The OPCUA32 client driver does not resume communication after short network connection loss under specific circumstances.

The OPCUA32 client driver does not resume communication after short network connection loss under specific circumstances.

Summary

When the network connection between the OPCUA32 client driver and the OPC UA server is lost for a specific short period where TCP retransmits may still reach the server after the connection is established and where the connection loss is long enough for the subscription lifetime to expire on the server, the OPCUA32 client driver does not resume communication if in this case the OPC UA server returns a service result error code "0x80790000" with subscription ID 0.   Variables remain INVALID in the runtime after the network connection is established again.

Description

When the network connection between the OPCUA32 client driver and the OPC UA server is lost for a specific short period where TCP retransmits may still reach the server after the connection is established and where the connection loss is long enough for the subscription lifetime to expire on the server, the OPCUA32 client driver does not resume communication if in this case the OPC UA server returns a service result error code "0x80790000" with subscription ID 0.   Variables remain INVALID in the runtime after the network connection is established again.

Solution

An issue has been addressed in the OPCUA32 client driver where the driver did not resume communication when an OPC UA server returned a service result with the error code "0x80790000" and the (invalid) subscription ID 0. The OPCUA32 client driver rejected the publish response with the invalid subscription id before evaluating the service result.  

Issue Number: 35548
Fixed on Date: 13.11.2015
Versions: 7.11 0 BUILD 24090 | 7.20 0 BUILD 24121