Siemens SINUMERIK 802D sl Programming And Operating Manual page 258

Programming
10.5 Special functions
Upper speed limit LIMS=
During machining from large to small diameters, the spindle speed can increase significantly.
In this case, it is recommended the upper spindle speed limitation LIMS=... . LIMS is only
effective with G96 and G97.
By programming LIMS=..., the value entered into the setting data (SD 43230:
SPIND_MAX_VELO_LIMS) is overwritten. This SD takes effect when LIMS is not written.
The upper limit speed programmed with G26 or defined via machine data cannot be
overwritten with LIMS=.
Deactivate constant cutting rate: G97
The function "Constant cutting rate" is deactivated with G97. If G97 is active, a programmed
S word is given in RPM as the spindle speed .
If no new S word is programmed, the spindle turns at the last defined speed with G96
function active.
Programming example
N10 ... M3
N20 G96 S120 LIMS=2500
N30 G0 X150
N31 X50 Z...
N32 X40
N40 G1 F0.2 X32 Z...
...
N180 G97 X... Z...
N190 S...
Information
The G96 function can also be deactivated with G94 or G95 (same G group). In this case, the
last programmed spindle speed S is active for the remaining machining sequence if no new
S word is programmed.
The programmable offset TRANS or ATRANS (see section of that name) should not be used
on the transverse axis X or used only with low values. The workpiece zero point should be
located at the turning center. Only then is the exact function of G96 guaranteed.
258
; Spindle's direction of rotation
; Activate constant cutting speed, 120 m/min, speed
limit 2,500 r.p.m.
; no change in speed, because block N31 with G0
; no change in speed, because block N32 with G0
; Approach on contour, new speed is automatically set as
is required for the beginning of block N40
; Feedrate 0.2 mm/revolution
; Deactivating constant cutting rate
; new spindle speed, r.p.m.
Programming and Operating Manual, 11/2012, 6FC5398-5CP10-3BA0
Surface grinding