1. Relevant Points l Currently the RS232/RS485 connection is used for:  Device monitoring  Remote Parameters setting  Remote Devices On/Off l All safety actions are performed via relays and dedicated wiring l It would be preferable to keep this schema if possible because direct wiring is safer and more reliable then commanding via any serial (RS232, RS485) or field bus l So, if:  All parameter setting can be done locally near the device via the controllers keyboard  All critical safety commanding can be done via direct wiring There should be no stringent need to have the PLCs connected via fieldbus to the controllers

2. Possible Architecture Eth/Serial Bridge Controller 1Controller 2 Controller 3 WS DAQ DEV3 low level critical controls (safety) DEV2DEV1 Sensors ADC Field bus over Ethernet PLCs Coordination and Supervision (no low level critical controls) Serial (RS232/RS485 ) Ethernet

3. Possible architecture l In this architecture:  Remote on/off commanding and controllers parameter setting could be done passing via the Ethernet/Serial bridges without the need to pass trough the PLC (the already well tested EasySysnc Netcom Ethernet/Serial bridges could be used for this purpose)  PLC will strictly implement only low level controls and safety actions  Local on/off commanding and controller parameter setting is done via the controllers native keyboards