Ignition 8.1 Siemens UDT via OPC UA trouble

To make the Solution concrete in case anyone else comes across this issue:

  • 1200 PLCs have a different OPC structure from 1500 PLCs due to the setup necessary on the PLC side.

  • On the 1500 PLC the checkbox “Standard server interface (SIMATIC namespace)” has to be enabled.

  • “Legacy data type definitions” should be enabled on the OPC.

  • Do not use the “Server Interface” method when communicating datatypes and structures on 1500 PLCs