Scanlab RTC 5 PC Interface Board - Page 143

RTC
®
5 PC Interface Board
Rev. 1.9 e
7 Basic Functions for Scan Head and Laser Control
143
innovators for industry
Notes on Loading a Scaling Function
The command load_position_control loads a table
for the scaling function Scale(Position) from an ASCII
text file. The text file can contain one or more tables.
Each table can contain up to 50 data points
(Position  Scale(Position)) for various positions. The
RTC
®
5 determines the scaling function
Scale(Position) from this data by linear interpolation.
The following rules apply for these tables:
• Each table must start with the instruction
(Caption)
[ PositionCtrlTable <No>]
where <No> must be replaced by a nonnegative
integer which denotes the table number.
• If the table contains multiple
[PositionCtrlTable<No>] entries with the same
<No> , then only the instructions after the first
entry will be used; instructions that follow further
entries will be ignored. Only instructions up to the
next ’[’ character (that is not preceded by a
semicolon) are used.
• Each data point (Position  Scale(Position)) is
described by two instructions:
Position<n> = <Value>
Scale<n> = <Value>
where <n> must be replaced by an integer
(1 
<n>  50) which denotes the number of the
data point. The values
<Value> can be specified as
(unsigned) floating point numbers. Use the
period
(.) as the decimal separator.
• If the table contains multiple data points with the
same Index <n> , then the most recently read one
will be used and the previous ones ignored.
• If the table contains multiple data points with the
same position value Position, then the data point
with the largest Index
<n> will be used and the
others ignored. Equality is checked to within
±0.01.
• The position value is specified radially as the
distance between the to-be-marked point and the
coordinate midpoint (= (x
2
+ y
2
)
1/2
) as a percent
value (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%
(with X
max
,Y
max
= 2
19
or 2
15
in RTC
®
4
compatibility mode)
•For
<Value> , the following ranges apply:
0.0  Position  150.0 and
0.0  Scale(Position)  4.0.
(Though the RTC
®
5 uses the scaling function only
for the range 0.0  Position  141.42, the inter-
polation also takes into account values in the
range 141.42  Position  150.0)
• Each instruction must be in a separate line.
• Spaces and tabs in a line (e.g. between ’
= ’ and
<Value> ) are ignored.
• Empty lines are ignored.
• Data points with invalid values are ignored.
• The data point of a particular index
<n> is ignored
if the corresponding
Position<n> and/or
Scale<n> definition is missing.
• The semicolon ’;’ can be used for comments. All
characters in a line following a semicolon are
ignored.
• The instructions for data points in the table can
be ordered as desired.
• Indices for data point pairs in the table can be
selected as desired within the range [1…50] (the
table will then be automatically sorted by
ascending position values).
• If the table contains no valid data point, the
command load_position_control will have no
effect (return value 1 or 13).
• If there is no entry for Position = 0.0, then an
entry with
Scale =Min( Scale<i> ) will be
inserted (the smallest allowed value defined in
the table will be used for lower positions values).
Likewise for Position = 150.0 with
Max(
Scale<i> ).
• If the selected text file only contains a single valid
data point with Scale<n> = S , then (for the entire
position range) the scaling function
Scale(Position)
=S will be loaded with the effect
that no position-dependent correction will be
executed. A 100% value set with
set_auto_laser_control (
Value parameter) will
be multiplied by
S . For S = 1.0, position-
dependent correction will therefore be fully
switched off. Alternatively, this can also be
achieved with
Name =0 in
load_position_control.