Starting And Stopping Lists; Interrupting Lists For Synchronization Of Processing - Scanlab RTC 5 PC Interface Board Installation And Operation Manual

6.4.4 Starting and Stopping Lists

List processing ("List 1" or "List 2") can be started
either by the control command
page 256) or via an external start signal (see the
section "Starting and Stopping Lists via External
Control Signals and Master/Slave Synchronization",
page 209).
The command execute_at_pointer (see page 256)
can be used to start output of a list at a specified
address. If an external start signal is used (see the
section "Starting and Stopping Lists via External
Control Signals and Master/Slave Synchronization",
page 209), then the command
(see page 421) allows definition of a start address for
external starting of the list.
®
Output by the RTC 5 begins immediately. Even
during 10 µs-clocked execution of the list commands,
you can still send control commands to the RTC
which will immediately execute them without
hindering execution of the list. This is useful, for
example, for loading a second list while the first list
is being processed (the PC and scan head then work
in parallel). But the second list can only be started
after the first list has finished processing. During list
processing, execute_list commands and external
start signals are ignored.
Execution of a list can also be stopped at any time,
e.g. for implementing an emergency shutdown or for
any other purpose. Use of the
command (see page 523) will immediately abort the
currently running list and turn off (but not deac-
tivate) all "laser active" laser control signals. The
range_checking command can be used to cancel a
list execution automatically (as with stop_execution)
as well.
If, during list processing, the end of the list is reached
without encountering a set_end_of_list
then processing will continue at the beginning of the
list. This will be repeated until either the
stop_execution (see page 523)
an external stop signal is transmitted to the RTC
If, on the other hand, a set_end_of_list
encountered during list processing, then list
execution will stop - unless an auto_change,
auto_change_pos or start_loop
previously issued. In the latter case, a list change will
take place (see "Automatic List Changing", page
The change occurs only upon reaching a
set_end_of_list command.
®
RTC 5 PC Interface Board
Rev. 1.9 e
6 Developing User Applications
Notes
• Lists are not automatically started. Regardless of
execute_list (see
• To also enable starting and stopping of a list via
6.4.5 Interrupting Lists for Synchro-
set_extstartpos_list
The list command
possible to set wait markers (break points) within a
list. Each marker is associated with a number greater
than zero.
®
5,
When the RTC
execution (see
processing of the list is temporarily interrupted and
the laser is turned off.
The command
ascertains whether processing is currently inter-
rupted at a marker. If processing is interrupted, the
command
(wait_word) of the corresponding marker. Otherwise
the command returns zero.
stop_execution
The wait markers are provided for synchronization
purposes. The application program should perform a
handling routine for each wait marker. When that
handling routine is finished, processing of the list can
be resumed via the control command
(see page
The
(queryable via get_status) to be set and the BUSY
command,
status to be reset. The opposite occurs after a subse-
quent
List execution can be interrupted at any desired point
command is called or
in time via the control command
®
5.
the synonym command stop_list) and resumed via
command is
the
causes the laser control signals to be disabled
keeps the scan system in the most recently defined
command was
state – even if in the middle of microvectoring. After
a subsequent
75).
resumes the planned movements (of the current
command) and the laser control signals are reenabled
(1) If the signals are disabled, the laser output ports (LASERON,
how many commands are loaded, a list must be
started as described above in order to be
processed.
®
external signals, the RTC 5 provides corre-
sponding control inputs (see
Stopping Lists via External Control Signals and
Master/Slave Synchronization", page
nization of Processing
set_wait (see page 500)
®
5 reaches a wait marker during list
"Structured Programming", page
get_wait_status (see page 293)
get_wait_status returns the number
392).
set_wait command causes the PAUSED status
release_wait command.
restart_list command. The
restart_list command, the scan system
LASER1 and LASER2) are in the (high impedance) tristate mode.
"Starting and
209).
makes it
76),
release_wait
pause_list (or via
pause_list command
(1)
and
74