Program Sequence With Preprocessing Memory (Stopfifo, Startfifo, Fifoctrl, Stopre) - Siemens SINUMERIK 840D sl Programming Manual

Work preparation
3.14 Path traversing behavior
Program code
N100 CPRECOF
N110 G0 ...
See also
Programming contour/orientation tolerance (CTOL, OTOL, ATOL) (Page 864)
3.14.5 Program sequence with preprocessing memory (STOPFIFO, STARTFIFO,
FIFOCTRL, STOPRE)
Depending on its expansion level, the control system has a certain quantity of so-called
preprocessing memory in which prepared blocks are stored prior to program execution and
then output as high-speed block sequences while machining is in progress. These sequences
allow short paths to be traversed at a high velocity. Provided that there is sufficient residual
control time available, the preprocessing memory is always filled.
Designate machining step
The beginning and end of the machining step to be buffered in the preprocessing memory are
identified in the part program with "STOPFIFO" and "STARTFIFO" respectively. The
processing of the preprocessed and buffered blocks starts only after the "STARTFIFO"
command or if the preprocessing memory is full.
Automatic preprocessing memory control
Automatic preprocessing memory control is called with the "FIFOCTRL" command.
"FIFOCTRL" acts initially just like "STOPFIFO". Whatever the programming, processing will not
start until the preprocessing memory is full. However, the response to the emptying of the
preprocessing memory does differ: With "FIFOCTRL", the path velocity is reduced increasingly
846
Comment
; Deactivate the "programmable contour accuracy".
Programming Manual, 12/2019, 6FC5398-2EP40-0BA0
NC programming