BACnet – Its Origins,

Evolution, and Future

The Pre-Pre-History – 1964 - 1981

1964 - Honeywell Selectrographic 6 installed

1975 – Diskless IBM System/7 arrives

1977 – The first System/7 with a hard disk and software from the IBM Palo Alto Research Center

The Pre-History – 1981-1987

DDC arrives at Cornell in the form of JCI DSC-8500s

Everyone wanted to sell us DDC – but none of it could interoperate!

The ASHRAE struggle begins and I attend my first meeting…

The Development – 1987-1995

An "SPC" is approved in NYC (January '87) and meets in Nashville in June

Who is in? Who is out?

We finally publish ANSI/ASHRAE Standard 135 in 1995!

Are we done yet? No! We're just starting!

There were, of course, many struggles...

BACnet Committee

Twenty-Two Years of Evolution –1995-2017

What the BACnet standard was –

and is...

Only standard protocol

specifically for buildings.

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A Data Communication Protocol

for Building Automation and

Control networks

Protocol rules apply to:

• Messages and their format

• Networking options (LANs, WANs, Dial-up, etc.)

• Joining networks together to form "internetworks"

Two Main Parts of Every Application Protocol

Transport

Application

Message

BACnet provides the capability to communicate

about the "application" of "building

automation" in all its diversity: HVAC, lighting,

security, access control, fire detection, utility

interaction, etc., by means of Objects, Messages,

and Transport Options (i.e., LANs and WANs).

Objects

Objects represent physical inputs, outputs and software processes

72

IF temp>72 THEN

ObjectsEach object is characterized by a set of “properties” that describe its behavior or govern its operation

72

Object_Name SPACE TEMP

Object_Type ANALOG INPUT

Present_Value 72.3

Status_Flags Normal,

Out-of-Service

High_Limit 78.0

Low_Limit 68.0

ObjectsBACnet 2016 defines a collection of 60 standard objects

Binary Input

Binary Output

Binary Value

Analog Input

Analog Output

Analog Value

Multi-state Input

Multi-state Output

Calendar

Notification Class

Command

File Program

Schedule

Group

Event Enrollment

Device

Loop

Load Control

Multi-state Value

Averaging

Trend Log

Life Safety Zone

Life Safety Point

Accumulator

Pulse Convertor

Trend Log Multiple

Event Log

Access Door

Structured View

DEVICE

LOOP

BI AI AO

SCHEDULE

BACnet Device

GROUP

BO

AV

Messages

• Object Access Services

• Alarm and Event Services

• File Access Services

• Remote Device Management Services

• Miscellaneous

Transport Options• Ethernet

• ARCNET

• Master-Slave/Token-Passing (MS/TP)

• Point-to-Point (PTP)

• Echelon's LonTalk

• BACnet/IP (Internet Protocol)

• BACnet/WS (Web Services)

• ZigBee

BACnet LAN - Ethernet, ARCNET, MS/TP, LonTalk, BACnet/IP or ZigBee

Sensors and Actuators

BACnet

Field Panels

BACnet

Workstation

"Native" BACnet

Native BACnet devices provide BACnet

communications directly, device to device

BACnet LAN - Ethernet

BACnet Field Panel

BACnet Workstation

Vendor A

Sensors and Actuators

Vendor CVendor C

BACnet LAN - ARCNET

Sensors and Actuators

Ethernet to ARCNET

Router

Vendor BVendor B

BACnet Field

Panels

BACnet Field

Panels

Ethernet to MS/TP Router

BACnet LAN - MS/TP

Sensors and Actuators

Routers -

"re-package" BACnet messages and re-transmit them unchanged

Net 1

Net 3Net 2

BACnet LAN - Ethernet, ARCNET, MS/TP, LonTalk, BACnet/IP or ZigBee

BACnet Field

Panels

BACnet Workstation

Sensors and Actuators

Proprietary LAN

Sensors and Actuators

BACnet to

Vendor B Gateway

Non-BACnet

Field Panels

Gateways -

must "translate" messages before retransmission

BACnet, of course, also

works with the Internet

BBMDBACnet Device

IP Router

Internet

BBMD BACnet Device

IP Router

A

B

BACnet Device

BACnet Device

BACnet Device

BACnet Device

BACnet/IP"Unicast" Messages

(BACnet devices speak

using IP directly)

BBMD BACnet Device

IP Router

BBMDBACnet Device

IP Router

A

B

BACnet Device

BACnet Device

BACnet Device

BACnet Device

BACnet/IP"Broadcast" messages

("BBMD" required to pass

broadcasts through IP routers)

Internet

BACnet/IPv6

BACnet over IPv6(Specified in 135-2016)

Object ModelMessagesTransport Options

++

In summary,

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Where is BACnet being used?

More than 100,000 systems are installed today world-wide in 82 countries and on all continents. About 10,000 involve multiple vendors.

BACnet on Capitol Hill

Diagnostic Lab NorthLangmuirLiddellMarmotaOrnithology Lab

ArthropodBaker InstituteCISEREHOBSchwardt LabSmall Animal Holding

226 BACS Facilities

Rowing Center

0

2000

4000

6000

8000

10000

12000

14000

1/1/2005 1/1/2006 1/1/2007 1/1/2008 1/1/2009 1/1/2010 1/1/2011 1/1/2012 1/1/2013 1/1/2014 1/1/2015

Growth in EMCS Device Count Since 2005

14,644

501

ANSI/ASHRAE Standard 135-2016, BACnet®“A Data Communication Protocol for Building Automation and Control Networks”

- After 22 addenda to BACnet-2012

- Protocol Revision 19

- No addenda yet

- Will become ISO 16484-5 20xx

ANSI/ASHRAE Standard 135.1-2013, BACnet Testing“Method of Test for Conformance to BACnet®”

- Conformance Test Specifications

- Device Testing, not System Testing

- Will become ISO 16484-6 20xx

Current Standards

BACnet Development – Two Tracks

➢ "Legacy BACnet" Enhancements

New objects and services

New properties

New datalink types

➢ New Technologies

IPv6

BACnet/IT Existing IT infrastructures

IoT integration

BACnet/WS Enterprise web services

What's new in BACnet-2016?"Legacy Enhancements"

Six new object types including the Network Port Object

Three new services for COV reporting

MS/TP large frames (6loBAC)

"Value Source" mechanism

Gateway specifications

Support for elevators / escalators

Improved lighting support

IPv6

Improved BACnet Web Services

New data model for BACnet/WS and device definition and discovery

Support for both XML and JSON

What's new in BACnet-2016?"New Technologies"

BACnet for Elevator Monitoring(Addendum 135-2012aq, in 135-2016)

Elevator Monitoring

BACnet XD

BACnet Extended Data Model(Addendum 135-2012am, in 135-2016)

Data

‘/’

Data

Data Data

Metadata

Data

Data Metadata

Metadata

/path/to/data/data/path/to/data/data/$metadata

“From Modbus registers to BACnet objects to Arbitrary Data and Metadata”

BACnet XD Solves Several Problems

How do you represent "as built" BACnet device configurations?

How do you represent "profiles" in BACnet objects?

How do you collect together various objects for specific applications?

BACnet XD

BACnet XD Device Descriptions(Addendum 135-2012ba, in 135-2016)

- New Profile_Location property in allBACnet objects

- Device description machine readable via XML

- Includes Devices, Objects and Properties

- Located in Device itself, or on some server

BACnet Objects

“BACnet XD”

XDD File

Profile_Name

Profile_Location

BACnet XD

Tags in BACnet Objects(Specified in 135-2016)

- New 'Tags' property for Semantic / Value Tags in eachobject type

- New 'Subordinate Tags' property for Semantic Tags of subordinates in Structured View object

- Arbitrary / mix of dictionaries possible

BACnet

Object

Tags

BACnet

Object

Tags

Structured View

Tags

Subordinate Tags

Subordinate Tags

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Tags can be useful for both machine-to-machine and human-to-

machine communication:

• Presentation and Visualization of data

• Reporting of status and functioning

• Grouping of related data

• Analysis and Operational Decision Making

Each of these functions is likely to have a huge impact on the

building automation systems of the future, especially when the

"Internet of Things" (IoT) takes off and the number of available data

points grows exponentially!

Tag Definition and Implementation

Tag Definition and Implementation

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"Tags" describe the meaning ("semantics") of data. A given object

can have multiple tags. They can be a simple attribute or description

(a "semantic tag")equipment

point

degrees-C

chiller

air-handler

or have values associated with them (a "value tag")

location, “Clark Hall”

yearInstalled, 2012

assetTagID, 165423

Proposed ASHRAE Standard 223P

“Designation and Classification of Semantic Tags for Building Data”

- The purpose of this standard is to provide a dictionary of uniform semantic tags. These tags enable interoperable use of descriptive information on building data.

- SSPC 135 will create initial draft

Proposed Standard

BACnet/WS

BACnet RESTful Web Services

- REST style API to BACS Information- Secure via HTTPS and OAuth 2.0- Full access to BACnet XD Data and Metadata- Full discovery of Data and Metadata- Event and Change-Of-Value Subscriptions- Queries and Filters- "Localized" data, i.e., support for multiple

languages- XML, JSON or Plain Text Representation Formats

{ "$base":"Composition","$nodeType":"equipment","$displayName":"Example Co. Air Handler, Single Duct with AC2 Mixed","Mixed_Air_Temp": {

"$base":"Real", "$variability":"status","$displayName":"Mixed Air Temperature", "$units":"degrees-Fahrenheit"

},"Min_Outside_Air": {

"$base":"Real", "$units":"percent", "$writable":true,"$variability":"config” },

}

<?xml version='1.0' encoding='utf-8'?><Composition xmlns="http://bacnet.org/csml/1.2"

nodeType="equipment" displayName="Example Co. Air Handler, Single Duct with AC2

Mixed" ><Real name="mixed-air-temp"

variability="status" displayName="Mixed Air Temperature" units="degrees-Fahrenheit"/>

<Real name="min-outside-air" units="percent"writable="true"variability="config” />

</Composition >

XML

JSON

The Future – 2017-????

Here are some things being worked on:

Improved Integration/Convergence with IT Networks

Smart Grid Implementation in Buildings

Improved Building Intelligence

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To learn more, please consider this book:

To stay current with BACnet developments, please visit:

4914.-18.03.201

WWW.BACNET.ORG

Thanks for your attention!

Questions?