Control Types; Continuous Control - ABB i-bus KNX FCA/S 1.1M Product Manual

ABB i-bus KNX
4.3.4

Control types

4.3.4.1

Continuous control

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Planning and application
The following control types are commonly used for the control of valves
in heating, air-conditioning and ventilation applications.
Continuous control
Pulse width modulation
Pulse width modulation – calculation
With continuous control, a control value is calculated based on the target
temperature and the actual temperature and is used for optimum control of
the temperature. The valve is brought to a position which complies with the
calculated control value. With this method the valve can be fully opened,
fully closed and even positioned in every intermediate position.
Control value
Valve position
100 %
0 %
With continuous control the most accurate control of the temperature can be
achieved without any resulting overshoots. At the same time the positioning
frequency of the valve drive can be kept low.
Continuous control can be implemented with the Fan Coil Actuator for
electro-motor 3-point or ABB i-bus
This is implemented via a 1 byte control.
What is a 1 byte control?
For 1 byte control, a value of 0...255 (corresponds to 0 %...100 %)
is preset by the room thermostat. At 0 % for example, the valve is
closed and at 100 % it is fully opened.
(PWM)
Time
Time
®
valve drives.
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