Technical Manual
–
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4.8.3.3 Two-step control (switching)
If the control value is selected as 2-step control, the following setting options are available
(here: controller type heating):
Figure 24: Settings - 2-step control (switching)
The following table shows the possible settings for 2-step control:
ETS-Text
Dynamic range
[Default value]
Comment
Direction of controller
▪
normal
▪
inverted
Specifies the control behaviour when
the temperature rises.
Adaptation to normally open valves
Hysteresis (K)
0,5 K
–
5,0 K
[2,0 K]
Setting for upper and lower switch-on
and switch-off point
Send control value cyclic
or:
Send control value for
heating and cooling cyclic
Not send, 1 min
–
60 min
[not send]
Visible when heating only or cooling
only is set
.
Setting whether and at what interval
the control value is sent cyclically
Visible when heating and cooling is
set
Table 59: Settings - 2-step control (switching)
The 2-point controller is the simplest type of control. Only the two states ON or OFF are sent to the
control value.
The controller switches the control value (e.g. heating process) on when the temperature falls below
a certain reference temperature and switches it off again when the temperature exceeds a certain
reference temperature.
The switch-on and switch-off points, i.e. where the reference temperature is, depend on the
currently adjusted set point and the adjusted switching hysteresis.
The 2-point controller is used when the control value can only assume two states, e.g. an
electrothermal valve.
Hysteresis
The setting of the switching hysteresis is used by the controller to calculate the switch-on and switch-
off point. This is done taking into account the currently valid setpoint.
Example: In the controller, with controller type Heating, a basic comfort value of 21°C and a
hysteresis of 2K was set. In the comfort mode, this results in an activation temperature of
20°C and an deactivation temperature of 22°C.
When making the setting, please note that a large hysteresis leads to a large fluctuation of the actual
room temperature. However, a small hysteresis can cause the control value to be switched on and
off permanently, as the switch-on and switch-off points are close together.
