Smithy CNC Mills - Manual (Page 15)

SmithyCNC Programmer’s Reference Manual: Language Overview 1-11
For several modal groups, when a machining center is ready to accept com-
mands, one member of the group must be in effect. There are default settings
for these modal groups. When the machining center is turned on or otherwise
re-initialized, the default values are automatically in effect.
Group 1, the first group on the table, is a group of G codes for motion. One of
these is always in effect. That one is called the current motion mode.
It is an error to put a G-code from group 1 and a G-code from group 0 on the
same line if both of them use axis words. If an axis word-using G-code from
group 1 is implicitly in effect on a line (by having been activated on an earlier
line), and a group 0 G-code that uses axis words appears on the line, the activty
of the group 1 G-code is suspended for that line. The axis word-using G-codes-
from group 0 are G10, G28, G30, and G92.
It is an error to include any unrelated words on a line with O- flow control.