Scanlab RTC 5 PC Interface Board - 8.7 Processing-on-the-fly (Optional); 8.7.1 Intended Use and Initialization

RTC
®
5 PC Interface Board
Rev. 1.9 e
8 Advanced Functions for Scan Head and Laser Control
177
innovators for industry
8.7 Processing-on-the-fly
(Optional)
8.7.1 Intended Use and Initialization
With its Processing-on-the-fly option enabled, the
RTC
®
5 allows processing of parts in motion (e.g.
parts on a conveyor belt, rotating plate or XY trans-
lation stage), as well as stationary parts with a
moving scan system (e.g. via a robot arm).
To adjust laser scan processes to the current work-
piece position relative to the scan system, the
position of the workpiece or scan system can be indi-
rectly (via encoder counters) or directly (via the
McBSP interface) forwarded to the RTC
®
5. With acti-
vated Processing-on-the-fly correction, the coor-
dinate values of all vector and arc commands will be
transformed based on the forwarded position values.
If the position values are forwarded via encoder
counters, then the motion is simulated or detected
via user-supplied incremental encoders. The simu-
lated or detected encoder signals trigger an (RTC
®
5)
internal counter (encoder counter) whose counter
values then correspond to the current position and
are applied as the basis for Processing-on-the-fly
correction (see "Synchronization via Encoder Signals",
page 215). If forwarded via the McBSP interface, the
input values will be directly applied as the basis for
Processing-on-the-fly correction (see "Synchroni-
zation and Online Positioning via McBSP Signals",
page 216).
(1)
The commands for activating and deactivating
Processing-on-the-fly correction are supported by the
standard DLL (
RTC5Dll.Dll , if the Processing-on-the-
fly option is enabled by SCANLAB). No additional
drivers or software files (e.g. further DLL or DSP
program files) are needed. Initialization and program
launching remain unchanged as well (see page 62).
List commands are available for activating and deac-
tivating Processing-on-the-fly correction. The param-
eters required for activation can be determined via a
calibration procedure (see below).
Activated Processing-on-the-fly correction directly
affects only the X and Y output values, but (with the
3D option enabled) has no effect or only an indirect
effect on Z output values (also see page 126). If the
“second scan head control” option has been enabled
and both scan head connectors have been assigned a
2D correction table, then Processing-on-the-fly
corrections will be equally applied at both scan head
connectors.
For an installed RTC
®
5, the command
get_rtc_version can be used to check whether the
Processing-on-the-fly option is enabled.
Notes
• Activated Processing-on-the-fly correction can
affect not only vector and arc commands, but (as
of version OUT 515) also processing of normal list
commands that don’t produce scanner motion
(e.g. list_nop, set_control_mode_list). Even
with such commands, the positions of the X and
Y axes are continually tracked in accordance with
the current Processing-on-the-fly input signals
(position of the workpiece or scan system). In
older versions, execution of such commands was
sometimes followed by a hard jump to the
changed position value.
(1) Simultaneous usage of both forwarding methods for
Processing-on-the-fly correction of two independent motions
isn’t possible (see section "Overview" on page 178). The McBSP
interface can’t be simultaneously used for both Processing-on-
the-fly applications and online positioning (see page 166).