Standard Electric Supply Company

1
Welcome!
Standard Electric Supply Company Automation
Express March 13, 2003 Dan Blome, Senior
Applications Engineer
2
Todays Agenda

• Wireless benefits
• Wireless technology
• Spread spectrum technology
• Spread spectrum in industrial environments
• Industrial wireless applications

3
Benefits of Wireless

• Reduced installation costs
• Install quickly with no wires, conduit or
  drilling
• Real-time access to remote, difficult to reach,
  and / or mobile data
• Reduced operation costs
• Reduced personnel costs
• Eliminates leased line or wireless service fees
• Flexibility to easily reconfigure or scale
  networks

4
Traditional Cabling Costs

• Wire/conduit installation cost
• 30 to 100 per foot to install (material
  labor)
• Repeaters add cost to wiring longer routing
  distances
• Cost to rewire as requirements change
• Time value of money costs
• Lead time for cable / fiber
• Lead time for electrician installation
• Lost production while equipment is idle

5
Traditional Cabling Costs

• Cost of wiring problems
• Typically caused by wiring or connectors, not
  failed hubs, routers, or switches
• Machine down time -gt reduced plant effectiveness
• Troubleshooting/repair costs
• Cost of inflexibility
• When equipment is moved, typically requires
  rewiring
• Costly to test/implement improved production line
  layouts

6
Wireless Costs - 1

• Wireless installation costs
• Industrial quality wireless radios are 1250
  per node
• Antennas cost from 0 to 350, depending on
  antenna gain
• Repeaters may be necessary if obstructions, but
  can be also used as remotes
• Installation costs minimal
• Site surveys may be useful for large
  installations where obstructions might limit
  performance or for a mobile application

7
Wireless vs. Wiring Installation Costs - Example
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Wireless Cost Savings

• Wireless cost savings increase with distance and
  number of nodes

9
Wireless Solutions Where Cable is Difficult to
Install

• Revolving table - noise from slip ring contacts
  make communications difficult
• Remote sensors for solid, liquid and slurry
  storage vessels

10
Wireless Solutions for Mobile Applications

• Analog and discrete data communications to mobile
  carts or charging systems can be simplified
• Greater flexibility and faster change over time

Wireless modems with hazardous location ratings
simplify hardware Allows remote PLC programming
or uploading of new set point parameters
11
Wireless Data Technology

• Licensed radio
• Narrow band UHF, VHF
• Cellular technology
• Cellular digital packet data (CDPD)
• 3G cellular
• Spread spectrum
• 802.11 wireless LAN
• Industrial wireless radios
• Bluetooth

12
Wireless Data Comparison -1
13
Data Rate vs. Distance

• Distance for outdoor line-of-sight with high gain
  antennas

14
Wireless CommunicationsData Rate vs. Coverage
Area
Industrial Wireless
15
Example Long-Range Network
) ) ) 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 ( ( (
) ) ) 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 ( ( (
) ) ) 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 ( ( (
) ) ) 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 ( ( (
) ) ) 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 ( ( (
) ) ) 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 ( ( (
12.5 Miles
OS2400 Remote Radio
OS2400 Master Radio
AMFAM
LOCUS
American Family Insurance
Locus Inc.
16
Spread Spectrum Background

• Developed by the US Military in WWII
• A transmitted signal is spread over a wide
  frequency band
• The benefits of spreading the signal are
• 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

17
Spread Spectrum Rules

• FCC Part 15 rules specify unlicensed use of
  spread spectrum devices in the 900MHz, 2.4 GHz
  and 5.8 GHz bands for industrial, scientific and
  medical (ISM) purposes
• One watt maximum transmit power in US
• Radio waves propagate at the speed of light

18
Spread Spectrum Frequencies

• 900 MHz vs. 2.4 GHz ISM bands
• 2.4GHz offers 3X bandwidth
• 902MHz - 928MHz 26 MHz Bandwidth
• 2.400GHz - 2.4835GHz 83.5 MHz Bandwidth
• Out-of-band interference is more common at 900MHz
  than at 2.4GHz
• The advanced paging and messaging services are
  licensed at 930 MHz w/ 3500 Watts transmit power.
  Transmitters are widely distributed
• Significant signal loss in the ISM 900MHz
  receiver due to saturation of the input receiver

19
Spread Spectrum- International Regulations

• Unlicensed 900MHZ radios are not allowed to
  operate in Europe and many other countries
• 2.4 GHz radios can be used license-free
  throughout most of the world
• Must be type approved in each country
• EU now has harmonized standards - CE
• Output power limited to 100 mW in EU and Japan
• Frequency ranges can vary slightly by country
• Use of 2.4 GHz allows extension of automation
  projects proven in the US to plants in other
  countries

20
Worldwide Unlicensed Rules
21
Frequency Hopping vs. Direct Sequence Spread
Spectrum -1

• Direct Sequence (DSSS)
• Continuously spreads data over a wide portion of
  the frequency band
• In a high noise environment, data reliability is
  dependent on the signal-to-noise ratio

• There are limits to the strength of an
  interferer within the DSSS bandwidth and can be
  rejected
• If the interferer is too strong, all
  communication will be lost until the interferer
  is gone

22
Frequency Hopping vs. Direct Sequence Spread
Spectrum - 2

• Frequency Hopping (FHSS)
• Breaks incoming data into smaller individual
  packets and transmits them on separate
  frequencies
• If a packet is not sent successfully on a given
  frequency, it is re-sent on a another frequency
• By re-sending data that was corrupted, the method
  becomes inherently reliable
• Receiver recompiles packets into original form
• No matter how strong the interferer is the FHSS
  system will continue to communicate

23
Using Spread Spectrum in an Industrial Environment

• Antenna diversity to increase signal strength in
  noisy environments
• Repeater functionality to increase distance
• Immune to high interference environments

24
Antenna Diversity Increases Signal Strength

• Signals from multiple paths can cancel each
  other out - this is called fading
• Spread spectrum alone does not insure immunity to
  fading
• Moving the antenna 1/4? or automatic antenna
  diversity will correct the fading

25
Use Repeaters to Increase Distance Bypass
Obstructions

• Store/forward repeater to extend the network
  range
• Resolve line-of-sight issues i.e. hills,
  buildings, or other potential obstructions that
  restrict line-of sight
• Use to avoid in-building obstructions
• Illustration represents a network that would
  require repeaters

26
Repeater Illustration
27
Industrial Wireless Applications

• Industrial Automation
• Remote Lighting Systems
• Mobile stadium lights are currently controlled by
  a beacon light for positioning
• Radio modems could replace the beacon system
• Laser Cutting Machines
• There are several cutting heads mounted on a
  machine that are used for cutting sheets of metal
• Each head is fixed to a moving arm
• Remote PLC Controls
• Food Processing Industry

28
Reliable Operation in Weld Shop

• 25,000 sq ft metal building
• numerous metal racks/walls
• and overhead air handling
• each modem interfaced to PLC

• 4 welders work simultaneously
• and 6 arc welds present
• also plasma torch, metal shear,
• and break press

29
Distributed I/O Graphics Packaging

• One of the largest cereal box manufacturers in US
  with 23 plants
• Monitors pressure and temperature on an ink
  chiller system, which cools ink used in the
  printing presses. Ink temperature and flow are
  critical to quality printing

• Wireless solution more cost effective than
  installing 250 cable with a small
  number of I/O points

30
Distributed I/O Graphics Packaging - 2

• Chillers are monitored with temperature and
  pressure sensors
• Sensor data are interfaced to a remote modbus RTU
• Remote RTU is 250 - 300 ft. from the master and
  interfaced to a radio located inside the
  enclosure shown on previous slide
• Master radio communicates using a modbus driver
  within a PC based HMI program (Wonderware)
• Five additional remote sites monitor similar
  processes and report back to same master radio

31
District Energy Hot Water, Steam, and/or Chilled
Water Monitoring
The importance of industrial temperature
ratings Minneapolis Energy Center
downtown Minneapolis installation of OS2400
radios cover 1 square mile area to
monitor building consumption of steam and
chilled water
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Oil Natural Gas Production/Distribution
Sensors on wells, platforms, plants
pipelines Flow, pressure, temperature monitoring
control alarms
33
Water Wastewater Monitoring/Control
Wastewater lift station control Analog level
monitoring/on-off magnetic contactor Pump on/off
controls Alarm systems for high level
conditions Sewage treatment plant
monitoring Fresh water well pump house 4-20 mA AI
for pressure monitoring Discrete I/O for pump
on/off
34
Wireless Benefits in Industrial Applications

• Temperature range
• Shock and vibration
• Hazardous locations
• Input voltage
• Installation, set-up and diagnostics
• Reliability
• Security

35
Security

• System security is an increasingly important
  issue for numerous safety, liability, and
  economic concerns
• Wireless devices (e.g. Bluetooth and 802.11b, or
  Wi-Fi radios) intended for consumer and office
  applications are specifically designed to meet
  open standards and are intended to be easily
  interfaced to other device adhering to that
  standard
• In contrast industrial radios are specifically
  designed to operate in a very secure manner

36
Security - 2

• All 802.11b networks with 40/128 bit WEP
  encryption are vulnerable to attack from programs
  like AirSnort.
• Some nics no longer generate weak key
  combinations
• Passive attack - cannot detect
• AirSnort is a wireless LAN (WLAN) tool which
  recovers encryption keys
• http//airsnort.shmoo.com/
• " Weaknesses in the Key Scheduling Algorithm of
  RC4 " by Scott Fluhrer, Itsik Mantin and Adi
  Shamir
• http//www.securityfocus.com/cgi-bin/library.pl?ca
  t154offset10

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Summary

• Wireless has arrived for numerous industrial and
  process applications because of...
• 1. Cost Advantages
• Costs for industrial grade wireless radios are
  now less than cable for all but the very shortest
  cable runs. Wireless is significantly less
  expensive for communication distances greater
  than 100.

38
Summary - 2
2. Flexibility Radios offer flexibility that no
other technology can provide, for rapid equipment
or plant reconfiguration, outdoor installations
and networking, long distance communications, and
operation in hazardous or difficult site
conditions.
39
Summary - 3
3. Reliability New spread spectrum technologies
and built-in repeater capabilities are extremely
reliable and eliminate line-of- sight concerns
previously associated with higher frequency
radios. These radios can operate license-free
virtually anywhere in the world. A good wireless
radio with repeater capability will work in most
indoor and outdoor applications, even in
electrically noisy conditions.
40
Summary - 4
4. The Future Wireless will improve process,
monitoring, and control offer combined I/O and
radio provide a variety of protocols and offer
integrated Ethernet ...and all will increase
process and manufacturing efficiencies, reduce
costs, and provide for increased integration of
operations.
41
Thank you!

• Locus, Inc.
• 5540 Research Park Drive
• Madison, WI 53711-5377
• 608-270-0500
• www.locusinc.com