--- title: MQTT - v5 Generic slug: bhdo/mqtt-v5-generic createdAt: 2026-10-02T19:03:00.149Z --- ## Overview The MQTT - v5 Generic integration enables Belden Horizon Data Operations to connect to an MQTT v5 broker via TCP or SSL. ## Supported versions Compatible with MQTT Protocol version 3.1.0, 3.1.1, 5.0.0 ## Supported communication - Outbound (Publish data from Edge to MQTT Broker) - Yes - Inbound (Subscribe data from MQTT Broker to Edge) - Yes ## Configurations | **Field** | **Details** | **Required** | | -------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------ | | Name | Name of the connector instance. | Yes | | Connection Type | Choose tcp for an unencrypted connection or ssl for a TLS-encrypted connection to the MQTT broker. | Yes | | Hostname | DNS name of MQTT host. | Yes | | Port | Port of MQTT host. | Yes | | CA Certificate | CA certificate used to verify the server, in PEM format. Can also be installed in the system-wide certificate store. | No | | Certificate | Client certificate for mutual TLS authentication with the MQTT broker. Paste the PEM-encoded certificate here. | No | | Private key | Private key corresponding to the client certificate. Must match the **Certificate** field above. | No | | Insecure Skip Verify | `InsecureSkipVerify` controls whether a client verifies the server's certificate chain and host name. | No | | Client ID | Client ID is required by MQTT server. If left empty, the system uses `InstanceUUID`. | No | | Username | Username for authenticating with the MQTT broker. | No | | Password | Password for authenticating with the MQTT broker. | No | | QoS | Quality of Service delivery guarantee: `0` = at most once, `1` = at least once, `2` = exactly once. | No | | Integration Topic | MQTT topic path where data is published. | Yes | | User Properties | Custom key-value metadata attached to outgoing MQTT v5 packets. Passed through to the broker and available to subscribers. | 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 | ## Advanced configurations | **Field** | **Details** | **Required** | | --------------------------------- | ----------------------------------------------------------------------------------------------------------------------- | ------------ | | Parallel Publish Count | Number of messages published in parallel. Higher values increase throughput and resource usage. | No | | Response Topic | MQTT v5 topic the receiver should publish its response to. Used in request-response messaging patterns. | No | | Payload Format Indicator | Allowing the server to understand packet without having to operate on the actual data. | No | | Content type | MIME type describing the format of the message payload. Informational - passed to subscribers. | No | | Topic Alias Maximum | Decrease the size of the MQTT packet overhead by allowing the topic name to be abbreviated to a small integer. | No | | LWT topic | MQTT topic the broker publishes the Last Will message to if this client disconnects unexpectedly. | No | | LWT payload | Message content published to the LWT topic on unexpected disconnection. Typically a status or alert string. | No | | LWT payload type | Encoding of the LWT payload: `string` for plain text, `base64` for binary data. | No | | LWT QoS | QoS level for the Last Will message: `0` = at most once, `1` = at least once, `2` = exactly once. | No | | LWT retained | When enabled, the broker retains the Last Will message and immediately delivers it to any new subscriber on that topic. | No | | Will Delay Interval | Add the ability to specify a delay between the end of the connection and sending the will message. | No | | Session Expiry Interval (seconds) | The number that specifies how long a broker keeps a client's session information. | No | | Message Expiry Interval | Allow an expiry interval to be set when a message is published. | No | | Request Response Info | Request the broker to return response information in the CONNACK packet. | No | | Request Problem Info | Request the broker to include human-readable reason strings and user properties in error packets. | No | | Keep Alive | Ensure that client remains connected to the broker and maintains an active session. | No | | Connection Timeout | How long to wait for the connection process to complete in seconds. | No | ## Persistent storage configurations | **Field** | **Details** | **Required** | | ----------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------ | | Persistent storage | If enabled, messages in the outbound queue are stored on disk. If there are interruptions in connection or power loss, messages are retained and eventually sent when the connection is restored. | No | | Persistent storage size limit | Set the size limit for storing persisted data in GB. | No | | Queue mode | Select the sequence of data transfer: `FIFO` or `LIFO`. Selecting `FIFO` (First In First Out) sends the earliest message first. Selecting `LIFO` (Last In First Out) sends the latest message first. | No | ## Format directives | **Symbol** | **Definition** | **Context** | | ---------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------- | | $ | Special character indicates a variable character follows. A variable represents some dynamic string value. Supported variables defined as follows: | - | | $S | Additional Alias definition | from Connector Settings | | $D | Device Name | from DeviceHub Tag | | $N | Tag Name | from DeviceHub Tag | | $R | Raw Tag Type | from DeviceHub Tag | | $P | Tag Description | from DeviceHub Tag | | $H | Hostname | from OS | | % | Special character indicating a function character follows. A function represents some action to be taken on the next variable. Supported functions defined as follows: | - | | %L | Lowercase() | apply to next variable | | %U | Uppercase() | apply to next variable | ## Format directives notes To use a special character in its literal form, enter symbol twice (`$$` -> `$`, `%%` -> `%`) Example `"$$$D.%%$N" -> "$deviceABC.%tagXYZ"`