ABB i-bus KNX - Direct Operation; Switchover between Automatic and Direct Operation

ABB i-bus
®
KNX
Planning and application
242 2CDC508134D0202 | FCA/S 1.x.x.1
4.1.3 Direct operation
With direct fan control via the ABB i-bus
®
KNX, a fan drive is connected directly to the device and switched
via three floating contacts. A single-speed, two-speed or three-speed fan can be connected.
The device sets the fan speed in accordance with a value received via the ABB i-bus
®
. The value is
received as a 1 byte value.
1 byte value
Hexadecimal
Binary value bit
76543210
Fan speed
0
00
00000000
0 (OFF)
1
01
00000001
Fan speed 1
2
02
00000010
Fan speed 2
3
03
00000011
Fan speed 3
>3
>03
>00000011
Values greater than 3 are ignored
4.1.4 Switchover between automatic and direct operation
The device can be switched between automatic operation and direct operation. The changeover to manual
fan control is implemented via a 1 bit value. The fan speed is switched in accordance with the 1 byte value
received.
Fan control is changed back to automatic operation if a 1 is received on the respective communication
object.
The current status of automatic operation is fed-back via a 1 bit value.