Siemens MICROMASTER 420 - Manual (Page 112)

3 Functions Issue 07/04
MICROMASTER 420 Operating Instructions
112 6SE6400-5AA00-0BP0
3.12.2 Ramp-function generator (RFG)
Parameter range: P1120, P1121
r1119, r1170
P1130 – P1142
Warnings -
Faults -
Function chart number: FP5000, FP5300
The ramp-function generator is used to limit the acceleration when the setpoint
changes according to a step function. This therefore helps to reduce the stressing
on the mechanical system of the machine. An acceleration ramp and a braking
ramp can be set independently of one another using the ramp-up time P1120 and
the ramp-down time P1121. This allows a controlled transition when the setpoint is
changed (refer to Fig. 3-42).
Without roun
ding
t
f
f
max
P1120 P1121
f
2
f
1
f
f
max
P1133 P1132 P1131 P1130 t
f
2
f
1
t
up
t
down
With ro
undin
g
for P1131) P1130 (
2
1
P1120
P1082
f - f
1 2 + ≥ ⋅
P1120
P1082
f - f
P1131) P1130 (
2
1
t 1 2
up
⋅ + + =
for P1133) P1132 (
2
1
P1121
P1082
f - f
1 2 + ≥ ⋅
P1121
P1082
f - f
P1133) P1132 (
2
1
t
1 2
down
⋅ + + =
Fig. 3-42 Ramp-function generator