
B-63783EN-1/01 7.FEEDRATE CONTROL/ACCELERATION AND DECELERATION CONTROL
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Limitations
- Linear type positioning
Optimum torque acceleration/deceleration is not enabled unless linear
type positioning is enabled (LRP, bit 4 of parameter No. 1400, = 1).
- Modes and conditions
Optimum torque acceleration/deceleration is enabled if the system is in
look-ahead acceleration/deceleration mode (or in fine HPCC mode)
and the conditions under which look-ahead acceleration/deceleration
are satisfied.
- Target axes
Optimum torque acceleration/deceleration cannot be performed on a
specific axis only. All the axes subject to program commands are
subject to optimum torque acceleration/deceleration. The PMC axis is
not, therefore, subject to it.
- Limited acceleration curve (permissible acceleration)
Different limited acceleration curves (permissible accelerations) may
be set for acceleration and deceleration, provided that the ratio of the
deceleration acceleration to the acceleration is 1/3 or greater.
For example, if the acceleration at a certain acceleration setting point
(Pn) is set to 90%, the deceleration acceleration at that point must be
30% or greater. In the above example, therefore, the curve shown in
Fig.7.2.6(h) must be 1/3 of the curve shown in Fig.7.2.6(f) or greater.
Also, the limited acceleration curve data for deceleration must be set so
that the time required for the deceleration from the rapid traverse rate to
a speed of 0 does not exceed 4000 msec. Furthermore, if the high-speed
processing function is used, the acceleration must be set to 2000 msec
or less. This does not include the acceleration change time of bell-
shaped acceleration/deceleration.
If the deceleration acceleration ratio or the time required for the
deceleration to a speed of 0 exceeds the above range, OT alarm
(OT9710) will be issued at the time rapid traverse is executed.
A slight error will occur between the specified acceleration and the
actual acceleration.
- Relationship with a customer's board
Optimum torque acceleration/deceleration cannot be used from a
customer's board.
- Tool center point control
Optimum torque acceleration/deceleration is disabled in tool center
point control mode (except startup and cancellation) even if the
required parameters are set and the conditions for before-interpolation
acceleration/deceleration are satisfied. If this occurs, the acceleration/
deceleration for positioning follows the reference acceleration
specified with parameter No. 1671. This means that acceleration/
deceleration is performed with the reference acceleration specified
with parameter No. 1671 regardless of the limited acceleration curve.