1. ANSI/CEA709 (EN14908) Standards August 2006
Vijay Dhingra
04H1122

2. Background Data networks interconnect computers, servers, and printers
Control networks connect sensors, actuators, displays, and other machines to each other, to remote monitoring sites, and to the Internet
All control networks perform a common set of functions: they sense, process, actuate, and communicate
Internet

3. Control Network Technology Requirements
Robust, reliable communications
Peer-to-peer protocol supports multiple media, efficient addressing and authentication
No single point of failure in the control system
Predictable, autonomous applications regardless of network traffic
Open standards based and Interoperable products
Large Ecosystem of cost effective solution
Best of breed products in commercial and home market
Confidence and leverage in a future proof environment

4. Multiple Media Support
Control applications require flexibility in selecting communication medium
Protocol and routing technology that allows multiple media (Mixed as needed within system):
Power line
Twisted pair
Fiber optic RF
Coaxial cable
Infrared IP
Interface with other home networking standards/protocols
With simple application layer bridging

5. LONWORKS Control Networks
Flat Peer-Peer Network Architecture
Eliminate complex cabling
Lower installation and maintenance costs
Eliminate proprietary & closed gateways, and central controllers
Simplify HMI development
Open
Choose interoperable components from multiple vendors
Control networks are more common than you think. For example, your car may have several control networks in, for example, the seat belt warning system, the ABS braking system, or the engine management system. A control network may have 3 devices, or 300, or 30,000, or more, and can range in complexity from a few smart light switches on a timer to a jet passenger airplane (both of which are examples of existing LonWorks networks). It may be a simple alarm controlled by a remote occupancy sensor, or a city's traffic management system, monitoring and controlling signal lights, traffic flow, the actions of emergency vehicles, power distribution, etc. To many people, control networks are most easily understood as smart houses or home automation. However, most control systems in use today are in commercial buildings and factories doing such things as building cars, computer chips or controlling elevators, lights, and security systems.
LonWorks networks are used for all of these and more.

6. ANSI/CEA-709.1-B Control Networking Protocol

7. ANSI/CEA B Protocol
An open standard protocol for control applications
Control applications have different requirements than data applications
TCP/IP is an example of a data networking protocol
Reference document available from Global Engineering
Protocol implementations are available from multiple vendors
Protocol can be ported to any processor
Echelon’s implementation is called the LonTalk® protocol
Echelon’s Neuron® firmware includes the LonTalk protocol
Echelon development systems include a royalty-free unlimited license to use the Neuron firmware implementation

8. ANSI/CEA-709.1 Protocol Layers
Application
Presentation
Session
Transport
Network
Data Link
Physical
Physical Media
ANSI/CEA is layered
As recommended by the International Standards Organization Open Systems Interconnect (ISO OSI) reference model
OSI layers ensure that the required services are provided without unexpected interactions between the services
Device manufacturers only need to change the application

9. ANSI/CEA-709.1 Protocol Layers
OSI Layer
Purpose
Services Provided 7
Application
Application Compatibility
Network Configuration; Network Diagnostics; File Transfer;
Application Configuration, Specification, Diagnostics,
& Management; Alarming; Data Logging; Scheduling;
Time & Date Management 6
Presentation
Data Interpretation
Network Variables; Application Messages;
Foreign Frame Transmission; Standard Types 5
Session
Control
Request-Response; Authentication 4
Transport
End-to-End Reliability
Acknowledged & Unacknowledged Message Delivery;
Duplicate Detection 3
Network
Message Delivery
Unicast & Multicast Addressing; Routers 2
Link
Media Access and Framing
Framing; Data Encoding; CRC Error Checking;
Predictive CSMA; Collision Avoidance;
Priority & Collision Detection 1
Physical
Electrical Interconnect
Media-Specific Interfaces and Modulation Schemes
(twisted pair, power line, radio frequency, coaxial cable, infrared, fiber optic)

10. A Typical ANSI/CEA-709.1 Packet
Layer 2
Header
Layer 3
Address Information
Layer 4
Service Type
Layer 5/ 6
Header
DATA
Layer 2
CRC
2 Bytes
Unsigned
Long
2 Bytes
Network
Variable
Selector
2 Bytes
Service Type ID
Transaction Num
1 Byte
Addr Format, Domain Length
Source Addr (Subnet/Node)
Dest Addr (Group)
Domain ID (Zero Len Domain)
1 Byte
2 Bytes
1 Byte
0 Bytes
Backlog
Priority
Alt Path
1 Byte
12 Bytes

11. Layer 1—Physical Layer Electrical interconnect
Transmission of raw bits over a communication channel

12. Physical Layer—Common Channel Types
Optimize cost and performance for a broad range of control applications
Name
Media
Bit Rate
Definition
Standard
DC-1250
Direct-Connect Twisted Pair
1.25Mbps
Neuron Chip Data Book No
FO-20L
Fiber Optic
ANSI/CEA-709.4
Yes
FO-20S
IP-852
ANSI/CEA-852 IP Tunneling
N/A
ANSI/CEA-852
PL-20A
CENELEC A-band Power Line
2613bps
LONMARK Interoperability Guidelines
PL-20C
CENELEC C-band Power Line w/access protocol
156.3k/3987bps
ANSI/CEA-709.2
PL-20N
CENELEC C-band Power Line w/o access protocol
TP/FT-10
Free Topology Twisted Pair
78.13kbps
ANSI/CEA-709.3
TP/RS485-39
RS-485 Twisted Pair
39.06kbps
EIA/TIA-232-E
TP/XF-1250
Transformer-Isolated Twisted Pair

13. Typical Channel Capacities
PL-20x Channels
PL-20N ~20 packets/sec
PL-20C ~18 packets/sec
PL-20A ~11packets/sec
TP/FT-10 Channel
Peak: ~225 packets/sec
Sustained: ~180 packets/sec
TP/XF-1250 Channel
Peak: ~720 packets/sec
Sustained: ~576 packets/sec
IP-852 Channels
~10,000 packets/sec
Supports aggregation
PL-20x
TP/FT-10
TP/XF-1250
IP-852

14. Physical Layer—TP/FT-10 Channel
Defined by ANSI/CEA A Free-Topology Twisted Pair Channel Specification
Media is free topology twisted pair with optional link power
Supports commonly available unshielded and shielded 0.50mm (24AWG) to 1.3mm (16AWG) twisted pair wires
Polarity insensitive wiring
Reduces installation and maintenance costs
Up to 64 devices on a single network segment
Or 128 devices along with a link power source
Available in cost-effective device-on-a-chip
With all-in-one transceiver, application processor, and memory

15. Physical Layer—TP/FT-10 Link Power
LPT-11
Device
Power and network data carried over a common twisted wire pair
Power is supplied by a common central power supply
No power supplies required in any of the devices in the network when used with the LPT-11 Link Power Transceiver
Supports free topology wiring architecture
LPT-11
Device
48VDC
Power
Supply
LPI-10
Link Power
Interface
LPT-11
Device
LPT-11
Device
LPT-11
Device
LPT-11
Device

16. Physical Layer—PL-20 Channel
Advanced technology for reliable communication
Dual carrier frequency operation
Digital signal processing
Worldwide operation
Meets FCC, Industry Canada, Japan MPT, and European CENELEC EN regulations regulations
ANSI/CEA compliant
European utility support
Dual frequency DSP performance in the A-Band for AMR/DSM applications
Available in cost-effective device-on-a-chip
Transceiver, application processor, memory
Proven technology
Millions of devices installed worldwide
C-Band
115kHz
132kHz
A-Band
75kHz
86kHz

17. Layer 2—Link Layer Media access and framing
Ensures efficient use of a single communications channel
Raw bits of the physical layer are broken up into data frames
Link layer defines when a device can transmit a data frame
Also defines how destination devices receive the data frames and detect transmission errors
Features
CRC error checking
Media access—predictive p-persistent CSMA
Priority
Collision avoidance

18. Link Layer—Media Access
Predictive p-persistent CSMA
Channel access is always randomized over time slots
Number of time slots are varied based on collision avoidance algorithm
16 to 1008 slots
Non-priority Slots
Packet
Busy Channel Packet Cycle

19. Link Layer—Media Access Priority
Packet 1 2 3 n
...
Priority Slots
Busy Channel Packet Cycle
Non-priority Slots
Configurable priority messages
Reserved time slot
Reduces overall channel bandwidth
Priority slot number is assigned at installation time
No collisions possible during priority portion of packet cycle following preceding packet
Highest priority message has predictable response time

20. Link Layer—Media Access Benefits
Linear response time over 99% of channel bandwidth
Critical for open media such as power line
Remove and attach devices without halting communications
Predictable performance for high-priority messages

21. Link Layer—709.1 MAC vs. Ethernet
from: Computer Networks, Andrew S. Tanenbaum, Fourth Edition, 2003.

22. Layer 3—Network Layer Message delivery
How data frames are routed from a source device to one or more destination devices
Physical address
48-bit Neuron ID—used for initial configuration
Logical addresses
Domain Identifies subsystem on open media or large system
Subnet Subset of a domain typically associated with a channel
Node Identifies device within subnet
Group Additional device identifiers independent of subnet 1
SUBNET 1
127 1
SUBNET 2
127 1
SUBNET 3
127
GROUP 1 1
SUBNET 4
127 1
SUBNET 255
127
DOMAIN (32,385 Devices)

23. Network Layer—Addressing Modes
Address Mode
Address Format
Destination
Address Size
(bytes)
Domain-wide Broadcast
Domain (Subnet = 0)
All devices in
the domain 3
Subnet-wide Broadcast
Domain, Subnet
the subnet
Unicast
Domain, Subnet, Node
Specific device
within a subnet 4
Multicast
Domain, Group
the group
Neuron ID
Domain, Neuron-ID 9
Optimize bandwidth with multiple addressing modes
Application communications only requires 3- or 4-byte network addresses
Send messages to many devices using only a single 3-byte network address

24. Network Layer—Capacity
Room to grow from a few devices to millions
18,446,744,073,726,329,086 domains
255 subnets per domain
127 devices per subnet
32,385 devices per domain
256 groups per domain
64 devices per acknowledged group
32,385 devices per unacknowledged group

25. Network Layer—Routers
Domain
Subnet 1
Subnet 2
Subnet 1
...
Channel
Router
Repeater
Group 1
Router
Subnet 5
Subnet 3
Group 1
Router
Repeater
Group 2
Subnet 4
Extend channel segments
Improve reliability
Increase overall bandwidth
Simplify network configuration
Routers are transparent to devices and applications

26. Layer 4—Transport Layer
End-to-end reliability—allows reliable delivery of message packets
Three message delivery services
Acknowledged
Sending device requires acknowledgment from all receiving devices
All acknowledgments are end-to-end
Automatic retries if acknowledgement not received
Repeated
Configurable number of messages per transaction
Conserves bandwidth with large groups
Better response time
Three repeats provides > % probability of delivery
Unacknowledged
One message per transaction
Conserves network bandwidth and provides highest performance
Duplicate detection prevents repeated messages to the application S R
Acknowledged - Unicast R R R S R
Acknowledged - Multicast S R
Repeated- Unicast or Multicast S R
Unacknowledged - Unicast or Multicast

27. Layer 5—Session Layer
Adds control to the data exchanged by the lower layers
Request/response service
Used for device management, fetching values, and requesting other remote actions
Authentication
Verifies identity of message sender… S R R R R S R

28. Session Layer—Authentication
Sender
Authenticated Message
Receiver
64 bit Random Challenge
Key used to transform challenge
Key used to compare response to value transformed locally.
Challenge Response
Acknowledgment
Verifies identity of message sender
Uses a 48-bit secret key known by each device
Sender must provide correct reply to 64-bit random challenge from the receiver

29. Layer 6—Presentation Layer23
Room Temp
Set Point
Temp
Temp Sensor
(Made in USA)
Setpoint Display
(Made in Korea)
Boiler System
(Made in Europe)
Data exchanged using network variables
Propagation automatically handled by Neuron firmware
Provides fastest and most compact code
Devices from different manufacturers can exchange data with a common interpretation

30. Presentation Layer—Connections
Motion
Room Occupied
Feedback
Brightness
Motion Detector
Lamp
0% - 100%
Key Code
Control Knob
Alarm
Intruder
Arm / Disarm
Key Pad
Alarm Bell
Sensors “publish” information, and actuators “subscribe” to information
Devices are logically connected
Connections do not affect device applications

31. Presentation Layer—Standard Types
Standard network variable types
Over 170 standard types defined at types.LONMARK.org
XML definitions available for easy input/translation/interpretation by other systems

32. Presentation Layer—Standard Formatting
Ensures consistent data presentation in tools and HMIs
Example
A SNVT_temp_p value of 2940 is displayed as follows:
29.4 degrees C
84.9 degrees F
52.9 degrees F

33. Layer 7—Application Layer
Defines standard network services that use data exchanged by the lower layers
Network configuration and diagnostics
File transfer
Application configuration, diagnostics, management, and specification
Standard profiles
Alarming
Data logging
Scheduling
More than 60 others

34. Application Layer—Application Configuration
Configuration properties characterize the behavior of a device in the system
Types define data encoding, scaling, units, default value, range, and behavior
Standard configuration property types defined at types.LONMARK.org
XML definitions available for easy input/translation/interpretation by other systems

35. Application Layer—Application Specification
Node Object
Mandatory Network Variables
Configuration Properties
Optional Network Variables
nvoStatus
SNVT_obj_status
nv2
nvoAlarm2
SNVT_alarm_2
nv10
nvoDateResync
SNVT_switch
nv11
nvoAlarm
SNVT_alarm
nv4
nvoFileStat
SNVT_file_status
nv6
nvoFileDirectory
SNVT_address
nv8
nviRequest
SNVT_obj_request
nv1
nviTimeSet
SNVT_time_stamp
nv3
nviDateEvent
SNVT_date_event
nv9
nviFileReq
SNVT_file_req
nv5
nviFilePos
SNVT_file_pos
nv7
nvoLogStat
SNVT_log_status
nv13
nviLogReq
SNVT_log_req
nv12
Mandatory
Optional
Device Major Version
Device Minor Version
Functional Block Major Version
Functional Block Minor Version
Location
Maximum Status Send Time
Minimum Send Time (Send Throttle)
Network Configuration Source
Functional block
Portion of a device’s application that performs a task
Receives configuration and operational data inputs
Processes the data
Sends operational data outputs

36. Application Layer—Standard Profiles