The runtime and the OPC UA server in the process gateway may stop responding under specific circumstances where an OPC UA client calls "ConditionReferesh" to update events

The runtime and the OPC UA server in the process gateway may stop responding under specific circumstances where an OPC UA client calls "ConditionReferesh" to update events

Summary

When an OPC UA client calls "ConditionRefresh" under specific timing conditions, at the moment when alarms are generated in the runtime for which the OPC UA client has an active event subscription, both the runtime an the OPC UA server may stop responding resulting in a deadlock situation.

Description

When an OPC UA client calls "ConditionRefresh" under specific timing conditions, at the moment when alarms are generated in the runtime for which the OPC UA client has an active event subscription, both the runtime an the OPC UA server may stop responding resulting in a deadlock situation.

Solution

An issue has been addressed in the OPC UA server in the process gateway where under specific circumstances the OPC UA server and the runtime could end up in a deadlock situation when a ConditionRefresh called by an OPC UA client crosses an EventNotificationList to a OPC UA Client subscribing for event notifications. Now the runtime and the OPC UA process gateway no longer stop responding.  

Issue Number: 34585
Fixed on Date: 1.10.2015
Versions: 7.50 0 BUILD 25796