You could install Remote I/O stations with AS-i controllers. Use copper to link up the stations within the same process area. Use fiber optic to link up Remote I/O stations back to central control. The cost of equipment will be high, but you will also save on cabling (material & Labour)
1.If I'm using pair cable to supply 110v ac solenoid,Can I use screen core as Earth or should I float the sreen on field and provide separate earthing to the instrument?If yes to using screen core as earth,Is it not going to create Earth Loop?