1-st step: create a separate project (not in a multiproject) with panel (for example, OP77B).
2-nd step: create a multiproject with a project in which an OS is inserted.
3-rd step: insert a project with OP in multiproject with OS.
Only this sequence works. 1-st and 2-nd step may be changed of course Correct me if I've made a mistake.
And note: in order to PCS7 and WinCC Flex working together (including OP integration) PCS7 must be v.7.1 SP1 and WinCC Flex must be 2008 SP1 (in my case 2008 SP2 also works).
2-nd step: create a multiproject with a project in which an OS is inserted.
3-rd step: insert a project with OP in multiproject with OS.
Only this sequence works. 1-st and 2-nd step may be changed of course Correct me if I've made a mistake.
And note: in order to PCS7 and WinCC Flex working together (including OP integration) PCS7 must be v.7.1 SP1 and WinCC Flex must be 2008 SP1 (in my case 2008 SP2 also works).