in reply to String to hex
$ perl -le " printf qq{0x%04s\n},$_ for unpack '((H4)3)(H)', qq/COM7: +/ " 0x434f 0x4d37 0x003a 0x0000 [download]
$ perl -le " printf qq{0x%04s\n},$_ for unpack '((H4)*)(H)', qq/COM7: +/ " 0x434f 0x4d37 0x003a 0x0000 [download]