OPCUA Interface

The DS device is an OPC-UA server, this server organises information into nodes in an address space. The address space is accessed using a client that connects to the URL of the server.

Like a file system, there are standard directories for the operating system, there are standard nodes that form part of every OPC-UA server. The root node of the system, Root, has a child node, Objects, from which we can access the Logic node.

The Logic node contains the application specific nodes. The Logic node is based on the OPC UA Companion Standard “PLCopen: OPC UA for IEC 61131-3”. Inside the Logic node is the Application node where the objects related to the DS Controller application reside. Global user variables can be exposed under “GVL_USERVAR” while PLC variables are exposed in “PLC_PRG”, shown below:

DS opcua commands