Siemens SINUMERIK 840Di sl Operating Manual page 458

A
Appendix
B Terms
Block search
Keywords
Key-operated switch
Tool nose radius
compensation
Helical interpolation
Increment
Setting data
Safety Functions
A-458
distinction is made between → main blocks and → subblocks.
The block search function allows any point in the part program to be
selected, at which machining must start or be continued. The function
is provided for the purpose of testing part programs or continuing
machining after a program abort.
Words with a specific notation, which have a defined meaning in the
programming language for → part programs.
1. S7-300: The keylock switch is the mode selector switch on the
CPU. The keylock switch is operated by a removable key.
2. 840D: The key-operated switch on the → machine control panel
has 4 settings, to which functions are assigned by the operating
system of the control. Further, the key-operated switch has three
differently colored keys, which can be removed in the specified
positions.
Contour programming assumes that the tool is pointed. Since this is
not actually the case in practice, the curvature radius of the tool used
must be communicated to the control, which then takes it into account.
The curvature center is maintained equidistantly around the contour,
offset by the curvature radius.
The helical interpolation function is ideal for machining internal and
external threads using form milling cutters and for milling lubrication
grooves. The helix comprises two movements:
1. Circular movement in one plane
2. Linear movement perpendicular to this plane
Travel path length specification based on number of increments. The
number of increments can be stored as a → setting data or selected
with keys labeled with 10, 100, 1000, 10,000.
Data, which communicates the properties of the machine tool to the
NC control, as defined by the system software.
The control incorporates monitors, which are active at all times and,
which are designed to detect malfunctions in the → CNC, the
programmable controller (→ PLC) and the machine at an early stage,
in order to minimize the risk of damage to the tool, workpiece or
machine.
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.
SINUMERIK 840Di sl/840D sl/840D Operating Manual HMI-Advanced (BAD) - 01/2008 Edition
A
01/2008
© Siemens AG 2008 All rights reserved.