Siemens SIPART DR22 Manual page 102

1 Technical Description
1.5 Functional description of the structure switches
1.5.6 Controller output structures (S2, S61 to S68)
-- Split range function rising -- falling (S65 = 0)
y1, y2
[%]
100
80
60
40
Cooling
20
0 10 20
Figure 1-56 Split range function rising -- falling
With the parameters Y1 and Y2, the point of intersection of the characteristics y1 and y2 is
set with the 0 % line. Y1 can be set as you like in relation to Y2. As a rule a gap of 6 to 10%
is left between cooling end and heating start to save energy. Depending on the design of the
cooling and heating aggregate, related to the control range of the controlled variable, the
different line gains can be compensated by different slope settings and good control results
achieved in both branches. As a rule the cooling aggregate is underdimensioned for cost
reasons so that the slope of Y2 needs to be greater than that of Y1.
The manipulated variable display at S67=1 is made for the outputs y1 and y2 by an ID I and
II. Therefore only two positions are available for displaying the respective manipulated vari-
able value so that values from 100 % are identified by h. In the center of the dead zone the
display changes from y1 to y2.
When the characteristics Y1 and Y2 overlap, the display changes at Y = 50 %.
100
y2 y1
α
β
30 40 50 60
Y2 Y1
Heating
70 80 90 100
Manual
Y2 ≤ Y1
100 %
tanα =
100 % - Y1
100 %
tanβ =
Y2
y [%]
y-display
SIPART DR22 6DR2210
C79000-G7476-C154-03