Transcript LonWorks Network Design

3-19
Network Topologies
3-20
Free Topology
• Ring, star or combination
layout of network media
 All except ring are polarity
insensitive
 One terminator installed
anywhere on the segment
• Typical for device channels
• May be difficult to troubleshoot
bad devices
• Installers could possibly exceed
wiring limits
• Simple to expand and add new
devices
T
T
Bus Topology
3-21
• Daisy chain structure with beginning
and end
• Must be terminated at beginning and
end of segment


TP/FT-10 Free Topology terminators
are different from TP/FT-10 Bus
Topology terminators
TP/XF-1250 channels use different
terminators than TP/FT-10 channels
• Compared to Free Topology:



Easier to troubleshoot
Longer cable runs allowed
More difficult to expand and add
new devices
T
T
Backbone Topology
• Connects routers to a common
backbone channel
• Typically installed in a bus
topology and includes routers,
tool network interfaces, and
system wide controllers
• Can be high speed twisted pair
TP/XF-1250 or IP-852 channel
• Reserves bandwidth for network
tools and system control devices
such as web servers, data loggers,
schedulers, alarm generators, etc.
Backbone
3-22
Termination will
depend upon
typology used on
specific segments
13-23
Case Study Exercise:
Identify Network Architectures
Turn to the Laboratory Exercises chapter
of your workbook – this is Laboratory 1

Form a team with one or two fellow
students

Read exercise instructions

Write down your answers

Class review follows in 20 minutes
3-24
Installation Scenarios
3-25
Engineered Design –
Planned Installation Scenario
• Design tool is not attached to the
network devices during design
process
• Tools obtain device information
from the device external interface
file (xif)
• Allows network design to be
completed in parallel with
infrastructure installation
• Verifies device compatibility prior
to purchasing
• Allows distribution of design
workload
2. Program the
network off-site
1. Collect data
about devices
XIF File
XIF File
XIF File
3. Move engineered
database on site
4. Collect information
about physically present
devices
database files
5. Apply database content
to physical network
Installation
Server
3-26
Ad Hoc Installation
• Design tool is attached to the
network devices while the design is
created
• Tools can upload the device
interface information from the
device
 Use this method if XIF file is
not available
• Typical for small networks
• Design should be created while the
tool is OffNet to minimize traffic
consequences from updating device
information
1. Collect information
about physically present
devices
3. Apply database content
to physical network
2. Program the
network on-site
Site
Server
3-27
Matching the Design
with the Physical Network
• The logical device on the design
must match the physical device
installed on the network.
 The network tool first identifies
the network device using the
device’s unique Neuron ID
 Service Pin depression
 Manual entry
 Device discovery
 The match is completed using
the device’s channel and
program ID
database content:
XIF File
XIF File
XIF File
Device 1
Device 2
Channel 1
?
Device 3
3-28
Job Aids
• Guide for Determining
Installation Scenario
• Network Tool Selection
Guide
Selecting a Network Tool
3-29
• Should be based on the user and project’s needs
• Available from many manufacturers
• Tools should include the latest LONMARK resource
files documenting SNVT, SCPT and SFP
• Tools should perform multiple functions




Network design and engineering
Network commissioning and configuration
Network monitoring and control
Network maintenance and documentation
• Must be able to support up to 32,385 devices and
domain addresses of up to six bytes (248)
• While not required for an open system, tools based on
LNS provide


Interoperability and connectivity features
Capability to integrate LONMARK devices
3-30
1.
2.
3.
4.
5.
6.
Summary and Review
Do remote clients include the LNS network database?
No
What has a data server allowing it to communicate directly with devices
through its own network interface?
Fullweight client
What is required by LNS tools to perform network management tasks
The LNS database
Which topology is easier to troubleshoot and allows for longer cable runs?
Bus
Which channel type can take advantage of existing IP infrastructure?
IP-852
How many devices must a network tool be able to support? What size
domain address?
32,385, 248 (six bytes)
Selecting
Infrastructure
Components
Objectives
4-2
• Define the infrastructure components
of a LONWORKS network
• Select network media

Define the metrics and channel
characteristics of channels
• Select appropriate network interfaces
• Select LONWORKS routers and
repeaters

Describe the difference between a
router and a repeater
Identify
Architectures
Select Network
Components
PLAN THE NETWORK
Install Physical
Network
Program
Network
Commission
Network
IMPLEMENT THE NETWORK
Test and Verify
Network
Optimize
Network
TEST AND OPTIMIZE
Document
Network
Maintain
Network
DOCUMENT AND MAINTAIN
Main Infrastructure
Components
4-3
• LONWORKS Devices1
• Communication Channels


Communications media that connect
LONWORKS devices
Path between devices that exhibits
various physical characteristics.
NI
RTR
• Routers1 and Repeaters


Used to build large networks by
connecting channels and segments
Routers also used to transfer data
from one channel type to another
RTR
RPTR
RTR
RTR
• Network Interfaces1


Connect PC to LONWORKS network
Also referred to as LonTalk adapter
or LonTalk interface
1Most
commonly specified components
Physical vs. Logical (1)
4-4
Neuron ID

Unique 48 bit ID embedded into Neuron
Chip
Segment


Section of physical media connected to
router or repeater port
Unpowered TP/FT-10 can support
up to 64 devices
Domain 09E
Channel W
Segment A
RTR
1



4
61
62
63
Subnet 2
Channel X
Channel
Representation of physical media
segment(s).
Connected to other channels via routers
Characterized by device transceiver types
Can consist of two segments linked via
physical layer repeater
3
Backbone
Channel
Segment B
RTR

2
1
2
RPTR
62
Segment C
124
1
Subnet 1
Segment D
1
2
Subnet 4
3
3
Subnet 3
Channel Z
Channel Y
RTR
2
Segment E
RTR
1
2
55
Subnet 5
56
Physical vs. Logical (2)
4-5
Logical addresses are assigned during
commissioning to enable devices to
become active participants on network
Node ID




A logical collection of up to 32,385 devices
(nodes) on one or more channels
Can include up to 255 subnets
Direct communications can only take place
among devices configured in the same
domain
ID can be 1, 3 or 6 bytes (248) long
Subnet



A logical organization of up to 127 devices
Some channels may include more than one
Cannot span configured or learning routers
Example
09E, 2, 63
Domain 09E
Channel W
Segment A
RTR
A logical address assigned to device
Domain

Logical Address
Assigned by NI Tool
Domain, Subnet, Node
1
2
3
4
61
62
63
Subnet 2
Backbone
Channel
Channel X
Segment B
RTR
1
2
RPTR
62
Segment C
124
1
Subnet 1
Segment D
1
2
Subnet 4
3
3
Subnet 3
Channel Z
Channel Y
RTR
2
Segment E
RTR
1
2
55
Subnet 5
56
Possible LONWORKS
Media Types
4-6
• Twisted Pair Cable


LONMARK Guidelines supports
both TP/RS485-39 and TP/FT-10
TP/FT-10: low material cost, reduced
cabling, high stability
• Twisted Pair Cable with Link Power

Power and Communication on single
pair of wires
• Power Line


Reliable communications over
existing power wires
No additional cable or installation
interruption, limited range, 5400 bps
• IP (Internet or Intranet)


High transfer rate
Can use existing IP infrastructure
• Fiber Optic

Highest transfer rate in rough
(noisy) environments over
long distances
• Radio Frequency

Communicate with remote
locations without cabling
• Infrared
• Electric Fencing
4-7
Channel Metrics
• Topology support: free, bus
or other
• Maximum length
• Maximum device count
• Maximum number of
packets/sec
• Cable type: standard or
special
• Termination requirements
• Private or shared media
n
2
1
pkt/s
stub
length
Typical Channel Capacities
100%
No
Collisions
PL-20N
(3.6/5.4
kb/s)
TP/FT-10
(78 kb/s)
TP/XF-1250
and FO-20
(1.25 Mb/s)
~14 pps
~227 pps
~850 pps
84%
Maximum
Throughput
~12 pps
67%
Sustained
Throughput
~9 pps
~153 pps
~576 pps
50%
Design
Guideline
~7 pps
~115 pps
~425 pps
~192 pps
~720 pps
IP-852
(10/100
Mb/s)
PL-20x
TP/FT-10
15,000
pps or
greater
TP/XF-1250
IP-10x
pps: packets per second (average packet = 15 bytes)
IP-852 estimate based on 46 byte minimum payload
4-8
Job Aids
• Common LONWORKS Channel
Types
• Miscellaneous Channel Types
• LONMARK Standard Channel
Types
4-9
LONWORKS Routers
• Connects channels or subnets
to build large networks or
reduce traffic
• Can connect different channel
media types
• Filters or forwards messages
based on Subnet ID or Domain
ID (bridge) to provide network
segmentation
• Can be configured as repeater
to extend channel length
• Can be setup as learning,
configured or bridge
Channel 2 FT-10
Router
Channel 1 IP-852
• Bridge used to isolate packets
within networks that include
multiple network domains
• Learning router automatically
builds its own filter table by
monitoring traffic
4-10
Router and Physical Layer
Repeater Differences
While both provide signal refresh,
LONWORKS Routers…
• Segment or isolate local traffic (primary
function)
• Connect similar or different channel types
• Forward packets based on internal routing
tables of subnet and group addresses
maintained by LNS
• Can be configured as an intelligent repeater
Physical Layer Repeaters…
• Extend channel distance by amplifying signal
• Allows for higher device counts
• Have no filter function and dispatch each
message as received
• Pass all traffic – even noise
• Can lead to channel overload
Device 2
Device 3
Channel 2
Device 1
Router 1
Channel 1
LONMARK Guideline
The total network length and number
of devices may be extended by use
of ANSI/EIA/CEA-709.1 routers,
and/or one TP/FT-10 physical layer
repeater.
Routing Design Guideline
IP-852
IP-852
i.LON
Router
i.LON
Router
FT-10
XF-1250
LPR-12
LPR-12
XF-1250
Poor Design –
Slower channel
between
faster channels
For best performance
always route from
slower to higher
speed channels
FT-10
Improved Design –
Route from slow to fast
Multiple XF-1250
Channel Routing
IP-852
i.LON
Router
IP-852
i.LON
Router
i.LON
Router
XF-1250
XF-1250
LPR-15
Potential
Bottleneck
XF-1250
Poor Design –
LPR-15 throughput
less than single XF1250 channel
XF-1250
Improved Design –
i.LON routes at full
speed of XF-1250
channel
Large System Routing
IP-852
IP-852
i.LON
Router
i.LON
Router
FT-10
MPR-50
LPR-10
XF-1250
(or individual
LPR-12s)
FT-10
LPR-10
FT-10
FT-10
FT-10
LPR-10
FT-10
Poor Design – FT-10
Too many router hops
across slower channels
Improved Design –
Eliminates hops across
slower channels
FT-10
4-14
Network Interfaces
• Connect PC to LonTalk medium
• Also referred to as network adapters and
LonTalk interfaces
• Available in almost any PC form-factor,
transceiver type and bus configuration
• Must support NSI (Network Services
Interface) firmware for LNS applications
• Should support downloadable firmware
images to allow for easy LNS firmware
updates
• IP – virtual network interface (VNI) or
remote network interface (RNI)
 VNI creates a high performance IP-852
network interface with greater throughput
than NSI.
 RNI provides a remote IP network
interface
Network Tool
Which NSI ?
4-15
Connectivity Options
PCI
PCLTA-21:
FT-10, TP-78,
TP-1250, RS-485
PCLTA-20:
TP-1250 SMX
PCMCIA
PCC-10: FT-10, TP-78, TP-1250
EIA-232
STLA-10: FT-10, TP-78, TP-1250, RS-485
i.LON 100
i.LON SmartServer
Modem
FT-10, PL-20
(Modem Option)
USB
U20: PL-20
U10: TPFT-10
i.LON 10
i.LON 600
i.LON 100
i.LON
SmartServer
FT-10, PL-20
FT-10, XF-1250
FT-10, PL-20
FT-10, PL-20
i.LON 600
i.LON 100
i.LON SmartServer
10/100 Ethernet IP/RNI
IP-852 Routing
Modbus IP
(Router Option)
i.LON SmartServer
4-16
1.
2.
3.
4.
5.
Summary and Review
What are the most commonly specified components in a LONWORKS
network?
LonWorks devices, router and network interface
How many devices can a subnet support? How many can an
unpowered TP/\FT-10 segment support?
127, 64
Which channel type can provide the highest transfer rate in noisy
environments over long distances?
Fiber optic
What can segment or isolate local traffic and connect similar or
different channel types?
Routers
True or false: LONMARK Guidelines supports RS485 for use on
twisted pair.
True. RS-485 is supported as TP/RS485-39
Installing the
Physical Network
Objectives
5-2
• Define infrastructure installation tasks
• Select and install channel media



Decide where and when to use terminators for twisted pair
channels
Identify common installation pitfalls
Describe guidelines for installing channel topologies:
• Properly install shielded cable
• Describe device installation guidelines
5-3
Installation Tasks
• Install backbone channel
• Install device channels and
routers
• Install terminators where
needed
• Mount and install devices
• Provide power supplies to
devices
• Connect I/O wiring to devices
Most LONWORKS network problems
can be traced back to an inadequate
installation of cables and devices.
Identify
Architectures
Select Network
Components
PLAN THE NETWORK
Install Physical
Network
Program
Network
Commission
Network
IMPLEMENT THE NETWORK
Test and Verify
Network
Optimize
Network
TEST AND OPTIMIZE
Document
Network
Maintain
Network
DOCUMENT AND MAINTAIN
Cabling Installation
5-4
• Use Echelon tested cable types
• Match cable length limitations to
transceiver type and channel topology
• For link power transceiver devices
(LPT-11), size wire to accommodate
42 VDC voltage drops over distance
• Size distributed power cable to
accommodate voltage drops over
distance
• Avoid magnetic inductive interference
when laying cables




Keep nominal distance from AC cables
Separate from RF and high voltage
sources (low voltage sources okay)
Maintain “twisting” to terminal
Keep away from devices and actuators
that generate strong interference
• Use lightning-current arrestor
needed anytime twisted pair
goes outside building
• Follow local and national
regulatory requirements
5-5
Tested Twisted Pair
Cable Type Limitations
Bus Topology
Free Topology
Max Stub
Max Bus
Length
Max Node-toNode
Max Total
Cable
3 meters
600 meters
250 meters
450 meters
TIA 568A
Category 5
TP/FT-10
3 meters
TP/XF1250
0.3 meters
TP/FT-10
900 meters
TP/XF1250
130 meters
TP/FT-10
250 meters
TP/FT-10
450 meters
Beldon 8471
TP/FT-10
3 meters
TP/FT-10
2700 meters
TP/FT-10
400 meters
TP/FT-10
500 meters
Beldon 85102
TP/FT-10
3 meters
TP/FT-10
2700 meters
TP/FT-10
500 meters
TP/FT-10
500 meters
Level 4/
Level IV
TP/FT-10
3 meters
TP/XF1250
0.3 meters
TP/FT-10
1400 meters
TP/XF1250
130 meters
TP/FT-10
400 meters
TP/FT-10
500 meters
JY (st)
TP/FT-10
3 meters
TP/FT-10
900 meters
TP/FT-10
320 meters
TP/FT-10
500 meters
ISO/IEC
14908-2
Specified
Validated
5-6
Grounding Shielded
Twisted Pair Cable
• When using shielded cable,
terminate shield using the
recommended grounding circuit
• Ground the cable shield at least
once per segment and preferably
at each device
• Grounding the shield at every
device will assist in suppressing
50/60Hz standing waves.
• Communication wires are not
grounded
• Shielded cable not recommended
unless in high EMI environment.
Twisted Pair
Termination Circuit
Ra
Ca
100µF
50Vmin
Cb
100µF
50Vmin
Rb
Cc
Shielded
Twisted Pair
(STP)
Shield
Grounding
Circuit
5-7
Job Aids
• Cabling Installation –
Procedures
• Cabling Installation –
Common Pitfalls
• Miscellaneous Infrastructure
Components
5-8
Termination: What is it?
• A termination is a load connected
across the network pair
• Termination absorbs unwanted signal
reflections (resonance of date signal)
which would interfere with
communications causing packet errors
• Free topology uses one terminator
anywhere on segment
• Bus topology uses two terminators
one at each end of segment
• Verify termination for unknown
twisted pair media by checking wiring
impedance using an AC bridge
TP/FT-10 TP/LP-10 TP/LP-11
Channels
100 mF
52.3Ω Free Topology
105Ω Bus Topology
100 mF
Power Line
Channels
0.47 mF
100Ω
TP/XF-78 TP/XF-1250
Channels
59Ω
0.15 mF
340Ω
0.33 mF
102Ω
Device Installation
5-9
• Mount devices as close to I/O as possible
• Where possible, avoid high EMI sources
• Install application specific devices on
application specific channels
• Isolate device to device traffic where
possible

Use routers for each subsystem
• Install fewer than maximum allowed to
provide for future expansion
• Locate system-wide control devices and
network tools on or close to the backbone

Web server devices, trend loggers,
schedulers, etc…
LPT Link Power - Power and
Communication on TP/FT-10
5-10
• LPT Link Power devices draw power from central 42V power supply on
TP/FT-10 channel eliminating need for individual device supplies
• Link power transceiver separates 78 kbps communication and 42 VDC
power to supply +5VDC at up to 100mA to Neuron and I/O applications
• Both link power and locally powered TP/FT-10 devices can be supported on
a given segment, provided that the following constraint is met:
(1 x LPT) + (2 x TP/FT) ≤ 128

TP/FT-10 devices must be designed to ISO/IEC 14908-2 (ANSI/CEA709.3) which specifies appropriate blocking capacitors
• Considerations




The sum of the application current of all the devices in a segment must not
exceed 3.2A on 5V supply.
Voltage at LPT supply typically 41.0 to 42.4V
Voltage at end of cable must not be less than 26V - LPT transceiver lower limit
Actual number of devices on segment depends upon cable length and current
 Example: 500 meter Beldon 8471 and 85102 support 128 evenly distributed
LPT devices at 25mA, 64 at 50mA or 32 at 100mA
Job Aids
• Junction Box and Wiring
Guideline for Twisted Pair
LONWORKS Networks
• FTT-10A Free Topology
Transceiver User's Guide
• LPT-10 and LPT-11 Link
Power Transceiver User’s
Guides
These job aids are on your student CD.
Most recent versions on the Echelon Web site.
5-12
1.
2.
3.
4.
5.
6.
Summary and Review
What can most LONWORKS network problems be traced back to?
Inadequate installation of cables and devices
How can you avoid magnetic inductive interference when laying cables?
Keep nominal distance from AC cables .
Separate from RF and high voltage sources.
What must be used anytime twisted pair cable goes outside of a building?
Lightning-current arrestor
How many terminators are required on a twisted pair free topology segment?
Bus topology? Where should they be installed?
Free: One, anywhere on segment. Bus: Two, one at each end of segment.
How many non-link powered devices can be added to a segment which already
has 56 link-powered devices?
36 (128 – 56) / 2
Where and how should shielded cable be grounded?
At minimum once per segment, preferably at each device
5-13
Exercise: Selecting and Installing
Infrastructure Components
Turn to the Lab 2 in the Laboratory
Exercises chapter of your workbook

Form a team with one or two fellow
students

Read exercise instructions

Find answers

Lab discussion and class review
follows in 20 minutes
Review
• Describe the principles of LONWORKS networks
• Select network architectures and design strategies
• Determine installation and maintenance scenarios
• Select channel types, infrastructure devices, application
devices
• Install the physical network infrastructure
Lab 1, Case Study 1
L1-1
HMI
Tool
NM Tool
PSTN
NM Tool
NSI
Mode
m
SLTA10