Basic Documentation

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Siemens RDU341 Basic Documentation CE1P3172en
Building Technologies 2017-02-17
3.6.2 Application mode
The behavior of the thermostat can be influenced by a building automation and
control system (BACS) via bus with the command “Application mode”. With this
signal, cooling and/or heating activity can be enabled or disabled. Application mode
is supported in LTE mode and S-mode. The RDU KNX thermostats support the
following commands:
# Application
mode
Description Control sequence
enabled
0 Auto Thermostat automatically changes between
heating and cooling
Heating and/or cooling
1 Heat Thermostat is only allowed to heat Heating only
2 Morning
warm-up
If “Morning warm-up” is received, the room
should be heated up as fast as possible (if
necessary). The thermostat will only allow
heating
Heating only
3 Cool Thermostat is only allowed to provide cooling Cooling only
4 Night purge If “Night purge” is received, the room should
be aired with cool outside air if necessary.
The thermostat will open the damper and
does not heat/cool with the coils or the
electric heater.
Function will be terminated by any operation
on the thermostat.
Open damper fully
if night purge condition
is valid
1)
5 Pre-cool If “Pre-cool” is received, the room should be
cooled down as fast as possible (if
necessary). The thermostat will only allow
cooling
Cooling only
6 Off Thermostat is not controlling the outputs,
which means all outputs go to off or 0%
Neither heating nor
cooling
8 Emergency
heat
The thermostat should heat as much as
possible. The thermostat will only allow
heating
Heating only
9 Fan only All control outputs are set to 0% and only the
fan is set to high speed or damper fully
opened respectively.
Function will be terminated by any operation
on the thermostat
Open damper fully
With all other commands, the thermostat behaves like in Auto mode, i.e. heating or
cooling according to demand.
1) Conditions for “Night purge” function:
– Current room temperature > Comfort cooling setpoint
– If supply air temperature via KNX is available:
Supply air temperature < current room temperature
KNX
R
Application mode