The mask allows the following options:

Bit 0: NetworkMessageHeader = 1

Bit 1: DataSetMessageHeader = 1

Bit 2: SingleDataSetMessage = 0

Bit 3: PublisherId = 1

Bit 4: DataSetClassId configurable (default is 0)

Bit 5: ReplyTo configurable (default is 0)

Bit 6: WriterGroupName configurable (default is 0)

The mask allows the following options:

Bit 0: DataSetWriterId = 1

Bit 1: MetaDataVersion = 0

Bit 2: SequenceNumber = 1

The SequenceNumber is always omitted for Action messages.

Bit 3: Timestamp = 1

Bit 4: Status = 1

The Status is omitted for ActionRequest messages.

Bit 5: MessageType configurable (default is 0)

Bit 6: DataSetWriterName configurable (default is 0)

Bit 7: FieldEncoding1 = 0

Bit 8: PublisherId = 0

Bit 9: WriterGroupName configurable (default is 0)

Bit 10: MinorVersion = 1

Bit 11: FieldEncoding2 = 1

Configurable (default is 0)

The value shall be 0 or 0x20 if the MesageType is “ua-event”.

Configurable

If the KeyFrameCount is not 1, the MessageType bit shall be true.