A process for producing crystals of 2-ethoxy-1-2\u2032- biphenyl-4-ylmethyl-1H-benzimdazole-7-carboxylic acid ), characterized by dissolving or suspending the compound or a salt thereof in a solvent comprising an aprotic polar solvent and crystallizing it. The system also includes a serializer configured to provide a waveform corresponding to serialized input data. The present invention is useful for diagnosis or treatment of diseases such as chronic bronchial asthma.