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• Enabled
  • Whether or not the MQTT Engine module is enabled and connecting to configured MQTT Servers.
    
• Primary Host ID
  • The primary host ID to use for 'state' checks.  These checks are used to ensure that the primary backend MQTT Engine client remains connected.  If the primary host ID is set, MQTT Engine will publish it's connection state on a topic that contains the Primary Host ID.  In the event that MQTT Engine becomes disconnected from the server, a death certificate will be published on the same topic, setting the state to 'offline'.  Any connecting client that subscribes on the state topic will then be notified of the MQTT Engine state and walk to the next server is MQTT Engine is offline.
  • This must contain only letters, numbers, and the following special characters: . $ % @ ! - _ ^ *
• Group ID Filters
  • A comma separated list of group IDs to subscribe to.

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• Block Node Commands
  • Whether or not to block outgoing commands from MQTT Engine to Edge Nodes. This is true by default and provides a security mechanism for preventing accidental outgoing commands from MQTT Engine.
• Block Device Commands
  
  • Whether or not to block outgoing commands from MQTT Engine to Devices. This is true by default and provides a security mechanism for preventing accidental outgoing commands from MQTT Engine.
• File Policy
  
  • The policy for handling Files contained within a Sparkplug payload.
    • Ignore: The default policy. The file will be ignored.
    • Store: The file will be stored to the local file system in the directory specified by the File Location field.  A Tag will be created with a String value representing the file URI.
• File Location
  
  • The directory to store the files when using the Store policy described above.
• Store Historical Events
  • Whether or not to write historical change events directly to the Historian (if history is enabled on a Tag) instead of updating the live Tag value.

Advanced

These are advanced settings/features and they should be left with default values in almost all cases. Please be careful when changing these settings from their default values.

• Enable Tag Latching

  • Whether or not to enable Tag latching to synchronize MQTT Tag updates with events in Ignition.

• Latch Timeout

  • The amount of time to wait for a Tag latch to be released before timing out.

• Latch Tags

  • A list of Trigger Tag and Latch Tag pairs.
• Filtered Properties
  • A semicolon delimited list of Tag properties to filter/ignore on received Tags.

• Enable BD Sequence Validation

  • Whether or not to enable BIRTH/DEATH sequence number validation (required by Sparkplug specification).

• Enable Primary Host Subscriptions

  • Whether or not to enable MQTT Engine subscriptions on STATE/# and State/# topics even when a PrimaryHostID is not configured within MQTT Engine. This setting is for debugging purposes only.

Servers

The second tab is a list of MQTT Servers that MQTT Engine should connect to.  By default, MQTT Engine is configured to connect to the local MQTT Distributor based MQTT Server.  It is set up to connect to localhost, port 1883, using the default username/password pair of admin/changeme.  Out of the box MQTT Engine will work with MQTT Distributor and its default configuration.  The connection status of each server can be seen in the 'Status' column.  Clicking on the 'Create new MQTT Server' link will bring up the following form for adding a new MQTT Server setting.

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• Root Tag Folder
  • A name of a folder where all tags will be stored.  If configured, this folder will be the base folder where all tag paths will start.
• Tag Name
  • A tag name to be used for all tags.  If not configured, the last token in the topic will represent the tag.
• JSON Payload
  
  • A flag to indicate that the content of the string based payload is a JSON object.

Advanced

• Writable Tags
  • Enables writes on tags created by the Custom Namespace. Note: This will only make the tags writable; it will not result in outgoing MQTT messages.

Note: if a Tag Name is not specified, care must be taken so that published messages do not end up overwriting previous tags. 

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