Mike Newman's - father of BACnet presentation at BACnet User group New England in November. BACnet at Cornell: 20+ Years of Lessons Learned

1. BACnet @ Cornell:
20+ Years of
Lessons Learned

3. 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…

4. 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!

5. There were, of course, many
struggles...
BACnet
Committee

6. Twenty-Two Years of Evolution –
1995-2017
 What the BACnet standard was –
and is...

7. Only standard protocol
specifically for buildings.
=
A Data Communication Protocol
for Building Automation and
Control networks

10. Protocol rules apply to:
• Messages and their format
• Networking options
(LANs, WANs, Dial-up, etc.)
• Joining networks together
to form "internetworks"

11. A Protocol's Two Main Parts
Transport
Application
Message

12. 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).

13. Objects
Objects represent physical inputs,
outputs and software processes
72
IF temp>72 THEN

14. Objects
Each 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

15. Objects
BACnet-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

16. DEVICE
LOOP
BI AI AO
SCHEDULE
BACnet Device
GROUP
BO
AV

17. Messages
• Object Access Services
• Alarm and Event Services
• File Access Services
• Remote Device Management Services
• Miscellaneous

18. 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

19. 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

20. BACnet LAN - Ethernet
BACnet
Field
Panel
BACnet
Workstation
Vendor A
Sensors and Actuators
Vendor C
Vendor C
BACnet LAN - ARCNET
Sensors and Actuators
Ethernet to
ARCNET
Router
Vendor B
Vendor 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

21. BACnet LAN - Ethernet, ARCNET, MS/TP, LonTalk 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

22. BACnet, of course, also
works with the Internet

23. BBMD
BACnet
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)

24. BBMD
BACnet
Device
IP
Router
Internet
BBMD
BACnet
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)

25. BACnet/IPv6
BACnet over IPv6
(In BACnet-2016)

26. Object Model
Messages
Transport Options
+
+
In summary,
=

27. Diagnostic Lab North
Langmuir
Liddell
Marmota
Ornithology Lab
Arthropod
Baker Institute
CISER
EHOB
Schwardt Lab
Small Animal Holding
226 BACS Facilities
Rowing Center

28. 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
14,652
501

30. Lessons Learned
• Plan! Create site standards.
• Document them!
• Implement them!
• Monitor constantly!
• Enforce your standards!

31. #1: BACnet Network Numbers
Network #'s are 16-bit, i.e., 0-65535
Cornell's are based on a "Facility Code":
0000-0999 Open
1000-1999 Statutory Facilities
2000-2999 Endowed Facilities
3000-3999 Housing and Dining Facilities
4000-4999 Off-Campus Facilities
5000-5999 Utilities
Some facilities have a facility code with an alphabetic suffix to denote wings,
related structures, etc. The suffix will be ignored. Network numbers for
facility codes above 4193 will be assigned in the range 0000-0999.

32. #1: BACnet Network Numbers
Cornell's network numbers are formed as follows:
Network Number = "FFFFN" where
FFFF = Facility Code
N = 0-9 This allows up to 10 networks per facility or building
N = 0 will generally be assigned to a facility's BACnet Ethernet LAN.
Normally, this network is connected to the campus backbone. The
additional N-numbers will be assigned to any ARCNET, MS/TP or other
networks as required.
The Contractor shall contact BACSI for assignment, or confirmation,
of the Network Number(s) to be used prior to beginning device
configuration!

33. #2: Device Instance Numbering
DIN's are 22-bit, i.e., 0-4194302 (4194303 = wildcard)
Cornell's uses:
Network Number = "FFFFNDD" where
FFFF = Facility Code
N = 0-9 This allows up to 10 networks per facility or building
DD = 00 – 99 Allows up to 100 devices per network
This works well until we reach a facility code above 4194. At that point we have
to start stealing numbers from our "Open" category.

34. #3: Object Naming
So far, there is no agreed-upon standard!
At Cornell we use:
Facility.[sub-facility|location].device-
type[/point]
Examples:
HSB.FirstFloor.LGR25
HSB.FirstFloor.LGR25/RH
Olin-Hall.Rm131.IAQ-300/CO2_PPM

35. #4: Alarming
• Determine what is to be alarmed and its
priority
• Determine alarm destination(s) (Notification
Classes)
• Specify the content and format of the alarm
messages that will be delivered

36. #5: Change of Value Processing
• Specify COV increments for various kinds of
input data such as temperatures, air flows,
pressures, etc.
• COV increments should be writable using
BACnet services

37. #6: Time Synchronization
• If BACnet scheduling will be used, provide
for a "Time Master"

38. #7: Determine Site-Specific Command Priorities
"Prioritization" of commands from various control processes,
e.g., start-stop commands or setpoint changes, make it is
predictable which command will be carried out.
Priority Level Application Priority Level Application
1 Manual-Life Safety 9 Available
2 Automatic-Life Safety 10 Available
3 Available 11 Available
4 Available 12 Available
5 Critical Equipment Control 13 Available
6 Minimum On/Off 14 Available
7 Available 15 Available
8 Manual Operator 16 Available

39. #8: Determine Site-Specific Alarm/Event Priorities
Message Group Priority Range Network
Priority
Brief Description
Life Safety 0 - 31 Life Safety Message
Notifications related to an immediate threat to
life, safety or health such as fire detection or
armed robbery
Property Safety 32 - 63 Life Safety Message
Notifications related as an immediate threat to
property such as forced entry
Supervisory 64 - 95 Critical Equipment Message Notifications related to improper operation,
monitoring failure (particularly of Life Safety or
Property Safety monitoring), or monetary loss
Trouble 96 - 127 Critical Equipment Message
Notifications related to communication failure
(particularly of Life Safety or Property Safety
equipment)
Miscellaneous Higher Priority
Alarm and Events 128 - 191 Urgent Message
Higher-level notifications related to occupant
discomfort, normal operation, normal
monitoring, or return to normal
Miscellaneous Lower Priority
Alarm and Events 192 - 255 Normal Message
Lower-level notification related to occupant
discomfort, normal operation, normal
monitoring, or return to normal

40. #9: Object-Specific Specifications
• BI, BO, BV
• Inactive_Text, Active_Text
• Feedback_Value,Minimum On/Off times
• Change_Of_State_Time,
Change_Of_State_Count, and
Time_Of_State_Count_Reset

41. #10: Object-Specific Specifications
• MSI, MSO, MSV
• State_Text for all values
• Feedback_Value for MSO

42. #11: Object-Specific Specifications
• Calendar
• Provide the dates, date ranges, holidays,
vacations, special events, etc.
• Schedule
• Determine which systems are to be
scheduled

43. The Key to Success
• Monitor the Network!
• BI - Visual Test Shell
• Chipkin - BACnet Explorer
• Cimetrics - BAS-o-matic, Explorer
• Optigo - Visual BACnet
• Polarsoft - BACtrace, BACbeat
• Wireshark

44. Signs of Trouble
• Unanswered Who-Is messages
• Unanswered Who-Is-Router-To-Network
messages
• COV storms
• Unnecessary, frequently repeated Global
Broadcasts, e.g., I-Am messages

45. Consider Your Own Junk Yard Dog!

46. 14.-18.03.201646
To learn more, please consider this book:

47. To stay current with BACnet developments,
please visit:
4714.-
WWW.BACNET.ORG
Thanks for your attention!

48. Questions?