Siemens SINUMERIK 840DE Programming Manual page 268

Feedrate Control and Spindle Motion
7.4 Positioning spindles (position-controlled axis operation) (SPOS, M19 and SPOSA)
The program advances to the next block if the end of motion criteria for all spindles or axes
programmed in the current block plus the block change criterion for path interpolation are
fulfilled. Example:
N10 POS[X]=100
N20 IPOBRKA(X,100)
N30 POS[X]=200
N40 POS[X]=250
N50 POS[X]=0
N60 X10 F100
N70 M30
Block changes if the X axis has reached position 100 and exact stop fine. Activate block
change criterion IPOBRKA braking ramp. Block change commences as soon as the X axis
starts to decelerate. The X axis does not brake at position 200, but moves on to position 250;
as soon as the X axis starts to brake, the block changes. The X axis brakes and returns to
position 0, the block is changed at position 0 and exact stop fine.
Synchronizing spindle motions WAITS, WAITS(n,m)
WAITS can be used to identify a point at which the NC program waits until one or more
spindles programmed with SPOSA in a previous NC block have reached their positions.
Example: The block waits until spindles 2 and 3 have reached the positions specified in
block N10.
N10 SPOSA[2]=180 SPOSA[3]=0
N20...N30
N40 WAITS(2,3)
WAITS can be used after M5 to wait until the spindle(s) has(have) stopped. WAITS can be
used after M3/M4 to wait until the spindle(s) has(have) reached the specified speed/direction
of rotation.
Note
If the spindle has not yet been synchronized with synchronization marks, the positive
direction of rotation is taken from the machine data (state on delivery).
Position spindle from rotation (M3/M4)
When M3 or M4 is active, the spindle comes to a standstill at the programmed value.
7-18
Programming Manual, 10.2004 Edition, 6FC5 298-7AB00-0BP1
Fundamentals