5:14 (16), 0-004-7516-1 (GB)
TAC AB, 1999-08-18
TAC Xenta 102 Handbook
Functional description
The sensor can be connected either directly to the controller, input
X2, or via the network, nviOccSensor. To be able to use a directly
connected sensor, bit 0 in nciAppOptions must be set to 1. When
nviOccSensor has received a valid value, this is used, whether
there is a directly connected sensor or not.
Bit 8 in nciAppOptions indicates whether input X2 should mean
normally open (NO) or normally closed (NC). Bit 8=0 means
normally open, Bit 8=1 normally closed.
The directly connected sensor’s value is sent out on the network
in nvoOccSensor. If there is no sensor connected (according to
nciAppOptions), the value OC_NUL is sent out.
There is a 20 minute delay before the operation mode is
changed from comfort to economy in nvoEffectOccup. The
change in nvoOccSensor only takes 250 ms to make other uses
of the occupancy sensor possible (lighting, alarm etc.).
5.3.6 Minimum value for heating valve (TAC Xenta 102-VF only)
During cold periods, there is often a back draught at the
windows in the room. To avoid this, TAC Xenta 102 offers a
possibility to have a little heat on even if it is not really
necessary to keep the temperature in the room.
This is done by setting a lowest permitted value for the opening
of the heating valve. TAC Xenta 102 makes sure that the
opening never falls below this value. The value is given as a
percentage in nciHeatPrimMin (min. output heating controller).
The function can only be used when using analogue actuators.
The values of the network variables, which shows how TAC
Xenta 102 positions the heating valve nvoUnitStatus
(heat_output_primary), and nvoTerminalLoad which shows the
position of the valve, should not be lower than nciHeatPrimMin.
Index Variable name
Description
2
nvoUnitStatus
Unit status output
8
nvoTerminalLoad
Heating/cooling demand output
44
nciHeatPrimMin
Minimum output heating controller
Index Variable name
Description
1
nvoEffectOccup
Effective occupancy output
24
nciAppOptions
Application options
42
nvoOccSensor
Occupancy sensor output
43
nviOccSensor
Occupancy sensor input