The following DataSets are used for the following JSON message examples.
Table A.13 shows the field for example DataSet1.
|
Field Name |
DataType |
ValueRank |
|
Active |
Boolean |
Scalar |
|
Temperature |
Double |
Scalar |
|
Counter |
UInt32 |
Scalar |
|
AdditionalInfo |
String |
Scalar |
Table A.14 shows the field for example DataSet2.
|
Field Name |
DataType |
ValueRank |
|
LocationName |
String |
Scalar |
|
Coordinate |
MyStruct |
Scalar |
|
X |
Float |
Scalar |
|
Y |
Float |
Scalar |
|
Measurements |
Int32 |
Array |
Table A.15 shows the field for example DataSet3.
|
Field Name |
DataType |
ValueRank |
|
BooleanValue |
Boolean |
Scalar |
|
Int32Value |
Int32 |
Scalar |
|
Int64Value |
Int64 |
Scalar |
|
UInt32Value |
UInt32 |
Scalar |
|
UInt64Value |
UInt64 |
Scalar |
|
DoubleValue |
Double |
Scalar |
|
DateTimeValue |
DateTime |
Scalar |
|
StringValue |
String |
Scalar |
|
GuidValue |
Guid |
Scalar |
|
StatusCodeValue |
StatusCode |
Scalar |
|
LocalizedTextValue |
LocalizedText |
Scalar |
|
ByteStringValue |
ByteString |
Scalar |
|
NodeIdValue |
NodeId |
Scalar |
|
QualifiedNameValue |
QualifiedName |
Scalar |
The following example shows the DataSetMetaData message for DataSet1.
{
"MessageId": "66D65CA4-92EE-4195-9867-E6E27794B692",
"MessageType": "ua-metadata",
"PublisherId": "MyPublisher",
"DataSetWriterId": 101,
"MetaData": {
"Fields": [
{
"Name": "Active",
"FieldFlags": 0,
"BuiltInType": 1,
"DataType": {"Id": 1},
"ValueRank": -1,
"MaxStringLength": 0,
"DataSetFieldId": "f355bfe8-d5c0-4073-aa89-c8d9d9f8c0c4"
},
{
"Name": "Temperature",
"FieldFlags": 0,
"BuiltInType": 11,
"DataType": {"Id": 11},
"ValueRank": -1,
"MaxStringLength": 0,
"DataSetFieldId": "4b91e1cc-61f5-411a-9fb3-ea9087d2154c"
},
{
"Name": "Counter",
"FieldFlags": 0,
"BuiltInType": 7,
"DataType": {"Id": 7},
"ValueRank": -1,
"MaxStringLength": 0,
"DataSetFieldId": "885d0b3b-8a83-41ae-882a-3a528041140f"
},
{
"Name": "AdditionalInfo",
"FieldFlags": 0,
"BuiltInType": 12,
"DataType": {"Id": 12},
"ValueRank": -1,
"MaxStringLength": 0,
"DataSetFieldId": "b020c4a8-c427-4d33-83ea-b0f437a9c6ea"
}
],
"DataSetClassId": "e95258a4-0b50-41b0-9f37-505e90565584",
"ConfigurationVersion": {
"MajorVersion": 672338910,
"MinorVersion": 672341762
}
},
"DataSetWriterName": "Writer101"
}
The following example shows the DataSetMetaData message for DataSet2.
{
"MessageId": "66D65CA4-92EE-4195-9867-E6E27794B692",
"MessageType": "ua-metadata",
"PublisherId": "MyPublisher",
"DataSetWriterId": 102,
"MetaData": {
"Namespaces": [
"urn:DEMO-5:UA Sample Server",
"http://test.org/UA/Data/"
],
"StructureDataTypes": [
{
"DataTypeId": {"IdType": 1, "Id": "CoordinateDataType", "Namespace": 2},
"Name": {"Name": "CoordinateDataType", "Uri": 2},
"StructureDefinition": {
"DefaultEncodingId": {"Id": 24351, "Namespace": 2},
"BaseDataType": {"Id": 22},
"StructureType": 0,
"Fields": [
{
"Name": "X",
"Description": {"Text": "The X coordinate."},
"DataType": {"Id": 10},
"ValueRank": -1,
"MaxStringLength": 0,
"IsOptional": false
},
{
"Name": "Y",
"Description": {"Text": "The Y coordinate."},
"DataType": {"Id": 10},
"ValueRank": -1,
"MaxStringLength": 0,
"IsOptional": false
}
]
}
}
],
"Fields": [
{
"Name": "LocationName",
"FieldFlags": 0,
"BuiltInType": 12,
"DataType": {"Id": 12},
"ValueRank": -1,
"MaxStringLength": 0,
"DataSetFieldId": "8968e376-e281-47bf-b621-e1fb710c8954"
},
{
"Name": "Coordinate",
"FieldFlags": 0,
"BuiltInType": 22,
"DataType": {
"IdType": 1,
"Id": "CoordinateDataType",
"Namespace": 2
},
"ValueRank": -1,
"MaxStringLength": 0,
"DataSetFieldId": "4a1a1f3c-76c0-46ac-92bd-b02bfbe59dcf"
},
{
"Name": "Measurements",
"FieldFlags": 0,
"BuiltInType": 6,
"DataType": {"Id": 6},
"ValueRank": 1,
"MaxStringLength": 0,
"DataSetFieldId": "7d177014-32de-421e-a0a3-bc48ede8ac9d"
}
],
"DataSetClassId": "4f457b18-32f8-48a5-a6f0-18ae5ebdc7f4",
"ConfigurationVersion": {"MajorVersion": 672338910, "MinorVersion": 672341762}
},
"DataSetWriterName": "Writer102"
}
One of the use cases for PubSub is the publication of data to IT applications through a topic or message queue where the IT application does not have any knowledge about OPC UA. In such a use case, the messages that are sent to the message queue can only contain one DataSetMessage and there should be no OPC UA specific information or header.
The header layout described in this section is optimized for this use case.
A minimal message has the following settings:
- Each NetworkMessage contains one DataSetMessage
- The NetworkMessage header is not included
- The DataSetMessage header is not included
- The DataSet field encoding can be configured
The header layout URI for the mimimal layout as specified in A.3.2.4 is
http://opcfoundation.org/UA/PubSub-Layouts/JSON-Minimal
Table A.16 defines the values for the WriterGroup configuration parameters representing this layout.
Table A.16 – Values for WriterGroup configuration parameters
|
Parameter |
Value |
|
JsonNetworkMessageContentMask |
0x00000004
This value results of the following options: Bit 0: NetworkMessageHeader = 0 Bit 1: DataSetMessageHeader = 0 Bit 2: SingleDataSetMessage = 1 Bit 3: PublisherId = 0 Bit 4: DataSetClassId = 0 Bit 5: ReplyTo = 0 Bit 6: WriterGroupName = 0 |
Table A.17 defines the values for the DataSetWriter configuration parameters representing this layout.
Table A.17 – Values for DataSetWriter configuration parameters
|
Parameter |
Value |
|
JsonDataSetMessageContentMask |
0x0
This value results of the following options: Bit 0: DataSetWriterId = 0 Bit 1: MetaDataVersion = 0 Bit 2: SequenceNumber = 0 Bit 3: Timestamp = 0 Bit 4: Status = 0 Bit 5: MessageType = 0 Bit 6: DataSetWriterName = 0 Bit 7: ReversibleFieldEncoding = 0 Bit 8: PublisherId = 0 Bit 9: WriterGroupName = 0 Bit 10: MinorVersion = 0 |
|
DataSetFieldContentMask |
0 |
|
KeyFrameCount |
configurable |
Example for DataSet1.
{
"Active":true,
"Temperature":25.5,
"Counter":0,
"AdditionalInfo":"The system is running normally (1)"
}
Example for DataSet2.
{
"LocationName":"Building A",
"Coordinate":
{
"X":0,
"Y":0.2
},
"Measurements":
[
20030,
20020,
20010
]
}
Example for DataSet3.
{
"BooleanValue":false,
"Int32Value":0,
"Int64Value":"1",
"UInt32Value":1,
"UInt64Value":"1",
"DoubleValue":0.5,
"DateTimeValue":"2021-09-14T07:14:30Z",
"StringValue":"String 1",
"GuidValue":"ebfc352a-3142-4b99-9bbe-89a517d6a77e",
"StatusCodeValue":
{
"Code":2147483648,
"Symbol":"Bad"
},
"LocalizedTextValue":"Localized text 1",
"ByteStringValue":"AAEC",
"NodeIdValue":
{
"IdType":1,
"Id":"Boilers.Boiler #1.PipeX001.ValveX001.Input",
"Namespace":"http://test.org/UA/Data/Instance"
},
"QualifiedNameValue":
{
"Name":"PipeX001",
"Uri":"http://test.org/UA/Data/"
}
}
One of the use cases for PubSub is the publication of data to IT applications through a message queue where one DataSet is related to one message queue.
The IT application does not need to have knowledge about OPC UA but OPC UA specific header may be used for the message processing.
In such a use cases, the messages sent to a message queue can only contain one DataSetMessage but a OPC UA specific header is provided.
The header layout described in this section is optimized for this use case.
A single DataSet message has the following settings:
- Each NetworkMessage contains one DataSetMessage
- The NetworkMessage header is not included
- The DataSetMessage header is included, the header fields can be configured
- The DataSet field encoding can be configured
The header layout URI for the single DataSetMessage layout as specified in A.3.3.4 is
http://opcfoundation.org/UA/PubSub-Layouts/JSON-DataSetMessage
Table A.18 defines the values for the WriterGroup configuration parameters representing this layout.
Table A.18 – Values for WriterGroup configuration parameters
|
Parameter |
Value |
|
JsonNetworkMessageContentMask |
0x00000006
This value results of the following options: Bit 0: NetworkMessageHeader = 0 Bit 1: DataSetMessageHeader = 1 Bit 2: SingleDataSetMessage = 1 Bit 3: PublisherId = 0 Bit 4: DataSetClassId = 0 Bit 5: ReplyTo = 0 Bit 6: WriterGroupName = 0 |
Table A.19 defines the values for the DataSetWriter configuration parameters representing this layout.
Table A.19 – Values for DataSetWriter configuration parameters
|
Parameter |
Value |
|
JsonDataSetMessageContentMask |
The mask allows the following options: Bit 0: DataSetWriterId = 1 Bit 1: MetaDataVersion = 0 Bit 2: SequenceNumber = 1 Bit 3: Timestamp = 1 Bit 4: Status = 1 Bit 5: MessageType configurable (default is 0) Bit 6: DataSetWriterName configurable (default is 0) Bit 7: ReversibleFieldEncoding = 0 Bit 8: PublisherId = 1 Bit 9: WriterGroupName configurable (default is 0) Bit 10: MinorVersion = 1 |
|
DataSetFieldContentMask |
configurable (default is 0) |
|
KeyFrameCount |
configurable If the KeyFrameCount is not 1, the MessageType bit shall be true. |
Example for DataSet1 with all configurable JsonDataSetMessageContentMask flags set to false and no flags set for DataSetFieldContentMask.
{
"PublisherId":"MyPublisher",
"DataSetWriterId":101,
"SequenceNumber":68468,
"MinorVersion":672341762,
"Timestamp":"2021-09-27T18:45:19.555Z",
"Payload":
{
"Active":true,
"Temperature":25.5,
"Counter":0,
"AdditionalInfo":"The system is running normally (1)"
}
}
Example for DataSet2 with all configurable JsonDataSetMessageContentMask flags set to true and no flags set for DataSetFieldContentMask.
{
"PublisherId":"MyPublisher",
"DataSetWriterId":102,
"SequenceNumber":25460,
"MinorVersion":672341762,
"Timestamp":"2021-09-27T18:45:19.555Z",
"Status":1073741824,
"MessageType":"ua-keyframe",
"WriterGroupName":"WriterGroup1",
"DataSetWriterName":"Writer102",
"Payload":
{
"LocationName":"Building A",
"Coordinate":
{
"X":1,
"Y":0.2
},
"Measurements":
[
20030,
20020,
20010
]
}
}
Example for DataSet1 with all configurable JsonDataSetMessageContentMask flags set to false and with SourceTimestamp and StatusCode flags set in the DataSetFieldContentMask. The Status is omitted if the Code is 0.
{
"PublisherId":"MyPublisher",
"DataSetWriterId":101,
"SequenceNumber":68468,
"MinorVersion":672341762,
"Timestamp":"2021-09-27T18:45:19.555Z",
"Payload":
{
"Active":
{
"Value":true,
"Status":{"Code":1073741824,"Symbol":"Uncertain"},
"SourceTimestamp":"2021-09-27T11:32:38.349925Z"
},
"Temperature":
{
"Value":25.5,
"SourceTimestamp":"2021-09-27T11:32:38.349925Z"
},
"Counter":
{
"Value":0,
"SourceTimestamp":"2021-09-27T11:32:38.349925Z"
},
"AdditionalInfo":
{
"Value":"The system is running normally (1)",
"SourceTimestamp":"2021-09-27T11:32:38.349925Z"
}
}
}
One of the use cases is streaming of multiple different data and event DataSets through a single message queue for further processing in cloud applications.
The header layout described in this section is optimized for this use case.
A minimal message has the following settings:
- Each NetworkMessage contains an array of DataSetMessages
- The NetworkMessage header is included, the header fields can be configured
- The DataSetMessage header is included, the header fields can be configured
- The DataSet field encoding can be configured
The header layout URI for the multiple DataSetMessages layout as specified in A.3.4.4 is
http://opcfoundation.org/UA/PubSub-Layouts/JSON-NetworkMessage
Table A.20 defines the values for the WriterGroup configuration parameters representing this layout.
Table A.20 – Values for WriterGroup configuration parameters
|
Parameter |
Value |
|
JsonNetworkMessageContentMask |
The mask allows the following options: Bit 0: NetworkMessageHeader = 1 Bit 1: DataSetMessageHeader = 1 Bit 2: SingleDataSetMessage = 0 Bit 3: PublisherId enabled Bit 4: DataSetClassId configurable (default is 0) Bit 5: ReplyTo configurable (default is 0) Bit 6: WriterGroupName configurable (default is 0) |
Table A.21 defines the values for the DataSetWriter configuration parameters representing this layout.
Table A.21 – Values for DataSetWriter configuration parameters
|
Parameter |
Value |
|
JsonDataSetMessageContentMask |
The mask allows the following options: Bit 0: DataSetWriterId = 1 Bit 1: MetaDataVersion = 0 Bit 2: SequenceNumber = 1 Bit 3: Timestamp = 1 Bit 4: Status = 1 Bit 5: MessageType configurable (default is 0) Bit 6: DataSetWriterName configurable (default is 0) Bit 7: ReversibleFieldEncoding = 0 Bit 8: PublisherId = 0 Bit 9: WriterGroupName configurable (default is 0) Bit 10: MinorVersion = 1 |
|
DataSetFieldContentMask |
configurable (default is 0) |
|
KeyFrameCount |
configurable If the KeyFrameCount is not 1, the MessageType bit shall be true. |
Example for DataSet1, DataSet2 and DataSet3 with all configurable JsonNetworkMessageContentMask and JsonDataSetMessageContentMask flags set to false and no flags set for DataSetFieldContentMask.
{
"MessageId":"9279c0b3-da88-45a4-af74-451cebf82db0",
"MessageType":"ua-data",
"PublisherId":"MyPublisher",
"Messages":
[
{
"DataSetWriterId":101,
"SequenceNumber":68468,
"MinorVersion":672341762,
"Timestamp":"2021-09-27T18:45:19.555Z",
"Payload":
{
"Active":true,
"Temperature":25.5,
"Counter":0,
"AdditionalInfo":"The system is running normally (1)"
}
},
{
"DataSetWriterId":102,
"SequenceNumber":25460,
"MinorVersion":672341762,
"Timestamp":"2021-09-27T18:45:19.555Z",
"Status":1073741824,
"Payload":
{
"LocationName":"Building A",
"Coordinate":{"X":0,"Y":0.2},
"Measurements":[20030,20020,20010]
}
},
{
"DataSetWriterId":103,
"SequenceNumber":66915,
"MinorVersion":672341762,
"Timestamp":"2021-09-27T18:45:19.555Z",
"Payload":
{
"BooleanValue":false,
"Int32Value":0,
"Int64Value":"1",
"UInt32Value":1,
"UInt64Value":"1",
"DoubleValue":0.5,
"DateTimeValue":"2021-09-14T07:14:30Z",
"StringValue":"String 1",
"GuidValue":"ebfc352a-3142-4b99-9bbe-89a517d6a77e",
"StatusCodeValue":
{
"Code":2147483648,
"Symbol":"Bad"
},
"LocalizedTextValue":"Localized text 1",
"ByteStringValue":"AAEC",
"NodeIdValue":
{
"IdType":1,
"Id":"Boilers.Boiler #1.PipeX001.ValveX001.Input",
"Namespace":"http://test.org/UA/Data/Instance"
},
"QualifiedNameValue":
{
"Name":"PipeX001",
"Uri":"http://test.org/UA/Data/"
}
}
}
]
}