Hi,

I encounter a problem about the communication between HMI and PLC, plase see my structure of network in attached picture.

My objective is make both HMI (server pc and multi panel) can communicate with PLC together, but sometimes one of them is not able to connect to PLC if the HMI is restart.

I have to keep restart the lost connection HMI until it get back the communication with PLC.

Is anyone here know what the root cause is? Is multi panel or the wonderware problem?

I used to connected 1 more multi panel to the same PLC, it caused the existing server PC and old multi panel lost connection to PLC, only the additional multi panel has communication.

Can’t we connect multiple multi panel to same PLC too?

Appreciate if there is any idea given here.

Thanks.