2nd July 2026 – We've tested the latest Mervis IDE/RT 2.7.17, and the conclusion is simple – this is a release worth upgrading to. It brings a large number of fixes, improved security, and one new feature that integrators in particular will appreciate: native MQTT support. Below we summarize what's changing, what the main benefits are, and how to handle the upgrade itself.
Improved security and plenty of fixes
The main benefit of version 2.7.17 may be subtle, but it's all the more important: the developers have fixed a number of known bugs and strengthened security.
Some of our customers are already using Mervis 2.7. Some adopted it on their own initiative; others upgraded on our direct recommendation, to eliminate a specific bug. The version is now proven, and we recommend deploying it across the board.
Now with native MQTT support
The biggest new feature is support for the MQTT protocol. We've verified it in practice and used it without any problems to read data in Mervis from a sensor that supports MQTT.
Good to know:
- Mervis always acts as an MQTT client (not as a broker).
- It can both publish and subscribe.
- Due to a general limitation of channels in Mervis, the string (text) data type cannot be transferred. This isn't a limitation of MQTT itself (devices routinely send strings), but a limitation on the Mervis side that you need to account for in your design.
MQTT is now a widespread standard for IoT and smart devices. Thanks to native support, you can connect Mervis more easily to a wider ecosystem of sensors, gateways, and services.
Upgrading preserves your license
Good news for existing installations: when upgrading from version 2.6.5 to 2.7.17, your license is preserved automatically, without any complicated steps. If you do still run into any license issue, contact our support.
Caution is needed with significantly older versions: updating directly from version 2.4.2 or older may cause complications. In that case, we recommend proceeding together with support.
TIP: When upgrading from Mervis 2.5 to 2.7, check your network settings first.
Other fixes
WattPrice now works with the new SOAP OTE-ČR API. OTE has switched to updated public web services, and the original interface stopped working, so without this fix WattPrice would stop downloading price data.
Lib.Unipi and Edge: We've added our Edge-series controllers to the Lib.Unipi library and updated the library for the new Mervis version. Mervis 2.7.17 also extends support to devices we're still preparing, including custom (OEM) solutions.
Known issue with Modbus RTU
After upgrading to the new version, some users may experience faulty Modbus RTU communication. In that case, we recommend increasing the timeout (Mervis > Max. Telegram Duration).
How to get Mervis 2.7
Mervis IDE – you'll always find the latest version on the Mervis IDE download page in our Knowledge Base. We recommend choosing the tested version 2.7.17.
Mervis OS – we're preparing a new Mervis OS image with Mervis RT 2.7.17. You'll find it on the Mervis OS image overview page. For now, the current image is still based on Debian 12.
Run into a problem? Contact our support
If you run into trouble while upgrading to 2.7, get in touch with our support. We'll be glad to look into it, and you'll also help us catch anything that still needs fine-tuning.
- E-mail: [email protected]
- Phone: +420 533 433 391
