Any or unique VLAN ID is dynamically assigned to a user terminal connected to a network, and communication by the assigned VLAN ID is enabled. A plurality of predicted output values of the controlled system are received from a mathematical model. The configuration of the nozzle plate is selected to adjust a volume of the fluid cavity to obtain a desired mechanical impedance matching between the fluid and the actuator. The measurement can be compared to a set of thresholds provided by the base station. The end of the centering element facing the retaining screw has an engagement section for engagement with the screw. A communication terminal device of this invention comprises a housing 8 provided with a display 5, and a touch panel input unit 6 arranged covering a screen of the display 5, and is capable of executing one operation mode selected by a user from a plurality of operation modes.