In this section, we will try to build a simple IoT app for sending data from a sensor simulator module to a receiver device (a PC or a cloud), using a Raspberry Pi hub and the OPC UA protocol:
The OPC UA protocol is similar to Modbus, but works with more data types, and has no serious limitations, while providing for security, compression, and low latency.
The protocol was developed by the OPC Foundation as an industrial machine-to-machine communication protocol. OPC UA is an improved version of the Open Platform Communications (OPC) protocol, with one of the major changes being that the new protocol is available free of charge without any restrictions.
In the following table, you can find a more detailed description of the protocol to understand whether it is suitable for your needs...