Siemens SINUMERIK 840D

9
Path Traversing Behavior 08.97
9.6 Pro
g
ram run with
p
re
p
rocessin
g
memor
y,
STARTFIFO
,
STOPFIFO
,
9
840D
NCU 571
840D
NCU 572
NCU 573
FM-NC 810D 840Di

Siemens AG 2000. All rights reserved
9-330
SINUMERIK 840D/840Di/810D/FM-NC Programming Guide Advanced (PGA) – 04.00 Edition
9.6 Program run with preprocessing memory, STARTFIFO, STOPFIFO, STOPRE
Explanation of the commands
STOPFIFO
Stop high-speed processing section, fill preprocessing memory,
Preprocessing memory until STARTFIFO, "Preprocessing memory full"
or "End of program" is detected.
STARTFIFO
Start of high-speed processing section, in parallel to filling the
preprocessing memory
STOPRE
Preprocessing stop
Function
Depending on its expansion level, the control system
has a certain quantity of so-called preprocessing
memory in which preprepared 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.
STARTFIFO stops the machining process until the
preprocessing memory is full or until STOPFIFO or
STOPRE is detected.
NC program Preprocessing
memory
Machining in process
(blocks output in fast succession)
Sequence
Mark processing section
The high-speed processing section to be buffered
in the preprocessing memory is marked at the
beginning and end with STARTFIFO and STOPFIFO
respectively.
Example:
N10 STOPFIFO
N20…
N100
N110 STARTFIFO
Execution of these blocks does not begin until the
preprocessing memory is full or command STARTFIFO
is detected.