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Building Technologies
Basic documentation: Communication via the KNX bus
CE1P3127en
HVAC Products
Appendix
30.08.2007
9.2.1 Changeover
via digital input
The changeover thermostat in the flow is wired to universal input "x"(configured as
a digital input) of the "H/C changeover" function block in controller 1 (RMU7x0B).
The heating/cooling changeover signal transmitted over the KNX bus affects all
controllers (in this case controllers 1 and 2) in the same heating/refrigeration
distribution zone, provided all controllers have the same heating/refrigeration zone
address.
1
M
T
1
T
KNX
1
S1
S1
S1
S2
S2
x
S2
S3
Q
Y
d
1
2
3
9
x
Kältebedarf
Q
Y
d
S4
S4
S4
S5
1
2
3
9
2
M
T
2
x
Q
23
9
2
S1
S1
S1
S2
S2
x
S2
S3
Q
Y
d
1
2
3
9
x
Kältebedarf
Q
Y
d
S4
S4
S4
S5
1
2
3
9
x
Q
23
9
T
DI
H/C changeover
Refrig demand
Supervision
Controller
Controller
Supervision
Heat demand
H/C changeover
Refrig demand
Supervision
Controller
Controller
Supervision
Heat demand
Htg/ClgCoil 1
Htg/ClgCoil 2
31
2
7
S
0
3
e
n
Flow
Return
Heating/cooling changeover signal
Heat/refrig distribution zone 1
Changeover source
digital input DI
Changeover signal via
KNX