Siemens Sinumerik 802D sl Programming Manual page 185

04.07
Preprocessing
memory, dynamic
Preprocessing stop
Preset
Program
Programmable frames
Programmable logic
controller
Programmable working
area limitation
© SIEMENS AG 2007 All rights reserved
SINUMERIK 802D sl/840D sl840D/840Di sl/840Di/810D ISO Turning - - 04.07 Edition
The traversing blocks are preprocessed prior to execution and
stored in a "preprocessing memory". Block sequences can be
executed at a very fast rate from the memory. Blocks are uploaded
continuously to the preprocessing memory during machining.
Program command. The next block in a part program is not
executed until all other blocks which have already been
preprocessed and stored in the preprocessing memory have been
executed.
See also "Preprocessing memory".
The control zero point can be redefined in the machine coordinate
system by means of the Preset function. Preset does not cause the
axes to move; instead, a new position value is entered for the
current axis positions.
1. Control operating area
2. Sequence of instructions to the control system.
Programmable --> frames can be used to define new coordinate
system starting points dynamically while the part program is
running. A distinction is made between absolute definition using a
new frame and additive definition with reference to an existing
starting point.
Programmable logic controllers (PLC) are electronic controllers
whose functions are stored as a program in the control unit. The
design and wiring of the unit are not, therefore, dependent on the
control functions. Programmable logic controllers have the same
structure as a computer, i.e. they consist of a CPU with memory,
input/output modules and an internal bus system. The I/Os and
programming language are selected according to the requirements
of the control technology involved.
Limitation of the movement area of the tool to within defined,
programmable limits.
Terms
B-185