Siemens SIPART DR20, Руководство по планированию проекта, Страница: 38 / 136

Project Planning Manual SIPART DR20
In the following, the defined (adjustable using the pushbuttons 12) ratio factor is referred to as the
setpoint ratio w
v
and indicated as the setpoint on the digital display. The range of adjustment of the
ratio factor v is defined by the parameters w
a
and w
e
within the limits 0.000 and 9.999 where
LA < w
a
and LE > w
e
.
The current ratio is referred to as the actual ratio xv and is obtained by reversing the ratio formula:
x
v
= (x1 - c1) / x2
It is indicated as the actual value in the digital display and used for x-tracking if applicable.
The display range for ratio factors is 0.000 to 9.999 (negative values are suppressed) The negative
deviation display indicates xd = w - x as with the other controller types.
The setpoint ramp Tw is only effective at OFF or from 1 to 100 s. The alarm function enables
monitoring of the actual ratio or the setpoint ratio.
x1
INT
+
INT
gn
SP - w
w
vi
w w
x2
w
va
w
ve
T
w
x1
0 0 0 0
S20 = 1, S21
Display
Key
88
8 8
8 8 8 4
W
Xd
0
2
1
S23
A2
A1
a1 a2
x2
x
v
=
x1 - c1
x2
x
v
S17
A
A
0 1
w
v
∗
x2 + c1 = w
+
-
X
+
-
S22
1)
1)
S22 = 0, effective starting with software version A09
x
v
- tracking
A = H or N or Bl or Si
Fig. 3/15
Processing of command variable and formation of negative deviation in ratio controller
38