Project Planning Manual
SIPART DR20
A follow-up controller connected in series to the ratio station can then display the variables w and x
in addition so that a complete process image is available. The ratio station also has the automatic
(w)/manual (yH) switchover (which can be switched off by S31 = 1). Switchover to manual is
always hitchless, switching back to w is only hitchless if the ratio factor is tracked accordingly with
S17 = 1 (x-tracking).
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
y
W
Xd
0
2
1
S23
A2
A1
a1 a2
x2
x
v
=
x1 - c1
x2
y' - c1
x2
x
v
S17
A
A
0
1
y'
w
v
∗
x2 + c1 = w
+
-
X
+
-
S22
1)
1)
S22 = 0, effective starting with software version A09
Fig. 3/17
Processing of command variable as an output signal of the ratio station
•
S1 = 9 Manual/automatic control station, DDC manual control station (Fig. 3/18)
Manual control station S31 = 2
In this type of circuit the device outputs a signal which can be adjusted using the manipulated
variable pushbuttons. It is output directly in percent in the two-digit display in a standard K
controller and a standard S controller with three-position step output if the position signal is fed
back to the device via the input yR.
Manual/automatic control station, DDC manual control station S31 = 0
When configuring the digital input with the CB function or when operating via the serial interface,
the SIPART DR20 can also be used as a DDC manual control station in this mode. The
manipulated variable is made to track yN or yES during DDC mode with a K output, with an
S output / two-position controller and only yES with an S output / three-position step controller with
external feedback of the manipulated variable. The output is blocked during DDC mode with an
S output / three-position step controller with internal feedback.
40
