Siemens 420 manual Ramp-function generator RFG, With rounding

3 Functions Issue 07/04

3.12.2Ramp-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).

	f
roundingWithout	fmax
	f2
	f1	P1120	P1121	t
	f
	fmax
	f2

With rounding

f1

P1130

tup

P1131

P1132

tdown

P1133

t

f 2

- f1

⋅ P1120 ≥

1

(P1130

+ P1131)

for

P1082

2

tup

=

1

(P1130 + P1131) +

f 2 - f

1

⋅ P1120

2

P1082

for

f 2

- f1

⋅ P1121 ≥

1

(P1132

+ P1133)

P1082

2

tdown =

1

(P1132

+ P1133) +

f 2

- f1

⋅ P1121

2

P1082

Fig. 3-42 Ramp-function generator

MICROMASTER 420	Operating Instructions
112	6SE6400-5AA00-0BP0