Scanlab RTC 5 PC Interface Board, Installation And Operation Manual

Page: 501 / 622

RTC
®
5 PC Interface Board
Rev. 1.9 e
10 Commands And Functions
501
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Delayed Short
List Command set_wobbel
Function defines the parameters for an ellipse-shaped wobbel motion. “Wobbel” is a motion of
the output position which is added to the regular marking movement (see
page 167 ).
Call
set_wobbel( Transversal, Longitudinal, Freq )
Parameters
Transversal
Amplitude of the elliptical or figure-8 movement perpendicular to the
momentary direction of motion or to the one defined via
set_wobbel_direction in bits (unsigned 32-bit value).
Allowed range: [0 … 131.071 (=2
17
-1)]. Excessive values will be clipped.
Longitudinal
Amplitude of the elliptical or figure-8 movement parallel to the
momentary direction of motion or to the one defined via
set_wobbel_direction in bits (unsigned 32-bit value).
Allowed range: [0 … 131.071 (=2
17
-1)]. Excessive values will be clipped..
Freq
Frequency of the wobbel movement in Hz
(number of ellipses per second, 64-bit IEEE floating point value)
Allowed range: [–6000 … 6 000]. Larger values will be clipped.
Comments • The wobbel mode can be used for marking lines with various line widths. A ellipse-
shaped movement is added to the linear marking movement, resulting in a spiral move-
ment of the laser focus in the image field. Alternatively, a figure-of-8 wobbel shape
(horizontal or vertical to the direction of motion) can be activated via
set_wobbel_mode . The line width can be set via appropriate values for the amplitude
and frequency (frequency and marking speed should be compatible with each other).
For arcs, too, the wobbel motion follows the current marking direction (exception: see
below). Therefore, independently of the cartesian angle, the effective line width is
always the same.
As of Version DLL 537, any desired “direction of motion” can also be specified via
set_wobbel_direction . “freely definable wobbel shapes” are likewise possible (see
set_wobbel_vector ).
• The wobbel mode is terminated by setting both amplitudes and/or the frequency to
zero (more accurate for –n

Freq

n with n = 50000/65536 = 0.7629…).
• The frequency is signed. The wobbel vector rotates clockwise for positive values and
counter-clockwise for negative values. Thus, the inner and outer point densities of arcs
can be individually set independently of their actual direction of rotation.
• At the beginning of a marking, (after set_wobbel or a jump), the wobbel start point is
generally set for the same value relative to the vector/arc startpoint; it is repeatedly
continued, however, for polylines (including arcs). For identical amplitudes
(
Longitudinal
=
Transversal
), the wobbel startpoint is permanently referenced to the
coordinate system, i.e. independent of the current direction of motion (as with the
RTC
®
4).
• For an angle, ellipse-shaped wobbel movements can result in more or less small jumps
after reaching the corner, depending on the current wobbel phase. This does not occur
(= “rounded corners”) if the wobbel motion is exactly circular (
Longitudinal
=
Transversal
).
•
Longitudinal
= 0 produces a sine-shaped wobbel motion across the direction of
movement.
• When defining the wobbel shape and its frequency take the dynamics of the scan head
and laser into account. Otherwise, an overheating and even a permanent damage of
the system may occur, see
chapter 8.4.1 "Wobbel Shapes – Important Notes on Choo-
sing Appropriate Parameter Values" .