In this work, the optimum operational mode of an RFID tunnel gate and a linear conveyor is analyzed experimentally. Therefore, a test box is equipped with UHF RFID transponders for the frequency range from 865 MHz to 868 MHz. This box is driven through the tunnel at different velocities of the linear conveyor. Besides, the transmitting power is varied at four reader antennas that are mounted at different positions and with different orientations inside the tunnel. The number of successfully registered transponders is analyzed for the different conditions and some recommendations for the optimum setting are given.