Industrial M2M protocols – Modbus

In this section, we will try to build a simple IoT application for sending data from a sensor simulator module to a receiver device (a PC or a cloud), using a Raspberry Pi hub and the Modbus protocol:

Data flow from a sensor simulator to a receiver device

For devices with limited hardware resources, it makes sense to use the Modbus protocol for serial communication. While simple, it has several open and proprietary implementations that vary in functionality.

Note that this protocol can be used on the transport layer, but, in our example, we are going to use Modbus TCP, working on the application level.

In the following table, you can find a more detailed description of the protocol to understand whether it is suitable for your needs:

Key	Value
Open source	Yes*
The OSI layer	Transport or an application
Data types ...