kb5004442 - PLC Programming & Automation

OPC DA to OPC UA: What Changed, and the Tunneller You No Longer Need

The path of one OPC DA read drawn as six boxes: SCADA client calling IOPCSyncIO Read, the COM runtime marshalling with the caller identity, TCP 135 as the RPC endpoint mapper, a second connection to a dynamic port above 49152, the DA server executable and its account question, and the EtherNet or IP driver to the controller

OPC DA to OPC UA: What Changed, and the Tunneller You No Longer Need KB5004442 stopped being optional on 14 March 2023, and with it went the last registry value that could keep an OPC DA link alive between two Windows machines. RequireIntegrityActivationAuthenticationLevel is still sitting under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Ole\AppCompat on every machine somebody set it on, … Read more