A fire curtain assembly is presented that is collapsible for easy transport and quickly and easily assembled for use. A pair of openings is provided in each of the carrier sheets. The pressure difference sensor is contactable by a first media pressure via the first process connection flange and by a second media pressure via the second process connection flange; and a housing, which contains an electronic evaluating circuit. The center electrode assembly is movable with the coupling shaft relative to the first and second counter electrodes, for instance in one or more of dimensions including laterally and normally. The method further includes sending an Axon-ARP request to the second Axon using the first route, and receiving an Axon-ARP reply from the second Axon, where the Axon-ARP reply includes a second route.