This is achieved by utilizing a split-architecture design that puts part of the barrier in an isolator card located in the safe area (power supply rack) & the other part in each of the spurs of field-mounted device couplers/segment. The barrier in the isolator allows 350 mA to be run through the segment up to the Spur/junction Box through trunk cable. Since infallible resistors are used, devices from Zone 0/1 or 2 can be direct connected. Having 350 mA, now allows users to power up to 16 Fieldbus devices (20 mA each) at 500 m while retaining intrinsic safety.