Scanlab RTC 5 PC Interface Board, Installation And Operation Manual

Page: 148 / 622

RTC
®
5 PC Interface Board
Rev. 1.9 e
7 Basic Functions for Scan Head and Laser Control
148
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• After vector-defined laser control is activated via
set_vector_control (
Ctrl
= 7), the focus shift for
2D or 3D para commands will change if the 3D
option is enabled and a 3D correction file has
been loaded and assigned.
Encoder-Speed-Dependent Laser Control
Encoder-speed-dependent laser control allows the
most recently read encoder speed (counter pulse
rate) of an encoder counter (or of both encoder
counters) to be used for controlling a laser signal
parameter. This lets you, for instance, adjust the
laser’s impact on moving objects in accordance with
the transport system’s current conveyance speed.
For initializing encoder-speed-dependent laser
control, the command
set_auto_laser_control ,
set_auto_laser_params or
set_auto_laser_params_list must be called for spec-
ifying (via the
Ctrl
parameter) which signal
parameter will be readjusted according to the current
encoder speed (counter pulse rate) (parameter
Mode
= 5).
Via set_encoder_speed_ctrl or set_encoder_speed ,
you can choose which of the two encoders should be
used for measuring the speed (or if both encoders
should be used to determine a vectorial encoder
velocity). Here, you can also specify a target encoder
speed and a smoothing factor for a two-stage low-
pass filter (see command description).
For subsequent mark and arc commands (also timed
mark commands), the RTC
®
5 will then perform an
automatic correction of the selected signal parameter
dependent on the current encoder speed: The 100%
value defined via
set_auto_laser_control ,
set_auto_laser_params or
set_auto_laser_params_list (
Value
parameter) will
be multiplied by the correction factor
v
a
/
v
s
(exception: for the output period
HalfPeriod
, the
correction factor is
v
s
/v
a
). Here,
v
s
is the target
encoder speed defined with set_mark_speed and
v
a
is the current encoder speed.
Notes
• Encoder-speed-dependent laser control can be
combined with position-dependent and vector-
defined laser control, but not with speed-
dependent laser control.
• Observe all notes on position-dependent laser
control in the section "General Notes", page 141 :
the correction factor for encoder-speed-
dependent laser control will, if necessary, be
multiplied by a position-dependent laser-control
factor and a nonlinearity factor before being
applied to the 100% value.