Siemens SINUMERIK 840D sl Programming Manual page 583

Safety Functions
The control is equipped with permanently active montoring functions that detect faults in the
→ CNC, the → PLC, and the machine in a timely manner so that damage to the workpiece,
tool, or machine is largely prevented. In the event of a fault, the machining operation is
interrupted and the drives stopped. The cause of the malfunction is logged and output as an
alarm. At the same time, the PLC is notified that a CNC alarm has been triggered.
Scaling
Component of a → frame that implements axis-specific scale modifications.
Selecting
Series of statements to the NC that act in concert to produce a particular → workpiece.
Likewise, this term applies to execution of a particular machining operation on a given → raw
part.
Serial RS-232-C interface
For data input/output, the PCU 20 has one serial V.24 interface (RS232) while the PCU 50/70
has two V.24 interfaces. Machining programs and manufacturer and user data can be loaded
and saved via these interfaces.
Setting data
Data, which communicates the properties of the machine tool to the NC, as defined by the
system software.
Softkey
A key, whose name appears on an area of the screen. The choice of soft keys displayed is
dynamically adapted to the operating situation. The freely assignable function keys (soft keys)
are assigned defined functions in the software.
Software limit switch
Software limit switches limit the traversing range of an axis and prevent an abrupt stop of the
slide at the hardware limit switch. Two value pairs can be specified for each axis and
activated separately by means of the → PLC.
Spline interpolation
With spline interpolation, the controller can generate a smooth curve characteristic from only
a few specified interpolation points of a set contour.
Fundamentals
Programming Manual, 09/2011, 6FC5398-1BP40-2BA0
Glossary
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