Control Types; Continuous Control - ABB i-bus KNX Product Manual

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ABB i-bus KNX
Planning and application
4.3.3

Control types

The following control types are commonly used for the control of valves in heating, air-conditioning and
ventilation applications.


Continuous control


Pulse width modulation (PWM)

Pulse width modulation – calculation
4.3.3.1 Continuous control
With continuous control, a control value is calculated based, on the target temperature and the actual
temperature, and is used to optimally set 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.
Continuous control is the most precise form of temperature control. At the same time, the positioning
frequency of the valve drive can be kept low. Continuous control can be implemented with the device for
electro-motor 3-point valve drives. This is implemented via a 1 byte control.
248 2CDC508134D0202 | FCA/S 1.x.x.1
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.