.2 To check if the grain code is right by pressing
and releasing the Function key. Such code can
be changed by the Plus/Hold key or Minus/Zero
key when the `cdxx` is on the display. Here
`cd` is the abbreviation for `code` and `xx` is
the grain code no. If keep depressing the
Plus/Hold or Minus/Zero key, the material
code will step into next code about every
second and releasing it till the grain code is
right