A system, method, and program product that uses statistical sampling to determine whether a pallet has been received when the pallet-level RFID tag is not read. In the method and device, a restriction is applied so as not to enable an additional recording on the recording medium at the time when a number of the recording units recorded on the recording medium has reached the maximum number of recording units and recording of up to a first sub-recording unit within the last recording unit has been performed. Two or more of a plurality of optical parts that are disposed in a light path extending from the light source device to the superimposing optical system are mounted to a base frame having a plurality of mounting portions for defining the locations of the two or more optical parts.