Description Of Communication Objects - Siemens RDG400KN Basic Documentation

Obj Object name
1 System time
System time for display on the room thermostat. See parameter
P07 (3 or 4)
3 Time of day
Another object for receiving the time of day for display on the room
thermostat. See parameter P07 (3 or 4)
4 Fault information
Common alarm output. If an alarm occurs, the alarm number is
transmitted
5 Fault state
Common alarm output. If an alarm occurs, the alarm flag is set
6 Fault
transmission
A supervisor alarm system can disable the broadcasting of alarms
by the devices. This has no impact on the local display of alarms.
After a timeout of 48 hours, the sending of faults will automatically
be enabled again.
7 Room operating
mode:
Preselection
Controls the room operating mode selection of the thermostat via
bus.
The command can also be submitted as four 1-bit communication
objects (8...11). The last interaction wins – either from local
operating mode button or via bus.
Note: The thermostat will transform Precomfort either into
Economy or Comfort (selectable via P88).
Operating mode:
Preselection
8 Auto
9 Comf
10 Eco
11 Prot
Switch room operating mode to either Auto, Comfort, Economy or
Protection.
The last interaction wins – either from the local operating mode
button or via bus.
12 Room operating
mode: Time
switch
This information is provided by a central time switch or a
supervisor and defines the actual HVAC operating mode.
The command can also be submitted via three 1-bit
communication objects (13...15).
Protection has the highest priority and cannot be overridden.
Note: The thermostat will transform Precomfort either into
Economy or Comfort (selectable P88).
Time switch
13 Comfort
14 Economy
15 Protection
Switch the HVAC mode to either Comfort, Economy or Protection
mode.
Siemens
Building Technologies

3.11.2 Description of communication objects

Function Type/ length
Time and 19.001
date 8 Byte
Time and 10.001
date 3 Byte
Alarm 219.001
Info 6 Byte
Faulty / 1.005
normal 1 bit
Enable / 1.003
disable 1 bit
Auto 20.102
Comfort 1 Byte
PreComf.
Economy
Protection
Trigger 1.017
1 bit
Comfort 20.102
Economy 1 Byte
PreComf.
Protection
Trigger 1.017
1 bit
RDG400KN Basic documentation
Functions
Flags Obj Object name
CWU 16 Room operating
mode: State
Effective room operating mode used by the thermostat
(considering time switch, user selection, window contact, etc.) This
CWU
state information is available via one 8-bit enumeration or three 1-
bit communication objects (17...19). Note: The thermostat does not
support Precomfort.
Room operating
CT
mode:
17 State Comfort
18 State Economy
19 State Protection
CT
Corresponding communication object sends "True"
20 Window state
CWU
The thermostat is set to Economy mode if value "1" (open) is
received. It switches back to the previous mode when the value is
"0" (closed).
"Window state" is sent e.g by a KNX switch or a KNX presence
detector. It has the same effect as the local operating mode
switchover contact X1, D1 (parameter P38, P42).
CWTU
Only one input source must be used, either local input X1/ D1 or
KNX bus.
21 Room temperature
The value of the room temperature measured via built-in or
external sensor is available via this communication object.
22 Room tempera-
ture: Comfort
basic setpoint
If function "Temporary setpoint" is enabled via parameter P69, then
after an operating mode change, the setpoint adjustments made by
the user and via communication object 23 will be dismissed and
CW
the thermostat will be reset to the Comfort basic setpoint.
Note: Setpoints that have been changed via the local HMI may be
overwritten during a system startup from a central master
controller, e.g.RMB795.
The Comfort basic setpoint is stored in EEPROM (see section

3.3.2). The service life of the EEPROM depends on the number
of write cycles. Never write this communication object cyclically!
23 Room temperature:
Comfort setpoint
Communication object used to shift the setpoint used by the
CWU
thermostat (see section 3.3.2). Same priority as local setpoint shift
on the thermostat. The last intervention wins.
Note: The Comfort basic setpoint (object 22) will not be changed.
24 Room temperature:
Current setpoint
Current setpoint, including shift, compensation, etc., used by the
thermostat for temperature control
25 Control output
VAV
Indicates the position of the air damper. E.g. single duct
CW 26 Heating output
primary
Indicates the position of the heating actuator of the auxiliary
heating. E.g. single duct with electric heater application: Output of
the electric heater.
Function Type/ length
Comfort 20.102
Economy 1 Byte
Protection
ON 1.002
OFF 1 bit
Open 1.019
Closed 1 bit
Temp. 9.001
value 2 Bytes
Temp. 9.001
value 2 Bytes
Temp. 9.001
value 2 Bytes
Temp. 9.001
value 2 Bytes
0...100% 5.001
8 bit
0...100% 5.001
8 bit
CE1P3192en
20 Jul 2010
Flags
CRT
CT
CWU
CRT
CWU
CWTU
CRT
CRT
CRT
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