Newport ESP300 Series, Руководство пользователя

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These move segments can be sequenced in any order. Arcs can be
followed by arcs or lines, and lines by arcs or other lines as shown in
the following figures. Since there is no pre-processing of move
segments involved in making a contour, the user must ensure that
there is no change in tangential velocity at the transition from one
move to another. If this constraint is not satisfied, the transition from
one move segment to another may cause excessive accelerations and
shocks that could damage the stages.
Figure 4.1: A contour with multiple circular moves
Figure 4.2: A contour with multiple linear and circular moves
Circular move #1
Circular move #2
Circular move #3
Position of axis #1
Pos
iti
on
of
ax
is
#2
Start
Stop
Linear moves
Circular moves
Position of axis #1
P
ositio
n of
axi
s #2
In order to store the multiple move segment commands needed to
make a contour, we make use of a "via point" buffer. This "via point"
buffer contains group move commands essential to make a new move
segment upon completion of the move segment currently in progress.
The new move commands are pulled out of the buffer on a FIFO
basis. The "via point" buffer can hold a maximum of 10 group move
commands. If more than 10 group move commands are issued by a
user, the excess commands are flow-controlled by the firmware.
Section 4 – Advanced Capabilities 4-5