28
ED 15117
Detailed Data Point Information
This section lists the information (i.e. data) that is available to the BAS via BACnet or LONWORKS
communication protocols. This information is used to safely operate and log the performance of the
chiller. The systems integrator also uses this information when creating custom graphics.
Note:
Data points are referred to as “properties in the BACnet protocol and “network variables” or
“configuration parameters” in the L
ON
W
ORKS
protocol. In this document, the text refers to this
information as a “data point.” In general, the data point is applicable to both BACnet and
L
ON
W
ORKS
. When a data point is specific to the BACnet protocol, the text refers to a
“property.” When a data point is specific to the L
ON
W
ORKS
protocol, the text refers to a
“network variable” or “configuration parameter.”
Active Setpoint
This read only network variable indicates the current setpoint used to control the chiller. The setpoint
that is used is based on the operating mode (Ice, Cool or Heat) of the chiller and any “LWT reset”
functions that are in effect. See “Chiller Mode Output” and “Chiller Mode Setpoint – Network”. The
default mode is Cool. There are three possible setpoints. See “Cool Setpoint – Network”, “Heat
Setpoint – Network” and “Ice Setpoint – Network”.
Measurement
Units
Data Type
Usable Range
Default Value
Temperature
°F/°C
BACnet: Real
L
ON
W
ORKS
: Fixed Point Scalar
signed long
15.08 to 149.9°F
-9.4 to 65.5°C
NA
BACnet
Object Identifier
Property Identifier
Object Type
Type Enumeration
Instance
Property Name
Property Enumeration
Analog Value
2
5
Present Value
85
Object Name
ActiveLvgWaterTarget
L
ON
W
ORKS
L
ON
W
ORKS
Name
Profile
SNVT Type
SNVT Index
SNVT Size
nvoActiveSetpt Chiller temp_p
105
two
bytes
Actual Capacity
This read only network variable indicates the percent of maximum capacity the chiller is producing
under the present operating conditions. At 100%, the chiller may be producing more or less than its
nominal rating due to variations in operating conditions.
Measurement
Units
Data Type
Usable Range
Default Value
Percent of chiller
capacity
NA BACnet:
Real
L
ON
W
ORKS
: Fixed-Point Scalar
signed long
0–100% NA
BACnet
Object Identifier
Property Identifier
Object Type
Type Enumeration
Instance
Property Name
Property Enumeration
Analog Value
2
2
Present Value
85
Object Name
ChillerCapacity
