MMS Connections with CS, high Total System Load
We have one controller with high Total System Load (95%). The cyclic load is in 33%. I think the high Total System Load is caused by the MMS Connections. The controller has more than 150 transactions/s with de Primary CS. What can cause the large amount of MMS connections with the CS?
Thanks in advance.
Unless the AC 800M OPC Server has "gone berserk on its own", the only viable explanation is one or more OPC clients connecting the server have added an extreme high number of OPC items and/or are exercising read/refresh at a very high rate.
Has the OPC server's MMS Update rate setting been adjusted downwards from its default of 500ms? Select the controller, then call Update Rate from the menu.
Does the AC 800M OPC Servers OPC DA statistics indicate a high number of items?
If the System 800xA's OPC DA Connector service is riding on top of the AC 800M OPC server, there is an applog operation called OPC DA Connector Statistics that will list all clients having OPC items sent to the OPC server. Refer to the attached document. Each listed client can be further interrogated using OPC DA Communicator Statistics (with argument D, full detail with item name, etc is displayed).
All OPC items funneled through the 800xA framework will be added using a commonly prefixed group name "AdapterGroupXXX". If you see other group names in the AC 800M OPC Server's statistics, they are coming from a third party having a direct connection. Also, the total client count with only 800xA on top is one (1). If you see more, there are third party clients involved.