Distributed Wireless Sensor

Measurements

Mircea Stremtan

Technical Consultant&Sales Manager

National Instruments Romania

2

Wireless Is Everywhere

Environmental

Monitoring

Resource

Monitoring

Industrial

Measurements

3

The Benefits of Wireless Measurements

• Reduce installation costs and time

• Reduce maintenance costs

Reduce Costs

• Optimize measurement processes

• Access data almost anywhere and anytime

• Decrease downtime

Increase Efficiency

• Overcome power and infrastructure limitations

• Solve new and previously challenging applications

Monitor Anywhere

4

Motivation for Wireless Measurements

• Cost reduction WAS the driving

force behind industrial in the first

part of the decade

• Flexibility and agility are growing in

importance

• Moving forward, it will be about

both

2008 VDC research study: 2012 numbers are projections

5

Monitoring or Control?

• Wireless monitoring is often

layered in on top of, or alongside

existing wired monitoring solutions

– not replacing them

• Factory and plant managers are

approaching wireless networking

suppliers – not necessarily

automation experts – for advice

and counsel

• Control is added most often as a

2nd/ 3rd phase project

Worldwide Shipment Shares

of Industrial Wireless Products (Share of Shipments)

2008 VDC research study: 2012 numbers are projections

6

Reduced Installation Costs

• Eliminates need for laying wired

infrastructure

• Reduced material and labor costs

• Appealing to today’s market and

economy

“Using this information and based on the savings of $400,808 on the

initial capital investment of the PA replacement, we showed 58

additional points added to the wireless network at a savings of 80%

per point would provide additional savings of $192,400”

http://www.isa.org/InTechTemplate.cfm?Section=Article_Index1&template=/ContentManagement/ContentDisplay.cfm&ContentID=73003

7

Application Areas

Energy Efficiency Smart grid, power monitoring

Environmental Monitoring CO2 emission, climate change

Structural Health Monitoring Bridge infrastructure, building monitoring

Industrial Measurements Machine monitoring, hazardous area measurements

8

Wireless Sensor Networks (WSNs)

Applications include:

• Environmental monitoring

• Structural monitoring

• Industrial machine monitoring

• Power quality and consumption

• Building and home automation

• Health care

• Asset monitoring

Defined as a wireless network that consists of spatially distributed

devices that use sensors to monitor physical or environmental

conditions

9

Wireless Sensor Network

10

Frequency Spectrum

11

Protocols & Comparison

Wi-Fi™ 802.11 Family

Bluetooth™ 802.15.1

Wireless USB ZigBee™ & 802.15.4

Applications Enterprise, networking

(internet)

PC peripherals,

cable replacement

PC peripherals, cable

replacement,

multimedia

Sensors, home/building

automation, toys

Range 50 m 10 – 100 m 3 – 10 m 50 – 100 m

Data Rate 54 Mbps (540Mbps) 750 kbps 110 – 480Mbps 250 kbps

Nodes per Network > 1,000 7 127 65,000

Battery Life Hours Days Hours/Days Years

Set-Up/Usability Better Good Better Good Best

Frequency 2.4 GHz, 5 GHz 2.4 GHz 3 – 10 GHz 900 MHz, 2.4 GHz

Security Best Good Best/Good Better

12

Wireless HART, 802.11n and Zigbee are expected to capture material share

Industrial Wireless Market Protocols

IEEE 802.11 a/b/g/n

IEEE 802.15.4

13

Wireless Standards

Data Rate (b/s)

Po

we

r C

on

sum

pti

on

, C

ost

, an

d C

om

ple

xity

100 k 1 M 10 M 100 M

ZigBee IEEE 802.15.4

IEEE 802.11 Wi-Fi

WPAN

WLAN

Low (Battery)

High

Bluetooth

Cellular

Short

Medium

Long

Transmission Distance

14

IEEE 802.11

• IEEE 802.11defines:

2.4 GHz / 5 GHz radios

OFDM, CCK, MIMO

a/b/g/n data rates

• Application and Network adds:

Packetizing data (TCP)

Addressing (IP)

Data protocols (HTTP, FTP, etc)

Host Layers

Session Layer Inter-host communication

Presentation Layer Data representation and encryption

Application Layer Network process to application

Media Layers

Transport Layer End-to-end connections & reliability

IEEE 802.11 Wi-Fi or Host App

Physical Layer Radio, RF properties/definitions

Data Link Layer Physical addressing

Network Layer Path determination & logical addressing

15

2.4 GHz Channels, IEEE 802.11

• IEEE 802.11

2400-2483.5 MHz

Up to 14 channels (1-14), 1-11 most common

Channel Width – 22 MHz

Channel Spacing – 5 MHz apart

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IEEE 802.15.4/ZigBee • Popular for WSN devices

• IEEE 802.15.4 defines:

868, 915 MHz, 2.4 GHz radios Up to 250 kb/s Low-power communication

• ZigBee adds:

Device coordination Network topologies Interoperability with other wireless products

• NI-WSN

Sits on top Makes protocol proprietary Other ZigBee devices CANNOT join the

NIWSN network

Physical Layer 868 MHz/915 MHz/2.4 GHz

Medium-Access Control Layer

Network Layer Routing, Network Topologies, and Security

Application Layer

IEEE 802.15.4 ZigBee

Application Framework User Profiles

ZigBee Device Objects Device coordination: gateway, router, or

end device

Application Support Data service and management

NI-WSN Sits on top – makes protocol proprietary

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Reliable NI-WSN, Based on IEEE 802.15.4

• Channels 11-24

• Defines joining, re-joining, mesh routing

• Ensures data integrity

• Performs device authentication

• Manages node sleep times, acquisition intervals, and heartbeats

36 nodes

per gateway

1 gateway per

wireless channel

14 wireless

channels

4 analog channels

per node

2,016 analog channels

in a single environment! = X X X

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2.4 GHz Channels, IEEE 802.15.4

IEEE 802.15.4 2400-2483.5 MHz

Up to 16 channels (11-26) • NI-WSN supports 11-24

Channel Width – 2 MHz

Channel Spacing – 5 MHz apart

IEEE

802.15.4

Channel

Center Frequency (MHz)

19

Wi-Fi and NI-WSN Co-existence

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Ways to Ensure Co-Existence

1. Set Wi-Fi Access Points and NI-WSN channels to avoid overlap

2. Create spatial distance between systems with same channel

ie, separate Wi-Fi APs on channel 1 by >30 m

ie, separate NI-WSN networks on channel 15 by >300m

21

Avoid Overlap: Example # 1

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Avoid Overlap: Example # 2

IEEE

802.15.4

Channel

Center Frequency (MHz)

23

Wireless Sensor Network

• Open Discussion

24

Data Flow

25

Single Point Acquisition

26

Single Point Acquisition

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NI-WSN Protocol: Acquisition Loops

Host Node Gateway

200 ms Sample Interval

(User Configurable)

Host VI Loop Rate

(User Configurable)

28

Waveform Acquisition (NEW!)

Msg Check

Data to GW

Waveform Interval (s)

Waveform Sample Rate (Hz)

29

Data Correlation and Node Timestamping

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Node Timestamping

Gateway

Node

Msg

Check

Data

T

… …

… …

All nodes remain within 1 second of gateway

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Wireless Sensor Network

32

Network Topologies

Star Mesh

Reliability

Latency

Cluster/Tree

Distance

Complexity

Gateway

Router Node

End Node

WSN and WiFi DAQ WSN and WiFi DAQ WSN Only!

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NI WSN Topology 1: 8 WSN Nodes

X

G

N

N

N

N

N

N

N

N

X= Distance

Gateway and 8 End Nodes

N

G

R1

Gateway

Router

End Node

34

E R4

R3 R1

G

R2

N x 8

N x 8

NI WSN Topology Example: One Hop

N

G

R1

Gateway

Router

End Node

N x 8

N x 8

Gateway + 4 Routers + 32 End Nodes

35

NI WSN Topology 3: Two Hops

G R2 N x 7 R1

R3

R4

R7

R8 N x7

N x7

R5 R6 N x 7

N

G

R1

Gateway

Router

End Node

Gateway + 8 Routers + 28 End Nodes

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NI-WSN Protocol: Joining

Power

On

Scan

Channel

Go to

next

channel

Connect

Request

Connection

Denied

Configure

Node

Connection

Confirmed

Sample

37

NI-WSN Protocol: Rejoining

Power

On

Scan

Channel

Connect

Request

Connection

Denied

Configure

Node

Connection

Confirmed

Sample

No Network

Found

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CHOOSING A WIRELESS

MEASUREMENT SYSTEM FROM NI

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Choosing the Right Wireless Technology

IEEE 802.11

NI Wi-Fi DAQ

IEEE 802.15.4

NI WSN

Throughput Up to 250 kS/s < 10 S/s

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Choosing the Right Wireless Technology

IEEE 802.11

NI Wi-Fi DAQ

IEEE 802.15.4

NI WSN

Throughput Up to 250 kS/s < 10 S/s

Range Up to 100 m Up to 300 m

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Determining Range

• Wireless range – depends on YOUR environment Spec’d distances are “typical”

Vendors provide indoor and outdoor ranges

• Factors that impact range Indoor

• Building construction (i.e. metal vs. wood vs. glass)

• Office configurations (cubes vs. offices)

Outdoor (line of sight) • Lack of line of sight

• Trees or other objects

42

Choosing the Right Wireless Technology

IEEE 802.11

NI Wi-Fi DAQ

IEEE 802.15.4

NI WSN

Throughput Up to 250 kS/s < 10 S/s

Range Up to 100 m Up to 300 m

Topology Star, Tree Star, Tree, Mesh

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Choosing the Right Wireless Technology

IEEE 802.11

NI Wi-Fi DAQ

IEEE 802.15.4

NI WSN

Throughput Up to 250 kS/s < 10 S/s

Range Up to 100 m Up to 300 m

Topology Star, Tree Star, Tree, Mesh

Power Line / Wall-Powered Up to 3 years battery power

44

Choosing the Right Wireless Technology

IEEE 802.11

NI Wi-Fi DAQ

IEEE 802.15.4

NI WSN

Throughput Up to 250 kS/s < 10 S/s

Range Up to 100 m Up to 300 m

Topology Star, Tree Star, Tree, Mesh

Power Line / Wall-Powered Up to 3 years battery power

Security WPA2 (IEEE 802.11i) Gateway Authentication

(NO Encryption)

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NI Wireless Sensor Network

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Key Vocabulary

• Gateway

• Node, end node, router node, “mote”

• Mesh

• ZigBee

• LabVIEW WSN, “VI on the node”

Gateway

Router Node

End Node

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Key NI-WSN Terminology

• Sample Interval

Time between measurements (in sample per minute or seconds)

User configurable – can be set programatically using LabVIEW WSN

• Heartbeat Interval ( = 61s)

Time between periodic handshake between Gateway and Nodes. User messages and

timebase are sent/received

Will occur even if sample interval is >61 seconds

• Sensor Power

Appx 12 volts (see datasheet/specifications for tolerance range)

Power sourced from NI voltage nodes (3202 and 3226) to drive external sensors

What Is a Wireless Sensor Network (WSN)?

What Is a Wireless Sensor Network (WSN)?

End Nodes Mesh Router

Mesh Router

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Dissolved

Oxygen

WSN System Architecture Example

IEEE 802.3

Ethernet

Battery

Microcontroller

Analog Circuit

Radio

WSN Gateway

WSN Measurement

Nodes Host Controller

Sensor Interface Voltage

Temperature

OR

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WSN System Architecture: Software

Database

Servers

LabVIEW

Real-Time

LabVIEW for

Windows

WSN

Measurement

Nodes

Wireless Enabled

Smart Objects

Worldwide

Web

LabVIEW

WSN

Gateways

• NI-WSN: Network config, drag-and-drop programming

• LabVIEW Web Services

• LabVIEW DSC: Database and SCADA

• LabVIEW WSN: Node-level programming

52

NI 9792 WSN Architecture Example

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NI Wi-Fi DAQ

(IEEE 802.11g)

NI WSN

(IEEE 802.15.4)

Battery Lifetime 1 to 2 days 2 to 3 years

Max. Bit Rate 54 Mbit/s 250 kbit/s

Range 100 m 300 m

Security IEEE 802.11i

(WPA2 Enterprise)

Gateway

Association

Choosing the Right Wireless

Measurement Platform

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Simple. Secure. NI Wi-Fi Data Acquisition.

Simple: NI C Series modules with direct sensor connectivity and NI-DAQmx driver software

Secure: Highest commercially available data encryption and authentication (WPA2)

Wi-Fi: Streaming waveform measurements over 802.11g or Ethernet network infrastructure

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Wireless and Ethernet

C Series Module Support

Measurement Module Signal # Chan Rate

Analog Input

NI WLS-9205 ±10 V analog input, 16 bits 32 250 kS/s

NI WLS-9206 600 VDC isolated, 16 bits 16 250 kS/s

NI WLS-9215 Simultaneous sampling, 16 bits 4 100 kS/s/ch

Thermocouple NI WLS-9211 Thermocouple, 24 bits 4 14 S/s

NI WLS-9213 Thermocouple, 24 bits 16 75 S/s/ch

Universal NI WLS-9219 Universal (11 modes) 4 100 S/s/ch

Sound/Vibration NI WLS-9234 IEPE (accelerometer), 24 bits 4 51.2 kS/s/ch

Bridge NI WLS-9237 Bridge completion, 24 bits 4 50 kS/s/ch

Digital I/O

NI WLS-9421 11 to 30 VDC sinking digital input 8 Software timed

NI WLS-9472 6 to 30 VDC sourcing digital output 8 Software timed

NI WLS-9481 60 VDC, 250 Vrms relay 4 Software timed

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Low-Power. Reliable.

Wireless Sensor Networks.

• Low-Power

Up to 3-year lifetime with 4 AA batteries

• Reliable

NI WSN protocol and mesh routing

• Wireless Sensor Networks

Remote wireless measurements

57

NI WSN-9791 Wireless Sensor Network Ethernet Gateway

Features

• 2.4 GHz, IEEE 802.15.4 radio

• 10/100 Ethernet

• Connect up to 36 measurement nodes

• Outdoor range up to 300 m

• 9 to 30 VDC power input

Specifications

• 2U compact form factor

• Panel or DIN rail mounting

• Industrial ratings

• Operating temperature -30 to 70 ºC

• 50 grms shock 5 g vibration

• Status LEDs

58

NI WSN-3202 and NI WSN-3212 Wireless Sensor Network Measurement Nodes

2.4 GHz IEEE 802.15.4 radio

• Outdoor range up to 300 m

• Up to 3-year battery life with 4 AA batteries

• Optional 9 to 30 VDC power input

• Configurable as a mesh router

• Four bidirectional digital I/O lines

• Industrial ratings • Operating temperature -40 to 70 ºC

• 50 grms shock 5 g vibration

Node Analog

Input

Digita

l I/O

Sample

Interval

(seconds)

Sample Rate

(samples/

minute)

Resolution

(bits)

Features

NI WSN-3202

Analog Input Node

4 4 1 60 16 Sensor power: 20 mA at 12 V

Input Ranges: ±10 V, ±5 V,

±2 V, ±0.5 V

NI WSN-3212

Thermocouple Input Node

4 4 2 30 24 Supports types J, K, R, S, T,

N, B, E

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WSN-3214: Strain/Bridge Completion Node

• Perfect Solution for Wireless SHM

Bridges, Buildings, Tunnels, Dams, Equipment

Civil Engineers, Maintenance technicians,

Construction, Oil/Gas/Energy

• 4 Channels, Full/Half/Quarter bridge

Internal excitation

High speed, High resolution modes

• 2 DIO channels

NIST Research Project for NI Wireless Strain Joint venture: NI, UT Civil Engineering, and WJE Assoc.

Goal: develop and field-test wireless system to reduce the cost of inspecting and monitoring highway bridges

WFM data

60

WSN-3230 (RS-232) & WSN-3231 (RS-485)

• Wireless interface to serial sensors and

instruments

“Programmable Sensor/Instrument Control”

Adds support for thousands of devices

• Many different applications

Environmental monitoring

Control board interface

Solar inverter monitoring

• Programmable ONLY

Showcases key feature of WSN platform

Command /

Query

Respond /

Parse

To GW/Host

“Any

Sensor”

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NI WSN Accessories and Starter Kit

• Outdoor Enclosure IP rating pending

I/O glands for wire feedthrough

External antenna

• NI WSN Starter Kit WSN-9791 Ethernet Gateway

2 programmable nodes

Sensors and power accessories

LabVIEW Evaluation Software

Getting Started Guide

NI WSN-3291

NI WSN Starter Kit

62

Energy Harvesting & NI WSN

63

Example

Node 1

Node 2

Node n

…

64

Wireless Application Areas

Environmental

Monitoring

Resource

Monitoring Industrial

Measurements

Process

Monitoring

Air/

Climate

Water/

Soil Power

Monitoring

Solar

Monitoring

Wind Farm

Monitoring

Machine

Condition

Monitoring

Indoor

Monitoring Structural

Health

Monitoring

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Biofuels from Algae

• Algae converts sunshine into chemical energy

• Why algae as a fuel source?

Does not rely on commercial crops

Can be grown on arid land or in the ocean

More efficient (water and land) than crop-based

biofuels

• NI WSN hardware used to monitor pH levels

and control the rate of feed

• LabVIEW WSN software performs data

analysis and local decision making “The newly released WSN product family combines many attractive features … wireless

networking, low power consumption, LabVIEW compatibility, and a flexible I/O portfolio.”

66

Ronald Reagan Hospital Parking Monitoring –

UCLA Campus Benefits

• Get people to open spaces

• Reduce traffic in parking garage

• Reduce campus traffic due to people searching for parking spots

Solution Components

• WSN hardware interface with IR sensors to monitor traffic flow

• Web service publishes parking

information to students, faculty,

and staff

67

Process Monitoring and Control with LabVIEW

and Wi-Fi DAQ

Application: Monitor and control the frequency of cement granules bursting in a furnace to characterize and optimize the cement manufacturing process

Challenge: Continuous, real-time monitoring under harsh conditions from a control room located 100+ m from the furnace

Products: LabVIEW and Wi-Fi DAQ

Key Benefit: Retrofit an existing control system using existing code to add remote measurements with no additional cabled infrastructure

“With the flexibility of LabVIEW, we were able to reuse our existing code to quickly expand the

reach of our measurements using Wi-Fi data acquisition devices.”

– Jean-Michel Chalons, President, Saphir

68

Application: Researching economical methods for inspecting and monitoring the temperature, strain, and acceleration of steel-girder highway bridges at the Ferguson Structural Engineering Lab at The University of Texas

Challenge: Continuous, real-time monitoring of a loaded steel bridge several hundred feet long

Products: LabVIEW, Wi-Fi DAQ, and WSN

Key Benefit: Time and money saved by eliminating cables and wiring

Inspection and Monitoring of Fracture-Critical Steel

Bridges