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Modbus RTU is old, simple and still absolutely everywhere.
You will find it inside energy meters, variable-frequency drives, remote I/O modules, temperature controllers, HMIs and all sorts of industrial devices. The annoying part is that a connection can look perfectly correct while communication remains completely dead because one setting—baud rate, parity or device address—is wrong.
The Udemy course Modbus RTU: Theory and Simulation in 1 Hour offers a fast introduction to the protocol without stretching the subject into an unnecessarily long training program.
I believe it is a very good short course for students, electricians and automation technicians who need to understand the basic language used by Modbus devices.
[Modbus RTU: Theory and Simulation in 1 hour]
What Does the Course Cover?
Created by Haithem Jebali, the course contains four sections, 21 lectures and approximately 50 minutes of video. It was last updated in June 2026. The listing currently describes it as a new course, so the number of ratings and enrolled students is still very small.
The curriculum covers:
- Modbus RTU operating principles
- Device addressing
- Memory mapping
- Modbus data types
- Message-frame structure
- Common function codes
- Reading holding registers
- Writing a single register
- Reading coils
- Writing multiple coils
- Serial-port configuration
- Software-based Modbus simulation
It is a focused curriculum. There is no lengthy history lesson or ten-minute discussion about what a PLC is. The instructor moves fairly quickly into the information needed to understand a Modbus exchange.
Understanding Modbus Memory
One of the first hurdles for beginners is the Modbus memory model.
The course introduces coils, discrete inputs, input registers and holding registers. These areas represent different kinds of information, such as Boolean states or numerical process values.
This matters when reading a device manual. A value may be listed at register 40001, yet software might expect address 0 or 1 depending on how that particular program handles register numbering.
Yes, it can be irritating.
A basic understanding of memory mapping makes those strange-looking register tables much easier to interpret.
Frames and Function Codes
The theory section explains how Modbus RTU messages are structured and how function codes tell the receiving device what action to perform.
The lessons include examples covering:
- Read Holding Registers
- Write Single Register
- Read Coils
- Write Multiple Coils
Both requests and responses are demonstrated, helping learners see what the controller sends and what the slave device returns.
This is particularly useful for troubleshooting. When communication fails, examining the request and response can reveal whether the problem is an incorrect address, unsupported function or badly configured device.
Practical Simulation
The final main section uses software tools to simulate Modbus RTU communication.
Students configure a virtual serial connection and practise reading and writing registers and coils. The course also discusses a limitation of the free virtual serial-port tool used in the lessons.
Simulation is a sensible approach for beginners because it removes the need to purchase a PLC, meter or drive before practising. You can deliberately change communication settings, break the connection and then figure out what went wrong.
That is often more memorable than simply watching another diagram.
Who Is This Course For?
The course is aimed at:
- Complete Modbus beginners
- Electrical and electronics students
- Automation engineers
- PLC programmers
- Industrial maintenance technicians
- Anyone integrating drives, meters or controllers
A Windows computer is required. Basic knowledge of electricity or industrial automation may help, but previous Modbus experience is not required.
Are There Any Downsides?
At only 50 minutes, this is an introductory course.
It does not deeply cover RS-485 wiring, termination resistors, biasing, CRC calculations, communication diagnostics or PLC-specific programming. It also focuses on Modbus RTU rather than Modbus TCP.
The course is therefore best used as a starting point before moving into detailed network design and real hardware integration.
Final Verdict
Modbus RTU: Theory and Simulation in 1 Hour is a very good compact introduction to industrial serial communication.
Its strongest feature is the combination of clear theory and short simulation exercises. In less than an hour, learners can understand registers, function codes, message frames and the basic exchange between Modbus devices.
It will not make someone a Modbus expert, but it should make the next device manual considerably less intimidating.
Check the current course price and availability here: