Siemens SINUMERIK 840D sl Programming Manual page 541

8.3 Program sequence with preprocessing memory (STOPFIFO, STARTFIFO, FIFOCTRL, STOPRE)
Automatic preprocessing memory control
Automatic preprocessing memory control is called with the FIFOCTRL command. FIFOCTRL
initially works 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
once the fill level reaches 2/3 in order to prevent complete emptying and deceleration to
standstill.
Preprocessing stop
Programming the STOPRE command in a block will stop block preprocessing and buffering.
The following block is not executed until all preprocessed and saved blocks have been
executed in full. The preceding block is halted in exact stop (as with G9).
Syntax
Table 8- 1
STOPFIFO
...
STARTFIFO
Table 8- 2
...
FIFOCTRL
...
Table 8- 3
...
STOPRE
...
Note
The STOPFIFO, STARTFIFO, FIFOCTRL, and STOPRE commands have to be programmed
in a separate block.
Job Planning
Programming Manual, 06/2009, 6FC5398-2BP20-0BA0
Identify machining step:
Automatic preprocessing memory control:
Preprocessing stop:
Path traversing behavior
541