ABB i-bus
®
KNX
Parameters
FCC/S 1.X.X.1 | 2CDC 508 200 D0211 Rev A 169
The differences between the individual controller types are explained in the following:
•
2-point 1 bit (On/Off)
: 2-point control is the simplest form of control. The controller switches on if
the room temperature has dropped below a specific level (temperature setpoint minus hystere-
sis) and off as soon as a specific value (temperature setpoint plus hysteresis) is exceeded. The
switch-on and switch-off commands are sent as 1-bit commands.
The dependent
Status Control value Basic-stage heating
group object is enabled as a 1-bit
group object.
•
2-point 1 byte (0/100 %)
: This is also two-point control as above. The difference is that switch-
on and switch-off commands are sent as 1-byte values (0 %/100 %).
The dependent
Status Control value Basic-stage heating
group object is enabled as a 1-byte
group object.
•
PI continuous (0…100 %)
: The PI controller adjusts its output value, between 0 % and 100 %,
to the difference between the actual value and setpoint and permits exact regulation of the
room temperature to the setpoint. It outputs the control value on the bus as a 1-byte value
(0...100 %). To reduce the bus load, the control value is only sent if it has changed by a previ-
ously specified percentage in relation to the value sent last. In addition, the control value can be
sent cyclically.
The dependent
Status Control value Basic-stage heating
group object is enabled as a 1-byte
group object.
•
PI PWM (On/Off)
: This is also a PI controller. The output is as a 1-bit command. For this pur-
pose the control value calculated is implemented using a pulse-pause ratio.
The dependent
Status Control value Basic-stage heating
group object is enabled as a 1-bit
group object.
•
PI continuous (0…100 %) for Fan Coil
: The fan coil controller operates like the PI continuous
controller. In addition, the fan output is also actuated in the automatic mode corresponding to
the control value for the basic-stage heating.
The dependent
Status Control value Basic-stage heating
group object is enabled as a 1-byte
group object.
Note
For a detailed description of the individual controller types, see Explanation of controller function,
Page 365.
7.5.1.6.1.1
2-point 1 bit (On/Off), 2-point 1 byte (0/100%)
The following parameters are enabled if the
2-point 1 bit (On/Off)
or
2-point 1 byte (0/100%)
option
has been selected in the
Basic-stage heating control value type
parameter.