Does the ABB Compact HMI 6 provide a built-in OPC (DA, HA, A&C) driver?
It's basicaly a PC with Compact HMI 6 only as a graphical interface to R/W process values
and Alarms/Events to the Siemens PCS 7 via Ethernet level.
There is no such thing as an "opc driver".
CHMI provides OPC **CLIENT** connections. ie it can subscribe data from any OPC-DA and OLPC-AE server.
You will need to connect either to the existing OPC-DA server in the Siemens PCS system or use a third party OPC server to connect to the PLCs.
For alarms and events, CHMI can also connect to any OPC-AE server. Again thats either the OPC-AE server in the Siemens PCS or a third party OPC-AE server.