Operating Instructions

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Siemens RXB (KNX) application library RXB Description of functions for FC-10, FC-11, FC-12, FC-13 CM110385en_08
Building Technologies Control sequences 2013-06-17
8.3.3 Electric reheater RXB21.1 (relay)
In the case of the RXB22.1 room controller, the electric reheater is switched directly via
output Q44 (max. 1.8 kW resistive).
The controller output of the electric reheater can be disabled locally via a safety
thermostat connected to one of the hardware inputs. The alarm input and the way in
which it operates can be configured with the tool (see "Digital inputs", page 142).
When the safety thermostat trips, an alarm is generated, which is output via the
communication object Alarm (see page 150).
The "position" of the electric reheater is also mapped to the bus.
In S-mode, the following communication object is used for this purpose:
Heating output bus electric heating (Output communication object)
Flags
Type Send heartbeat Value
R
W
K
T
U
1 0 1 1 0 5.001
DPT_scaling
yes 0...100% 0 = 0%
255 = 100%
In LTE mode, the "position" of the electric reheater is transmitted as follows:
Heating output bus electric heating (Output)
Possible partner function blocks
Known partner
devices
ActPosSetpHeatStageB
352 HVA
HVAC Valve Actuator
369 EHEA
Electric Heater Element Actuator
---
Geographical zone
If the LTE bus information is not required, it can be disabled
(see pages 91 and 161 for notes on reducing the load on the bus).
HandyTool See parameters in the last column of the following table.
Short name
Range
Basic setting
HandyTool
Heating outp bus el heating 0 = Disabled / Off
1 = Enabled / On
Disabled(0) *089
In applications involving an electric reheater, the latter can be disabled (e.g. for reasons
associated with tariff regulations).
The communication objects are as follows:
Enable electric heating (Input communication object)
Flags
Type Receive timeout Value
R
W
K
T
U
0 1 1 0 0 1.003
DPT_Enable
yes
0 = Disabled
1 = Enabled
Controller output
Safety thermostat
Desired output
CO
Reducing the bus load
Central disable signal
CO