Siemens Ramp generator

[Diijay]

We are having a problem in our paper impregnating factory where the tension changes too fast during the joint sequence.

Example :
Running tension = 600 N/m
Tension during joint = 420 N/m

When the line is running and the joint comes (the reel changes at the unwinder), the program takes up the settings from [Tension during joint] immediately, without any kind of ramp -function, which cause´s the line tension to drop too fast and the line "falls on the ground".

I am supposed to solve this situation somehow, but i have no kind of experience how to make some kind of a ramp generator which decreases the tension step by step, during some amount of time, instead of decreasing it immediately.

Any kind of help will be appreciated

The software im using :

STEP 7 - V5.3 + SP3

 

[userxyz]

...

there may be better solutions, anyway, put this in an FC:

L #Staptijd
L 1.000000e+003
*R
RND
T #Pulstime
AN #T_bit
A #Enable
= #T_IN
CALL "TON" , "IDB SFB4"
IN:=#T_IN
PT:=#Pulstime
Q :=#T_bit
ET:=

A #Reset_0
JCN RFG
L 0.000000e+000
T #SETP


RFG: A #T_bit
FP #Membit
JC UP
BE
UP: A #Ramp_up
JCN DOWN
L #SETP
L #Stap
+R
T #SETP
L #Limit
L #SETP
<=R
JCN DOWN
TAK
T #SETP
DOWN: A #Ramp_down
JCN END
L #SETP
L #Stap
-R
T #SETP
L #Limit
NEGR
L #SETP
>=R
JCN END
TAK
T #SETP
END: BE




On the outside of the FC:


CALL "RFG" , "IDB 1"
Ramp_up :=I0.0
Ramp_down:=I0.1
Stap :=5.000000e+001
Staptijd :=5.000000e-001
Enable :=TRUE
Reset_0 :=I0.2
SETP :=MD50


U can play with staptijd and stap

 

[Diijay]

hmm.. ..Can you explain me, which of these variables are used as what position inside the FC :

IN =
OUT =
IN_OUT =
TEMP =

 

[userxyz]

...

I was wrong, it's an FB, not an FC:


IN: = bool
Ramp_up = bool
Ramp_down = bool
Stap = real
Staptijd = real
Enable = bool
Reset_0 = bool

OUT:
SETP = real

STAT:
T_IN = bool
T_bit = bool
Pulstime = time
Membit = bool
Limit = real