RPC based services unavailable in certain situations (leading to improperly handled Plug Alarms and other issues)

In certain situations it may happen that IO Controller is not able to perform RPC based services.

This issue will occur if more than 4 configured ARs exist which are not available in the network. If the configuration consists of e.g. 8 ARs of which 4 are established and 4 can not be established because corresponding IO Devices are not availabe, the "error situation" is reached and the issue occurs.

Once the issue occurs, the following will happen

• Plug submodule alarms are not handled correctly (no RPC parameterization is sent)
  • this leads to a blocked alarm channel and alarms of this IO Device can not be received any more
• unexpected long time required to Release an AR
• ParameterBegin sequence can not be issued any more
  • this service is not yet available as official service for application, only used internally for testing purposes

Applicative acyclic services (Read Record and Write Record) are still possible and thus not affected by this issue.

If less than 4 configured devices are not available in the network, this issue will not occur.