Hello!!

I've similar questions...On a present profibus network with a CPU+HMI I need to add a new plc, and connect it on the hmi. Do i need to define the second plc as slave? it's not necessary to exchange data between two plcs.

Thanks

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Split from Connect two PLCs to one HMI on profibus.

Hello biadiogim;

You do not have to do anything on the second PLC,  just as you did not have to do anything on the first PLC. The configuration for the connections between a PLC and an HMI must be done in WinCC,  and only in WinCC.

When you are ready to connect the second PLC to the HMI,  open WinCC, create a connection over Profibus to the second PLC (use its Profibus address), create tags allowing data exchanges with the second PLC, compie and download to the HMI. Connect the second PLC tp the Profibus- betwork, it should start communicating.

If you have error messages, correct the issues, such as checking the availlable HMI connection ressources available on your PLC, sometines they have to be tweaked.

Hope this helps, 

Daniel Chartier