Opc server for ac 800M, Installation and Configuration
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| Refreshing OPC Clients
The OPC Server needs to refresh the OPC clients in the following situations: • After adding a new subscription or deleting a subscription to a controller. • After a communication error to a controller and when the communication is OK again. • After overflow in the event subscriptions queue in the controller (the controller setting "AE Event subscription queue size") and when the queue again is filled to less than 75%. • Five minutes after an alarm was added or removed from the controller, for example after application download. • After overflow in the list of all alarms that are not idle (the OPC Server setting MaxNoOfAlarms) and when that list again is filled to less than 90%. • After overflow in queue to OPC client (the OPC Server setting Queue Size) and when the queue is filled less than 75% again. Before refresh of the OPC clients, the OPC Server refreshes itself first on all alarms that are not in an idle state. When the OPC Server is ready with its update, the refresh of OPC clients start. However, there is a delay of 30 seconds to avoid to many refreshes. Section 5 Alarm and Event Performance 3BSE035983-510 65 Performance Response time to OPC clients will slow down considerable if more than 10 OPC clients are connected to the OPC server. Sending alarms to OPC server is done with the limitations of MMS traffic, but are time stamped correctly. |