What is Modbus Communication Protocol? | Basics of Modbus TCP/IP and Modbus RTU

TL;DR

This video explores the basics of the open Modbus protocol, including its history, functionality, and different types.

Transcript

in this particular session we are going to learn what is modbus protocol you might have seen a lot of videos related to modbus protocol but most of them are actually not very clear that's why i decided to make one video which is easy for you to understand before understanding the core concept of a modbus protocol it's important to understand what i... Read More

Key Insights

• 🤗 Modbus protocol is an open and royalty-free protocol that enables industrial communication between different vendor devices.
• 🤗 It was originally designed by Modicon in the 1970s and later made open to allow widespread adoption.
• 🅰️ Modbus has different types, including Modbus RTU and Modbus TCP, each with specific configurations and communication methods.
• 😒 Modbus RTU uses unit IDs and physical cables like RS485 or RS232, while Modbus TCP uses IP addresses and Ethernet cables.
• 👻 In Modbus RTU, only the master can initiate commands, while Modbus TCP allows all devices to send commands.
• ®️ Modbus memory areas store different types of data, such as discrete inputs, discrete outputs, input registers, and holding registers.
• 🌥️ Modbus networks can connect up to 247 devices without a repeater, and repeaters are used for larger networks.

Questions & Answers

Q: What is an open protocol, and why is it important in a manufacturing phase?

An open protocol is a protocol that can be used by any company without paying any fee. It is important in manufacturing as it allows different vendors to use the same protocol and communicate with each other seamlessly.

Q: How does Modbus protocol facilitate communication between different vendor devices?

Modbus protocol acts as a common language that enables devices from different vendors, such as Allen Bradley PLC and Siemens PLC, to connect and share data. It eliminates the challenges posed by industrial communication between different vendors.

Q: What is the difference between Modbus RTU and Modbus TCP?

Modbus RTU uses unit IDs and physical cables like RS485 or RS232, while Modbus TCP uses IP addresses and Ethernet cables. Modbus RTU requires a master-slave configuration, whereas Modbus TCP allows all devices to act as masters.

Q: What types of data can be stored in Modbus memory areas?

Modbus memory areas include discrete inputs, discrete outputs (coils), input registers, and holding registers. Discrete inputs store information for devices with two states, while output coils handle discrete signals. Input registers and holding registers store analog input and output values, respectively.

Key Insights:

• Modbus protocol is an open and royalty-free protocol that enables industrial communication between different vendor devices.
• It was originally designed by Modicon in the 1970s and later made open to allow widespread adoption.
• Modbus has different types, including Modbus RTU and Modbus TCP, each with specific configurations and communication methods.
• Modbus RTU uses unit IDs and physical cables like RS485 or RS232, while Modbus TCP uses IP addresses and Ethernet cables.
• In Modbus RTU, only the master can initiate commands, while Modbus TCP allows all devices to send commands.
• Modbus memory areas store different types of data, such as discrete inputs, discrete outputs, input registers, and holding registers.
• Modbus networks can connect up to 247 devices without a repeater, and repeaters are used for larger networks.
• Modbus TCP has no distance limitations and can use fiber optic cables for long-distance communication.

Summary & Key Takeaways

• The Modbus protocol is an open protocol that allows different vendors to communicate and share data in the industrial communication world.

• Originally designed by Modicon, the protocol was later made open and royalty-free, leading to its widespread adoption by numerous companies.

• Modbus has different types, including Modbus RTU and Modbus TCP, each with unique features and use cases.