7.2.5.6.1 Action NetworkMessage
Each JSON Action NetworkMessage can contain one or more JSON Request or Response messages. A JSON Action NetworkMessage is a JSON object with the fields defined in Table 195.
All fields are encoded using CompactEncoding OPC UA JSON Data Encoding defined in OPC 10000-6 .
| Name | Type | Description |
| MessageId | String | A globally unique identifier for the message. This value is mandatory. |
| MessageType | String | This value shall be “ua-action-request” Request messages or “ua-action-response” for Response messages. This value is mandatory. |
| PublisherId | String | The PublisherId of the Responder for the “ua-action-request” and “ua-action-response” message. This value is mandatory. |
| Timestamp | UtcTime | When the message was first sent to the Middleware. This value is mandatory. |
| ResponseAddress | String | The address used to send the Response messages. The handling of the ResponseAddress and default values are defined for the different transport protocol mappings. This value is mandatory for Request messages. This value shall be omitted for Response message. |
| CorrelationData | ByteString | Data provided by the Requestor in the Request message that is returned to the Requestor in the Response message. The value may be provided in the Request message. The value shall be provided in the Response message if it was included in the Request message. |
| RequestorId | String | The PublisherId of the Requestor for the “ua-action-request” and “ua-action-response” message. This value is mandatory. |
| TimeoutHint | Duration | The timeout used by the Requestor to wait for a Response messages and by the Responder to stop processing the request. This value is mandatory for the Request message. This value is not used for Response messages. |
| Message | * | A JSON array of JSON ActionRequest or JSON ActionResponse messages. This value is mandatory. |
It contains one or more ActionRequest or ActionResponse messages with a layout defined by the Request and Response fields in the ActionMetaData.
The Action execution sequences and execution related request and response message values are defined in 6.2.11.2.