Enter the proportion of the total ramp-up time (
parameter 3-71 Ramp 4 Ramp Up Time
) in which the acceleration torque decreases.
The larger the percentage value, the greater the jerk compensation achieved, and thus the lower the torque jerks in the application.
Parameter 3-77 Ramp 4 S-ramp Ratio at Decel. Start
Table 209: Parameter 3-77 Ramp 4 S-ramp Ratio at Decel. Start
3-77 Ramp 4 S-ramp Ratio at Decel. Start
Default value: 50%
Parameter type: Range, 1 - 99%
Setup: All setups
Conversion index: 0
Data type: Uint8
Change during operation: True
Enter the proportion of the total ramp-down time (
parameter 3-72 Ramp 4 Ramp Down Time
) where the deceleration torque increa-
ses. The larger the percentage value, the greater the jerk compensation achieved, and thus the lower the torque jerks in the applica-
tion.
Parameter 3-78 Ramp 4 S-ramp Ratio at Decel. End
Table 210: Parameter 3-78 Ramp 4 S-ramp Ratio at Decel. End
3-78 Ramp 4 S-ramp Ratio at Decel. End
Default value: 50%
Parameter type: Range, 1 - 99%
Setup: All setups
Conversion index: 0
Data type: Uint8
Change during operation: True
Enter the proportion of the total ramp-down time (
parameter 3-72 Ramp 4 Ramp Down Time
) where the deceleration torque decrea-
ses. The larger the percentage value, the greater the jerk compensation achieved, and thus the lower the torque jerks in the applica-
tion.
4.4.7 3-8* Other Ramps
Parameter 3-80 Jog/Homing Ramp Time
Table 211: Parameter 3-80 Jog/Homing Ramp Time
3-80 Jog/Homing Ramp Time
Default value: Size related
Parameter type: Range, 0.01 - 3600 s
Setup: All setups
Conversion index: -2
Data type: Uint32
Change during operation: True
Enter the jog ramp time, that is the acceleration/deceleration time between 0 RPM and the rated motor frequency n
s
. Ensure that
the resulting output current required for the given jog ramp time does not exceed the current limit in
parameter 4-18 Current Limit
.
The jog ramp time starts after activation of a jog signal via the LCP, a selected digital input, or the serial communication port. When
jog state is disabled, then the normal ramping times are valid.
e
3
0
b
a
0
7
0
.1
1
Time
P 3-80
RPM
P 4-13 RPM
high limit
P 1-25
Motor speed
Jog speed
P 3-19
P 3-80
Ramp up
(acc)
Ramp down
(dec)
t jog
t jog
P 4-11 RPM
low limit
Illustration 45: Jog Ramp Time
AU373327181955en-000101 / 130R1208 | 119
Danfoss A/S © 2021.08
Parameter Descriptions
VLT® AutomationDrive EZ FC 321
Programming Guide
