UA Part 14: PubSub - 6.3.2 JSON message mapping

The parameter NetworkMessageContentMask defines the optional header fields to be included in the NetworkMessages produced by the WriterGroup. The DataType for the JSON NetworkMessage mapping is JsonNetworkMessageContentMask.

The DataType JsonNetworkMessageContentMask is formally defined in Table 106.

Table 106 – JsonNetworkMessageContentMask values

Value	Bit No.	Description
NetworkMessageHeader	0	The JSON NetworkMessage header is included in the NetworkMessages. If this bit is false, bits 3 and 4 shall be 0.
DataSetMessageHeader	1	The JSON DataSetMessage header is included in each DataSetMessage. If this bit is false then the DataSetMessage header is not included and the header related bits in DataSetMessageContentMask for the DataSetWriters are ignored (see 6.3.2.3.1). Bits in the DataSetMessageContentMask related to the payload (like FieldEncoding1 and FieldEncoding2) are applied.
SingleDataSetMessage	2	Each JSON NetworkMessage contains only one DataSetMessage.
PublisherId	3	The PublisherId is included in the NetworkMessages.
DataSetClassId	4	The DataSetClassId is included in the NetworkMessages. The NetworkMessage can only contain DataSetMessages with the same DataSetClassId. If DataSetMessages have different DataSetClassIds they must be sent in individual NetworkMessages.
ReplyTo	5	Not used.
WriterGroupName	6	The WriterGroup name is included in the NetworkMessages.

The JsonNetworkMessageContentMask representation in the AddressSpace is defined in Table 107.

Table 107 – JsonNetworkMessageContentMask definition

Attribute	Value
BrowseName	JsonNetworkMessageContentMask
IsAbstract	False
References	Node Class	BrowseName	DataType	TypeDefinition	Others
Subtype of UInt32 defined in OPC 10000-5
HasProperty	Variable	OptionSetValues	LocalizedText []	PropertyType
Conformance Units
PubSub Parameters JSON

6.3.2.1.2 JsonWriterGroupMessageDataType structure

This Structure DataType is used to represent the JSON NetworkMessage mapping specific WriterGroup parameters. It is a subtype of WriterGroupMessageDataType defined in 6.2.6.7.3.

The JsonWriterGroupMessageDataType is formally defined in Table 108.

Table 108 – JsonWriterGroupMessageDataType structure

Name	Type	Description
JsonWriterGroupMessageDataType	Structure	Subtype of WriterGroupMessageDataType defined in 6.2.6.7.3.
NetworkMessageContentMask	JsonNetworkMessageContentMask	Defined in 6.3.2.1.1.

Its representation in the AddressSpace is defined in Table 109.

Table 109 – JsonWriterGroupMessageDataType definition

Attributes	Value
BrowseName	JsonWriterGroupMessageDataType
IsAbstract	False
Subtype of WriterGroupMessageDataType defined in 6.2.6.7.3.
Conformance Units
PubSub Parameters JSON

6.3.2.2 JSON ReaderGroup Parameters

There are no JSON specific message mapping parameters defined for the ReaderGroup.

6.3.2.3 JSON DataSetMessage Writer

6.3.2.3.1 DataSetMessageContentMask

The DataSetMessageContentMask defines the flags for the content of the DataSetMessage header. The JSON message mapping specific flags are defined by the JsonDataSetMessageContentMask DataType.

The JsonDataSetMessageContentMask DataType is formally defined in Table 110.

Table 110 – JsonDataSetMessageContentMask values

Value	Bit No.	Description
DataSetWriterId	0	If this flag is set, a DataSetWriterId shall be included in the DataSetMessage header.
MetaDataVersion	1	If this flag is set, the ConfigurationVersion is included in the DataSetMessage header.
SequenceNumber	2	If this flag is set, the DataSetMessageSequenceNumber is included in the DataSetMessage header.
Timestamp	3	If this flag is set, a timestamp shall be included in the DataSetMessage header.
Status	4	If this flag is set, an overall status is included in the DataSetMessage header.
MessageType	5	If this flag is set, the message type is included in the DataSetMessage header.
DataSetWriterName	6	If this flag is set, a DataSetWriterName shall be included in the DataSetMessage header.
FieldEncoding1	7	The definition of field encoding configuration through the bits FieldEncoding1 and FieldEncoding2 is defined in Table 111.
PublisherId	8	The PublisherId is included in the DataSetMessages. This bit shall be false if the NetworkMessageHeader is active.
WriterGroupName	9	The WriterGroup name is included in the DataSetMessages. If the WriterGroup name is included in the NetworkMessage header, it shall not be included in the DataSetMessages.
MinorVersion	10	If this flag is set, the MinorVersion field of the ConfigurationVersion is included in the DataSetMessage header.
FieldEncoding2	11	The definition of field encoding configuration through the bits FieldEncoding1 and FieldEncoding2 is defined in Table 111.

The definition of field encoding configuration through the bits FieldEncoding1 and FieldEncoding2 is defined in Table 111.

Table 111 – Field endcoding configuration

FieldEncoding1	FieldEncoding2	Description
False	True	The JSON VerboseEncoding is used for the DataSetMessage field encoding.
True	True	The JSON CompactEncoding is used for the DataSetMessage field encoding.
False	False	The deprecated JSON NonReversibleEncoding is used for the DataSetMessage field encoding. The RawData bit of the DataSetFieldContentMask shall be ignored.
True	False	The deprecated JSON ReversibleFieldEncoding is used for the DataSetMessage field encoding. The RawData bit of the DataSetFieldContentMask shall be ignored.

The JsonDataSetMessageContentMask representation in the AddressSpace is defined in Table 112.

Table 112 – JsonDataSetMessageContentMask definition

Attribute	Value
BrowseName	JsonDataSetMessageContentMask
IsAbstract	False
References	Node Class	BrowseName	DataType	TypeDefinition	Others
Subtype of UInt32 defined in OPC 10000-5
HasProperty	Variable	OptionSetValues	LocalizedText []	PropertyType
Conformance Units
PubSub Parameters JSON

6.3.2.3.2 JsonDataSetWriterMessageDataType structure

This Structure DataType is used to represent JSON DataSetMessage mapping specific DataSetWriter parameters. It is a subtype of the DataSetWriterMessageDataType defined in 6.2.4.5.3.

The JsonDataSetWriterMessageDataType is formally defined in Table 113.

Table 113 – JsonDataSetWriterMessageDataType structure

Name	Type	Description
JsonDataSetWriterMessageDataType	Structure	Subtype of DataSetWriterMessageDataType defined in 6.2.4.5.3.
DataSetMessageContentMask	JsonDataSetMessageContentMask	Defined in 6.3.2.3.1.

Its representation in the AddressSpace is defined in Table 114.

Table 114 – JsonDataSetWriterMessageDataType definition

Attributes	Value
BrowseName	JsonDataSetWriterMessageDataType
IsAbstract	False
Subtype of DataSetWriterMessageDataType defined in 6.2.4.5.3.
Conformance Units
PubSub Parameters JSON

6.3.2.4 JSON DataSetMessage Reader

6.3.2.4.1 Network‌Message‌ContentMask

The NetworkMessageContentMask with DataType JsonNetworkMessageContentMask indicates the optional header fields included in the received NetworkMessages. The JsonNetworkMessageContentMask DataType is defined in 6.3.2.1.1.

6.3.2.4.2 DataSetMessage‌ContentMask

The DataSetMessageContentMask with the DataType JsonDataSetMessageContentMask indicates the optional header fields included in the DataSetMessages.

The JsonDataSetMessageContentMask DataType is defined in 6.3.2.3.1.

6.3.2.4.3 JsonDataSetReaderMessageDataType structure

This Structure DataType is used to represent JSON DataSetMessage mapping specific DataSetReader parameters. It is a subtype of the DataSetReaderMessageDataType defined in 6.2.9.13.3.

The JsonDataSetReaderMessageDataType is formally defined in Table 115.

Table 115 – JsonDataSetReaderMessageDataType structure

Name	Type	Description
JsonDataSetReaderMessageDataType	Structure	Subtype of DataSetReaderMessageDataType defined in 6.2.9.13.3.
NetworkMessageContentMask	JsonNetworkMessageContentMask	Defined in 6.3.2.4.1.
DataSetMessageContentMask	JsonDataSetMessageContentMask	Defined in 6.3.2.4.2.

Its representation in the AddressSpace is defined in Table 116.

Table 116 – JsonDataSetReaderMessageDataType definition

Attributes	Value
BrowseName	JsonDataSetReaderMessageDataType
IsAbstract	False
Subtype of DataSetReaderMessageDataType defined in 6.2.9.13.3.
Conformance Units
PubSub Parameters JSON

6.3.2.4.4 DataSetClassId

The parameter DataSetClassId with DataType Guid defines a DataSet class related filter. If the value is null or the parameter is not set, the DataSetClassId filter is not applied.

The parameter is configured in the DataSetReaderProperties with the Key 0:DataSetClassId.