README
¶
BACnet controller
Configuration
Example (add under controllers.bacnet in your app config):
controllers:
bacnet:
enabled: true
addr: "0.0.0.0:47808" # BACnet/IP UDP listen address
device_instance: 1 # BACnet device instance number (0..4194303)
sync_interval: 0.5s # Retained for parity; currently unused
Environment variables:
| Variable | Description |
|---|---|
TMK_CONTROLLER |
Set to bacnet to start only the BACnet controller |
TMK_ADDR |
Override addr (e.g. 127.0.0.1:47808) |
TMK_CONTROLLERS_BACNET_DEVICE_INSTANCE |
Override device instance number |
BACnet interface
The controller implements BACnet/IP over UDP and handles three services:
- Who-Is / I-Am — Responds to Who-Is broadcasts with an I-Am containing the configured device instance.
- ReadProperty — Returns
PresentValue(property 85) for all supported objects. - WriteProperty — Sets
PresentValuefor writable objects. Returns SimpleACK on success, Error on failure.
Only PresentValue (property ID 85) is supported. Requests for other properties receive an Error response.
PresentValue is encoded with the BACnet datatype that matches the object type — Real for Analog objects, Enumerated for Binary Value, and Unsigned for Multi-State Value — so a conformant client (e.g. bacpypes3) decodes each object with its expected datatype. A write must use that same datatype; a value of any other datatype is rejected with an invalid-data-type error rather than coerced.
Object mapping
| BACnet Object | Instance | Variable | Access |
|---|---|---|---|
| Analog Input (0) | 0 | ambient_temperature |
Read-only |
| Analog Value (2) | 0 | temperature_setpoint |
Read / Write |
| Analog Value (2) | 1 | temperature_setpoint_min |
Read / Write |
| Analog Value (2) | 2 | temperature_setpoint_max |
Read / Write |
| Analog Value (2) | 3 | fault_code |
Read / Write |
| Binary Value (5) | 0 | enabled |
Read / Write |
| Multi-State Value (19) | 0 | mode |
Read / Write |
| Multi-State Value (19) | 1 | fan_speed |
Read / Write |
Value encoding
- Temperatures (AI:0, AV:0, AV:1, AV:2):
Real— IEEE 754 float32 in degrees Celsius. - Fault Code (AV:3):
Real— integer transported as float32 (truncated to int on write). - Enabled (BV:0):
Enumerated—1= active,0= inactive. - Mode (MSV:0):
Unsigned—1= heat,2= cool,3= fan,4= auto. - Fan Speed (MSV:1):
Unsigned—1= auto,2= low,3= medium,4= high.
Error handling
- Reading or writing an unknown object returns
ErrorClassObject/ErrorCodeUnknownObject. - Writing to a read-only object (Analog Input) returns
ErrorClassService/ErrorCodeServiceRequestDenied. - Writing a value whose datatype doesn't match the object type returns
ErrorClassProperty/ErrorCodeInvalidDataType. - Requesting a property other than
PresentValuereturnsErrorClassService/ErrorCodeServiceRequestDenied.
Known library issues
This controller uses github.com/ulbios/bacnet. Two bugs in the library are worked around in the controller code:
IAmObjectsignores the device instance parameter — hardcodes instance 321. The controller builds I-Am objects manually.DecObjectIdentifierbit-shift error — uses>> 20instead of>> 22, causing object types to decode astype * 4. The controller implements its own decoders.
See also
- HTTP controller docs: ../http/README.md
- MQTT controller docs: ../mqtt/README.md
- Modbus controller docs: ../modbus/README.md
Documentation
¶
Index ¶
Constants ¶
const ( ObjectTypeAnalogValue uint16 = 2 ObjectTypeBinaryValue uint16 = 5 ObjectTypeMultiStateValue uint16 = 19 )
BACnet object types not defined in the library.
const ( ErrorClassProperty uint8 = 2 ErrorCodeInvalidDataType uint8 = 9 )
BACnet error class/code not defined in the library.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Config ¶
type Config struct {
// Identity
DeviceID string
DeviceInstance int // BACnet device instance number (0..4194303)
// Network
Addr string // bind address, e.g. "0.0.0.0:47808" or "127.0.0.1:0" for ephemeral port in tests
// Behavior
SyncInterval time.Duration // retained for parity; unused by WhoIs handling
}
Config for the BACnet controller.
type Controller ¶
type Controller struct {
// contains filtered or unexported fields
}
func New ¶
func New(svc thermostat.Service, cfg Config, logger *slog.Logger) (*Controller, error)
New creates a BACnet controller. DeviceInstance must be in the BACnet range 0..4194303.
func (*Controller) LocalAddr ¶
func (c *Controller) LocalAddr() net.Addr
LocalAddr returns the controller's bound address (useful for tests).
Source Files