Siemens sinumerik 808d Programming And Operating Manual page 66

Programming principles
1.5 Special turning functions
Upper speed limit LIMS=
During machining from large to small diameters, the spindle speed can increase significantly.
In this case, it is recommended to program 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 by 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 S1000
N20 G96 S120 LIMS=2500
N30 G0 X150
N40 X50 Z20
N50 X40
N60 G1 F0.2 X32 Z25
N70 X50 Z50
N80 G97 X10 Z20
N90 S600
N100 M30
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 "Programmable work offset:
TRANS, ATRANS (Page 30)") should not be used on the transverse axis X or used only with
low values. The work piece zero point should be located at the turning center. Only then is the
exact function of G96 guaranteed.
66
; 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.
Turning Part 2: Programming (Siemens instructions)
Programming and Operating Manual, 05/2012, 6FC5398-5DP10-0BA0