TAC AB, 1999-08-18
0-004-7516-1 (GB), 5:13 (16)
TAC Xenta 102 Handbook
Functional description
Not to open or close the damper in vain, the CO
2
level must differ
by more than ±30 ppm from the latest read value.
nvoSpaceCO2 shows current carbon dioxide level in the zone. If
nviSpaceCO2 has a valid value, the current carbon dioxide level
will be identical to the input.
Current CO
2
level is always sent, no matter which options are
set in the variable nciAppOptions. Air quality control is enabled
when bit 5=1 in nciAppOptions.
Index Variable name
Description
9
nvoSpaceCO2
Zone CO
2
sensor output
18
nviSpaceCO2
Zone CO
2
input
24
nciAppOptions
Application options
33
nciMinFlow
Minimum flow
34
nciMaxFlow
Maximum flow
39
nciCO2PerVolt
Conversion factor ppm CO
2
per volt
40
nciSpaceCO2Low Zone CO
2
for closed damper
41
nciSpaceCO2High Zone CO
2
for open damper
5.3.4 Window contact
TAC Xenta 102 is designed to be able to limit the energy con-
sumption when a window in the room is open. You can connect
a local sensor directly to the controller, digital input X3, or use
nviEnergyHoldOff. The energy hold off is enabled when either
of these signals indicate an open window. The energy hold off is
made by the controller being set to off mode.
To be able to use a sensor (local or connected to the network),
bit 1 in nciAppOptions must be set to 1.
nvoEnergyHoldOff has the value of the locally connected sensor.
This is true even if bit 1 in nciAppOptions is set to 0.
If the energy hold off has been active for 60 seconds the window
contact alarm cuts out, bit 2 in nvoAlarmstatus (only in economy
and off modes).
Index Variable name
Description
3
nvoAlarmstatus
Alarm status output
10
nvoEnergyHoldOff
Energy hold off output
19
nviEnergyHoldOff
Energy hold off input
24
nciAppOptions
Application options
5.3.5 Occupancy sensor
There can be a sensor connected to TAC Xenta 102 to
determine whether someone is in the room or not. If there is no
occupancy sensor connected, the controller supposes that there
is always someone in the room. The controller uses the
information to determine whether the operation mode should be
comfort or economy. When the controller is used stand-alone,
the sensor is used to choose between comfort mode or off mode.
See table 5.1 in chapter 5.2.1.