Max expansions supported OPC

Author: mcmchris

content/hardware/07.opta/opta-family/opta/tutorials/01.user-manual/content.md

@@ -1226,12 +1226,14 @@ It provides a platform independent and secure method for exchanging information
 
 The [**open62541** library](https://github.com/open62541/open62541) is an open-source implementation of the **OPC UA** standard. It is lightweight, efficient and written in C, making it ideal for embedded systems like the Opta. The library provides a flexible framework to create **OPC UA** servers and clients, ensuring compatibility with the standard while maintaining high performance.
 
-The [**OPC UA library**](https://github.com/arduino-libraries/Arduino_OPC_UA) supports secure communication and interoperability for industrial automation applications, with the capability to automatically detect, configure, and expose up to two Arduino Opta Expansion Boards via **OPC UA**. Supported expansion boards include:
+The [**OPC UA library**](https://github.com/arduino-libraries/Arduino_OPC_UA) supports secure communication and interoperability for industrial automation applications, with the capability to automatically detect, configure, and expose up to **two** Arduino Opta Expansion Boards via **OPC UA**. Supported expansion boards include:
 
 - Digital Expansion with mechanical relays (D1608E)
 - Digital Expansion with solid-state relays (D1608S)
 - Analog Expansion (A0602)
 
+***The OPC UA library supports a maximum of __two__ Opta expansions connected simultaneously.***
+
 ### Setting up the OPC UA Server
 
 To set up the **OPC UA** server, upload the [**`opta_opcua_server`** example](https://github.com/arduino-libraries/Arduino_OPC_UA/blob/main/examples/opta_opcua_server/opta_opcua_server.ino) to your Opta. This can be done using either the Arduino IDE or the Arduino CLI.