For connecting to digital centres and interfaces that support the s88 feedback bus for instance mrklin interface mrklin memory central station 1 and 2 intellibox twin center easycontrol viessmann commander and hsi 88 usb the feedback module possesses 16 opto coupler inputs for potential separation and for high interference security simpler and safer connection of switching tracks contact tracks track busy reporters and reed contacts etc via screw clamps the feedback module is e