PT-Link Interface
PT-Link-LON
®
Technical Guide
25
Appendix D - VCM-X LON Parameters
SNVTs for the VCM-X Controller
Binary Output SNVTs are SNVT_lev_disc
all other SNVTs are SNVT_count_inc_f
Parameter
Name
Object
Description
Limits
Modulating
Heat
Position
MdHtPos
Analog
Output
Current position of
the modulating
heating signal (hot
water or SCR heat).
Unit Mode
UnitMode
Analog
Output
Needed only in
legacy application.
Return Air
CO
2
Level
CO2Level
Analog
Output
Current value of the
CO
2
sensor.
Bypass
Damper
Position
ByPas-
Dmp
Analog
Output
Current position of
the bypass damper
signal.
Return
Damper
Position
RaDmp
Analog
Output
Current position of
the return damper
signal.
Coil
Temperature
CoilTp
Analog
Output
Current coil
temperature reading
added on version
1.09.
Outdoor Air
CFM
OaCFM
Analog
Output
Current Outdoor
Airfl ow
Measurement
Exhaust
CFM
EtCFM
Analog
Output4
Current Exhaust
Airfl ow
Measurement
Supply Air
CFM
SaCFM
Analog
Output
Current Supply
Airfl ow
Measurement
Current
Calculated
OA CFM
setpoint
OACfm-
StM
Analog
Output
Current calculated
Outdoor Air CFM
based on CO
2
level.
Dewpoint
Setpoint
DptSt
Analog
Input
If the outdoor
dewpoint rises
above this setpoint,
the unit will
activate the
Dehumidifi cation
Demand.
35
80
Occupied/
Mode
Enable
Cooling
Setpoint
OcpClSt
Analog
Input
If the control tem-
perature rises one
degree above this
setpoint, the control
will activate the
cooling demand.
If the control
temperature is the
Supply Air Sensor,
then the cooling
demand is always
active.
0
99
SNVTs for the VCM-X Controller
Binary Output SNVTs are SNVT_lev_disc
all other SNVTs are SNVT_count_inc_f
Parameter
Name
Object
Description
Limits
Occupied/
Mode
Enable
Heating
Setpoint
OcpHtSt
Analog
Input
If the control
temperature drops
one degree below
this setpoint,
the control will
activate the heating
demand. If the
control
temperature
is the Supply
Air Sensor, then
there is no heating
demand.
99
Outdoor
Air Sensor
Offset
OaTpOst
Analog
Input
If the Outdoor
Temperature Sensor
is reading
incorrectly, you can
use this option to
enter an offset
temperature to
adjust the Sensor’s
Temperature.
-100
100
Return
Air Sensor
Offset
RaTpOst
Analog
Input
If the Return Tem-
perature Sensor is
reading incorrectly,
you can use this
option to enter an
offset temperature
to adjust the Sen-
sor’s Temperature.
-100
100
Schedule
Force
SchdFrc
Analog
Input
0 = Auto/
Unoccupied Mode
1 = Forced On
2 = Forced Off
0
2
Space
Sensor
Offset
SpcTpOst
Analog
Input
If the Space
Temperature
Sensor is reading
incorrectly, you can
use this option to
enter an offset
temperature to
adjust the Sensor’s
Temperature.
-100
100
SAT/Reset
Source
Cooling
Setpoint
SaClSt
Analog
Input
Supply Air setpoint
or Reset Source
target temperature
in Cooling Mode.
40
80
SAT/Reset
Source
Heating
Setpoint
SaHtSt
Analog
Input
Supply Air setpoint
or Reset Source
target temperature
in Heating Mode.
40
200
Supply
Air Sensor
Offset
SaTpOst
Analog
Input
If the Supply Air
Temperature Sensor
is reading incor-
rectly, you can use
this option to enter
an offset
temperature to
adjust the Sensor’s
Temperature.
-100
100
