Siemens RDG400KN Basic Documentation page 45

# Function of
input
5 Enable electric
heater
K NX
R
Enable elec-
tric heater
6 Fault
K NX
R
Fault
information
7 Monitor input
K NX
R
(Digital)
D1, X1
(Digital)
8 Monitor input
K NX
R
(Temperature)
X1, (Temp.)
Damper position VAV
via U1
K NX
R
U1 (0...100%)
Siemens
Building Technologies
Description
Digital input to enable / disable the electric heater via
remote control.
Enable electric heater is also possible via bus.
In this case, the function must not be assigned to any
local input X1, D1. See also section 3.6.
Digital input to signal an external fault (example: dirty air
filter).
If the input is active, "ALx" is displayed and a fault is
sent on the bus. See also section 3.10.11.
(Alarm x, with x = 1 for X1, x = 3 for D1).
Note: Fault displays have no impact on the thermostat's
operation. They merely represent a visual signal.
Digital input to monitor the state of an external switch via
bus.
Sensor input to monitor the state of an external sensor
(e.g. QAH11.1) via bus.

Operational action can be changed between normally open (NO) and normally
closed (NC) via parameter P39, P41 (or P43 if it is a digital input)

Each input X1 or D1 must be configured with a different function (1...5).
Exception: 1 or 2 or 3 inputs can be configured as fault (6) or monitor input
(7,8)

X1 is factory-set to "External sensor" (1) and D1 to "Operating mode
switchover" (3)
For more detailed information, refer to section 3.4 "Applications".
The information about the thermostat's damper position can be used to influence
the fan speed of a primary air handling unit. The thermostat receives the damper
position from a damper actuator or a VAV compact controller as a DC 0...10 V
signal using input U1. The damper position (0...100%) is sent on the bus.
An RMU7xx primary controller will use the LTE information of all connected room
thermostats to calculate the total air flow demand.
The state of U1 can be monitored via communication object 38 "U1".
RDG400KN Basic documentation
Functions
Type Type
X1 DI
DI DI
DI DI
DI DI
AI --
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CE1P3192en
20 Jul 2010