Xylem WTW DIQ/S 281 Operating Manual page 87

DIQ/S 281
Characteristic
curves
ba77244d01
switched more often or less often.
Relay
t = 0.3 s
On
On
Off
T
figure 6-5 Relay output of frequency output
While the selected switching duration (t
stant, the switching frequency at which the relay switches changes
depending on the measured value.
 If the measured value is at the end of the proportional range (End
value), the switching frequency is higher.
 If the measured value is at the beginning of the proportional range
(Start value), the switching frequency is low.
Through the selection of the Start value and End value, the proportional output
can be operated with a positive or negative characteristic curve.
 Positive characteristic curve:
Select the End value to be greater than the Start value.
The turn-on duration or frequency increases with an increasing measured
value (see page 89).
 Negative characteristic curve:
Select the End value to be smaller than the Start value.
The turn-on duration or frequency decreases with an increasing measured
value (see page 90).
The maximum values for the pulse width or switching frequency are assigned to
the End value value and the minimum values for turn-on duration or frequency
are assigned to the Start value value.
08/2020
Time [s]
= 0.3 s) always remains con-
on
Outputs
87