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Network Topologies
3-19
3-20 Free Topology
• Ring, star or combination layout of network mediaà All except ring are polarity
insensitiveà 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
3-21 Bus Topology
• Daisy chain structure with beginning and end
• Must be terminated at beginning and end of segmentà TP/FT-10 Free Topology terminators
are different from TP/FT-10 Bus Topology terminators
à TP/XF-1250 channels use different terminators than TP/FT-10 channels
• Compared to Free Topology:à Easier to troubleshootà Longer cable runs allowedà More difficult to expand and add
new devices
T
T
3-22 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.
Ba
ck
bo
ne
Termination will depend upon
typology used on specific segments
Case Study Exercise:Identify Network Architectures
Turn to the Laboratory Exercises chapter of your workbook – this is Laboratory 1
à Form a team with one or two fellow students
à Read exercise instructionsà Write down your answersà Class review follows in 20 minutes
13-23
Installation Scenarios
3-24
3-25Engineered 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
4. Collect informationabout physically present
devices
5. Apply database contentto physical netw ork
2. Program thenetw ork off-site1. Collect data
about devices
3. Move engineereddatabase on site
XIF F ile
X IF F ile
X IF F ile
database files
Insta lla tionServer
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 deviceà 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 informationabout physically present
devices
3. Apply database contentto physical netw ork
2. Program thenetw ork on-site
SiteServer
3-27Matching the Design with the Physical Network
• The logical device on the design must match the physical device installed on the network. à The network tool first identifies
the network device using the device’s unique Neuron ID Service Pin depression Manual entry Device discovery
à The match is completed using the device’s channel and program ID
database content:
XIF F ile
X IF F ile
X IF F ile
C hannel 1
D evice 1 D evice 2 D evice 3
?
Job Aids
• Guide for Determining Installation Scenario
• Network Tool Selection Guide
3-28
3-29 Selecting a Network Tool
• 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
à Network design and engineeringà Network commissioning and configurationà Network monitoring and controlà 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 à Interoperability and connectivity featuresà Capability to integrate LONMARK devices
3-30 Summary and Review
1. Do remote clients include the LNS network database? No
2. What has a data server allowing it to communicate directly with devices through its own network interface?
Fullweight client3. What is required by LNS tools to perform network management tasks
The LNS database4. Which topology is easier to troubleshoot and allows for longer cable runs?
Bus5. Which channel type can take advantage of existing IP infrastructure?
IP-8526. How many devices must a network tool be able to support? What size
domain address?32,385, 248 (six bytes)
Selecting Infrastructure Components
4-2 Objectives
• Define the infrastructure components of a LONWORKS network
• Select network mediaà Define the metrics and channel
characteristics of channels• Select appropriate network interfaces• Select LONWORKS routers and
repeatersà Describe the difference between a
router and a repeater
IMPLEMENT THE NETWORK
IdentifyArchitectures
Select NetworkComponents
Install PhysicalNetwork
ProgramNetwork
CommissionNetwork
Test and VerifyNetwork
OptimizeNetwork
DocumentNetwork
MaintainNetwork
DOCUMENT AND MAINTAIN
PLAN THE NETWORK
TEST AND OPTIMIZE
Main Infrastructure Components
• LONWORKS Devices1
• Communication Channelsà Communications media that connect
LONWORKS devices à Path between devices that exhibits
various physical characteristics. • Routers1 and Repeaters
à Used to build large networks by connecting channels and segments
à Routers also used to transfer data from one channel type to another
• Network Interfaces1
à Connect PC to LONWORKS networkà Also referred to as LonTalk adapter
or LonTalk interface1Most commonly specified components
RTRRTR
RPTRRTR
RTR
NI
4-3
4-4 Physical vs. Logical (1)
Neuron IDà Unique 48 bit ID embedded into Neuron
Chip
Segmentà Section of physical media connected to
router or repeater portà Unpowered TP/FT-10 can support
up to 64 devices
Channelà Representation of physical media
segment(s).à Connected to other channels via routersà Characterized by device transceiver types
à Can consist of two segments linked via physical layer repeater
BackboneChannel
Domain 09E
2 551 2 3
Segment DRTR
1 56
Subnet 5
Channel Y
Segment E
Channel Z
Subnet 4
RTR
1 21 2 62
Segment B Segment CRPTR
124 3
Subnet 1
Channel X
RTR
Segment A
Channel W
Subnet 2
1 2 3 4 61 62 63
RTR
Subnet 3
4-5 Physical vs. Logical (2)
Logical addresses are assigned during commissioning to enable devices to become active participants on network
Node IDà A logical address assigned to device
Domainà A logical collection of up to 32,385 devices
(nodes) on one or more channelsà Can include up to 255 subnetsà Direct communications can only take place
among devices configured in the same domain
à ID can be 1, 3 or 6 bytes (248) long
Subnetà A logical organization of up to 127 devicesà Some channels may include more than oneà Cannot span configured or learning routers
BackboneChannel
Domain 09E
2 551 2 3
Segment DRTR
1 56
Subnet 5
Channel Y
Segment E
Channel Z
Subnet 4
RTR
1 21 2 62
Segment B Segment CRPTR
124 3
Subnet 1
Channel X
RTR
Segment A
Channel W
Subnet 2
1 2 3 4 61 62 63
RTR
Logical AddressAssigned by NI ToolDomain, Subnet, Node
Example09E, 2, 63
Subnet 3
Possible LONWORKS Media Types
• Twisted Pair Cableà LONMARK Guidelines supports
both TP/RS485-39 and TP/FT-10à TP/FT-10: low material cost, reduced
cabling, high stability• Twisted Pair Cable with Link Power
à Power and Communication on single pair of wires
• Power Lineà Reliable communications over
existing power wiresà No additional cable or installation
interruption, limited range, 5400 bps• IP (Internet or Intranet)
à High transfer rateà Can use existing IP infrastructure
4-6
• Fiber Opticà Highest transfer rate in rough
(noisy) environments over long distances
• Radio Frequencyà 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
max length pkt/s
1
2 stublength
n m
in node
distance
max node count
max node-to-node
distance
Typical Channel Capacities
TP/FT-10
TP/XF-1250
PL-20x
IP-10x
PL-20N(3.6/5.4
kb/s)TP/FT-10(78 kb/s)
TP/XF-1250 and FO-20(1.25 Mb/s)
IP-852(10/100 Mb/s)
100%No
Collisions~14 pps ~227 pps ~850 pps
84%Maximum
Throughput~12 pps ~192 pps ~720 pps
15,000 pps or greater
67%Sustained
Throughput~9 pps ~153 pps ~576 pps
50%Design
Guideline~7 pps ~115 pps ~425 pps
pps: packets per second (average packet = 15 bytes)
IP-852 estimate based on 46 byte minimum payload
Job Aids
• Common LONWORKS Channel Types
• Miscellaneous Channel Types• LONMARK Standard Channel
Types
4-8
• 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
LONWORKS Routers
Channel 2 FT-10
Channel 1 IP-852
Router
4-9
• Bridge used to isolate packets within networks that include multiple network domains
• Learning router automatically builds its own filter table by monitoring traffic
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
R outer 1
C hanne l 1
C hanne l 2
D evice 2
D evice 1
D evice 3
LONMARK GuidelineThe 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.
4-10
IP-852
LPR-12LPR-12
i.LONRouteri.LONRouter
FT-10FT-10
XF-1250XF-1250
Routing Design Guideline
Improved Design – Route from slow to fast
IP-852
LPR-12LPR-12
i.LONRouteri.LONRouter
Poor Design – Slower channel
between faster channels
FT-10FT-10
XF-1250XF-1250For best performance
always route from slower to higher speed channels
Poor Design – LPR-15 throughput less than single XF-
1250 channel
Multiple XF-1250 Channel Routing
IP-852
LPR-15LPR-15
i.LONRouteri.LONRouter
XF-1250XF-1250
XF-1250XF-1250
PotentialBottleneckPotential
Bottleneck XF-1250XF-1250
i.LONRouteri.LONRouter
i.LONRouteri.LONRouter
XF-1250XF-1250
Improved Design – i.LON routes at full speed of XF-1250
channel
IP-852
Large System Routing
Poor Design – Too many router hops across slower channels
FT-10
IP-852
FT-10
FT-10
FT-10 Improved Design – Eliminates hops across
slower channels
IP-852
LPR-10LPR-10
LPR-10LPR-10
LPR-10LPR-10
(or individual LPR-12s)
(or individual LPR-12s)
FT-10
MPR-50MPR-50
FT-10
FT-10
XF-1250XF-1250
i.LONRouteri.LONRouter
i.LONRouteri.LONRouter
FT-10
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)à VNI creates a high performance IP-852
network interface with greater throughput than NSI.
à RNI provides a remote IP network interface
Which NSI ?
Network Tool
4-14
Connectivity Options
PCC-10: FT-10, TP-78, TP-1250
STLA-10: FT-10, TP-78, TP-1250, RS-485
FT-10, XF-1250
i.LON 100
FT-10, PL-20
FT-10, PL-20(Modem Option)
U20: PL-20U10: TPFT-10
i.LON 100
i.LON 10
(Router Option)
i.LON 600
i.LON SmartServer
i.LON SmartServer
FT-10, PL-20
PCLTA-20:TP-1250 SMX
PCLTA-21: FT-10, TP-78,
TP-1250, RS-485
FT-10, PL-20
i.LON 100i.LON 600 i.LON SmartServer
i.LON SmartServer
Modem
PCI
PCMCIA
EIA-232
IP-852 Routing
10/100 Ethernet IP/RNI
USB
Modbus IP
4-15
4-16 Summary and Review
1. What are the most commonly specified components in a LONWORKS network?
LonWorks devices, router and network interface2. How many devices can a subnet support? How many can an
unpowered TP/\FT-10 segment support?127, 64
3. Which channel type can provide the highest transfer rate in noisy environments over long distances?
Fiber optic4. What can segment or isolate local traffic and connect similar or
different channel types? Routers
5. True or false: LONMARK Guidelines supports RS485 for use on twisted pair.
True. RS-485 is supported as TP/RS485-39
Installing thePhysical Network
5-2 Objectives
• Define infrastructure installation tasks• Select and install channel media
à Decide where and when to use terminators for twisted pair channels
à Identify common installation pitfallsà Describe guidelines for installing channel topologies:
• Properly install shielded cable• Describe device installation guidelines
5-3
IMPLEMENT THE NETWORK
IdentifyArchitectures
Select NetworkComponents
Install PhysicalNetwork
ProgramNetwork
CommissionNetwork
Test and VerifyNetwork
OptimizeNetwork
DocumentNetwork
MaintainNetwork
DOCUMENT AND MAINTAIN
PLAN THE NETWORK
TEST AND OPTIMIZE
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.
5-4 Cabling Installation
• 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
à Keep nominal distance from AC cables à Separate from RF and high voltage
sources (low voltage sources okay) à Maintain “twisting” to terminalà 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
Tested Twisted Pair Cable Type Limitations
5-5
Bus Topology Free Topology
Max Stub Max Bus Length
Max Node-to-Node
Max Total Cable
ISO/IEC 14908-2 3 meters 600 meters 250 meters 450 meters Specified
TIA 568A Category 5
TP/FT-103 meters
TP/XF12500.3 meters
TP/FT-10900 metersTP/XF1250130 meters
TP/FT-10250 meters
TP/FT-10450 meters
Validated
Beldon 8471 TP/FT-103 meters
TP/FT-102700 meters
TP/FT-10400 meters
TP/FT-10500 meters
Beldon 85102 TP/FT-103 meters
TP/FT-102700 meters
TP/FT-10500 meters
TP/FT-10500 meters
Level 4/Level IV
TP/FT-103 meters
TP/XF12500.3 meters
TP/FT-101400 metersTP/XF1250130 meters
TP/FT-10400 meters
TP/FT-10500 meters
JY (st) TP/FT-103 meters
TP/FT-10900 meters
TP/FT-10320 meters
TP/FT-10500 meters
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.
ShieldedTwisted Pair
(STP)
Ca100µF
50Vmin
Rb Cc
Cb100µF50Vmin
RaTwisted Pair
Termination Circuit
ShieldGrounding
Circuit
5-6
Job Aids
• Cabling Installation – Procedures
• Cabling Installation – Common Pitfalls
• Miscellaneous Infrastructure Components
5-7
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
100 mF
100 mF
52.3Ω Free Topology105Ω Bus Topology
TP/FT-10 TP/LP-10 TP/LP-11Channels
0.15 mF59Ω
340Ω
102Ω
0.33 mF
TP/XF-78 TP/XF-1250Channels
100Ω
0.47 mF
Power LineChannels
5-9 Device Installation
• 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
possibleà 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 backboneà Web server devices, trend loggers,
schedulers, etc…
LPT Link Power - Power and Communication on TP/FT-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) ≤ 128à TP/FT-10 devices must be designed to ISO/IEC 14908-2 (ANSI/CEA-
709.3) which specifies appropriate blocking capacitors• Considerations
à The sum of the application current of all the devices in a segment must not exceed 3.2A on 5V supply.
à Voltage at LPT supply typically 41.0 to 42.4Và Voltage at end of cable must not be less than 26V - LPT transceiver lower limità 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
5-10
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 Summary and Review
1. What can most LONWORKS network problems be traced back to? Inadequate installation of cables and devices
2. How can you avoid magnetic inductive interference when laying cables? Keep nominal distance from AC cables . Separate from RF and high voltage sources.
3. What must be used anytime twisted pair cable goes outside of a building?Lightning-current arrestor
4. 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.
5. How many non-link powered devices can be added to a segment which already has 56 link-powered devices?36 (128 – 56) / 2
6. Where and how should shielded cable be grounded?At minimum once per segment, preferably at each device
Exercise: Selecting and Installing Infrastructure Components
5-13
Turn to the Lab 2 in the Laboratory Exercises chapter of your workbook
à Form a team with one or two fellow students
à Read exercise instructionsà Find answersà 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 1L1-1
Modem
SLTA-10
PSTN
NM Tool
NSI
HMI ToolNM Tool