Hi Terry,
G96 turns CSS on
G97 turns CSS off
G94 feed per min
G95 feed per rev
G96 uses metres or feet/min, but you also have to be in feed per rev (G95) and have spindle feed back for it to work. Feed and speed change relative to the dia been cut.
G97 is a fixed speed
As far as I know there is no G48 command, ISO g-code uses G50 Snnnn to set maximum speed, Mach3 uses G50 for scaling. It is one thing that has been asked for but lathe always get put on the back burner, don't hold your breath.
CSS
G21 G95 (Metric feed/rev)
G96 S100 M3 (CSS at 100 metres / min)
None CSS with spindle feed back (RPM)
G21 G95 (Metric feed/rev)
G97 S1000 M3 (set to 1000 rpm)
None CSS no spindle feed back (RPM)
G21 G94 (Metric feed/min)
G97 S1000 M3 (set to 1000 rpm)
Graham.