MTConnect.NET-MQTT 6.4.4

MTConnect.NET-MQTT

MTConnect.NET-MQTT is an extension library to MTConnect.NET that provides an MQTT Broker & Client interface to an IMTConnectAgentBroker interface.

Topic Structures

Document - Topics are the same as HTTP (Probe, Current, Sample, & Assets). Payloads are the corresponding MTConnect Response Documents. This provides a simple protocol that is performance based for applications with high frequency updates.

Entity - Topics are expanded where each Entity has it's own topic. This provides an easy to read interface for tools such as NodeRed, etc.

Document Topic Structure

This topic structure is the official MQTT based protocol for MTConnect.

Topics

The Document Topic Structure uses the standard MTConnect Response documents as message payload and the standard MTConnect API endpoints as topics.

[TOPIC_PREFIX]/Probe/[DEVICE_UUID] - The topic where MTConnectDevices Response documents are published

[TOPIC_PREFIX]/Current/[DEVICE_UUID] - The topic where MTConnectStreams Response documents are published at the configured CurrentInterval

[TOPIC_PREFIX]/Sample/[DEVICE_UUID] - The topic where MTConnectStreams Response documents are published at the the configured SampleInterval when new data is added to the Agent

[TOPIC_PREFIX]/Asset/[DEVICE_UUID]/[ASSET_ID] - The topic where MTConnectAssets Response documents are published

Protocol

Probe

Each device is sent in an MTConnectDevices Response document. The message is published upon Agent start/restart or when a Device is changed or a new Device is added.

Topic

[TOPIC_PREFIX]/Probe/[DEVICE_UUID]

Payload

The payload currently defaults to use the json-cppagent Document Format ID.

Learn More : See example MTConnectDevices Response Document Payload

Current

Topic

[TOPIC_PREFIX]/Current/[DEVICE_UUID]

Payload

The payload currently defaults to use the json-cppagent Document Format ID.

Learn More : See example MTConnectDevices Response Document Payload

Sample

Topic

[TOPIC_PREFIX]/Sample/[DEVICE_UUID]

Payload

The payload currently defaults to use the json-cppagent Document Format ID.

Learn More : See example MTConnectDevices Response Document Payload

Asset

[TOPIC_PREFIX]/Asset/[DEVICE_UUID]/[ASSET_ID]

Payload

The payload currently defaults to use the json-cppagent Document Format ID.

Learn More : See example MTConnectDevices Response Document Payload

Entity Topic Structure

This topic structure is designed to supplement the Document topic structure and be used for use cases that may require a more simple protocol that requires less payload parsing or the ability to subscribe to specific DataItems.

Devices

The MTConnect/Devices topics are used to send data that is in an MTConnectDevicesResponse document.

MTConnect/Devices/[DEVICE_UUID]/Device

Observations

Observations may use the MTConnectMqttFormat.Flat or MTConnectMqttFormat.Hierarchy option to specify how the topics are structured.

MTConnectMqttFormat.Flat Format:

MTConnect/Devices/[DEVICE_UUID]/Observations/[DATA_ITEM_ID]

MTConnectMqttFormat.Hierarchy Format:

MTConnect/Devices/[DEVICE_UUID]/Observations/[COMPONENT_TYPE]/[COMPONENT_ID]/[DATA_ITEM_CATEGORY]/[DATA_ITEM_TYPE]/[DATA_ITEM_ID]
MTConnect/Devices/[DEVICE_UUID]/Observations/[COMPONENT_TYPE]/[COMPONENT_ID]/[DATA_ITEM_CATEGORY]/[DATA_ITEM_TYPE]/SubTypes/[DATA_ITEM_SUBTYPE]/[DATA_ITEM_ID]

The "Flat" format is typically used for brokers that limit the topic depth (number of forward slash "/" characters). For example, AWS IoT Core.

Device Condition Observations

Condition messages are sent as an array of Observations since a Condition may have multiple Fault States. This is similar to how the Current request functions in an HTTP Agent.

Device Assets

MTConnect/Devices/[DEVICE_UUID]/Assets/[ASSET_TYPE]/[ASSET_ID]

Topics

[Node] = (Payload)

- MTConnect
   ─ Devices
      ─ [DEVICE_UUID]
        - Device = (JSON)
        - Observations
          - [DATA_ITEM_ID] = (JSON Array)
          - [DATA_ITEM_ID] = (JSON Array)
          - [DATA_ITEM_ID] = (JSON Array)
        - Assets
          - [ASSET_TYPE]
            - [ASSET_ID] = (JSON)

Example

- MTConnect
   ─ Devices
      ─ OKUMA.Lathe.123456
        - Device
        - Observations
          - L2avail = {"dataItemId":"L2avail","name":"avail","type":"AVAILABILITY","timestamp":"2023-02-07T20:02:26.8978653Z","result":"AVAILABLE"}
          - L2estop = {"dataItemId":"L2estop","name":"estop","type":"EMERGENCY_STOP","timestamp":"2023-02-07T20:02:26.8978653Z","result":"ARMED"}
          - L2p1execution = {"dataItemId":"L2p1execution","name":"p1execution","type":"EXECUTION","timestamp":"2023-02-07T20:02:26.7671421Z","result":"UNAVAILABLE"}
          - L2p1system = [{"level":"WARNING","dataItemId":"L2p1system","name":"p1system","type":"SYSTEM","timestamp":"2023-02-07T20:30:16.8639659Z","result":"Not Found","nativeCode":"404"},{"level":"FAULT","dataItemId":"L2p1system","name":"p1system","type":"SYSTEM","timestamp":"2023-02-07T20:30:38.9662297Z","result":"Interval Error","nativeCode":"500"}]         
        - Assets
          - CuttingTool
            - 5.12 = {"assetId":"5.12","type":"CuttingTool","timestamp":"2023-02-07T13:36:04.7288143Z","deviceUuid":"OKUMA.Lathe.123456","serialNumber":"12345678946","toolId":"12","cuttingToolLifeCycle":{"cutterStatus":["AVAILABLE","NEW","MEASURED"],"location":{"type":"SPINDLE"},"programToolGroup":"5","programToolNumber":"12","measurements":[{"type":"FunctionalLength","value":7.6543,"units":"MILLIMETER","code":"LF"},{"type":"CuttingDiameterMax","value":0.375,"units":"MILLIMETER","code":"DC"}]}}