The parameter NetworkMessageNumberwith the DataType UInt16is a read-only parameter set by the Publisherin the case of a fixed NetworkMessagelayout. The default value is 0 and indicates that the position of the DataSetMessagein a NetworkMessageis not fixed.

If the NetworkMessagelayout is fixed and all DataSetMessagesof a WriterGroupfit into one single NetworkMessagethe value of NetworkMessageNumbershall be 1. If the DataSetMessagesof a WriterGroupare distributed or chunked over more than one NetworkMessagethe first NetworkMessagein a PublishingIntervalshall be generated with the value 1, the following NetworkMessagesshall be generated with incrementing NetworkMessageNumbers. To avoid a roll-over the number of NetworkMessagesgenerated from one WriterGroupwithin one PublishingIntervalis limited to 65535.