Version 23.3.8698


The MQTT Connector supports publishing MQTT messages and subscribing to MQTT topics.


Sending data through an MQTT Connector will publish the data to the configured topic, and messages received on any of the topics that the connector is subscribed to will be placed in the Output Folder.

Connector Configuration

This section contains all of the configurable connector properties.

Settings Tab

Host Configuration

Settings related to the remote MQTT server connection.

  • Remote Host The hostname or IP address of the remote MQTT server.
  • Remote Port The port on which to connect to the remote MQTT server.

Client Authentication

Settings related to authenticating against the remote MQTT server.

  • Username The username credential with which to authenticate.
  • Password The password for the specified username.

SSL Settings

Settings related to establishing a secure connection via SSL.

  • Use SSL/TLS Whether the connector will negotiate SSL when connecting to the remote server.
  • SSL Server Certificate The public certificate used to verify the identity of the remote server when establishing an SSL connection. This setting can be set to ‘Any Certificate’ to unconditionally trust the target server’s identity.


Settings related to publishing MQTT messages.

  • Topic The topic for the message to publish.
  • QoS Whether the delivery of messages should be non-guaranteed, guaranteed, or guaranteed without duplicates.


Settings related to subscribing to MQTT messages.

  • Enable MQTT Receiver Whether the connector should receive MQTT messages.
  • Topic Filters A comma-separate list of topics for the connector to subscribe to.
  • QoS Whether the delivery of messages should be non-guaranteed, guaranteed, or guaranteed without duplicates.

Automation Tab

Automation Settings

Settings related to the automatic processing of files by the connector.

  • Send Whether files arriving at the connector will automatically be sent as messages to the MQTT server.
  • Retry Interval The amount of time before a failed send is retried.
  • Max Attempts The maximum number of times a failed send will be retried.

Advanced Tab

SSL Client Authentication

Settings related to client authentication when two-way SSL authentication is required.

  • Private Certificate The private certificate presented during SSL client authentication.
  • Certificate Password The password required to access the SSL client certificate.


Settings related to the allocation of resources to the connector.

  • Max Workers The maximum number of worker threads consumed from the threadpool to process files on this connector. If set, this overrides the default setting on the Settings > Automation page.
  • Max Files The maximum number of files sent by each thread assigned to the connector. If set, this overrides the default setting on the Settings > Automation page.

Other Settings

Settings not included in the previous categories.

  • Keep Alive Interval The maximum period of inactivity the connector will allow before sending a keep-alive packet.
  • Last Will Message The message that the server should publish in the event of an ungraceful disconnection.
  • Last Will Topic The topic of the Last Will Message.
  • Local File Scheme A scheme for assigning filenames to messages that are output by the connector. You can use the following macros to reference contextual information:
    %ConnectorId%, %Filename%, %FilenameNoExt%, %Ext%, %ShortDate%, %LongDate%, %RegexFilename%, %DateFormat%, %Header%.
    For example: %FilenameNoExt%_%ShortDate%%Ext%
  • Republish Interval The interval that the connector will wait before republishing unacknowledged messages.
  • Timeout The duration that the connector will wait for a response from the server before throwing a timeout error.


Miscellaneous settings are for specific use cases.

  • Other Settings Enables you to configure hidden connector settings in a semicolon-separated list (for example, setting1=value1;setting2=value2). Normal connector use cases and functionality should not require the use of these settings.

Establishing a Connection

At a minimum, set Remote Host to the domain name or IP address of the MQTT server, as well as Remote Port if a non-standard port is used. If authentication is required, the Username and Password fields should also be set. If a secure connection is desired, check Use SSL/TLS, and optionally specify the SSL Server Certificate to the public certificate of the server, or Any Certificate in order to accept any certificate presented by the server. If used improperly, this value will create a security breach. Use it at your own risk.


In order to publish data, set the Topic in the Publish section to the topic where the connector should publish messages. QoS value range from 0 to 2 and have the following meanings:

  • 0: At most once - The published message is sent once, and if it does not arrive it is lost.
  • 1: At least once - Guarantees that the published message arrives, but there may be duplicates.
  • 2: Exactly once - Guarantees that the publish message arrives and that there are no duplicates.

In the Advanced page, Republish Interval may be set to the number of seconds that the connector will wait for acknowledgements to messages that require them. If this time elapses without receiving an acknowledgement, the connector will republish the message. Republished messages reuse the packet Id from the original message, and will automatically set the Duplicate flag on the message. Specifying a value of 0 for Republish Interval will prevent the connector from automatically republishing messages.


In the Subscribe section of the settings page, the Enable MQTT Receiver option may be checked in order to indicate that the connector should also receive data. When checked, the connector will subscribe to the topics specified on a background thread, and incoming messages will automatically be placed in the Output Folder, named according to the value specified in Local File Scheme in the advanced tab. By default, the connector will name files with the topic and packet id of the message, using “” as the value for Local File Scheme.

Topic Filters may be set to a comma separated list of topic filters that the connector should subscribe to. Certain characters have special meanings in a topic filter:

  • / - The topic level separator
  • # - The multi-level wildcard (zero or more levels)
  • + - The single-level wildcard (exactly one level)
  • Leading $ - Denotes a “system topic”

In the advanced tab, Last Will Message and Last Will Topic may be set to the message that the server should publish, and the topic it should publish that message to, respectively, in the event of an ungraceful disconnection.