Network Topologies 3-19. 3-20 Free Topology Ring, star or combination layout of network media All...

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