yokogawa corporation of america network solutions business unit an introduction to industrial...

Yokogawa Corporation of AmericaNetwork Solutions Business Unit

An Introductionto

Industrial Wireless Networking

Presented byYokogawa North AmericaNetwork Solutions Business Unit

February 2007

YCA Network Solutions 2007 Business Plan

RF Wireless Industrial Applications


Industrial RF Wireless Technology Applications

Information Layer– HMI, Computer, Database

Server

Control Layer– Recorder, Data

Acquisition I/O, Controller, PLC

Device Layer– Transmitters, Sensors,

Actuators

Device Layer

Control Layer

Information Layer


Technology must support the ApplicationConsiderations– Packet Size– Throughput– Response Time– Network Size

Our Focus– Info & Control Layers– 2.4 GHz– Spread Spectrum

Technology

Industrial RF Wireless Technology Applications

802.11

Proprietary S

S

Bluetooth

Zigbee


Control Layer Communications Protocols

Requirements– More throughput– Faster Response Time– Large Networks– More data

Typical Protocols– Modbus RTU

• RS232, RS422, RS485– Modbus TCP

• Ethernet– Proprietary TCP

• Ethernet– Standard Ethernet

• FTP• SMTP• SNTP• HTTP

Device Layer

Control Layer

Information Layer


Wireless cost savings increase with Wireless cost savings increase with distance & number of nodesdistance & number of nodes

Wireless – A Money Saving Solution

$0

$5,000

$10,000

$15,000

$20,000

$25,000

$30,000

25' 50' 100' 250' 500' 1000'

Wireless - 1st NodeWireless -2nd NodeWireless - 3rd NodeWire $20/ftWire $30/ftWire $50/ft


Wireless for Hazardous Locations

Wiring costs increase for tougher environmentsReduced operator costs– Clean rooms too!

UL Class I Div 2 approved radios


History of Wireless LANs

Wireless Networks were first developed by the MilitaryEventually Moved to Private Sector– High Cost, Low Data Rate and Complexity prevented the

widespread use– Used when other options weren’t possible

ALOHAnet developed at the University of Hawaii, was one of the first private wireless data networksTurning Point - Late 1990s IEEE ratified 802.11B– Data Rates Increased– Hardware Cost & Availability– Performance similar to Wired Ethernet


Radio Frequencies

Radio frequency spectrum is assigned by governments– CB radio: 26.96 - 27.41 MHz– FM radio: 88 - 108 MHz– WiFi for PC’s: 2.4 GHZ

Licensed vs. Unlicensed bands– Licensed provides more power!

Two licensed frequency bands– 400 MHz– 900 MHz

3 unlicensed frequency bands in U.S.– ISM bands (Industrial, Scientific, Medical)– 902-928 MHz– 2.4 to 2.483 GHz– 5.725 to 5.875 GHz (U-NII*)

*Unlicensed National Information Infrastructure


RF Propagation

Higher frequencies have higher data rates (bandwidth)– There is 1000 times more spectrum between 1-2 GHz as there is between

1-2 MHz.

RF waves lose power as they travel in the air– Higher frequencies lose power (attenuate) faster

RF waves attenuate as they pass through objects– Higher frequencies attenuate faster

Lower Frequencies (i.e. 900 MHz have greater distance)


Understanding Power in Radios

• RF transmitter and receiver power is expressed in watts.

• RF power can also be expressed in dBm (decibels relative to milliwatts)

• dBm for RF power is useful when calculating radio system gains (since other gains and losses from cables & Antennas are in dB’s)

The relation between dBm and watts can be expressed as follows:

Power(dBm) = 10 x Log10 Power(mW)

1 Watt = 1000 mW; PdBm = 10 x Log10(1000) = 30 dBm

100 mW; PdBm = 10 x Log10 (100) = 20 dBm

1mW: PdBm = 10 x Log10 (1) = 0 dBm

Power(mW) = 10(Power(dBm)/10)

15 dBm = 10 (15/10) = 10 (1.5) = 32 mW


A Table of mW to dBm


Understanding Gain Measurements

Antenna performance is primarily established by its gain. There are three common references used when defining gain in radios:

Gain referenced to a dipole antennae: dBd

Gain referenced to an isotropic source: dBi

Gain referenced to power in milliwatts: dBm


EIRP (Effective Isotropic Radiated Power)

www.breezecom.com

Take the following example:

transmitter power out = Pout = 50mWcable loss (attenuation) = Ct = 4dBtransmitting antenna gain = Gt = 6 dBi

convert transmitter power from mW to dBm10 x log (50/10) = 17 dBm

EIRP = 17dBm - 4 dBm + 6 dBm = 19 dBm

EIRP is the effective power transmitted from the antenna.

EIRP = (power at transmitter) - (cable attenuation) + antenna gain

EIRP = Pout - Ct - Gt

Pout = output power of transmitter in dBmCt = transmitter cable attenuation in dB

Gt = transmitting antenna gain in dBi


A Quick Comparison: Office vs. Industrial

Power

Distance

OperatingTemp

ConstructionMounting

500 mW

20 miles outdoor

-30 C to 60 C

Aluminum

32 mW

200 feet indoors

0 C to 40 C

Plastic


Performance of 2.4 GHZ vs. 900 MHz

Typical Outdoors with Line of Sight

2.4GHz, 1W plus 6dB gain antennas 5 – 15 miles

900MHz, 1W plus 6dB gain antennas 15 – 25 miles

2.4GHz, 100mW plus 16dB antennas 10 – 40 miles

900MHz, 100mW plus 16dB antennas 20 – 60 miles

Typical Indoors in Congested Environment

2.4GHz, 1W 100 – 600 feet

900MHz, 1W 500 – 5000 feet


Spread Spectrum & IEEE


Introduction to Spread Spectrum

Spread spectrum – a class of modulation techniques that spreads a signal’s power over a wider band of frequencies than is necessary for the information being transmittedBenefits of spreading the signal:– signal is immune to unwanted noise / interference– coding and decoding allow simultaneous transmission

of multiple signals within the same frequency band– provides inherent data encryption / security


Spread Spectrum Introduction - 2

Two main classes:– Frequency Hopping Spread Spectrum

(FHSS) Random Hops to difference frequency. 1 MHZ band. More Secure proprietary interface.

– Direct Sequence Spread Spectrum (DSSS) Hot Spot WIFI 22 MHZ band. 802.11b, 11 Megabit

New modulation technique for higher data rates:– Orthogonal Frequency Division

Multiplexing (OFDM) achieves 54MBPS• 802.11g and 802.11a – Split byte and transmit

pieces simultaneous.


Frequency Hopping Spread Spectrum


Spread Spectrum vs. Narrow Band

Wide bandwidth of spread spectrum make more immune to interference vs. narrow band signal shown in the center of the graph (Older Radios use narrow band)


IEEE Standards “Soup”

IEEE 802.3 specifies wired connection between radios and devicesIEEE 802.11 specifies an over-the-air interface between a wireless LAN client and a base station or between two wireless LAN clients.

802.11a

802.11b

802.11g

Wi-Fi

HomeRF

802.11

HomeRF 2.0Wi-Fi5

Bluetooth


802.11x WLAN “S-p-e-l-l-e-d Out”

802.11– 1 or 2 Mbps transmission in the 2.4 GHz band – frequency hopping spread spectrum (FHSS)

or direct sequence spread spectrum (DSSS)

Wi-Fi– Wireless Ethernet Compatibility Alliance

(WECA) certification for 802.11b devices

802.11b (Current Offering)– 11 Mbps transmission in the 2.4 GHz band– Only DSSS– Vendor access points not compatible


802.11x WLAN “S-p-e-l-l-e-d Out” - 2

802.11a– Up to 54 Mbps in the 5GHz U-NII band– 300 MHz bandwidth indoor, OFDM– Orthogonal frequency division multiplexing (OFDM)– 50m range at 11 Mbps

802.11g– 54 Mbps speed extension of 802.11b in the 2.4 GHz band

with OFDM– Backward compatible with 802.11b for <11 Mbps

Wi-Fi5 (Newer Technology)– Wireless Ethernet Compatibility Alliance (WECA)

certification for 802.11a devices


802.11x WLAN “S-p-e-l-l-e-d Out” - 3

802.11i (Incorporated into WIFI Standard)

– Security Enhancements to 802.11– Encryption & Authentication

• TKIP – Temporal Key Integrity Protocol – interim solution• AES – Advanced Encryption Algorithm – new hardware

– 802.1x Authentication Framework included in 802.11i

• Authentication protocol (EAP-TTLS, LEAP)• Dynamic encryption key distribution method• Supported in Windows XP


802.11b Wireless LAN

2.4 GHz Direct Sequence Spread Spectrum (DSSS)Channels– 11 US, Canada– 13 Europe– 14 Japan

Data rates: 1, 2, 5.5, 11 Mbps (auto)– Signal level can cause lower data rate.

Access points, clients, bridges (Example Hardware)

Other notes:– Vendor Access Points do not generally communicate– 802.11b and 802.11g clients will communicate– 802.11a will not communicate with 802.11b/g


802.11b Channels

1 2 53 4 76 8 13121110961 11


802.11 Access Points, Bridges and Clients

Wired Network

Access Point

Client (Station)

CoverageArea

Access Point – Root Mode Access Point – Repeater Mode

Bridge or Access Point in Bridge Mode Bridge – Repeater Mode

Ad hoc – no AP


Security


Wireless Security

Keep intruders out of your network– Authenticate users

Stop others from “sniffing” your data– Data encryption – proprietary or Wi-Fi

Protected Access (WPA)

Minimize detection of your network– Turn off identifiers in beacon– Appropriate coverage area

Detect “rogue” access points– Wireless network maintenance software


802.11 Wireless SecurityData Encryption 1

WEP (Wired Equivalent Privacy)– RC4 based 40/128/256 bit keys– Key scheduling algorithm weaknesses

Wi-Fi Protected Access (WPA)– Solves weakness in WEPSolves weakness in WEP– Temporal Key Integrity Protocol - TKIP– Message Integrity Checking (MIC)– Extensible Authentication Protocol (EAP) /

RADIUS• Authentication, authorization & accounting system


802.11 Wireless SecurityData Encryption 2

AES (Advanced Encryption System)– 802.11i & new hardware– Symmetric 128 bit block data encryption– Will be supported in a few months.

Other Steps– 802.11 – remove SSID from beacon– MAC ID white list (Limit MAC Addresses)

Must Enable to Be Effective


Wireless Network Planning


Wireless Network Planning Overview

Can this distance be covered?

X kilometers

Radio

Radio

Which antenna cables?

Which antennas? What’s a dBi?

What questions should I ask to qualify the application?

How high do the antennas need to be installed to clear this hill?

Where can / should the antenna go?

What is meant by line of sight and why is the

Fresnel Zone important

How do I get terrain data?

How can I predict link performance? How do

I test it?

What about interference?


Throughput and latency considerations

Throughput– # bits of data x frequency sent

• Add I/Os, PLC messaging, etc.

– Repeater / master must be able to handle sum of remotes

– Radio technology must fit or slow update rate / report by exception

– Similar analysis to specifying PLCs• Throughput will determine update rate• Seconds to poll vs. hours


Radio coverage area


Radio Network Architectures:Point-to-Point

Point-to-point, stationary network easiest to designUse directional antennas on both sides– Maximize signal strength– Minimize noise pickup

Must have line-of-sight between points….but plan ahead if network will be expanded in the future– If Site A will be hub for additional sites, may need an omni or sector

antenna– With less directional antennas, low noise at Site A – test– Can Site A “see” the future sites – or need additional height– Plan for bandwidth too – can radio at Site A handle 100’s of remotes?

Point A Point B


Radio Network Architectures:Point-to-Multipoint

Hub site can be omni-directional or sectorized with multiple directional antennas – e.g. like slice of pie– Use sectors when more bandwidth is needed– Each sector antenna attached to radio on different

hopping pattern or different 802.11b channel– Line-of-site more important – site survey

Hub site

CoverageArea

CoverageAres

Sector 1(Ch. 1)

Sector 2(Ch. 6)

Sector 1(Ch. 11)


Use of Wireless Repeaters

Use repeaters to:– Extend range of the wireless network– Avoid obstacles

For YLinx RLX-FH series– Use of repeater reduces bandwidth by factor of two - but

does not decrease more for additional repeaters– For some radios bandwidth reduced by 1/# repeaters

RLX

RLX

RLX RLX

Link too long for Repeater on top of hill

Repeater on top of hillor on one side to goAround the hill


Information required to design wireless network and select accessories

Minimum information required to design all but the simplest systems– Number of sites today and planned– Location of sites & if indoor / outdoor

• Drawing of building with scale and site locations and structure information• GPS coordinates or location on a drawing / topographic map with

distances between sites to link• If device will move – show track / area where link is required

– Structures where antennas can be placed and any rules on antenna structures (e.g. luxury living areas)

– Protocol of devices to connect– Which devices need to communicate– Data throughput requirements for each node– Country radios will be installed– Any other radio systems in-use if known


Methods to collect application information

Verbal or electronic description of application from customerElectronic drawings of buildingsTopographic maps showing site location and any obstructions or Topo USA type programElectronic path study using digital elevation data and GPS coordinates of sitesSite review – visit site and physically inspect links– If very clear line of sight should not be an issue

– High power strobe light for longer links - but visual LOS only

– Test with RLX IF using same antennas and antenna locations

Complete site survey including RF noise analysis at key points


Handheld Spectrum Analyzer & 802.11 Analyzers


In-Building Site Survey

Building drawingsConstruction materials

– Metal interior walls? – Ceiling height

Equipment / product informationCoverage required

– Fixed vs. mobile– If mobile – where?

Existing wireless infrastructure

– Type / channels

Conduct site survey – walking plant and taking measurements

Signal-to-noise measurements with Ekahau Site Survey Tool


Topographical Maps


Outdoor – Computerized Path Studies

GPS coordinatesDigital terrain dataPaths feasible?Antenna heightRepeaters? LocationPerformance prediction


Example Wireless Outdoor Path

PROSOFT T ECHNOLOGY

RADIOLINX

Aug 05 03 wjg

Northern Digital c /o Semi Valley

Mount McCoyLatitude 34 15 36.00 NLongitude 118 48 22.00 WAzimuth 167.90°Elevation 382 m ASLAntenna CL 32.9 m AGL

WOOD RANCH #2 T ANKLatitude 34 13 32.00 NLongitude 118 47 50.00 WAzimuth 347.91°Elevation 393 m ASLAntenna CL 13.7 m AGL

Frequency (MHz) = 2400.0K = 1.33

%F1 = 60.00

Path length (3.91 km)0 0.5 1.0 1.5 2.0 2.5 3.0 3.5

Ele

va

tio

n (

m)

240

260

280

300

320

340

360

380

400

420

440


Site Survey – The Real World

“Shoot and scoot”– For less involved / shorter range installations

– Bring radios, equipment and test links – if look good, finalize install

Formal site survey– Identification of all potential interference

• Environment & radio – spectrum analysis

– Collection of site data for each potential site• Geographical coordinates including elevation

• Access roads, building code restrictions / solutions

• Installation considerations – site preparation / building access, etc.

• Nearby towers / structures for repeaters– access / rent

• Power availability

– Corroborate path study data with actual field measurements• Signal strength, throughput statistics, etc.

– Identify man-made / tree height obstacles not evident from USGS data

– We can provide site surveys ($1000 per day + plus per diam)


Selecting Antennas & Cables


Antennas – The Basics

Antennas transform electromagnetic signals from transmission lines into electromagnetic waves (& vice-versa)Antennas (most) are passive – focus radio energy not amplify itAntennas work equally well transmitting or receiving RF energyElectromagnetic waves from antennas have an E field and H field components– Polarization describes the orientation of the antennas electric

field


High Quality, Low RF Loss Cables

Remote antenna placement requires lower loss RF cable to maintain system gainCable should be 50 ohm for RadioLinx impedance matchingQuality connectors, weather proofing, lightning protectionPoE and placing radio by antenna

Cable Type dB loss per 100’

@ 2400 MHz RG-316 42

LMR 195 19 LMR 400 6.8 LMR 600 4.4

LMR 1200 2.3 Heliax LDF 4 3.5 Heliax LDF 5 2.0 Heliax LDF 7 1.3


Connector types

Common types– N-type– SMA– TNC– BNC– MMCX (PC card)

Matching connector types– Jack = threads on outside– Plug = threads on inside– So a jack will connect to a

plug (if polarity matches)Polarity– Standard polarity – plug

has inner conductor pin– Reverse polarity – jack has

the inner conductor pin

RP-TNC-MaleRP-TNC-Female

RP-SMA-Female RP-SMA-Male SMA-Female

MMCX-Male

N-Male N-Female-Bulkhead


Configuring & Implementing Wireless Networks


Wireless Network Design Best Practices

Install antennas as high as possibleAvoid high gain omni-directional antennas (Harder to hit the target)Design the system with a margin– 10 dB minimum– 20 dB if anticipate foliage growth

Use industrial routers in-front of wireless industrial Ethernet– Prevents LAN broadcast traffic from using RF

bandwidth


Wireless Network Design Best Practices - 2

Put switch with IGMP snooping in-front of RadioLinx RLX-FH if multicast traffic – e.g. industrial Ethernet I/O messagingAfter installation, test radio network before automation– Verify RF performance– Test throughput before & after automation added– Ethernet use ping or pathping (latter shows latency for

each segment to identify bottlenecks)


RadioLinx Antenna Installation Notes

Avoid attaching antenna too close to buildings, towers, tanks, etc. to avoid reflections– Use side mount kits for at least 50 cm distance

Outdoor installations should be weatherproofed– At each cable splice – At antenna connection

Cable hangers / ties


Maintaining Wireless System Reliability

Changing environment– Inside the company – coordinate wireless networks /

frequency uses– New equipment / infrastructure (metal walls)– Joes’s Neighborhood WISP now on your channel

Monitor performance for – Performance degradation / bottlenecks– Increasing throughput requirements– Increase ping latency– Re-transmit %

Monitor security


Wireless Network Monitoring Tools


Wireless Protocol Analyzer / Security Audit Tools

One differentiator is level of expert analysis to help sort through large number of packetsWildPacket AiroPeek, CommView WiFi, Packetyzer, Ethereal (Linux)


Application Examples


YLinx Frequency Hopping Ethernet (2.4GHz)

• Mobile configuration and data logging without wires!• Frequency hopping 2.4 GHz unlicensed (ISM band)• Not compatible with 802.11 wireless (Wi-Fi)• Designed for industrial environment (-40 to 158 degF)• Up to 16 mile range with line of sight with hi gain antennas• Proprietary radio frequency protocol (158 hopping patterns)• 40 or 128 bit hardware data encryption

$1,581 per radio


YLinx Frequency Hopping Ethernet (2.4 GHz)

DX104

DX104

DX104

YLinx -FHE

YLinx -FHE

YLinx -FHE

YLinx -FHE

RS232 MODBUS

RTUSlave #1

RS232 MODBUS

RTUSlave #2

RS232 MODBUS

RTUSlave #3

10BaseTEthernet

Data from Remote DX100’s is Consolidated in PC

PC running:• DAQStandard (configuration)• DAQLogger• SCADA/HMI with OPC


Product Samples: Ethernet Radio Modems

MDS iNET900ELPRO 905U-D YLinx RadioLinx

2.4 GHz FHSS900 MHz FHSS900 MHz FHSS

SCADALINK LANBRIGDE

900 MHz FHSS


Product Samples: Serial Radio Modems

SCADALINK SM900

900 MHz FHSS

Prosoft RadioLinx

2.4 GHz FHSS

Put serial devices on radio


YLinx Frequency Hopping Serial (2.4GHz)

• Mobile data logging without wires!• Frequency hopping 2.4 GHz unlicensed (ISM band)• Modbus RTU, Modbus ASCII, DF1, generic ASCII• RS232, RS422, or RS485• Flexible set-up modes

• Point to point• Point to multi-point• Peer to peer

• Designed for industrial environment (-40 to 158 degF)• Up to 16 mile range with line of sight with hi gain antennas• Proprietary radio frequency protocol (158 hopping patterns)• 40 or 128 bit hardware data encryption

$1,416 per radio


YLinx Frequency Hopping Serial (2.4 GHz)

DX104

DA100

UT450

YLinx-FHS

YLinx-FHS

YLinx-FHS

YLinx-FHS

DX220RS232

MODBUSRTU

RS232 MODBUS

RTUSlave #1

RS485 MODBUS

RTUSlave #2

RS485 MODBUS

RTUSlave #3

10BaseTEthernet

Data from Remote DX100’s is Consolidated in DX200


YLinx 802.11b Industrial Wireless Radio

• Mobile configuration and data logging without wires!• 802.11b direct sequence spread spectrum radios• Can be implemented with a single radio!• 2.4 GHz unlicensed (ISM band)• Compatible with standard PC wireless cards• Designed for industrial environment• Up to 20 mile range in outdoor settings

$1,755 per radio


UT351 with YLinx 802.11b Hotspot

Laptop with 802.11b“Wi-Fi” wireless ability

Laptop with 802.11b“Wi-Fi” wireless ability


Typical Wireless Network

MX100192.168.20.20

FA-M3 PLC192.168.20.8

Linksys G Wireless Router192.168.20.1

802.11gwireless

802.11bwireless

UT351192.168.30.2

CX1000192.168.30.3

Radiolinx192.168.30.1


Wireless Ethernet Organizations

IEEE WLAN Working Groups– http://grouper.ieee.org/groups/802/11/

WECA www.weca.net Wi-Fi Alliance www.wi-fi.org WLANA www.wlana.com Bluetooth www.bluetooth.org HiperLAN http://www.etsi.org/frameset/home.htm?/technicalactiv/Hiperlan/hiperlan1.htm


Thanks!

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