Scanlab RTC6 PCIe Board - Position-Dependent Laser Control

RTC6 boards
Doc. Rev. 1.0.21 en-US
7 Basic Functions for Scan Head Control and Laser Control
199
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Position-Dependent Laser Control
To activate the position-dependent laser control for
the output port specified by
set_auto_laser_control, a user-defined scaling
function must be loaded by load_position_control,
see Section ”Notes on Loading a Scaling Function”,
page 199.
This scaling function represents a scaling factor as a
function of the distance to the center of the Image
Field. After load_program_file, it is initialized for all
distances with “factor 1.0”. The “position-
dependent” laser control is de facto deactivated by
that. The table can be saved by create_dat_file.
When calculating the correction for “position-
dependent laser control“, the current Cartesian
control values are used as a basis:
• including wobbel correction (#2 in Chapter 7.3.6
”Output Values to the Scan System”, page 181)
• including coordinate transformation in the virtual
Image Field (#3)
• including Processing-on-the-fly correction (#4)
• excluding head-specific coordinate
transformation (#5)
• excluding Image Field correction (#6)
Notes on Loading a Scaling Function
• For the Scale(Position) scaling function,
load_position_control loads a table from an
ASCII text file.
• The ASCII text file can contain one or several
tables.
(1)
• Each table can contain up to 50 data points
(Position | Scale(Position)).
• The Scale(Position) function is linearly
interpolated from the data points.
For the scaling function tables, the following rules
apply:
• Each table must begin with the line:
[PositionCtrlTable<No>]
<No> represents the table number.
• If the table contains multiple
[PositionCtrlTable<No>] entries with the same
<No> , then only the lines after the first entry are
used. Only lines up to the next ’[’ character (that
is not preceded by a semicolon) are used.
• Each data point (Position  Scale(Position)) is
defined as follows:
Position<n> = <Value>
Scale<n> = <Value>
where <n> corresponds to the index (1  <n>  50)
of the data point. The values <Value> can be
specified as (unsigned) floating point numbers.
Decimal separator: period ( . ).
• If the table contains multiple data points with the
same Index <n> , then the most recently read one
is used.
• If the table contains multiple data points with the
same position value Position, then the data point
with the largest Index <n> is used. Equality is
checked to within ±0.01.
• The position value is specified radially as the
di
stance between the to-be-marked point and the
coordinate midpoint (= (x
2
+ y
2
)
1/2
) as percent of
half the image-field side length.
Example: (X
max
|0) corresponds to 100%,
(X
max
|Y
max
) corresponds to 2
1/2
× 100%.
(1) Even of another type, see table 1, page 153.