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obrazki wyróżniające - blog (22)

Date:
4.07.2025
Author:
Inventia Team

BLOG

Extend Modbus based on MT-221 wireless communication gateway programmable in CODESYS® environment – now with LTE modem  

Industrial automation starts where communication runs smoothly. And if your Modbus infrastructure needs to reach further than the RS-485 standard stipulates, the question is: how do you safely, stably and wirelessly extend the reach of this bus?  
 
The answer is simple – the MT-221 a wireless communication gateway with LTE, programmable in the CODESYS® environment.

MT-221 – a communication gate that opens up new possibilities

Modbus without limits - LTE instead of cables

The traditional RS-485-based Modbus RTU is a proven standard, but with limited physical range. In the age of distributed systems, sprawling production halls or remote measurement points, wired connections are becoming a barrier. The MT-221 breaks through this barrier by enabling access to Modbus devices over LTE cellular networks 

This means that your Modbus devices can communicate regardless of distance – even if they are separated by kilometres. Do you have a facility at the other end of town, in a hard-to-reach area or simply don’t want to invest in an expensive cable infrastructure? 
No worries, the MT-221 with LTE will do it for you.

MT-221 – flexibility and power through CODESYS® environment – now with LTE modem  

At the heart of the MT-221 gateway is the CODESYS® development environment, which gives you complete freedom to create communication logic. It’s not just a gateway – it’s a programmable PLC controller that you can tailor to the needs of your system.  

With CODESYS you can:  

  • create your own control and measurement analysis applications,  
  • implement local offline control scenarios (e.g. in the absence of LTE connectivity),  
  • flexibly handle different data sources and Modbus RTU/Modbus TCP devices.
      

Find out more about working in the CODESYS environment, read the blog article:
CODESYS® – the modern PLC programming environment – Inventia.online

LTE modem and IoT-ready features

The MT-221 gateway is equipped with a state-of-the-art LTE Category 1 (Cat 1) modem with fallback to 2G – a guarantee of connectivity in all conditions. With support for MQTT, the device is ready for use in Modern Industrial environments.  

In addition, the MT-221 offers:  

  • RS-232/RS-485 port with Modbus RTU support (Master/Slave),  
  • Ethernet port with Modbus TCP support (Client/Server),  
  • USB-C port for local configuration and diagnostics of the unit,  
  • support for remote software updates and configuration.  

Data logger - your safeguard in the event of a communications outage

The MT-221 is not only a communication gateway, but also a reliable data logger. Thanks to its built-in memory, the device can store measurement data locally in the event of a temporary loss of connection to the PBX. This means that:  

  • you don’t lose any measurements – the data is safe, when connectivity is restored, the MT-221 automatically sends the storeddata to the host system,  
  • the central SCADA system or the IoT cloud need not worry about gaps in measurement history 

In practice? The MT-221 acts like a black box – it records everything, even when the outside world disappears from range. This is a functionality that many classic Modbus gateways lack.

Applications? You are limited only by your imagination

MT-221 will prove itself wherever:  

  • you need to remotely supervise and control Modbus devices in remote locations,  
  • you need to start communication quickly without building a cable infrastructure,  
  • local control logic is needed – independent of the connection to the head office – data continuity is important – even in the event of LTE network problems.   

It is the ideal solution for industries such as water and sewerage, energy, district heating, chemical industry or building automation.  

An example of an implementation? Imagine…

You have a distributed network of sewage pumping stations. Each equipped with a controller with Modbus RTU. Traditional cabling between them? Unrealistic. With the MT-221, you can collect data from each location and transmit it via LTE to the control panel. And what if there is no coverage for a few hours? The data will be stored locally and transmitted as soon as the connection is resumed. At the same time, you can implement basic control logic locally – all in one device. Fast. Flexible. Modern.

 

Your Modbus deserves more – give it LTE coverage with MT-221!

Find out more and check the technical specifications at:
MT-221 – CODESYS® programmable gateway – Inventia.online

Using an older module? It's time for an upgrade!

With the development of technology and changing market needs, many older telemetry modules have been discontinued. They have been replaced by modern equivalents – more efficient, functional and ready for the future.

The new modules not only support LTE, but also offer better performance, wider integration options, greater data transmission security and significantly more configuration options. If you are using older solutions, now is a good time to check if a new, upgraded version is available for your device.
 

A perfect example of such a change is the replacement of the popular MT-202 module with its more modern counterpart – MT-221, which offers extended functionality, higher performance and full support for modern communication standards. 

Check which modules have been discontinued and what they have been replaced with.
You will find all the details in this document:

👉PDF – Select compatible telemetry modules 

Need help? We will be happy to advise you on replacing modules.
Contact us via the contact form or call us. 

Get to know the MT-221 better – questions and answers

What is the MT-221 and what is it used for?

The MT-221 is a wireless communication gateway for automation systems. It allows Modbus RTU/TCP data to be transmitted over an LTE network, eliminating the need to run RS-485/Ethernet cables over long distances. Additionally, it can act as a local PLC thanks to programming in CODESYS®

What communication interfaces does the MT-221 offer?

  • RS-232/RS-485 with Modbus RTU support (master/slave)  
  • Ethernet with Modbus TCP support (Client/Server)  
  • LTE Cat 1 with fallback to 2G  
  • USB-C for programming, local configuration and diagnostics.

 

What are the advantages of communication via LTE?

  LTE communication allows:  

  • connect devices regardless of the distance between them,
  • avoid the cost and hassle of installing cables,  
  • run systems in hard-to-reach locations.
     

Does the MT-221 work offline if it loses LTE coverage?

Yes. The device can:  

  • perform local control logic,  
  • buffer data in internal memory and transfer it when connectivity is restored,  
  • prevent loss of measurements and data gaps.

 

Can I update the MT-221 software remotely?

Yesthe MT-221 supports remote update of internal software, control software and configuration via cellular or Ethernet.  

 

What typical applications does the MT-221 support?

The MT-221 is great for 

  • distributed metering systems (water, energy, district heating),  
  • building automation and HVAC,  
  • retrofitting of legacy Modbus RTU installations  
  • IoT and Industry 4.0 systems,  
  • wherever independence from cabling is important.
     

 

Can the MT-221 act as a data logger?

Yes – the MT-221 has a local data logging function, which means it acts as a ‘black box’ – data is recorded locally and sent later to a central system.
 

 

Do I need a separate PLC?

Not necessarily. With CODESYS®, the MT-221 can act as a PLC that performs local logic, collects data from local I/Os and communicates with host systems – all in one device.  

 

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