A one-way information flow control device , between an isolated Industrial Control System, ICS, network and a public access network , comprising: a first network interface card on a transmission side, the first network interface card including a first transceiver and a second transceiver , each of the first and second transceivers having a transmit port (TX) and a receive port (RX); a second network interface card on a receiving side, the second network interface card including at least one receive port (RX); characterized in that the one-way information flow control device further comprises: a first data connection segment connecting the first transceiver transmit port (311, TX) of the first network interface card to the second transceiver receive port (312, RX) of the first network interface card ; a second data connection segment connecting the second transceiver transmit port (312, TX) of the first network interface card to the first transceiver receive port (311, RX) of the first network interface card ; and a third data connection segment connecting the first transceiver transmit port (311, TX) of the first network interface card to the receive port (RX) of the second network interface card ; whereby interconnection of the first and second transceivers provides for sensing a datalink connection, while connection of the first transceiver transmit port (311, TX) of the first network interface card and the receive port (RX) of the second network interface card enables one-way data transfer. a first network interface card on a transmission side, the first network interface card including a first transceiver and a second transceiver , each of the first and second transceivers having a transmit port (TX) and a receive port (RX); a second network interface card on a receiving side, the second network interface card including at least one receive port (RX); characterized in that the one-way information flow control device further comprises: a first data connection segment connecting the first transceiver transmit port (311, TX) of the first network interface card to the second transceiver receive port (312, RX) of the first network interface card ; a second data connection segment connecting the second transceiver transmit port (312, TX) of the first network interface card to the first transceiver receive port (311, RX) of the first network interface card ; and a third data connection segment connecting the first transceiver transmit port (311, TX) of the first network interface card to the receive port (RX) of the second network interface card ; whereby interconnection of the first and second transceivers provides for sensing a datalink connection, while connection of the first transceiver transmit port (311, TX) of the first network interface card and the receive port (RX) of the second network interface card enables one-way data transfer. a first data connection segment connecting the first transceiver transmit port (311, TX) of the first network interface card to the second transceiver receive port (312, RX) of the first network interface card ; a second data connection segment connecting the second transceiver transmit port (312, TX) of the first network interface card to the first transceiver receive port (311, RX) of the first network interface card ; and a third data connection segment connecting the first transceiver transmit port (311, TX) of the first network interface card to the receive port (RX) of the second network interface card ; whereby interconnection of the first and second transceivers provides for sensing a datalink connection, while connection of the first transceiver transmit port (311, TX) of the first network interface card and the receive port (RX) of the second network interface card enables one-way data transfer. <EOS>