ABB i-bus KNX Yucus YUB/U1.0.1 Series Technical Reference Manual page 111

KNX Technical Reference Manual
ABB i-Bus ® KNX Yucus
Note: This parameter is only available when "Control value type" parameter is
set either on "PI continuous, 0 – 100%", "PI PWM, On/Off" or "Fan coil".
The minimum control value of the PI controller defines the minimum value output by the
controller. If a minimum value greater than zero is chosen, the controller will not output a
lower value, even if it calculates a value that is lower. This parameter can be used to set
a basic load, e.g. for operating floor heating. Even if the controller calculates the control
value zero, a heating medium will flow through the floor heating system to prevent the
floor from cooling down. Under "Settings of basic load", it is also possible to define
whether this basic load will be permanently active or whether it will be switched by the
"Basic load" object.
12.34.28 Control of heating additional stage – Control value type
Options
Note: Only available when the "Device function" parameter is set on either
"Single device" or "Master device" and the control function parameter is set on either
"Heating with additional stage" or "Heating and cooling with additional stages".
The actuation of the control valve is determine by the selection of the controller type.
– 2-Point 1 Bit, Off/On: The 2-point control is the simplest type of control. The controller
switches on when the room temperature drops below a certain level (setpoint temperature
value minus hysteresis) and switches off when a particular value (setpoint temperature
value plus hysteresis) is exceeded. The switch-on and switch-off commands are
transmitted as 1-bit commands.
– 2-Point 1 Byte, 0/100%: This is another two-point control as described above. In this
case, however, the switch-on and switch-off commands are transmit as 1-byte values (0%
/ 100%).
– PI continuous, 0-100%: The PI controller adjusts its output value between 0% and 100%
to match the difference between the actual value and the setpoint value and enables a
precise regulation of the room temperature to the setpoint value. It sends the control value
to the bus as a 1-byte value (0% - 100%). To reduce the bus load, the control value is
only transmitted if it has changed by a predefined percentage in relation to the previous
sent value. The control value can also be transmit cyclically.
– PI PWM, On/Off: This also is a PI controller. Here, the output is a 1-bit command. For
this to occur, the calculated control value is convert into a pulse-interval signal.
– Fan coil: The fan coil controller operates like the PI continuous controller. In addition, it
allows the separate activation of the fan in the fan coil unit (e.g. fan speed levels 1 – 3/5).
2-point 1 bit, Off/On
2-point 1 byte, (0/100%)
PI continuous, 0-100%
PI PWM, On/Off
Fan coil
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