Example Of Heating And Cooling Demand Zone; Send Heartbeat And Receive Timeout - Siemens RDF800KN Series Manual

Explanation relating to
the above illustration
Notes:
LTE mode/S-mode
56 / 94
Siemens
Smart Infrastructure

3.11.4 Example of heating and cooling demand zone

The building is equipped with Synco controls on the generation side and with
RDF../RDU../RDG.. room thermostats on the room side.
RMH760
Controller 1
T
T
T
Heat source DHW heating
Heat requistion
Heat demand
Heat distr zone 1
Setting values
Controller 1
In typical applications, the individual RDF../RDU../RDG.. room thermostats send
their heat demand directly to the primary controller (in the above example to the
RMH760).
 ‚
and designate the numbers of the distribution zone.
· This type of application can analogously be applied to refrigeration distribution
zones.
· If no 2-pipe fan coil unit is used, heat and refrigeration demand signals are sent
simultaneously to the primary plant.

3.11.5 Send heartbeat and receive timeout

In a KNX network, S-mode and LTE mode communication objects can be exchanged
between individual devices. The Receive timeout defines the period of time within
which all the communication objects requested from a device is received at least
once. If a communication object is not received within this period, a predefined value
is used.
Similarly, the Send heartbeat defines the period of time within which all the commu-
nication objects requested must be transmitted at least once.
Fixed times are specified as follows:
· Receive timeout:
· Send heartbeat:
RDF800KN.., RDF800KN/VB, RDD810KN/NF
RMH760 RMB795
Controller 3
Controller 2
2
T
1
Heating circuit
fan coil
Heat demand
Heat requistion
Heat distr zone
source side: 1
Heat distr zone 2
Controller 2 Controller 3
31 minutes
15 minutes
Basic documentation
Konnex TP1
RDF..
RDU..
Controller 4 Controller 5
T
V V M M
T
Fan coil VAV box
room A room B
Heat demand
Heat demand
Heat distr zone 2 Heat distr zone 2
Controller 4 Controller 5
RDG..
Controller 6
T
Fan coil
room C
Heat demand
Heat distr zone 2
Controller 6
CE1P3174en
2020-02-21