Ramp-Function Generator - Siemens SINAMICS S120 Function Manual

2.2.8

Ramp-function generator

Description
The ramp-function generator is used to limit acceleration in the event of abrupt set-
point changes, which helps prevent load surges throughout the drive train. The
ramp-up time p1120[D] and ramp-down time p1121[D] can be used to set an accel-
eration ramp and a deceleration ramp independently of each other. This allows a
controlled transition to be made in the event of setpoint changes.
The maximum speed p1082[D] is used as a reference value for calculating the
ramps from the ramp-up and ramp-down times. A special adjustable ramp can be
set via p1135 for fast stop (OFF3), e.g. for rapid controlled deceleration when an
emergency stop button is pressed.
There are two types of ramp-function generator:
S Simple ramp-function generator with
-- Acceleration and deceleration ramps
-- Ramp for fast stop (OFF3)
-- Tracking can be selected via a binector input
S Extended ramp-function generator with
-- Initial and final rounding off
-- Setting values for the ramp-function generator
Note
The ramp-function generator cannot be frozen (via p1141) in jog mode
(r0046.31 = 1).
Properties of the simple ramp-function generator
Fig. 2-12
S RFG ramp-up time Tup
S RFG ramp-down time Tdn
S OFF 3 deceleration ramp
-- OFF3 ramp-down time
© Siemens AG, 2005. All rights reserved
SINAMICS S120 Function Manual, 06/05 Edition
x
p1082
x
--p1082
y
p1082
--p1082
Ramp-up and ramp-down with the simple ramp-function generator
Extended Setpoint Channel
Extended setpoint channel
Tup Tdn
t
t
Tup Tdn
p1120[D]
p1121[D]
p1135[D]
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