U Page 28
Digital controller RK 4004
Integral actuator:
The smaller the set proportional range is for the maximum correction
path of the actuator (parameter ".4.5. prop stroke ±"), the greater the
amplification of the web guider.
A negative proportional range causes negative amplification, the
effective direction in automatic mode is thus inverted.
Correction positioning
path
.4.5. prop stroke ±
25 mm
Proportional range
.1.3. prop range ±
2.0 3.5
Control deviation of
1.5 mm
Set position
(Sensor measuring range
center)
established correction
positioning path depen-
ding on proportional
range
Correction
positioning path
Control deviation
18 mm
10.5 mm
By reducing the proportional range the characteristic curve (see fig.)
becomes steeper. The steeper the characteristic curve the greater
the positioning path of the actuator given a control deviation and the
more sensitive the system becomes. The correction positioning path
of the actuator may be established on the basis of the characteristic
curve independently of the control deviation.
In this example a proportional range of 2 mm or 3.5 mm has been
assumed with a correction positioning path of 25 mm.
Given a control deviation of 1.5 mm the correction positioning path
amounts to approx.
18 mm
with a proportional range of 2 mm and
with a proportional range of 3.5 mm approx.
10.5 mm
.
