Optical modules and a method of precisely assembling the modules are provided. Revaprazan or its salt has an excellent treatment effect for gastrointestinal mucosal damage by potentiating a defensive factor in the gastrointestinal mucosa, simultaneously with acting as an acid pump antagonist. The control device transmits information indicating whether a data size of the data communication has a fixed length or a variable length. A track assembly is attached to the support bracket.