66 / 88
For internal use only
Siemens
KNX bus communications
CE1P3127en
Building Technologies
Appendix
2013-04-08
9.2.1
Changeover via digital input
The changeover thermostat in the flow is wired to universal input "x" (configured as
digital input) of the "H/C changeover" function block in controller 1 (RMU7x0B).
The heating/cooling changeover signal transmitted over the KNX bus acts on all
controllers (here, controllers 1 and 2) in the same heating/cooling distribution zone,
provided all controllers have the same heating/cooling zone address.
1
M
T
1
T
KNX
1
S1
S1
S1
S2
S2
x
S2
S3
Q
Y
d
1
2
3
x
Kältebedarf
Q
Y
d
S4
S4
S4
S5
1
2
3
2
M
T
2
x
Q
23
2
S1
S1
S1
S2
S2
x
S2
S3
Q
Y
d
1
2
3
x
Kältebedarf
Q
Y
d
S4
S4
S4
S5
1
2
3
x
Q
23
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
3
1
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