Scanlab RTC6 PCIe Board - Undelayed Short List Commands, Delayed Short List Commands

RTC6 boards
Doc. Rev. 1.0.21 en-US
10 RTC6 Commands
303
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The maximum number of up to 8 short
list commands may change in the future. For fully
future-safe applications, only one short
list command should precede a normal
list command. If necessary, you should explicitly
insert a list_continue or list_nop (list_nop
interrupts the Polyline).
• The command execution lengths of variable
list commands are dependent on additional
parameters and the user program. Details are
provided in the corresponding command
description.
• About multiple list commands, see Section
”Multiple List Commands”, page 304.
Notes
• The total execution time of normal and variable
list commands equals the sum of the command
execution time and the execution time of the
process initiated by the command. A subsequent
list command only runs after this total execution
time has completed. Example: the total execution
time of the normal list command mark_abs is
10 µs (command execution time) + the execution
time of the marking process. The latter is
dependent on the settings of such parameters as
marking length, mark speed, and delays etc.
Undelayed Short List Commands, Delayed
Short List Commands
Most short list commands (for example,
list_jump_pos, list_call, sub_call or list_return)
execute before the next list command and prior to a
possible scanner delay (Jump Delay, Mark Delay,
Polygon Delay). These commands are called
“undelayed short list commands” in the
corresponding command descriptions (in
Chapter 10.2 ”RTC6 Command Set”, page 315).
However, some short list commands only execute
after the respective scanner delay (that is, directly
before the next command). Such commands are
called “delayed short list commands” in the
corresponding command descriptions. These include
commands that immediately affect output or laser
power (for example, set_rot_center_list,
set_wobbel_mode, write_da_x_list,
set_laser_pulses, set_standby_list,
set_mark_speed, set_encoder_speed) or
commands that affect data acquisition or time
measurement (for example, set_trigger or
s
ave_and_restart_timer).
W
ithout this delayed execution, such commands
would, for example, result in a laser power change
already being effective at the end of a
Mark Command (that is, during a still-active
Mark Delay or Polygon Delay) and not at the
beginning of the following Mark Command.
If such a power changing command, such as a
peripheral output or set_laser_power, is called
immediately before a set_end_of_list, it is not
executed because set_end_of_list “clears up” the
laser control. Add a list_nop to be sure that the
command is actually executed.
set_trigger and save_and_restart_timer would
erroneously take into account the delay of a
preceding command instead of the delay of the
subsequent command.
If these commands are directly before a
set_end_of_list, add a list_nop so that they are still
executed within the list.
For several short list commands in a row, even a
“delayed short list command” only executes delayed
if no further “delayed short list commands” directly
follow.