Siemens MICROMASTER 440 - Ramp-Function Generator (RFG)

Issue 10/06 3 Functions
MICROMASTER 440 Operating Instructions
6SE6400-5AW00-0BP0
183
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. 3-62).
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
⋅++=
Where the rounding times are increased to be greater than the ramp period then the ramp
period is determined by the following equations:
()
()
()
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛
+⋅
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛
+⋅
⋅⋅−⋅
=
1130P
1131P
1
1131P1130P
f
1130P1120P
ff
2
t
max
2
12
up
()
()
()
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛
+⋅
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛
+⋅
⋅⋅−⋅
=
1132P
1133P
1
1133P1132P
f
1132P1120P
ff
2
t
max
2
12
down
Fig. 3-62 Ramp-function generator