I have two GE9030 PLCs talking to each other over an enhanced genius bus. The Quickpanel mini is connected to the power supply port of one of the PLCs. Both PLCs generate global data bits, which are boolean and looked at on the HMI. The HMI also looks at WORDS in registers in the PLC it is connected to. However, the Quickpanel will not accept a global reference (%G) for an address so it can look at registers in the other PLC.