Good day experts.

So there's an S7-1200 currently communicating with a SCADA. 

We plan to make this S7-1200 CPU as a Profinet i-Slave to a S7-300 CPU (IO controller).

Can we do this without affecting the S7-1200 current communication with SCADA?

I think I don't have to change IP address after I convert it to i-Slave right? I think the SCADA won't be affected if IP won't change?

Thanks a lot for any response. 

Nice to hear that. So that's true whether it's WinCC SCADA or some form of third party OPC server?

Would the config "Parameter assignment of PN interface by high-level IO controller" matter? I think even if I check this IP address won't be affected.

So the S7-1200 i-Device (PN Slave), the existing SCADA/OPC, and the new S7-300 IO controller (PN Master) will all be connected in 1 Ethernet switch?

For this I probably need 1 ethernet CP on the S7-300 IO controller (since the onboard has its own communication with his own SCADA) to adapt the IP subnet of the S7-1200 i-Device which has existing SCADA communication right?

The S7-300 has onboard PN but it's communicating with its own SCADA. 

I think even there's 2 PN they have both same IP right? 

So for another IP subnet (to adapt the i-Device) I probably need CP?