90
Installation and user guide
Rev: 4.0
NTT 240/460
Operation mode
Another ramp type supported by drive is the S ramp (Type S) that, besides just described parameters, uses a further
parameter called JERK (RPM/s
2
); this last parameter, also called smooth factor, introduces another ramp coefficient
related to acceleration and deceleration profile, and lets drive to smooth speed profile around reference change;
knowing
T
RAMP-A
time to reach
RAMP
-V parameter, acceleration and deceleration ramps (
JERK or smooth factor
) are
provided by following formula:
Smooth factor effect on speed profile is shown below:
6.11 Motor brake
Motor brake function provides that drive, at any SWITCH-OFF command (load torque disabled), performs a ramp
to stop load, before brake enabling and before leaving SWITCH-ON state.
!
If application requires motor brake function,
do NOT use a control feedback from incremental channel
only (without HALL sensors)
because, in this condition, drive needs to perform, at every SWITCH-ON
command, a rotation angle, in order to align poles, more or less pronounced, depending on the rotor position
in that moment.
!
It’s recommended NOT to connect OUT-x output directly to motor brake command contact. Please use a
mechanical contact (as a relay) or any other proper mechanical/electric contact as long as OUT-x current
consumption is lower than limit imposed by drive electrical features.
‘Time brake enable’ and ‘time brake disable’ must be appropriate to estimated time for brake handling.
Into
Advanced Setup
item, into
Output
sub-item, output OUT-x can be set for motor brake management (please see
to learn about output setting), with features shown below:
1. convention used for output provides to ‘disable’ brake (disengage) at high logic signal and ‘enable’ brake
(engage) at low logic signal.
2. ‘time brake enable’ and ‘time brake disable’ setting from 10 to 2000 ms.
3. ‘speed brake enable’ setting: it is the speed target to enable brake.
4. deceleration ramp setting, to reach speed target, at any SWITCH-OFF command (only with operating speed
grater than speed target).
During engaging brake, drive provides to stop load keeping block torque, after reaching speed target, and, at this
time, it provides output signal; drive holds torque until ‘time brake enable’ set is expired.
Summary of Contents for NTT 240
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