Choosing the right software

Software openness of Unipi controllers provides you with the option to choose from a wide selection of available software solutions, ranging from Mervis, the officially supported platform, to third-party platforms to your software. This guide will help you to navigate between the available software and to choose the best option for your project.


A complete software platform provided for free to all Unipi controllers. The Mervis IDE development environment, a core of the solution, is suitable also for users without any deeper PLC programming knowledge thanks to its user-friendly interface and clear design. Mervis also offers a professional SCADA interface, HMI editor, cloud database and a mobile app. That makes it an ideal choice for a variety of users such as installation companies looking for a reliable and stable solution with full technical support. Detailed info about Mervis is available on this link.

Note: Additionally, Mervis training courses are organized throughout a year. These courses are suitable for both beginners and experienced users. Learn more about the courses and closest course dates on this link.

Application programming interface (API)

Unipi controllers are based on the Linux open-source operating system, for which we provide an application programming interfaces (API) as a method of direct access to inputs, outputs and communication interfaces of Unipi controllers. Thanks to the API the Unipi hardware can be quickly and easily integrated into your software or third-party solutions, making it an ideal choice for software developers. Our technical support team is ready to help you with implementation.

Unipi API consists of three main components:

  • Modbus TCP protocol representing a standard interface for interaction with Unipi PLC I/Os
  • SysFS driver providing filesystem-level access to Unipi controller inputs/outputs
  • EVOK - a set of web-based APIs for interaction with all I/Os of Unipi controllers and extension modules

More info about the individual APIs is available on this link

Note: Using the Mervis platform does not prevent access to the controller’s Linux OS, eg. you can use your software along with Mervis on a single controller. A good example of this feature is the SSCP to SQL Bridge service for storing data from Mervis-running Unipi PLCs into an external SQL database.

Commercial or open-source?

Open-source solutions are characterized by freely accessible and editable source code, allowing its users to modify and update the software according to their needs or to add new tools and functions. The main disadvantage is the absence of technical support - in case of issues, users have to rely on various community forums. Open-source software also cannot always guarantee compatibility with hardware. Aside from open APIs, Unipi technology also provides preassembled operating system images suitable for developers and OEM customers - an open-source OS image and a custom OS image.

Note: For Unipi-developed APIs (see above) we provide full technical support and complete documentation. We also guarantee their full compatibility with all Unipi controllers.

Commercial solutions are closed software platforms that often require paid licences to be used. Their users are limited only to officially developed tools and functions provided by the solutions’ developers. This disadvantage is, however, compensated by the availability of official technical support, dynamic development, regular updates and a guarantee of full functionality on systems listed as compatible. The official supported solution for Unipi controllers is Mervis (see above) for which we provide direct technical support and we guarantee its full compatibility with all Unipi controllers.

What is the extent of Unipi technical support?

Full support is provided for Mervis and the Unipi-developed APIs. Direct technical support is also available along with complete documentation, tutorials, OS images and assistance with implementation and/or installation.

Partial support is available for Node-RED, taking the form of a preassembled OS image available on Unipi Knowledge Base. The support is limited to preparation of Unipi hardware - in case of software issues please consult Node-RED community forum or the Node-RED section of the Unipi technology forum.

For other third-party solutions, technical support is not provided. If you encounter trouble with commercial platforms, please consult the corresponding tech support department. In the case of open-source solutions please visit community forums dedicated to the solution.

Officially supported platforms

Name Developed by Unipi OS image Unipi support Full functionality
Mervis Yes Yes Yes All Unipi PLCs
API Yes Yes Yes All Unipi PLCs

Third-party solutions

Name Developed by Unipi OS image Unipi support Full functionality
Node-RED No Yes Partial¹ All Unipi PLCs
HomeAssistant No No No Not guaranteed²
CODESYS No No No Not guaranteed²
REXYGEN No No Third-party Unipi 1.1
FHEM No No No Not guaranteed²
Pimatic No No No Not guaranteed²
Domoticz No No No Not guaranteed²
OpenPLC No No No Unipi Neuron, Unipi 1.1 (Not guaranteed)
openHAB No No No Not guaranteed²
Nymea No No No Unipi Patron, Neuron & Axon (through SysFS)
Homebridge No No No Unipi Neuron, Unipi 1.1
Others³ No No No Not guaranteed²


  1. Tech. support provided only for the preparation of Unipi hardware for Node-RED implementation
  2. Functionality may be limited only to certain product lines or models. We recommend consulting the corresponding tech support or community forum
  3. Open-source solutions not included in the list that may be compatible with Unipi controllers.

If you have any software-related questions, feel free to get in touch at [email protected], or contact our technical support at [email protected].