An image pickup module comprises a lens assembly including a lens having a flange part, and a frame component for shading a circumferential surface excluding a neighborhood of a top portion of the flange part in the lens; an image pickup element which the top portion of the flange part touches; and an illumination element arranged around the lens assembly and the image pickup element. To provide a light-emitting element having a long lifetime. The packing includes a bending part, and the groove includes a guiding part that guides a tip of the bending part to a predetermined position on the bottom surface of the groove in the first case. To transmit information in addition to the data for safely controlling the railway signaling devices without reducing the transmission capacity for the data for the safe control, a portion of the data can include the identifier of the origination device, the information and the identifier of the target device. When the second BER is equal to or less than the predefined BER target, an optimal Vt is set to the second Vt.