Siemens MICROMASTER 420 - Ramp-Function Generator (RFG)

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 rounding
t
f
f
max
P1120 P1121
f
2
f
1
f
f
max
P1133P1132P1131P1130 t
f
2
f
1
t
up
t
down
With rounding
for
P1131) P1130(
2
1
P1120
P1082
f
-
f
12
+≥⋅
P1120
P1082
f
-
f
P1131) P1130(
2
1
t
12
up
⋅++=
for
P1133) P1132(
2
1
P1121
P1082
f
-
f
12
+≥⋅
P1121
P1082
f
-
f
P1133) P1132(
2
1
t
12
down
⋅++=
Fig. 3-42 Ramp-function generator