

Server monitoring connection state

Concept

The connection state between the OPC-DA server and a server can be read as a BOOLEAN value from the OPC-DA device in the OnSphere hierarchy (i.e. root.opc_da.server1 for example). If the connection is not working the state will be set to false.

Usage

A typical use case would be to monitor the status of an OPC-DA server

Reading values using subscription

Concept

OnSphere will read a specific itemId once the server is reachable (once the connection state value is set to true). Once it was read for the first time it will then subscribe to it and notice OnSphere when a change occurs. The module allows you to read an itemId by defining a owner.

When reading a value please refer to the correct OnSphere type following this table.

Usage

A typical use case would be to monitor a temperature of a boiler.

Writing values

Concept

The module allows you to write on an OPC-DA device on demand. OnSphere allows OPC-DA writing through callbacks: define your output and simply reference it in a callback.

When writing a value please refer to the correct OnSphere type following this table.

Usage

A typical use case would be to control the speed of a motor.