Scanlab RTC6 PCIe Board - Page 163

RTC6 boards
Doc. Rev. 1.0.21 en-US
7 Basic Functions for Scan Head Control and Laser Control
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For LaserOnShift = 0, the Signals for “Laser Active”
Operation are switched on (off) with a delay of
Timelag relative to the set starting position (set
ending position).
By setting the parameter Timelag to the actual
Tracking Error (and the parameters Nprev and Npost to
sufficiently large values), it is ensured that:
• the Signals for “Laser Active” Operation switch
on/off precisely at the endpoints of the desired
vector
• the Tracking Error becomes constant even before
the vector’s startpoint is reached
• the vector is executed right up to its endpoint
with constant mark speed
The Laser Delays from set_laser_delays are not
effective with Sky Writing.
The switch-on time point of the Signals for
“Laser Active” Operation can be adjusted with the
parameter LaserOnShift (for example, to the
HalfPeriod of set_laser_pulses or to the reaction
times of the laser itself), so that the first laser pulse
occurs exactly with the set starting position. Positive
LaserOnShift values delay the switching on of the
Laser Control Signals. Negative LaserOnShift values
advance the switching on of the Laser Control Signals
(at the earliest, however, until the beginning of the
forward run). Negative values are also necessary to
“make room” for a Q-Switch delay or a
FirstPulseKiller signal in one of the YAG modes.