title: When it is justified to use UA OPC and UA OPC architectures over MQTT
body: <p>I am new to using OPC UA, I would like me to clarify some doubts I have about OPC UA which are as follows:</p>
  
  <p>– In what situations is the use of OPC UA.</p>
  
  <p>– OPC UA Architectures over MQTT.</p>
  
  <p>If there is any document that explains these two doubts, I thank you</p>