Fault Diagnosis And Functional Test; Coordinate Transformations - Scanlab RTC 5 PC Interface Board Installation And Operation Manual

8.1.9 Fault Diagnosis and Func-
tional Test
If a problem occurs, the versatile status return func-
®
tions of the iDRIVE scan system can be used for scan
system diagnosis, too. These functions allow to read
for instance
• the current operating state
• the operating state at the moment of the most
recently occurred operation interruption and
• an event code, indicating which particular event
caused the scan head to enter a temporary or
permanent error state.
To verify that data transfer capability between the
®
RTC 5 and a scan system is intact,
control_command can transmit an 8-bit value –
separately for each axis– to the scan system. Subse-
quently, a 20-bit value will be returned on the corre-
sponding status channel: If data transfer is error-free,
then the upper 8 bits of the returned 20-bit value will
be identical with the originally sent 8-bit value, and
the next lower 8 bits will be identical with the
complement of the sent 8-bit value.
These 20-bit values will be returned until the
control_command is used to select another return
data type (see section "Configuring Status Return
Behavior" on page 153).
To facilitate – after a data transfer verification – resto-
ration of the status return behavior in effect prior to
the data transfer verification, the
allows the prior data type to be temporarily stored for
later retrieval.
®
RTC 5 PC Interface Board
Rev. 1.9 e
8 Advanced Functions for Scan Head and Laser Control

8.2 Coordinate Transformations

For precise set-up of the scan system relative to the
image field (if the "second scan head control" option
has been enabled, two scan heads can be adjusted
relative to a common image field), a linear coordinate
transformation can be defined (separately for the
primary and secondary scan head connectors) for all
X and Y output coordinates (x|y) defined by vector or
arc commands:
The (2 x 2) total matrix M is thereby automatically
calculated by the RTC
matrix M
formation matrix M
The coefficients of the three matrices (M
M ) and the offset values (x
T
defined for the primary and secondary scan head
connector.
The offset (x
set_offset_list.
For 3-axis scan systems,
set_offset_xyz_list
the Z coordinate, too (z
set_defocus
control_command
applies:
The coefficients of the scaling matrix M
set_scale
that is common to both axes:
The coefficients of the rotation matrix M
set_angle
angle
produce counterclockwise rotation):
x' x

o o
M
= +
y' y
o o
®
5 as a product of a scaling
, a rotation matrix M and a general trans-
S R
:
T
 
M M M
=
T
R
|y ) can be individually
0 0
|y ) is set via set_offset
0 0
set_offset_xyz
enables setting of an offset z
has the opposite effect of
0
or set_defocus_list). The following
z' z z
= +
o
o
or set_scale_list using a scaling factor k
k 0
M
=
S
0 k
or set_angle_list by specifying a rotation

(mathematical definition: positive angles

cos sin
– –
o
M
=
R

sin cos
–
o
x
o
y
o
M
S
, M and
S R
or
or
for
0
are set via
S
are set via
R

o

161