User Documentation
Table Of Contents
- Table of contents
- 1 Introduction
- 2 Safety instructions
- 3 System overview
- 4 Operating behavior
- 5 Software installation
- 6 Configuration
- 7 Program development
- 8 Licensing
- 9 Device Administration (DevAdmin)
- 10 Software units
- 11 OPC UA Server
- 12 Node-RED
- 13 LongtermDiagnosticMonitor
- 14 Data recorder
- 15 Diagnostics
- 16 Maintenance
- 17 Technical data
- 18 Directives and standards
- 19 Appendix: Tutorial - creating an IEC project
- 20 Appendix: Addressing in the Ethernet (basics)
- 21 Appendix: Tutorial FoE
- 22 Appendix: Tutorial - call C function from IEC
- Index

OPC UA Server
System manual
2696790000/02/04.2020
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The client requests a sampling interval of 70 ms. The server answers that
the monitored item (MonitoredItem) recorded at intervals of 100 ms.
11.4 Generic variable tree
The generic variable tree is used to display the system variables of the IEC
application and can be activated / deactivated via the expert entry Show-
VariableTree (in u-create studio). By default, the generic variable tree is
deactivated.
[OpcUa]
[OpcUa.Application]
ShowVariableTree = 1 // 1 = activate, 0 = deactivate
After activating the generic variable tree and restarting the controller, the
generic variable tree is located in the directory Root/Objects (NodeId:
Name space URI = "KeControlOpcUa/KeControlVar", Numeric ID = 0, Dis-
playName = "KeControl Variables").
The generic variable tree is an image of the KeStudioU4 u-create studio
Variable Browser. The directory structure consists of the root nodes APPL, in
which the approved IEC variables are located, and SYS, which contains the
data of the system configuration. With the exception of SYS.CAT, all variable
browser data are also visible in the OPC UA Server. The application and
configuration data are displayed using object nodes (FolderType) and vari-
able nodes. The node ID of the node is always of type String and is derived
from the path of the data. All nodes are created in the "KeControlOpcUa/Ke-
ControlVar" namespace.
Example
The boolean application variable VarBool under APPL.system has the node
ID "APPL.system.VarBool" and the OPC UA data type Boolean.
Arrays and structures are created in the generic variable tree using directo-
ries and individual variable nodes for the elements. All variable nodes offer
read and write access (Attribute AccessLevel). Whether or not read and
write operations work depends on the underlying data source. Approved sys-
tem variables of the IEC in the APPL directory now support read and write
access. Certain system configurations, however, cannot be overwritten. In
case of an unauthorized write access, a corresponding error code is re-
turned.
11.5 Creating an information model
The OPC UA Server supports the ability specified in the standard to create
an information model via an XML file. This means that the OPC UA Standard
address space can be expanded by adding a customer-specific information
model. You can also define the structure for displaying the data.