User`s manual

Programmed Motion
GFK-1742A Chapter 7 Programmed Motion 7-41
7
t
9
0
1
0
0
1
1
0
1
2
0
-10%
-
10%
+
10%
+10%
+
10%
v
%
Feedrate Override
Some applications require small modifications to a programmed velocity to handle outside
changes. A
Rate Override
%AQ immediate command, which is sent to the DSM through ladder
logic, allows changes to a programmed feedrate (velocity) during program execution. (Details
about the Rate Override command are found in Chapter 5.) When a program begins executing,
the override rate is initially set to 100%. Thus, changes to feedrate before the execute program bit
is turned ON will be ignored. However, a rate override commanded on the same sweep as an
execute program bit
will
be effective.
A percentage can be assigned to the feedrate override of from 0% to 120%. When a
Rate
Override
is commanded, the DSM314 internally multiplies the feedrate percentage by
programmed velocity to obtain a new velocity. If the axis is moving, the current move’s
Jog
Acceleration Mode
is used to change velocity to the new velocity. All future move velocities will
be affected by the feedrate change. Note that when a feedrate of 0% is applied, no motion will be
generated until a new feedrate is commanded. Also note the
Moving %I
bit stays ON when the
feedrate is 0%.
Rate Override has no effect on non-programmed motion such as
Jog, Find Home,
or
Move at
Velocity.
Example 17: Feedrate Override
During execution of this program, feedrate changes of + or -10% are commanded. Dotted lines
indicate -10%, dashed lines indicate +10%.
ACCEL 1000
VELOC 6000
PMOVE 110000, INCR,
LINEAR
Figure 7-21. Feedrate Override Example