Scanlab RTC6 PCIe Board - Notes on Optimizing the Delays; Recommended Sequence; Automatic Delay Adjustments

RTC6 boards
Doc. Rev. 1.0.21 en-US
7 Basic Functions for Scan Head Control and Laser Control
155
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7.2.3 Notes on Optimizing the
Delays
The delays are set by set_scanner_delays and
set_laser_delays.
They should be appropriate for:
• the set jump speed
• the set mark speed
• the Tracking Error of the used scan head
If the delays are not optimized, the quality of the
scanning results are under some circumstances
reduced and scanning time is extended. The figures
in Section ”Potential Errors when Optimizing the
Delays”, page 157 show the various effects of non-
optimized delays on the lettering “RTC“.
Notes
• Laser Delays are specified in units of 1/64 µs.
• In contrast, the Scanner Delays (Jump Delay,
Mark Delay, Polygon Delay) are specified in units
of 10 µs.
Recommended Sequence
Laser Delays should be optimized first. It is
recommended to set Jump Delays and Mark Delays
to a high value. The laser delay lengths have no
influence on the total scan time as long as positive
values are specified (see also following section).
After the Laser Delays have been set, the
Scanner Delays can be optimized.
Automatic Delay Adjustments
In principle, all delays can be set for any value within
the corresponding allowed range. In some situations
the laser control could be disturbed, for example,
when Laser-On and Laser-Off overlap. Therefore, for
each command that switches the laser, the
RTC6 PCIe Board checks the set Laser Delays, corrects
them and, if necessary, inserts a scanner delay
“artificially”. These situations, which are listed below,
should actually already be avoided in the
user program, because the “corrected” marking does
not necessarily meet the requirements.
Laser-On and Laser-Off Overlap
The RTC6 PCIe Board corrects the faulty laser delay so
that:
• the Laser-On occurs 1/64 µs after the currently
effective LaserOff Delay
• or the Laser-Off occurs 1/64 µs after the still
running LaserOn Delay
In both cases, the chronological next mark is cut off
somewhat, see also Figure 43.
Notes
• For further information on the general avoidance
of such automatic adjustments in
RTC5 Compatibility Mode, see
RTC5 Manual, Chapter 7.2.3 ”Notes on
Optimizing the Delays”.
43
Automatic adjustment of LaserOff Delay.
Laser
Laser
Time
Mark
command
Corrected!
Time
Mark
command
RTC6 tries
to switch
off
the laser
RTC6 does
not switch
off
the laser
LaserOff Delay
LaserOn Delay
LaserOff Delay
LaserOn Delay
With automatic correction
Without correction