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Paho MQTT Connector Extension

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The PahoMqtt Extension implements MQTT client subscription and publication to topics on an MQTT broker where messages on those topics contain current point values. It uses the Eclipse Paho MQTT java client for all MQTT Broker communication. This extension depends on pahoMqtt which is just a wrapper for the runtime Java jar files it requires.

Discovery and learn are not supported functions. As a result, brokers are not discoverable from within the Connectors app and from within the Builder app, the Connectors panel will not show the PahoMqtt Connector.

All PahoMqtt proxy points must be manually bound.

NOTE: Version 1.0.2 and above are SkySpark v3 built.

Main Configuration

The minimum configuration required to set up an PahoMqtt connector is:

Broker Authentication

If username is entered, then a password is also expected. These will be supplied to the broker on connection. If you have a non-authenticating broker, just leave username and password blank.

Password is stored in password db for connector's record id

Payload Structure

As message payload is largely undefined, this connector allows the user to decide how the payload should be parsed to extract point values and how to construct a payload for setting a point value.

You can configure at the connector level what the default payload parser and constructor should be for any points managed by this connector. Even if configured at this level it's possible to override it at the point level.

Kura Payload

Kura is an open source Java/OSGI-based framework for IoT gateways. It embraces MQTT as the underlying messaging system from edge devices to the cloud. Included in the framework is a Google Protobuf defined message payload structure.

This connector has built in support for the Kura payload structure both for messages received and sent. See pahoMqttParser and pahoMqttConstructor for how to configure the connector or points to receive/send Kura payload messages.

The Kura payload is binary and can be zipped. This connector will automatically detect if the payload is zipped and unzip it. It does not zip payload when publishing.

The main part of the Kura payload is a collection of Metric instances, which themselves are simply name/value pairs. The name used in a Kura Metric is what should be used in the pahoMqttPointName when multi-metric Kura messages are received.

Points and Topics

The connector allows for more than one point being subscribed to the same topic for its curVal. If the messages received from the topic only contain a single value, then all subscribed points will be updated to the same curVal. But if the message payloads contain multiple values, you need to also configure the pahoMqttPointName tag on each point. The value for the pahoMqttPointName tag will be used to extract from the Dict returned from the configured message payload parser.

Current Points

PahoMqtt proxy points are configured with pahoMqttCur tag, which maps to a topic at the MQTT Broker:

Writable Points

PahoMqtt proxy points are configured to write to remote system points via the pahoMqttWrite tag, which maps to a topic at the MQTT Broker:


History synchronization is not supported by PahoMqtt. You will need to use collection to store history.

Published by Crowley Carbon

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Paho MQTT Connector Extension
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Also available via SkyArc Install Manager
Package details
Build date2 months ago
on Fri 3rd Jul
Requirements SkySpark v3.0
Depends on
File namepahoMqttExt.pod
File size49.95 kB
SHA1 6c156515dee8a94077604977fbd3bc4097291919
Published by
Crowley CarbonDownload now
Also available via SkyArc Install Manager
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