⚡ Reduxi Configurator · User manual

MQTT v3 connector

Publish live device and strategy data to your own MQTT broker and accept commands from it.

⏱ approx. 10 minutes

📍 Settings → System → Connector → MQTT v3

👤 Installer · integrator

← Cloud connection ☰ Manual contents Flex connector →

📋 In this article

Overview
Connect to a broker
Parameters
Topics
Troubleshooting
Checklist

→ Overview

The MQTT v3 connector connects the controller as a client to an MQTT broker you choose, for example the broker of a building management system, a SCADA or a home automation platform. The controller then publishes the live values of all devices and strategies, the electricity prices and a keep-alive message, and it listens for commands such as device setpoints, strategy on/off, External EMS schedules and grid settings.

The connector is off until you enter a Host. It is independent of the Reduxi Cloud connection; both can run at the same time.

⛔

The broker can control the site

Anyone who can publish to the controller's command topics on your broker can change device setpoints, switch strategies off, change the grid limits and reboot the controller. Use a broker with user authentication, give the controller its own account, and allow write access to controllers/<Unit ID>/…/set and controllers/<Unit ID>/commands/… only to trusted clients.

1 Connect to a broker

Open the page

In the left menu, click Settings, System, Connector, then MQTT v3.

Enter the broker

Type the broker address in Host and its port in Port (1883 for plain MQTT, usually 8883 for TLS).

Enter the login

If the broker needs a login, fill in Username and Password.

Set up encryption (optional)

Switch Use SSL to Yes for a TLS connection. Upload the broker's CA certificate in Server CA chain (PEM format) and switch Verify server cert to Yes. For certificate login, also upload Client public certificate (PEM format) and Client private key (PEM format).

Add fixed topics (optional)

Under Additional topics, click Add and enter a Name or path and a Payload for each extra topic you want the controller to publish.

Set the readout interval

Enter how often live values are published in Readout interval, in seconds. Leave it empty for 60 s.

Save

Click Save. The connector restarts with the new settings.

Check the connection

Click the refresh icon in the Connected row. A green tick means the controller is connected to the broker.

MQTT v3 connection page: status rows Client (the unit ID), Host and Connected; Mqtt connection card with Host, Port 1883, Username, Password, Use SSL and Verify server cert set to No, three PEM file pickers, an empty Additional topics card with an Add button, the Readout interval field in seconds, and the buttons Clear connection configuration and Save

Settings → System → Connector → MQTT v3 with the status table, the Mqtt connection form, Additional topics and Readout interval

2 Parameters

Status

Parameter	What it does	Unit / default
Client	MQTT client ID the controller uses. It is the controller's Unit ID and also forms every topic: `controllers/<Unit ID>/…`. Read-only.	text
Host	The broker the saved configuration points to. Empty = connector off. Read-only.	text
Connected	Green tick = connected to the broker; red cross = not connected. Read-only.	—
Refresh icon	Reads the status again.	—

Mqtt connection

Parameter	What it does	Unit / default
Host	Host name or IP address of the broker. Leave empty to switch the connector off.	text · empty = off
Port	TCP port of the broker.	number · default 1883
Username	User name on the broker. Optional.	text
Password	Password on the broker. Only used together with Username. The field shows the password in plain text.	text
Use SSL	Yes opens the connection with TLS encryption. If you never set it, it is switched on automatically when a server CA chain or a client certificate is stored.	Yes / No · default No
Verify server cert	Yes checks the broker's certificate against Server CA chain (or against the controller's built-in trusted authorities if no chain is uploaded). No accepts any certificate: the connection is encrypted, but the controller does not check who it talks to. Only used with Use SSL = Yes.	Yes / No · default No
Server CA chain (PEM format)	Certificate (chain) of the authority that signed the broker certificate. Click Choose File and pick a PEM file. Once stored, the field shows a Download button instead.	PEM file
Client public certificate (PEM format)	The controller's own client certificate, for brokers that authenticate clients by certificate (mutual TLS). Needs the matching private key.	PEM file
Client private key (PEM format)	Private key of the client certificate.	PEM file

⚠️

Certificates and keys are secrets

The client private key and the broker password give access to your broker. Keep the files in a safe place, do not send them by email, and do not leave copies on shared computers. Anyone with access to this Configurator page can download the stored certificates and see the password.

💡

Replacing a certificate

A stored certificate shows only a Download button. To upload a different one, click Clear connection configuration, then enter the whole connection again with the new files.

Additional topics

Parameter	What it does	Unit / default
Name or path	Topic to publish, relative to `controllers/<Unit ID>/`. For example `site/name` is published as `controllers/<Unit ID>/site/name`. Rows with an empty name are skipped.	text
Payload	Fixed text published on that topic.	text
Add	Adds an empty row.	—
Trash icon	Removes the row. Takes effect after Save.	—

Additional topics are published together with the controller's metadata: each time the connector connects to the broker and each time the broker sends commands/refresh.

MQTT v3 page after clicking Add under Additional topics: one row with the fields Name or path and Payload and a trash icon

Additional topics card with one empty row: Name or path, Payload and a trash icon

Publishing and buttons

Parameter	What it does	Unit / default
Readout interval	How often the controller publishes the readout and setpoint of every device and the readout, state and parameter values of every strategy. Lower values give fresher data but more traffic.	s · empty = 60 s · minimum 0.25 s
Save	Stores the settings and restarts the connector. Recorded in the Audit log as `CONNECTOR_EDIT`.	—
Clear connection configuration	After the confirmation Are you sure to clear MQTT settings? (Yes / Cancel), deletes host, port, username, password, the SSL settings and all certificates. The connector switches off. Readout interval and Additional topics are kept.	—

⚠️

Clearing stops all MQTT traffic

After Clear connection configuration the controller no longer publishes data or accepts commands over MQTT. A system that relies on the data, or sends External EMS schedules, stops receiving or delivering them. You must re-enter the password and upload the certificates again to reconnect.

3 Topics

All topics start with controllers/<Unit ID>/. The controller publishes with QoS 0 and without the retain flag, and subscribes to command topics with QoS 1. Payloads are JSON or plain values; the full payload formats are in the help-center article "Reduxi Controller - MQTT API".

Published by the controller:

Topic	Content	When
`identifier`	Controller identification (unit ID, versions, …)	On connect and on `commands/refresh`
`settings/interval/readout`, `settings/interval/keepAlive`	Current intervals in ms	On connect and on refresh
`devices/list`, `devices/types`, `devices/<id>/info`	Configured devices and their types	On connect and on refresh
`strategies/list`, `strategies/types`, `strategies/<id>/info`, `strategies/<id>/parameters/list`, `strategies/<id>/parameters/<id>/info`	Configured strategies and their parameters	On connect and on refresh
`<additional topic>`	Payload from Additional topics	On connect and on refresh
`devices/<id>/readout`	Live values of a device	Every readout interval
`devices/<id>/setpoint`	Current setpoint of a device	Every readout interval
`strategies/<id>/active`, `strategies/<id>/readout`, `strategies/<id>/parameters/<id>/value`	Strategy on/off, live values, parameter values	Every readout interval
`prices`	Electricity prices for today and tomorrow	On connect, when prices change, on `prices/refresh`
`strategies/<id>/externalEMS/<type>`	Stored External EMS schedule (`battery`, `evse`, `hvac`, `pv`)	On `…/externalEMS/<type>/refresh`
`keepAlive`	Current time (Unix ms)	Every keep-alive interval, default 60 s

Commands the controller accepts:

Topic	Effect
`commands/refresh`	Publishes the metadata topics again.
`commands/reboot`	Reboots the controller about 5 s later.
`prices/refresh`	Publishes `prices` again.
`settings/interval/readout/set`	Changes the readout interval (ms) and stores it.
`settings/interval/keepAlive/set`	Changes the keep-alive interval (ms) and stores it.
`devices/<id>/setpoint/set`	Sets a device setpoint.
`strategies/<id>/parameters/<id>/value/set`	Sets a strategy parameter.
`strategies/<id>/active/set`	Switches a strategy on or off.
`strategies/<id>/externalEMS/<type>/set`	Loads an External EMS schedule for `battery`, `evse`, `hvac` or `pv`. Ignored unless the strategy has an External EMS optimization mode.
`strategies/<id>/externalEMS/<type>/refresh`	Publishes the stored External EMS schedule.
`settings/grid/set`	Changes the grid settings (location, fuses, import and export limit), optionally also in selected strategies.

⚠️

Commands overwrite local settings

settings/grid/set overwrites the values on Settings → Grid and, if requested, the limits of the strategies — the same effect as saving the Grid settings page. devices/<id>/setpoint/set writes the setpoint to the device directly. Do not send device setpoints for a device that a strategy also controls, or the two will overwrite each other.

4 Troubleshooting

Symptom	What to check
Connected stays red	Host and Port are right; the controller can reach the broker (TCP port test on the broker host and port); username and password; with TLS, the CA chain matches the broker certificate, or try Verify server cert = No to narrow the problem down.
Connected, but no data on the broker	Subscribe to `controllers/#` and check the Client value: topics use the Unit ID exactly as shown there.
Commands have no effect	The client sending them has publish rights on the broker; the topic uses the right device or strategy ID (see `devices/list`, `strategies/list`).

5 Checklist

Host and Port match the broker, and Connected shows a green tick after a refresh.
On production sites: Use SSL = Yes, the CA chain is uploaded and Verify server cert = Yes.
Data arrives under controllers/<Unit ID>/ at the configured Readout interval.
Write access to the command topics is limited to trusted clients on the broker.
Certificate files and passwords are stored safely outside the controller.