6:2 (4), 0-004-7516-1 (GB)
TAC AB, 1999-08-18
TAC Xenta 102 Handbook
Trouble-shooting
6.2
Inputs and outputs (nvi/nvo’s)
The most important variables for information on the current
status of the controller during operation, are the nvo’s and the
nvi’s.
With the help of these, you can check the controller’s operation
and redeem any faults or disturbances.
Below you find the nvi’s and the nvo’s with a short description.
In chapter 8, you find complete information on all variables’ in-
dex, variable name, function, accepted values, default values
etc.
Index Name
Description
1
nvoEffectOccup
Effective occupancy output
2
nvoUnitStatus
Unit status output
3
nvoAlarmStatus
Alarm status output (see section 5.3.7)
4
nvoEffectSetpt
Effective setpoint output
5
nvoSpaceTemp
Zone temperature output
6
nvoFlowControlPt
Effective setpoint output (I/s)
7
nvoBoxFlow
VAV box flow output
8
nvoTerminalLoad
Heating/cooling demand output. Positive value=cooling, negative value=heating
9
nvoSpaceCO2
Zone CO
2
sensor output
10
nvoEnergyHoldOff Energy hold off output, window contact status
11
nvoFlowSetpoint
Effective setpoint for VAV Compact (%)
12
nvoHeatSlave
Heating control output for slave
13
nviManOccCmd
Occupancy scheduler input
14
nviApplicMode
Application mode input (forcing the controller)
15
nviSpaceTemp
Zone temperature input, replaces input B1 at a valid value
16
nviSetpoint
Temperature setpoint input, which at a valid value recalculates
nciSetpoints
17
nviSetpntOffset
Setpoint offset input
18
nviSpaceCO2
Zone CO
2
input
19
nviEnergyHoldOff
Energy hold off input for window contact, determines operation mode together
with input X3
20
nviManOverride
Manual override input
21
nviEmergCmd
Emergency command input
22
nviBoxFlow
VAV box flow input
23
nviHeatSlave
Input heating sequence for slave
42
nvoOccSensor
Occupancy sensor output, only input X2 is copied, see
nviOccSensor for net
information
43
nviOccSensor
Occupancy sensor input, determines operation mode together with input X2
Table 6.1 Overview over all inputs and outputs.
