Properties and Known Restrictions

Owned by Martin Herberg
Last updated: May 02, 2024 by Michael Struwe
1 min read

The GOAL OPC UA server stack has some advantages over other stacks. The stack does not use dynamic allocation during operation. Only during the startup, dynamic allocation is done. Further, no task supported is necessary. Therefore, the GOAL OPC UA server stack is platform and OS independent. The stack supports up to two parallel secure channels, up to two concurrently sessions and two monitored items per session. Also, the stack is successfully tested in House using the OPC Foundation conformance test tool “UA CTT” and it's documented manual test cases. This is the same tool is used for official certifications done by the OPC Foundation.

 

Because of the missing dynamic allocation, it is not possible to change array sizes or create/delete nodes by an OPC UA client. Further writing of Node IDs is restricted to the same Node ID type, as before, i.e. a numerical Node ID cannot be overwritten by a string Node ID.

 

Simple Events are supported, but the content filter (Where Clause) has some restrictions:

  • The “Like” operator is not supported

  • The “Cast” operator does not support cast from and to strings.

  • The “Cast” operator does not support cast from and to (expanded) node IDs.

  • “Attribute operands” are not supported, only “Simple Attribute Operands” are allowed.