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Entry type: FAQ Entry ID: 109755860, Entry date: 02/22/2018

What are the possible causes and remedies for appearance of the status code in the OPC UA Client when using subscriptions?

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The following table gives you the necessary information for the S7-1500 CPUs, ET 200 CPUs, Software Controllers and Open Controllers.


Status codePossible causeRemedy
BadTooManyMonitoredItemsThe maximum number of monitored elements in a subscription has been reached.

You have to create a new subscription to register more elements.

In the case of projects with TIA Portal V15 and higher you can also set the maximum number of monitored elements via the CPU configuration. 
Request with too many elements Pay attention on the server to the specified maximum numbers in the "ServerCapabilities" object.
BadOutOfMemoryMaximum quantity framework of the OPC US server has been exceeded

Reduce the number of elements registered via OPC UA.

Using an OPC UA Server Diagnostics Tool (UaExpert of Unified Automation, for example) make sure that there are no inactive sessions and subscriptions. As a countermeasure you can select the corresponding timeouts (Subscription Timeout <= Session Timeout) in the Client.

BadTooManySubscriptionsThe maximum number of subscriptions has been exceededCreate a subscription in a new session.

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