In redundant systems, it is common to require that a particular Server in the Redundant Server Setbe taken out of the Redundant Server Setfor a period of time. Some items that could cause this may include:

• Certificate update
• Security reconfiguration
• Rebooting or restarting of the machine for
• software updates and patches
• installation of new software
• Reconfiguration of the AddressSpace

The removal from the Redundant Server Setcan be done through a complete shutdown or by setting the ServiceLevelof the Serverto Maintenancesub-range. This can be done through a Serverspecific configuration tool or through the Method RequestServerStateChangeon the ServerType. The Method is formally defined in OPC 10000-5.

This Methodrequires that the Clientprovide credentials with administrative rights on the Server.