OPC-UA
Current drivers include A-B Suite, ModbusTCP and Simple TCP/UDP, allowing users to connect to a multitude of devices such as PLCs, solar cells, lights, generators, flow meters, bar code scanners, etc.
The Ignition OPC-UA server implemented the first native Java OPC UA stack. Inductive Automation offers the OPC-UA module for free.
Read more about this topic: Inductive Automation