A.2.1.4 Header layout for NetworkMessages
A UADP NetworkMessage header shall contain the following fields according to this header layout:
Version/Flags
ExtendedFlags1
PublisherId
GroupFlags
WriterGroupId
GroupVersion
NetworkMessageNumber
SequenceNumber
Additional restrictions:
The datatype for the PublisherId shall be UInt16 or UInt64
The NetworkMessage header layout is shown in Figure A.1.
Table A.1 shows the configuration for the NetworkMessage header.
| Name | Type | Restrictions |
| UADPVersion | Bit[0-3] | The version shall be 1 |
| UADPFlags | Bit[4-7] | Bit 4: PublisherId enabled = 1 Bit 5: GroupHeader enabled = 1 Bit 6: PayloadHeader enabled = 0 Bit 7: ExtendedFlags1 enabled = 1 |
| ExtendedFlags1 | Byte | Bit range 0-2: PublisherId Type with one of the two following options 001 The PublisherId is of DataType UInt16 011 The PublisherId is of DataType UInt64 Bit 3: DataSetClassId enabled = 0 Bit 4: SecurityHeader enabled = 0 Bit 5: Timestamp enabled = 0 Bit 6: PicoSeconds enabled = 0 Bit 7: ExtendedFlags2 enabled = 0 |
| PublisherId | UInt16 or UInt64 | Configured value for the PubSubConnection. The datatype shall be UInt16 or UInt64. |
| GroupHeader | ||
GroupFlags | Byte | Bit 0: WriterGroupId enabled = 1 Bit 1: GroupVersion enabled = 1 Bit 2: NetworkMessageNumber enabled = 1 Bit 3: SequenceNumber enabled = 1 Bits 4-6: 0 Bit 7: 0 |
WriterGroupId | UInt16 | Configured value for the WriterGroup. |
GroupVersion | VersionTime | Configured value for the WriterGroup. |
NetworkMessage Number | UInt16 | Configured value for the WriterGroup. |
SequenceNumber | UInt16 | Defined by Table 154. |
Table A.2 defines the values for the configuration parameters representing this layout.
| Parameter | Value |
| UadpNetworkMessageContentMask | 0x0000003F This value results of the following options: Bit 0: PublisherId enabled = 1 Bit 1: GroupHeader enabled = 1 Bit 2: WriterGroupId enabled = 1 Bit 3: GroupVersion enabled = 1 Bit 4: NetworkMessageNumber enabled = 1 Bit 5: SequenceNumber enabled = 1 |
When a PubSubConnection is created by using the Method AddConnection() the element PublisherId contained in the argument PubSubConnectionDataType shall be of the datatype UInt16 or UInt64.