Siemens SINUMERIK 828D Programming Manual page 466

Path traversing behavior
8.3 Program sequence with preprocessing memory (STOPFIFO, STARTFIFO, FIFOCTRL, STOPRE)
Note
The preprocessing memory is not filled or filling is interrupted if the machining step contains
commands that require unbuffered operation (search for reference, measuring functions,
etc.).
Note
The control generates an internal preprocessing stop in the event of access to status data
($SA...).
If tool offset or spline interpolations are active, a
programmed, as this will lead to contiguous block sequences being interrupted.
Example: Stop preprocessing
Program code
...
N30 MEAW=1 G1 F1000 X100 Y100 Z50
N40 STOPRE
...
466
CAUTION
command should not be
STOPRE
Comment
; Measurement block with probe at first
measuring input and linear
interpolation.
; Preprocessing stop.
Programming Manual, 07/2010, 6FC5398-2BP40-0BA0
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