Abstract: In a network including access points, via which communication units can connect to the network, wherein each of the access points belongs to a zone, a method comprising the steps of assigning a message type to each of the zones in the network; receiving from the communication unit a query message for each zone, where the query message for each zone is of the message type assigned to that zone; filtering the query messages at an access point, via which the communication unit is connected to the network, so that only the query message of the message type, which is assigned to the zone to which the access point belongs, is allowed to pass through; and determining the zone, to which the access point belongs, depending on the query message allowed to pass through in the step of filtering.

Abstract: In a network including access points, via which communication units can connect to the network, wherein each of the access points belongs to a zone, a method comprising the steps of assigning a message type to each of the zones in the network; receiving from the communication unit a query message for each zone, where the query message for each zone is of the message type assigned to that zone; filtering the query messages at an access point, via which the communication unit is connected to the network, so that only the query message of the message type, which is assigned to the zone to which the access point belongs, is allowed to pass through; and determining the zone, to which the access point belongs, depending on the query message allowed to pass through in the step of filtering.

Abstract: A damping device in pressurized fluid cylinders, especially in hydraulic cylinders, for end position damping of the piston stroke. The device comprises a closure member connected to the piston and adapted to enter during a damping process into an outlet opening in front of the piston. A ring, serving as a non-return valve, is arranged with an axial play in an annular groove so as to choke the flow of pressurized fluid through the annular passage between the wall defining the outlet opening and the closure member, while permitting a fluid flow in the opposite direction during the return stroke of the piston. According to the invention, the ring has a cross-section permitting at least a radial deformation, and circumferentially distributed by-pass openings located in the region of the inside of the annular groove so as to permit said fluid flow during the return stroke of the piston.