BACnet Overview

About BACnet

BACnet stands as a data communications protocol designed for Building Automation and Control Networks. It holds the status of an approved and standardized protocol by esteemed organizations such as the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE), the American National Standards Institute (ANSI), and the International Organization for Standardization (ISO). This protocol facilitates communication and control across various applications, including heating, ventilation, air-conditioning, lighting, access, and fire detection systems, along with their associated equipment.

BACnet Object IDs

Object	Number	Description
Analog Input	0	Represents a continuously variable physical input, such as temperature or humidity.
Analog Output	1	Controls an analog output, such as a variable-speed fan or dimmable lighting.
Analog Value	2	Stores and processes analog values for calculations or logic operations.
Binary Input	3	Represents a digital (on/off) input, such as a switch or sensor.
Binary Output	4	Controls a digital (on/off) output, such as a relay or actuator.
Binary Value	5	Stores and processes binary values for logical operations.
Calendar	6	Defines date-based schedules for automation processes.
Command	7	Executes predefined commands or sequences.
Device	8	Represents a BACnet device and its associated properties.
Event Enrollment	9	Manages event-based notifications and alerts.
File	10	Represents a file object used for data storage and transfer.
Group	11	Groups multiple objects for simplified control and monitoring.
Loop	12	Represents a control loop for process control applications.
Multi-state Input	13	Represents an input with multiple discrete states.
Multi-state Output	14	Controls an output that has multiple states.
Notification Class	15	Manages notifications and alarms for BACnet objects.
Program	16	Represents executable logic, such as scripts or automation routines.
Schedule	17	Defines time-based automation schedules for devices.
Multi-state Value	19	Stores and processes values with multiple discrete states.

BACnet Common Property's

Property Name	Number
objectName	77
presentValue	85
priorityArray	87
device	8

BACnet Common Property's for a Device

Property Name	Device	Identifier	Description
objectList	8	76	Lists all objects that belong to the device.
deviceName	8	77	The human-readable name of the device.
manufacturer	8	121	The name of the device manufacturer.
manufacturer-id	8	120	A unique identifier assigned to the manufacturer.
segmentationSupported	8	107	Indicates whether the device supports segmentation.
maxApduLengthAccepted	8	62	Specifies the maximum APDU size the device can process.

BACnet Property's

Property Name	Number
ackedTransitions	0
ackRequired	1
action	2
actionText	3
activeText	4
activeVtSessions	5
alarmValue	6
alarmValues	7
all	8
allWritesSuccessful	9
apduSegmentTimeout	10
apduTimeout	11
applicationSoftwareVersion	12
archive	13
bias	14
changeOfStateCount	15
changeOfStateTime	16
notificationClass	17
none	18
controlledVariableReference	19
controlledVariableUnits	20
controlledVariableValue	21
covIncrement	22
datelist	23
daylightSavingsStatus	24
deadband	25
derivativeConstant	26
derivativeConstantUnits	27
description	28
descriptionOfHalt	29
deviceAddressBinding	30
deviceType	31
effectivePeriod	32
elapsedActiveTime	33
errorLimit	34
eventEnable	35
eventState	36
eventType	37
exceptionSchedule	38
faultValues	39
feedbackValue	40
fileAccessMethod	41
fileSize	42
fileType	43
firmwareRevision	44
highLimit	45
inactiveText	46
inProcess	47
instanceOf	48
integralConstant	49
integralConstantUnits	50
issueConfirmedNotifications	51
limitEnable	52
listOfGroupMembers	53
listOfObjectPropertyReferences	54
listOfSessionKeys	55
localDate	56
localTime	57
location	58
lowLimit	59
manipulatedVariableReference	60
maximumOutput	61
maxApduLengthAccepted	62
maxInfoFrames	63
maxMaster	64
maxPresValue	65
minimumOffTime	66
minimumOnTime	67
minimumOutput	68
minPresValue	69
modelName	70
modificationDate	71
notifyType	72
numberOfAPDURetries	73
numberOfStates	74
objectIdentifier	75
objectList	76
objectName	77
objectPropertyReference	78
objectType	79
optional	80
outOfService	81
outputUnits	82
eventParameters	83
polarity	84
presentValue	85
priority	86
priorityArray	87
priorityForWriting	88
processIdentifier	89
programChange	90
programLocation	91
programState	92
proportionalConstant	93
proportionalConstantUnits	94
protocolConformanceClass	95
protocolObjectTypesSupported	96
protocolServicesSupported	97
protocolVersion	98
readOnly	99
reasonForHalt	100
recipient	101
recipientList	102
reliability	103
relinquishDefault	104
required	105
resolution	106
segmentationSupported	107
setpoint	108
setpointReference	109
stateText	110
statusFlags	111
systemStatus	112
timeDelay	113
timeOfActiveTimeReset	114
timeOfStateCountReset	115
timeSynchronizationRecipients	116
units	117
updateInterval	118
utcOffset	119
vendorIdentifier	120
vendorName	121
vtClassesSupported	122
weeklySchedule	123

Debugging

Wireshark/Tshark

Tshark

Install

sudo apt-get install tshark

Usage

sudo tshark -i eth0 -f "udp" | grep "BACnet-APDU"

Ping Port 47808

Check and see if port 47808 is open on your target device.

Netcat -v -u -z 192.168.15.155 47808