TFAB-DIGIO is a field connection module for DIGIO cards in redundant GA systems. Connected input signals are transmitted to all redundant DIGIO cards. For output signals, the module operates as a master / hot-standby voter: one of the cards operates on the output side as the master and its output signals are transmitted to the field. The other cards are on hot standby, ready to operate. In the event of a hardware failure of the active card, TFAB-DIGIO switches automatically to the next available output card.