AccessOPCUA32: Communication with the OPC UA server in the process gateway is no longer possible when the OPC UA client does not expire publish requests
Summary
When an OPC UA client uses a timeouthint with the value "0" in PublishRequests, indicating that the publish request does not time out, the OPC UA server does not correctly consider the value "0" as no expiry and instead immediately expires the publish request.
As a result, OPC UA communication using subscriptions with such an OPC UA client no longer works.
Description
When an OPC UA client uses a timeouthint with the value "0" in PublishRequests, indicating that the publish request does not time out, the OPC UA server does not correctly consider the value "0" as no expiry and instead immediately expires the publish request.
As a result, OPC UA communication using subscriptions with such an OPC UA client no longer works.
Solution
An issue has been addresed in the OPC UA server in the process gateway where the OPC UA server incorrectly immediately expired PublishRequests without an expiry time.
Now, when an OPC UA client specifies "0" for the timeoutHint, the OPC UA server does not expire the PubishRequests.
Information
As a workaround, an OPC UA client may be configured to use a different value for TimeoutHint
As another workaround, an OPC UA client may use read requests instead of communicating over subscriptions.
This behavior was introduced with the change documented in article ID 537838
Issue Number: 38603
Fixed on Date: 10.7.2017
Versions: 7.60 0 BUILD 39532