Evaporative cooling air handling unit controller · BACnet points list

Cambridge Air Solutions BACnet Controller - EVAP BACnet points list

Updated 11 November 2026

Short answer

The EVAP version of Cambridge's BACnet Controller is a BTL-listed, programmable BACnet MS/TP controller that runs the supply fan, pumps, fill and drain valves and the optional burner of an evaporative cooling unit. Commands, HOA modes, statuses and alarms are mostly multistate values; temperatures, setpoints, delays and water conductivity are analog values, with a few binary values for system enable, water flush and runtime resets. It runs on its own defaults without the network if a zone sensor is connected.

This page lists 101 BACnet objects for the Cambridge Air Solutions BACnet Controller - EVAP — 57 of them writable — with each object’s type, instance number, name, engineering units and access. It is re-typed from Cambridge Air Solutions’s own free documentation, linked below.

Manufacturer: Cambridge Air Solutions
Model: BACnet Controller - EVAP
Equipment: Evaporative cooling air handling unit controller
Equipment type: Rooftop units, AHUs & DOAS
BACnet objects: 101 (57 writable)
Transport: BACnet MS/TP
Firmware: 4.0.2.0003
Also known as: Cambridge EVAP controller, Cambridge evaporative cooler BACnet, EVAP Technical Manual 4.0.2.0003
Source document: Operating Instructions - BACnet Controller - EVAP (BACnet Controller EVAP Technical Manual) · Version 4.0.2.0003 · rev. 2023-01-31

Download CSV 101 rows Download EDE B.I.G.-EU JSON Manufacturer PDF ↗ Compare with your scan Download Easy BACnet Mobile App Google Play

Reference only, provided as-is: verify against Cambridge Air Solutions’s current documentation and the live device before use. Not official Cambridge Air Solutions information. Terms of use.

BMS integration notes: Cambridge Air Solutions BACnet Controller - EVAP

Integration in brief

Enable the unit with BV 29501 System Enable and command occupancy with MV 29548 Occupancy Override. Set the zone cooling and heating setpoints (AV 29541/29555), and choose fan and cooling behaviour per occupancy with the Occupied/Unoccupied Fan and Cooling Mode MVs. Read MV 29501 Unit Status, the supply fan status and fault, discharge air temperature and the alarm MVs. Without the network the controller runs on its own defaults as long as a zone sensor is connected.

Minimum points to map

The short list most integrators start with — enough to run the unit from a BMS. Map more as the job needs.

Object	Name	Why	Access
BV 29501	System Enable	Unit enable (1 = enable)	Write
MV 29548	Occupancy Override	Occupied / unoccupied / bypass / standby from the BAS	Write
MV 29546	Occupied Cooling Mode	Occupied cooling: auto / off / on	Write
AV 29541	Occupied Zone Cooling Set Point	Occupied zone cooling setpoint, °F	Write
AV 29555	Occupied Zone Heating Set Point	Occupied zone heating setpoint, °F	Write
MV 29501	Unit Status	Heating / satisfied / cooling / sensor unreliable	Read
MV 29507	Supply Fan Status	Supply fan proven on	Read
AV 29504	Discharge air temperature	Discharge air temperature, °F	Read
MV 29534	Supply Fan Fault	Supply fan alarm	Read
MV 29535	Sensor 1 Alarms	Low water switch 1 alarm (1 = alarm)	Read

Enable & remote start

BV 29501 System Enable (0 = disable, 1 = enable). Fan, pump and burner Hand/Off/Auto overrides (MV 29539, 29540, 29562, 29566) and the valve control modes (MV 29541, 29542) should stay in Auto for normal control.

Network setup

BACnet MS/TP only, up to 76.8 kbaud. MAC address 4-127 (default 4), set from the local display (Controller > Network) or a MAP gateway; also exposed as AV 29501.
Baud defaults to Auto (follows the bus supervisor); the manual suggests 38400 with a Smart Building Hub.
Device Object ID (AV 29502) must be unique on the network.
Disconnect the controller from the bus while changing network settings, then cycle power before reconnecting.
An EOL terminator is needed when the controller is at either end of the MS/TP trunk.

Watch out for

Two MV rows in the manual (valve 2 control modes) reuse the valve 1 instances; confirm on site which object the valves actually use.
The DAT low temperature alarm needs a manual reset; the other listed alarms reset automatically.
Confirm the filter alarm objects on site: MV 25973/25974 (points table) vs MV 29573/29574 (alarm table).
Points table defaults and the Default Settings list disagree for some setpoints; read the live values before writing.

Cambridge Air Solutions BACnet Controller - EVAP BACnet objects

Type: AI, AO, AV, BI, BO, BV, MI/MO/MV (multi-state) · Access: Read read-only, Write writable, Command writable with a priority array.

101 of 101 shown

Type

AnalogBinaryMulti-state

Access

Units

Show

Cambridge Air Solutions BACnet Controller - EVAP BACnet Points List
			Description			States
BVmin	29501	System Enable			Write	0=Disable, 1=Enable
BV	29502	Water System Flush			Write	0=Off, 1=On
BV	29512	Supply Fan Runtime Reset			Write	0=Off, 1=Reset
BV	29516	Humidity Lockout Enable			Write	0=Disable, 1=Enable
BV	29517	Burner Runtime Reset (optional)			Write	0=Off, 1=Reset
MVmin	29501	Unit Status			Read	1=Heating, 2=Satisfied, 3=Cooling, 4=Temperature Unreliable
MV	29505	FCB Baud Rate			Write	1=Auto, 2=1200, 3=9600, 4=19200, 5=38400, 6=76800
MV	29506	Operating Baud Rate			Read	1=Auto, 2=1200, 3=9600, 4=19200, 5=38400, 6=76800
MVmin	29507	Supply Fan Status	Hardware point BI:2		Read	1=Off, 2=On
MV	29525	Control Points			Write	1=State 0, 2=State 1
MVmin	29534	Supply Fan Fault			Read	1=Normal, 2=Alarm
MVmin	29535	Sensor 1 Alarms	Hardware point BI:5; I/O table name 'Low Water Switch #1'		Read	1=Alarm, 2=Normal
MV	29536	Supply Air Temperature Sensor Failure			Read	1=Normal, 2=Alarm
MV	29537	Outdoor Air Temperature Sensor Failure			Read	1=Normal, 2=Alarm
MV	29538	Zone Temperature Sensor Failure			Read	1=Normal, 2=Alarm
MV	29539	Supply Fan Control Mode			Write	1=Hand, 2=Off, 3=Auto
MV	29540	Indirect Pump Control Mode (optional)			Write	1=Hand, 2=Off, 3=Auto
MV	29541	Drain Valve 1 Control Mode			Write	1=Auto, 2=Close, 3=Open
MV	29542	Fill Valve 1 Control Mode			Write	1=Auto, 2=Close, 3=Open
MV	29543	Effective Occupancy			Read	Occupied / Unoccupied
MV	29544	Occupied Fan Mode			Write	1=Auto, 2=Off, 3=On
MV	29545	Unoccupied Fan Mode			Write	1=Auto, 2=Off, 3=On
MVmin	29546	Occupied Cooling Mode			Write	1=Auto, 2=Off, 3=On
MV	29547	Unoccupied Cooling Mode			Write	1=Auto, 2=Off, 3=On
MVmin	29548	Occupancy Override			Write	1=Occupied, 2=UnOccupied, 3=Bypass, 4=Standby, 5=Not Set
MV	29549	Occupancy Schedule			Write	1=Occupied, 2=UnOccupied, 3=Bypass, 4=Standby, 5=Not Set
MV	29555	Sensor 2 Alarms	Hardware point BI:6; I/O table name 'Low Water Switch #2 (optional)'		Read	1=Alarm, 2=Normal
MV	29557	Cooling Type			Write	1=X, 2=Y, 3=Z
MV	29562	Direct Pump Control Mode (optional)			Write	1=Hand, 2=Off, 3=Auto
MV	29563	Burner Status	Hardware point BI:1		Read	1=Off, 2=On
MV	29565	Burner Modulation Mode			Write	1=Auto, 2=Manual
MV	29566	Burner Control Mode			Write	1=Hand, 2=Off, 3=Auto
MV	29567	Burner Alarm Reset			Write	1=Off, 2=Reset
MV	29568	Heat/Cool Mode			Write	1=Heating, 2=Cooling
MV	29569	Burner Fault			Read	1=Normal, 2=Alarm
MV	29570	DAT Low Temperature Alarm			Read	1=Normal, 2=Lockout
MV	29571	Heater Lockout Alarm			Read	1=Normal, 2=Lockout
MV	29572	System Mode			Read	1=Heat, 2=Cool, 3=Fan Only, 4=Auto, 5=Off
MV	25973	Filter A			Read	1=Normal, 2=Alarm
MV	25974	Filter B			Read	1=Normal, 2=Alarm
AV	29501	Device Address	Range 4 to 127, default 4		Write
AV	29502	Device Object ID	Range 0 to 4194302		Write
AV	29510	DAT Sensor Offset	Range -10 to 10, default 0°F	°F	Write
AV	29512	Deadband	Range 0 to 20, default 0°F	°F	Write
AV	29513	High Drain Threshold	Range 0-10,000	μS/cm	Write
AV	29514	Drain Delay Time	Range 0 to 120	Minutes	Write
AV	29515	Drying Time	Range 0 to 120	Minutes	Write
AV	29516	Valve Delay	Range 0 to 120	Minutes	Write
AV	29517	Fan Fault Delay	Range 0 to 300, default 60 sec	seconds	Write
AV	29518	Water Flush System	Range 0-10,000	μS/cm	Write
AV	29519	OAT Sensor Offset	Range -10 to 10, default 0°F	°F	Write
AV	29520	Low OA Lockout Setpoint	Range 40 to 160, default 40°F	°F	Write
AV	29521	Pump Down Time	Range 0 to 120	Minutes	Write
AV	29522	Fan Start Delay	Range 0 to 120	Minutes	Write
AV	29524	ZNT Sensor Offset	Range -10 to 10, default 0°F	°F	Write
AV	29534	Supply Fan Cycle Count		Counts	Read
AV	29535	Supply Fan Runtime		hours	Read
AV	29536	Supply Fan Speed (optional)	Range 0 to 100, default 100%	%	Write
AV	29537	Effective Cooling Setpoint		°F	Read
AV	29538	OA Econ Lockout Setpoint	Range 40 to 160, default 65°F	°F	Write
AV	29539	Unoccupied Discharge Air Flow Setpoint	Range 40 to 160, default 65°F	°F	Write
AV	29540	Occupied Discharge Air Flow Setpoint	Range 40 to 160, default 65°F	°F	Write
AVmin	29541	Occupied Zone Cooling Set Point	Range 40 to 160, default 75°F	°F	Write
AV	29542	Unoccupied Zone Cooling Set Point	Range 40 to 160, default 85°F	°F	Write
AV	29543	Freeze Stat Setpoint	Range 40 to 160, default 65°F	°F	Write
AV	29544	Netsensor Temp	Range 32 to 104	°F	Read
AV	29545	Netsensor Humidity	Range 0 to 100	%	Read
AV	29546	RH Setpoint	Range 0-100, default 60%	%	Write
AV	29547	Inlet Air Cooler	Range 1-2		Write
AV	29548	Number of Pumps	Range 1-2		Write
AV	29549	Stage Up Delay	Range 0 to 30	Minutes	Write
AV	29552	OA Heating Lockout Setpoint	Range 0 to 130, default 65°F	°F	Write
AV	29553	Discharge Air High Set Point	Range 40 to 160, default 160°F	°F	Write
AV	29554	Discharge Air Low Set Point	Range 40 to 160, default 70°F	°F	Write
AVmin	29555	Occupied Zone Heating Set Point	Range 60 to 90, default 60°F	°F	Write
AV	29556	Unoccupied Zone Heating Set Point	Range 40 to 80, default 55°F	°F	Write
AV	29557	Burner Modulation Set Point		%	Read
AV	29560	Burner Fault Delay	Range 0 to 300, default 60 sec	seconds	Write
AV	29561	Low Temperature Cutout Setpoint	Range 45 to 55, default 45°F	°F	Write
AV	29562	Low Temperature Cutout Delay	Range 0 to 300, default 60 sec	seconds	Write
AV	29563	Effective Heating Set Point		°F	Read
AV	29564	Effective Discharge Air Set Point		°F	Read
AV	29565	Burner Runtime		hours	Read
AV	29566	Burner Cycle Count		Counts	Read
MV	29573	Clogged Filter Switch 1 (Optional)	Hardware point BI:3		Read	0=Normal, 1=Alarm
MV	29574	Clogged Filter Switch 2 (Optional)	Hardware point BI:4		Read	0=Normal, 1=Alarm
AVmin	29504	Discharge air temperature	Hardware point UI:14, range -50 - 250	°F	Read
AV	29550	Water Conductivity #2 (optional)	Hardware point UI:15, range 0-10,000	μS/cm	Read
AV	29506	Outdoor air temperature	Hardware point UI:16, range -50 - 250	°F	Read
AV	29507	Zone temperature (optional)	Hardware point UI:17, range -50 - 250	°F	Read
AV	29508	Water Conductivity #1 (optional)	Hardware point UI:18, range 0-10,000	μS/cm	Read
MV	29564	Burner command (optional)	Hardware point BO:4		Read	0=Off, 1=On
MV	29516	Indirect Pump command (optional)	Hardware point BO:6		Read	0=Off, 1=On
MV	29550	Direct Pump command (optional)	Hardware point BO:8		Read	0=Off, 1=On
MV	29520	Supply Fan command	Hardware point BO:10		Read	0=Off, 1=On
MV	29521	Drain Valve #1 command	Hardware point BO:11		Read	0=Open, 1=Closed
MV	29522	Fill Valve #1 command	Hardware point BO:12		Read	0=Closed, 1=Open
MV	29553	Drain Valve #2 command (optional)	Hardware point BO:13		Read	0=Open, 1=Closed
MV	29554	Fill Valve #2 command (optional)	Hardware point BO:14		Read	0=Closed, 1=Open
AV	29551	Burner Modulation (optional)	Hardware point AO:1, range 0 - 100	%	Read
AV	29509	Supply Fan Output (optional)	Hardware point AO:2, range 0 - 100	%	Read

Object ID lookup: Cambridge Air Solutions EVAP Controller point IDs by name

BV29501System Enable
BV29502Water System Flush
BV29512Supply Fan Runtime Reset
BV29516Humidity Lockout Enable
BV29517Burner Runtime Reset (optional)
MV29501Unit Status
MV29505FCB Baud Rate
MV29506Operating Baud Rate
MV29507Supply Fan Status
MV29525Control Points
MV29534Supply Fan Fault
MV29535Sensor 1 Alarms
MV29536Supply Air Temperature Sensor Failure
MV29537Outdoor Air Temperature Sensor Failure
MV29538Zone Temperature Sensor Failure
MV29539Supply Fan Control Mode
MV29540Indirect Pump Control Mode (optional)
MV29541Drain Valve 1 Control Mode
MV29542Fill Valve 1 Control Mode
MV29543Effective Occupancy
MV29544Occupied Fan Mode
MV29545Unoccupied Fan Mode
MV29546Occupied Cooling Mode
MV29547Unoccupied Cooling Mode
MV29548Occupancy Override
MV29549Occupancy Schedule
MV29555Sensor 2 Alarms
MV29557Cooling Type
MV29562Direct Pump Control Mode (optional)
MV29563Burner Status
MV29565Burner Modulation Mode
MV29566Burner Control Mode
MV29567Burner Alarm Reset
MV29568Heat/Cool Mode
MV29569Burner Fault
MV29570DAT Low Temperature Alarm
MV29571Heater Lockout Alarm
MV29572System Mode
MV25973Filter A
MV25974Filter B
AV29501Device Address
AV29502Device Object ID
AV29510DAT Sensor Offset
AV29512Deadband
AV29513High Drain Threshold
AV29514Drain Delay Time
AV29515Drying Time
AV29516Valve Delay
AV29517Fan Fault Delay
AV29518Water Flush System
AV29519OAT Sensor Offset
AV29520Low OA Lockout Setpoint
AV29521Pump Down Time
AV29522Fan Start Delay
AV29524ZNT Sensor Offset
AV29534Supply Fan Cycle Count
AV29535Supply Fan Runtime
AV29536Supply Fan Speed (optional)
AV29537Effective Cooling Setpoint
AV29538OA Econ Lockout Setpoint
AV29539Unoccupied Discharge Air Flow Setpoint
AV29540Occupied Discharge Air Flow Setpoint
AV29541Occupied Zone Cooling Set Point
AV29542Unoccupied Zone Cooling Set Point
AV29543Freeze Stat Setpoint
AV29544Netsensor Temp
AV29545Netsensor Humidity
AV29546RH Setpoint
AV29547Inlet Air Cooler
AV29548Number of Pumps
AV29549Stage Up Delay
AV29552OA Heating Lockout Setpoint
AV29553Discharge Air High Set Point
AV29554Discharge Air Low Set Point
AV29555Occupied Zone Heating Set Point
AV29556Unoccupied Zone Heating Set Point
AV29557Burner Modulation Set Point
AV29560Burner Fault Delay
AV29561Low Temperature Cutout Setpoint
AV29562Low Temperature Cutout Delay
AV29563Effective Heating Set Point
AV29564Effective Discharge Air Set Point
AV29565Burner Runtime
AV29566Burner Cycle Count
MV29573Clogged Filter Switch 1 (Optional)
MV29574Clogged Filter Switch 2 (Optional)
AV29504Discharge air temperature
AV29550Water Conductivity #2 (optional)
AV29506Outdoor air temperature
AV29507Zone temperature (optional)
AV29508Water Conductivity #1 (optional)
MV29564Burner command (optional)
MV29516Indirect Pump command (optional)
MV29550Direct Pump command (optional)
MV29520Supply Fan command
MV29521Drain Valve #1 command
MV29522Fill Valve #1 command
MV29553Drain Valve #2 command (optional)
MV29554Fill Valve #2 command (optional)
AV29551Burner Modulation (optional)
AV29509Supply Fan Output (optional)

Integration notes

Optional points (burner, second pump, second fill/drain valves, filter switches, zone sensor, conductivity, fan speed) only apply to units with those options.
The input table's Burner Status, Supply Fan Status and Low Water Switch #1/#2 rows point to the same MV objects as the multistate table (MV 29563, 29507, 29535 Sensor 1 Alarms, 29555 Sensor 2 Alarms); they are listed once with the hardware point in the description. The I/O tables show these as 0/1 while the MV table uses 1/2.
The manual prints Drain Valve 2 and Fill Valve 2 Control Mode with the same instances as valve 1 (MV 29541/29542), which looks like a typo; only the valve 1 rows are listed.
Cooling Type (MV 29557) is printed with placeholder states 1=X, 2=Y, 3=Z; the setup section names the cooling types Direct, Indirect and Direct/Indirect.
Default setpoints in the points table (unoccupied cooling 85°F, deadband 0°F) differ from the manual's Default Settings list (75°F, 5°F).
Filter A/B are printed as MV 25973/25974, while the alarm table gives the clogged filter switch alarms as MV 29573/29574; 25973/25974 may be a typo. The alarm table also gives the fan alarm as MV 29543 (Effective Occupancy in the points table), where the points table has Supply Fan Fault at MV 29534. Objects are listed here as the points table prints them.

Check it against the live device. A points list tells you what the controller can expose; the unit in front of you may differ by firmware or installed options. This list is provided as-is for reference only and may contain mistakes — confirming it before you write, map or commission anything is up to you (terms). Easy BACnet scans a network for BACnet IP devices from an Android phone, reads every object on the BACnet Controller - EVAP and exports what it actually has to Excel — free. New to BACnet? Start with what a BACnet points list is and what the object types mean.

Questions about the Cambridge Air Solutions BACnet Controller - EVAP

How many BACnet points does the Cambridge Air Solutions BACnet Controller - EVAP have?

This list has 101 BACnet objects: 51 analog values, 5 binary values, 45 multi-state values. The exact set on a given unit depends on its firmware, installed options and configuration.

Which Cambridge Air Solutions BACnet Controller - EVAP BACnet points are writable?

57 of the 101 objects accept a write. Points marked Command have a priority array: a write holds until it is released, so release it back to automatic when you are done.

Where is the official Cambridge Air Solutions BACnet Controller - EVAP BACnet documentation?

The source is Operating Instructions - BACnet Controller - EVAP (BACnet Controller EVAP Technical Manual) (Version 4.0.2.0003), revision 2023-01-31, published free by Cambridge Air Solutions at https://www.cambridge-eng.com/Portals/0/Operating%20Instructions%204_0_2_0003.pdf.

What are the minimum BACnet points to integrate the Cambridge Air Solutions BACnet Controller - EVAP?

Start with BV 29501 System Enable (Unit enable (1 = enable)); MV 29548 Occupancy Override (Occupied / unoccupied / bypass / standby from the BAS); MV 29546 Occupied Cooling Mode (Occupied cooling: auto / off / on); AV 29541 Occupied Zone Cooling Set Point (Occupied zone cooling setpoint, °F); AV 29555 Occupied Zone Heating Set Point (Occupied zone heating setpoint, °F); MV 29501 Unit Status (Heating / satisfied / cooling / sensor unreliable); MV 29507 Supply Fan Status (Supply fan proven on); AV 29504 Discharge air temperature (Discharge air temperature, °F); MV 29534 Supply Fan Fault (Supply fan alarm); MV 29535 Sensor 1 Alarms (Low water switch 1 alarm (1 = alarm)).

How do I enable BMS control of the Cambridge Air Solutions BACnet Controller - EVAP?

How do I check these points on the real BACnet Controller - EVAP?

Scan the network with a BACnet IP browser such as Easy BACnet, open the device and compare its object list with this table. Anything missing is usually an option that isn't installed or a point that is disabled in the controller's configuration.