Siemens Sinumerik 840D sl Programming Manual page 81

Program code
N10 S300 M3
...
N100 SETMS(2)
N110 S400 G95 F...
...
N160 SETMS
Further information
Interpretation of the S-value for the master spindle
If function G331 or G332 is active in G function group 1 (modally valid motion commands), the
programmed S-value will always be interpreted as the speed in rpm. Otherwise, the
interpretation of the S-value will depend upon G function group 15 (feedrate type): If G96,
G961 or G962 is active, the S-value is interpreted as a constant cutting rate in m/min; otherwise,
it is interpreted as a speed in rpm.
Changing from G96/G961/G962 to G331/G332 sets the value of the constant cutting rate to
zero; changing from G331/G332 to a function within the G function group 1 other than G331/
G332 sets the speed value to zero. The corresponding S-values have to be reprogrammed if
required.
Preset M commands M3, M4, M5
In a block with axis commands, functions M3, M4, M5 are activated before the axis movements
commence (basic setting on the control).
Example:
Program code
N10 G1 F500 X70 Y20 S270 M3
N100 G0 Z150 M5
Note
Machine data can be used to set when axis movements should be executed; either once the
spindle has powered up to the setpoint speed, or immediately after the programmed switching
operations have been traversed.
Working with multiple spindles
Five spindles (master spindle plus four additional spindles) can be available in one channel at
the same time.
One of the spindles is defined in machine data as the master spindle. Special functions such
as thread cutting, tapping, revolutional feedrate, and dwell time apply to this spindle. For the
remaining spindles (e.g. a second spindle and an actuated tool) the numbers corresponding
to the speed and the direction of rotation / spindle stop must be specified.
Fundamentals
Programming Manual, 01/2015, 6FC5398-1BP40-5BA2
7.1 Spindle speed (S), spindle direction of rotation (M3, M4, M5)
Comment
; Speed and direction of rotation for drive spindle = pre-
set master spindle.
; Machining of the right-hand workpiece side.
; S2 is now the master spindle.
; Speed for new master spindle.
; Machining of the left-hand workpiece side.
; Switching back to master spindle S1.
Comment
; The spindle ramps up to 270 rpm and the move-
ments then executed in X and Y.
; Spindle stop before the retraction movement
in Z.
Spindle motion
81