MQTT - Generic

4 min

Review the following guides:

Generic MQTT Integration Guide (HiveMQ)

Generic MQTT Integration Guide (Mosquitto)

Generic MQTT Integration Guide (Last Will and Testament)

Overview

MQTT Generic integration enables an Edge System to connect to an MQTT broker.

Supported Versions

Compatible with MQTT Protocol version 3.1.0 and MQTT Protocol version 3.1.1

Supported Communication

Outbound (Publish data from Edge to MQTT Broker) - Yes

Inbound (Subscribe data from MQTT Broker to Edge) - Yes

Configurations

Variable	Detail	Required
Name	Enter a name for the connector	Yes
Hostname	IP Address or Server FQDN of MQTT broker (Must be reachable from the Edge system)	Yes
Port	MQTT broker port	Yes
Client id	Unique client identity. If left blank, a default value is auto-generated.	No
Username	Enter the username	No
Password	Enter the user password	No
QoS	The Quality of Service (QoS) level represents an understanding between the message sender and receiver, outlining the assurance of message delivery for a particular message. Simultaneously publishing multiple messages can enhance throughput, but opting for higher values may increase the risk of message loss, even when QoS is set to 1. Please note that the actual QoS options available may vary based on the server configuration.	Yes
Parallel publish count	The number of messages that can be simultaneously published or sent in parallel. It is a measure of how many messages can be transmitted at the same time. As an example, in Mosquitto, you have the following settings: max_queued_messages (default 100) max_queued_bytes (default 0) As per the Mosquitto documentation, when this limit is reached, any additional messages are silently discarded. You have the option to either adjust the server configuration or specify this value based on the server settings.	Yes
Integration topic	Default topic for publishing	No
LWT topic	Specific topic where the last will message will be published.	No
LWT payload	Information or message that will be sent to the specified topic when the client disconnects unexpectedly or goes offline without sending a proper "goodbye" message.	No
LWT payload type	A payload type (raw string or base64 encoded bytes) for Last Will and Testament feature of MQTT	No
LWT QoS	A QoS value for Last Will and Testament feature of MQTT	No
LWT retained	If enabled, the broker will store the LWT message, and any new subscribers to the LWT topic will immediately receive this retained LWT message.	No
Connection Timeout	How long a single connection attempt may take before it is abandoned, in seconds.	No
Ping Timeout	How long to wait for the broker's keep-alive response before the connection is treated as lost. Checked every 5 seconds. The value is rounded up to the next 5 second step.	No
Reconnect Interval	How long to wait after a lost or failed connection before the next attempt, in seconds.	No
Publish Wait Timeout	How long a single publish may take before it is given up on, in seconds.	No
Throttling limit	Set a limit on the number of outbound messages per second. If sending data to a server that has restrictions on the rate of incoming messages, this ensures that no messages are lost.	No
Persistent storage	If enabled, messages in the outbound queue are stored on disk. If there are interruptions in connection or power loss, messages will be retained and eventually sent when the connection is restored.	No
Queue mode	Select the sequence of data transfer: FIFO or LIFO. Selecting FIFO (First In First Out) will send the earliest message first. Selecting LIFO (Last In First Out) will send the latest message first.	No

Compatibility Validation

This information is just for reference. More products and versions may be supported provided they are compatible with the supported version as mentioned above.

Product	Version	Date
Mosquitto Message Broker	1.x	Nov 14, 2019
HiveMQ	2.x	Nov 14, 2019