5:2 (16), 0-004-7516-1 (GB)
TAC AB, 1999-08-18
TAC Xenta 102 Handbook
Functional description
5.2
The controller’s basic functions
5.2.1 Operation modes
The controller has four selectable operation modes:
•
Comfort
•
Economy
•
Bypass
•
Off
The operation mode is controlled by nviManOccCmd, but is also
influenced by occupancy sensors and the bypass key on the wall
module. The connection between these is shown in table 5.1.
There you also find the controller’s values during stand-alone
operation.
Comfort mode
This is the default mode, when someone is in the zone, and the
controller should give the room a comfortable climate. The
controller is in this mode when nviManOccCmd=OC_OCCU-
PIED (or OC_NUL after a power down).
The LED on the wall module is lit with a steady red light and
you can use the setpoint knob on the wall module to make a
manual setting and air quality control is enabled. The setpoints
used are found in nciSetpoints (can be modified).
The alarms for the zone temperature deviation, high carbon
dioxide levels, and flow deviation can cut out, but the alarms
for window contact and low zone temperature are blocked.
Desired op. mode
Bypass timer
1
Occupancy sensor
2
Current
nvoEffectOccup
nviManOccCmd
operation mode
Comfort
Enabled
Without signific.
Comfort
OC_OCCUPIED
At a standstill
Occupancy detect.
Comfort
OC_OCCUPIED
OC_OCCUPIED
No occupancy
Economy
OC_STANDBY
Economy
Enabled
Without signific.
Bypass
OC_BYPASS
OC_STANDBY
At a standstill
Without signific.
Economy
OC_STANDBY
Off
Enabled
Without signific.
Bypass
OC_BYPASS
OC_UNOCCUPIED At a standstill
Without signific.
Off
OC_UNOCCUPIED
Stand-alone
Enabled
Occupancy detect.
Comfort
OC_OCCUPIED
operation
No occupancy
Bypass
OC_BYPASS
At a standstill
Occupancy detect.
Comfort
OC_OCCUPIED
OC_NUL
No occupancy
Off
OC_UNOCCUPIED
Table 5.1 The relation between desired operation mode, bypass timer, occupancy sensor and current
operation mode.
1
Activated by the bypass key on the wall module
2
See section 5.3.5 about occupancy sensors
