This illustration displays the integration diagram of the OPC UA Server with Oracle IoT Production Monitoring Cloud Service by using the Oracle IoT OPC UA Gateway software. 

1. Devices communicate with the OPC UA Server.
2. The OPC UA Server communicates with the gateway software using Milo Client Library. 
3.  OPC UA Gateway components use IoT REST APIs and Java Client library to interact with the Oracle IoT Production Monitoring Cloud Service.