Processing Of Command Variable And Formation Of Negative Deviation - Siemens SIPART DR20 Project Planning Manual

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