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Thermostat (multi-stage heat/cool, Wi-Fi BACnet IP) · BACnet points list
Contemporary Controls BASstat BAST-221C/CH-BW2 Wireless Multi-Stage Thermostat BACnet points list
Updated 11 November 2026
The BAST-221C-BW2 is a Wi-Fi BACnet IP thermostat for up to two cooling and two heating stages plus fan. The 221CH version adds humidity and dew point readings. It exposes temperatures, setpoints, system and fan modes, occupancy, relay control and status, and setup values as BACnet objects.
This page lists 61 BACnet objects for the Contemporary Controls BASstat BAST-221C/CH-BW2 Wireless Multi-Stage Thermostat — 45 of them writable — with each object’s type, instance number, name, engineering units and access. It is re-typed from Contemporary Controls’s own free documentation, linked below.
- Manufacturer
- Contemporary Controls
- Model
- BASstat BAST-221C/CH-BW2 Wireless Multi-Stage Thermostat
- Equipment
- Thermostat (multi-stage heat/cool, Wi-Fi BACnet IP)
- Equipment type
- Thermostats, sensors & meters
- BACnet objects
- 61 (45 writable)
- Transport
- BACnet IP
- Firmware
- Not stated
- Default device instance
- 100001
- Also known as
- BAST-221C-BW2, BAST-221CH-BW2, BASstat BW2, BASstat 221C
Reference only, provided as-is: verify against Contemporary Controls’s current documentation and the live device before use. Not official Contemporary Controls information. Terms of use.
BMS integration notes: Contemporary Controls BASstat BAST-221C/CH-BW2 Wireless Multi-Stage Thermostat
Turn the thermostat outputs on with On-Off Control (BV 5), set occupancy with Occupancy Command (BV 14), and write the system mode, cooling and heating setpoints and fan mode. Read the space temperature, occupancy status, output status and fan speed.
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 5 | On-Off Control | Thermostat outputs on/off (1 = on) | Write |
| BV 14 | Occupancy Command | 0 = occupied, 1 = unoccupied | Write |
| MV 1 | System Mode | Cool, heat or ventilation mode | Write |
| AV 0 | Cooling Temperature Setpoint | Occupied cooling setpoint | Write |
| AV 3 | Heating Temperature Setpoint | Occupied heating setpoint | Write |
| MV 0 | Fan Mode | Fan mode; 1 = auto | Write |
| AI 0 | Current Temperature | Space temperature in use | Read |
| BI 0 | Occupancy Status | 0 = occupied, 1 = unoccupied | Read |
| BI 2 | Cooling-heating Status | Heating/cooling output active | Read |
| MV 5 | Fan Speed Status | Current fan speed | Read |
Enable & remote start
On-Off Control (BV 5) switches the thermostat outputs. Occupancy Command (BV 14) only takes effect when the ESI contact is disabled in Lock (AV 18 bit value 64); by default occupancy comes from the ESI dry contact.
Heartbeat & communication loss
A space temperature written to Space Temperature Via BACnet (AV 1) is only used while the BMS keeps toggling Heartbeat signal (BV 16) within the Heartbeat Rate (AV 29) period, in seconds; otherwise the thermostat reverts to its own sensor.
Sensors & values from the BMS
Set Temperature Source (MV 3) to 3 (Assigned through BACnet) and write the space temperature to AV 1, toggling BV 16 as a heartbeat.
Network setup
- BACnet IP over Wi-Fi; the UDP port defaults to 47808 (BAC0) and can be set in the Engineering menu (UdP) or by writing UDP Port No (AV 21).
- Device instance = devH x 1000 + devL in the Engineering menu, or write Device Instance (AV 20) once online.
- DHCP or static IP addressing is set from the thermostat's Wi-Fi setup pages.
- The manual gives 100001 as the default device instance.
Watch out for
- Lock (AV 18) is bit-coded: add the bit values to lock buttons, ignore the ESI or door contact, block changes to the comms settings or hand the relays to BACnet (512).
- The manual text calls the Lock object AV17 in places and the heartbeat rate AV-29; the object table numbers are used here.
- Relay control BVs only drive the relays when Lock bit 9 (512) hands the outputs to the BACnet supervisor.
Contemporary Controls BASstat BAST-221C/CH-BW2 Wireless Multi-Stage Thermostat 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.
| Description | States | |||||
|---|---|---|---|---|---|---|
| AImin | 0 | Current Temperature | °F/°C | Read | ||
| AI | 1 | Active Temperature Setpoint | °F/°C | Read | ||
| AI | 2 | Built-in Temperature Sensor | Built-in Temperature Sensor Reading | °F/°C | Read | |
| AI | 3 | Remote Temperature Sensor | Remote Temperature Sensor Reading | °F/°C | Read | |
| AI | 4 | Current Humidity | Current Humidity (221CH models only) | %RH | Read | |
| AI | 5 | Current Dew Point | Current Dew Point (221CH models only) | °F/°C | Read | |
| AVmin | 0 | Cooling Temperature Setpoint | °F/°C | Write | ||
| AV | 1 | Space Temperature Via BACnet | BACnet Assigned Current Temperature | °F/°C | Write | |
| AVmin | 3 | Heating Temperature Setpoint | °F/°C | Write | ||
| AV | 4 | Hr-Running Time | Running Time of Valve (Hr.) | h | Write | |
| AV | 5 | M-Running Time | Running Time of Valve (M.) | min | Write | |
| AV | 6 | Sec-Running Time | Running Time of Valve (Sec.) | s | Write | |
| AV | 7 | Deadband | °F/°C | Write | ||
| AV | 8 | Unoccupied Cool Setpoint | Unoccupied Cooling Setpoint | °F/°C | Write | |
| AV | 9 | Unoccupied Heat Setpoint | Unoccupied Heating Setpoint | °F/°C | Write | |
| AV | 10 | Integral-Cycle Time | Integral Time and Output Cycle Time | s | Write | |
| AV | 13 | Low Setpoint Limit | Low Limit for Setpoint Temperature | °F/°C | Write | |
| AV | 14 | High Setpoint Limit | High Limit for Setpoint Temperature | °F/°C | Write | |
| AV | 15 | Temperature Offset | Offset for Current | °F/°C | Write | |
| AV | 16 | Proportional Band- Stage Width | Temperature Proportional Band or Stage Width | °F/°C | Write | |
| AV | 17 | Stage Differential | °F/°C | Write | ||
| AV | 18 | Lock | Bit-coded lock: buttons, ESI/door contacts, comms settings, DO control | Write | ||
| AV | 20 | Device Instance | Write | |||
| AV | 21 | UDP Port No | UDP Port Number | Write | ||
| AV | 22 | Humidity Offset | Humidity Offset Value (221CH models only) | %RH | Write | |
| AV | 23 | Cooling Short Cycle Delay | min | Write | ||
| AV | 24 | Cooling Maximum Cycles per Hour | Write | |||
| AV | 25 | Heating Short Cycle | Heating Short Cycle Delay | min | Write | |
| AV | 26 | Heating Maximum Cycles per Hour | Write | |||
| AV | 29 | Heartbeat Rate | Communication Heartbeat Minimum Rate | s | Write | |
| AV | 39 | Minimum Cooling Temperature Setpoint | Minimum Cooling Temperature Setpoint | °F/°C | Write | |
| AV | 40 | Maximum Heating Temperature Setpoint | Maximum Heating Temperature Setpoint | °F/°C | Write | |
| AV | 46 | Minimum Off Time | s | Write | ||
| AV | 47 | Minimum On Time | s | Write | ||
| BImin | 0 | Occupancy Status | Status of Occupancy | Read | 0=Room Occupied, 1=Room Unoccupied | |
| BImin | 2 | Cooling-heating Status | Status of Cooling/Heating Control Output | Read | 0=Close & Off, 1=Open & On | |
| BI | 3 | Relay 1 Status | Status of Relay 1 (Cooling Stage 1) | Read | 0=Off, 1=On | |
| BI | 4 | Relay 2 Status | Status of Relay 2 (Cooling Stage 2) | Read | 0=Off, 1=On | |
| BI | 5 | Relay 3 Status | Status of Relay 3 (Heating Stage 1) | Read | 0=Off, 1=On | |
| BI | 6 | Relay 4 Status | Status of Relay 4 (Heating Stage 2) | Read | 0=Off, 1=On | |
| BI | 9 | Relay 7 Status | Status of Relay 7 Fan | Read | 0=Off, 1=On | |
| BI | 10 | Dl 1 Status | Status of Digital Input 1 | Read | 0=Off, 1=On | |
| BI | 17 | Fan Status | Read | 0=Off, 1=On | ||
| BV | 0 | Occupancy Contact Definition | Occupancy(DI1) Contact Definition | Write | 0=N.O., 1=N.C. | |
| BVmin | 5 | On-Off Control | On/Off Status of Thermostat | Write | 0=Off, 1=On | |
| BV | 6 | Temperature Scale | °C/ °F | Write | 0=°C, 1=°F | |
| BV | 7 | Relay 1 Control | On/Off Control of Relay 1 (Cooling Stage 1) | Write | 0=Off, 1=On | |
| BV | 8 | Relay 2 Control | On/Off Control of Relay 2 (Cooling Stage 2) | Write | 0=Off, 1=On | |
| BV | 9 | Relay 3 Control | On/Off Control of Relay 3 (Heating Stage 1) | Write | 0=Off, 1=On | |
| BV | 10 | Relay 4 Control | On/Off Control of Relay 4 (Heating Stage 2) | Write | 0=Off, 1=On | |
| BV | 13 | Relay 7 Control | On/Off Control of Relay 7 Fan | Write | 0=Off, 1=On | |
| BVmin | 14 | Occupancy Command | Room Occupancy Setting | Write | 0=Occupied, 1=Unoccupied | |
| BV | 15 | Fan Output for Heating | Disable/ Enable Fan Output for Heating | Write | 0=Disable, 1=Enable | |
| BV | 16 | Heartbeat signal | Heartbeat Pulse Signal | Write | 0=Off, 1=On | |
| MVmin | 0 | Fan Mode | Write | 1=Auto, 1=Low, 3=Med., 4=Hi | ||
| MVmin | 1 | System Mode | Working Mode: Heat, Cool or Ventilation | Write | 1=Cool Mode, 2=Heat Mode, 3=Ventilation @ Cool Mode, 4=Ventilation @ Heat Mode | |
| MV | 3 | Temperature Source | Current Temperature Source | Write | 1=Built-In Temp. Sensor, 2=Remote Temp. Sensor, 3=Assigned through BACnet | |
| MV | 4 | Lowest Fan Speed | Lowest Fan speed in Auto Fan mode | Write | 1=Stop, 2=Low, 3=Med., 4=Hi | |
| MVmin | 5 | Fan Speed Status | Read | 1=Stop, 2=Low, 3=Med, 4=Hi | ||
| MV | 6 | Display Options | LCD Display Options | Write | 1=T & Time (if available), 2=SP & Time (if available), 3=T & CO2 (if available), 4=CO2 & Time (if available), 5=SP & CO2 (if available), 6=T & RH (if available), 7=T & Valve (if available) | |
| MV | 7 | Control Type | Control Type Selection | Write | 1=Cooling Only, 2=Cooling or Heating Manual Changeover, 3=Cooling and Heating Auto Changeover (default), 4=Heating Only NOTE: Cool only and Heat only types disabled |
No points match these filters.
Object ID lookup: Contemporary Controls BAST-221C-BW2 point IDs by name
AI0Current TemperatureAI1Active Temperature SetpointAI2Built-in Temperature SensorAI3Remote Temperature SensorAI4Current HumidityAI5Current Dew PointAV0Cooling Temperature SetpointAV1Space Temperature Via BACnetAV3Heating Temperature SetpointAV4Hr-Running TimeAV5M-Running TimeAV6Sec-Running TimeAV7DeadbandAV8Unoccupied Cool SetpointAV9Unoccupied Heat SetpointAV10Integral-Cycle TimeAV13Low Setpoint LimitAV14High Setpoint LimitAV15Temperature OffsetAV16Proportional Band- Stage WidthAV17Stage DifferentialAV18LockAV20Device InstanceAV21UDP Port NoAV22Humidity OffsetAV23Cooling Short Cycle DelayAV24Cooling Maximum Cycles per HourAV25Heating Short CycleAV26Heating Maximum Cycles per HourAV29Heartbeat RateAV39Minimum Cooling Temperature SetpointAV40Maximum Heating Temperature SetpointAV46Minimum Off TimeAV47Minimum On TimeBI0Occupancy StatusBI2Cooling-heating StatusBI3Relay 1 StatusBI4Relay 2 StatusBI5Relay 3 StatusBI6Relay 4 StatusBI9Relay 7 StatusBI10Dl 1 StatusBI17Fan StatusBV0Occupancy Contact DefinitionBV5On-Off ControlBV6Temperature ScaleBV7Relay 1 ControlBV8Relay 2 ControlBV9Relay 3 ControlBV10Relay 4 ControlBV13Relay 7 ControlBV14Occupancy CommandBV15Fan Output for HeatingBV16Heartbeat signalMV0Fan ModeMV1System ModeMV3Temperature SourceMV4Lowest Fan SpeedMV5Fan Speed StatusMV6Display OptionsMV7Control Type
Integration notes
- From the BACnet Object Table (manual pages 34-42). The table is shared across the BASstat family; rows printed in grey (objects this model does not use) are left out.
- Access is from the Readable/Writable column; R/W objects are shown as writable.
- Temperature objects follow the Temperature Scale object (BV 6: 0 = °C, 1 = °F).
- Fan Mode (MV 0) states are printed as "1: Auto 1: Low 3: Med. 4: Hi" and are kept as printed.
- Current Humidity (AI 4) and Current Dew Point (AI 5) are on the 221CH model only.
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 BASstat BAST-221C/CH-BW2 Wireless Multi-Stage Thermostat 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 Contemporary Controls BASstat BAST-221C/CH-BW2 Wireless Multi-Stage Thermostat
How many BACnet points does the Contemporary Controls BASstat BAST-221C/CH-BW2 Wireless Multi-Stage Thermostat have?
This list has 61 BACnet objects: 6 analog inputs, 28 analog values, 9 binary inputs, 11 binary values, 7 multi-state values. The exact set on a given unit depends on its firmware, installed options and configuration.
Which Contemporary Controls BASstat BAST-221C/CH-BW2 Wireless Multi-Stage Thermostat BACnet points are writable?
45 of the 61 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 Contemporary Controls BASstat BAST-221C/CH-BW2 Wireless Multi-Stage Thermostat BACnet documentation?
The source is BAST-221C/CH-BW2 Wireless Multi-Stage Thermostat User Manual (UM-15090500-AA3), published free by Contemporary Controls at https://www.ccontrols.com/pdf/um/BASstat-BW2-usermanual.pdf.
What are the minimum BACnet points to integrate the Contemporary Controls BASstat BAST-221C/CH-BW2 Wireless Multi-Stage Thermostat?
Start with BV 5 On-Off Control (Thermostat outputs on/off (1 = on)); BV 14 Occupancy Command (0 = occupied, 1 = unoccupied); MV 1 System Mode (Cool, heat or ventilation mode); AV 0 Cooling Temperature Setpoint (Occupied cooling setpoint); AV 3 Heating Temperature Setpoint (Occupied heating setpoint); MV 0 Fan Mode (Fan mode; 1 = auto); AI 0 Current Temperature (Space temperature in use); BI 0 Occupancy Status (0 = occupied, 1 = unoccupied); BI 2 Cooling-heating Status (Heating/cooling output active); MV 5 Fan Speed Status (Current fan speed).
How do I enable BMS control of the Contemporary Controls BASstat BAST-221C/CH-BW2 Wireless Multi-Stage Thermostat?
On-Off Control (BV 5) switches the thermostat outputs. Occupancy Command (BV 14) only takes effect when the ESI contact is disabled in Lock (AV 18 bit value 64); by default occupancy comes from the ESI dry contact.
Does the Contemporary Controls BASstat BAST-221C/CH-BW2 Wireless Multi-Stage Thermostat need a BACnet heartbeat or have a communication timeout?
A space temperature written to Space Temperature Via BACnet (AV 1) is only used while the BMS keeps toggling Heartbeat signal (BV 16) within the Heartbeat Rate (AV 29) period, in seconds; otherwise the thermostat reverts to its own sensor.
Can the BMS supply sensor values to the Contemporary Controls BASstat BAST-221C/CH-BW2 Wireless Multi-Stage Thermostat?
Set Temperature Source (MV 3) to 3 (Assigned through BACnet) and write the space temperature to AV 1, toggling BV 16 as a heartbeat.
How do I check these points on the real BASstat BAST-221C/CH-BW2 Wireless Multi-Stage Thermostat?
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.
More Contemporary Controls BACnet points lists
- Thermostat (single mode heat/cool/ventilation, BACnet MS/TP)
Contemporary Controls BASstat BAST-121C-B2 Single Mode Thermostat
Contemporary Controls BAST-121C-B2 wired thermostats for single-mode heating, cooling or ventilation equipment.
Also known as: BAST-121C-B2, BAST-121-B2, BASstat 121C - Thermostat (single mode heat/cool/ventilation, Wi-Fi BACnet IP)
Contemporary Controls BASstat BAST-121C-BW2 Wireless Single Mode Thermostat
Contemporary Controls BAST-121C-BW2 Wi-Fi thermostats for single-mode heating, cooling or ventilation equipment.
Also known as: BAST-121C-BW2, BAST-121-BW2, BASstat 121C Wi-Fi - Thermostat for 2-stage HP systems (BACnet MS/TP)
Contemporary Controls BASstat BAST-321HP-B2 Heat Pump Thermostat
Contemporary Controls BAST-321HP-B2 wired thermostats for single or dual compressor heat pumps with auxiliary heat.
Also known as: BAST-321HP-B2, BAST-321-B2, BASstat 321HP - Thermostat for 2-stage HP systems (Wi-Fi BACnet IP)
Contemporary Controls BASstat BAST-321HP-BW2 Wireless Heat Pump Thermostat
Contemporary Controls BAST-321HP-BW2 Wi-Fi thermostats for single or dual compressor heat pumps with auxiliary heat.
Also known as: BAST-321HP-BW2, BAST-321-BW2, BASstat 321HP Wi-Fi - Thermostat for modulating 4-pipe FCUs (Wi-Fi BACnet IP)
Contemporary Controls BASstat BAST-421C-BW2 Wireless Modulating Fan Coil Thermostat
Contemporary Controls BAST-421C-BW2 Wi-Fi thermostats for 4-pipe fan coils with modulating or floating valves.
Also known as: BAST-421C-BW2, BAST-421-BW2, BASstat 421C
Source: BAST-221C/CH-BW2 Wireless Multi-Stage Thermostat User Manual · UM-15090500-AA3. Object names, instances and units are reproduced as published; descriptions are our own.