A method generates a stream of data, wherein the stream comprises a plurality of encoded data blocks. The technique of the present invention registers classification of printers connecting with a network LAN into at least one group, and specifies target printers, which are objects of management, by the unit of registered group. The data processor determines whether the implement is aligned with the planned implement path. Based on these metrics, designers may fine-tune software for the embedded system. The gun does not point forward at anyone except it is operated to point at any direction, when controlled wirelessly with a special module.