Modbus RTU Client Source Code Stack

The Simplest and Easiest Way to Connect Your Automation Device to Modbus RTU Servers

When you purchase the Modbus RTU Client Source Code Stack, you get a product developed with more than 3,000 hours of engineering time. This is a solution that was written in-house and has been deployed in hundreds of unique devices over the last 30 years. This software package is reliable and thoroughly tested in demanding industrial applications.


  • 100% C-based source code
  • No nonsense, single product line licensing and no ongoing royalties
  • Easily extensible, table-driven object model structure
  • Complete integration guide for developing Modbus RTU devices
  • A ready-to-run sample application
  • Complete documentation
  • 30-day, no risk guarantee

Modbus RTU Client Source Code Stack



The royalty-free Modbus RTU Client Source Code Stack development kit is the simplest and easiest way to connect your automation device to Modbus RTU servers like valves, meters, barcode readers and other devices (from companies like Groupe Schneider and Rockwell Automation). With a simple architecture and implementation, you can be Modbus RTU-enabled in one day. With your royalty-free Modbus RTU license, you can ship unlimited binaries and never pay another dollar.

Why Modbus RTU?

The simple architecture and function code interface of Modbus RTU makes it the most common industrial network in North America. It is supported and implemented in the majority of industrial automation networks in North America. To effectively sell your device into that massive market, you need to be Modbus RTU-enabled.

How Do You Get Modbus RTU enabled?

The kit provides you with the encoding/decoding, transport and the required application layer interfaces. Your application controls what Modbus RTU data you read and write in the Modbus RTU servers and how you link that data (16-bit unsigned registers and 1-bit coils) to your internal data space, allowing you to modify or extend your Modbus RTU data implementation without outside assistance.

What Is the Modbus RTU Development Kit?

The Modbus RTU Client Source Code Stack development kit provides the software required to implement the Modbus RTU client protocol. A device with this software can read and write registers and coils in Modbus RTU server devices. The development kit is a collection of C-code source files. These source files encode Modbus RTU messages and decode responses from Modbus RTU server devices. The software requires access to a UART and functions to read, write and check the UART status. It also requires a timer tick that it can use to implement the serial communications timeout.

Why Use a Real Time Automation Source Code Development Kit?

You have many alternatives for getting connected to a Modbus RTU network. There are other vendors selling toolkits and open-source solutions that you can use to Modbus RTU-enable your device but there is no other alternative like RTA.

You’ll get a solution designed specifically for embedded microcontrollers. The RTA development kits are 100% written in-house by RTA, so if you need support, you can work with the Modbus RTU experts who actually wrote the code. And, you’ll be supported from Day 1 all the way through the optional conformance testing and beyond.

Is This Really Royalty Free?

Yes, there are no ongoing costs other than an optional maintenance program and your optional subscription to the Modbus IDA Organization.

What Is the Development Process?

The process begins with a detailed walk-through once you receive the source code followed by a joint meeting to design the application interface that meets your application requirements. You can get as much or as little assistance as you desire.

What to Do Next

Your next step is to contact us via email, phone or by completing the Request Software Information Form so we can schedule some time to discuss your application.

What our Customers are Saying

“When it came to getting the job done, we turned to Real Time Automation, and they performed. RTA helped us figure out a complex communications interface problem in short order, and provided hardware and software modification requirements for implementation before we even got off the plane!”

Kevin L. / HTS Engineering Ltd.

“We have worked with Real Time Automation on a variety of projects over the past few years. I have consistently found them enthusiastic to work with us throughout the development process to ensure that we receive a communications solution that meets our needs. More importantly, their commitment to providing timely support services after the initial release of the system is truly exemplary.”

Ken F. / Danfoss Graham