The KeyFrameCountwith DataType UInt32is the multiplier of the PublishingIntervalthat defines the maximum number of times the PublishingIntervalexpires before a key frame message with values for all published Variablesis sent. The delta frame DataSetMessagescontains just the changed values. If no changes exist, the delta frame DataSetMessageshall not be sent. If the KeyFrameCountis set to 1, every message contains a key frame.

For PublishedDataSetsthat provide cyclic updates of the DataSet, the value shall be greater than or equal to 1. PublishedDataItemsor custom sources with CyclicDataSetset to true provide cyclic updates.

For non-cyclic PublishedDataSetsthat provide acyclic event based DataSets, the value shall be 0.PublishedEventsor custom sources with CyclicDataSetset to false provide acyclic updates.

For a heartbeat DataSetMessage, the value shall be 1.