How-to I/O MQTT Driver

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License requirements

The MQTT functionality requires an Add-on on your license and is only available with:

Qinsy (9) Marine Construction
Qinsy (9) Offshore

If the add-on is not present and activated, the driver(s) will not be started when going Online.

Creating a driver configuration

Under Type: select 'Generic Input'
Press the 'New' button to create a new file
General Information
1. Enter a name
2. Select the MQTT option to create an MQTT Driver
3. Select the system types you want to decode
4. Press Next>
MQTT Parameters
1. Configure the connection to the MQTT broker and the topics that should be subscribed.
  More information can be found here: Generic Input - MQTT Configuration
Set the Decoding Properties
1. Method: Currently, we support ASCII and JSON, in ASCII we expect a plain value when decoding.
2. MQTT Topic: The sub-topic that the data will be derived from
3. JSON Key: The key on which the specific observation is stored in the JSON when selecting JSON as the decoding method

Examples for a JSON Key

Click here to see Topic/Key examples

Simple example

If you have a simple position JSON:

JSON

Vessel_1/Position {"lat": "x.xx","lon": "x.xx", "height": "x.xx"}

Or visualized differently:

Vessel_1
  Position {
    "lat": "x.xx",
    "lon": "x.xx", 
    "height": "x.xx"}

Item	Values	Notes
Base Topic	Vessel_1
Sub-Topic	Position
JSON Key	lat	For Latitude
JSON Key	lon	For Longitude
JSON Key	height	For Height

More complex example

If you have a more complex, nested JSON position:

JSON

Vessels/Vessel_1/Position {"Node Result":{"Priority":{"Vessel 1 CoG":{"Latitude": "x.xx","Longitude": "x.xx", "Height": "x.xx"}}}}

Or visualized differently:

Vessels
  Vessel_1
    Position {
      "Node Result":{
        "Priority":{
          "Vessel 1 CoG":{
            "Latitude": "x.xx",
            "Longitude": "x.xx", 
            "Height": "x.xx"}}}}

Item	Values	Notes
Base Topic	Vessels
Sub-Topic	Position
JSON Key	Node Result/Priority/Vessel 1 CoG/Latitude	For Latitude
JSON Key	Node Result/Priority/Vessel 1 CoG/Longitude	For Longitude
JSON Key	Node Result/Priority/Vessel 1 CoG/Height	For Height

Note on Vessel_1

As you might have noticed, is that you don’t define Vessel_1 in your driver configuration.
Please read more on this is the Core Topic part below.

Core topic

The core topic is inserted between a Base Topic and Sub Topic.

CODE

Base Topic/Core Topic/Sub Topic

Or visualized differently:

Base Topic
    Core Topic
        Sub Topic

The Core topic can be defined in your template setup, as shown below:

The reason to do this is in case you have similarly structured data coming from multiple vessels, for example.
The data could then look like this:

JSON

Vessels
  Vessel_1
      Position {
          "Node Result":{
            "Priority":{
              "Vessel 1 CoG":{
                "Latitude": "x.xx",
                "Longitude": "x.xx", 
                "Height": "x.xx"}}}}
  Vessel_2
      Position {
          "Node Result":{
            "Priority":{
              "Vessel 1 CoG":{
                "Latitude": "x.xx",
                "Longitude": "x.xx", 
                "Height": "x.xx"}}}}
  Vessel_3
      Position {
          "Node Result":{
            "Priority":{
              "Vessel 1 CoG":{
                "Latitude": "x.xx",
                "Longitude": "x.xx", 
                "Height": "x.xx"}}}}

Item	Values	Notes
Base Topic	Vessels
Core Topic	Vessel_x	For each vessel
Sub-Topic	Position
JSON Key	Node Result/Priority/Vessel 1 CoG/Latitude	For Latitude
JSON Key	Node Result/Priority/Vessel 1 CoG/Longitude	For Longitude
JSON Key	Node Result/Priority/Vessel 1 CoG/Height	For Height

The advantage is then that:

You don’t need to create a new MQTT input driver per vessel.
- So you only need to enter the connection values ones.
There is only one connection to the MQTT broker.

Note that this separation is only available for the Input drivers. The output driver needs to be defined as a single topic.

Return to: How-to I/O Driver Editor