Scanlab RTC6 PCIe Board Installation And Operation Manual page 250

For load_fly_2d_table, you need to provide an ASCII
text file that contains a 2D compensation table.
A 2D compensation table must have encoder
compensations for reference points on a rectangular
grid. The number of grid lines and their spacing is up
to you (both may also differ in x and y). Missing
reference point data is automatically assigned a
compensation of 0. The largest occurring encoder
reference points form a frame within which encoder
compensation values are bilinearly interpolated.
Encoder values outside this frame is clipped to this
frame prior to interpolation. Therefore, the reference
points should cover at least the range of the
xy positioning stage required by your application.
Reference points with values exceeding ±524,288
can result in some loss of precision.
After load_program_file, 2D encoder compensation
is inactive by default.
It becomes active as soon as a valid 2D compensation
table from an ASCII text file gets loaded onto the
RTC6 PCIe Board. You can subsequently deactivate it
by calling load_fly_2d_table
instead of the filename.
RTC6 boards
Doc. Rev. 1.0.21 en-US
8 Advanced Functions for Scan Head Control and Laser Control
using a NULL pointer
For the 2D compensation tables, the following rules
apply:
• The ASCII text file can contain one or several
(1)
tables.
• The 2D compensation table must begin with the
line:
[Fly2DTable<No>]
<No> stands for the table number No, which must
be specified with load_fly_2d_table. The first of
the two tables is loaded with
No = <No> + 65,536.
second with
• This is directly followed by a block of data points.
• If several tables with the same number exist, then
only data from the first encountered table is read.
The others are ignored.
• Reading of the ASCII text file terminates upon end
of file or upon a line containing a caption.
• All characters to the right of a semicolon are
treated as comments and ignored.
• The order of data points is up to you.
• The maximum length of a data line is 255
characters.
• A data line contains the two reference point
coordinates for "Encoder0" and "Encoder1"
(signed integers) and two compensation values
(signed integers), each separated by spaces or
tabs:
<Encoder0> <Encoder1> <Encoder0-delta>
<Encoder1-delta>
• If a data point reoccurs, then the most recently
read value is used; the others are ignored.
• Empty lines or incomplete data lines are invalid
and are ignored.
(1) Even of another type, see table 1,
No = <No> and the
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