a
`
`OCTOBER 2000 VOL. 17 NO. 10
`
`'
`
`$6.00
`
`:
`
`DA Systems and CoverStory
`
`Getting Control
`Ti |
`
`A New Magnetic
`Sensor
`
`Manufacture
`The Principles of
`eee
`Level Measurement
`
`Tea CieSensors—HoweaitaeCAaS :
`e
`5
`wae Also Inside:
`=
`Uncertainty Analysis
`i
`SensorsinAuto
`
`www.sensorsmag.com
`
`al
`ee”)
`.| ©
`mall
`fe)
`
`=5(
`
`S)
`aa
`te
`| 6
`
`=”aW
`
`ia i
`
`al
`
`—| aa4
`
`oa
`ie)
`te
`
`4f
`
`s
`i=)
`fe]
`aes]
`tT)
`eo
`aoa
`
`Petitioner's Exhibit 1006
`Page 1 of 16
`
`

`

`DUAL TEMPERATURE COMPARATORS
`SLASH BOARD SPACE BY 50% AND
`POWER BY 67%
`Factory Programmed: No External Components Required to Set Temperature Thresholds
`
`SAVES BOARD SPACE!
`
`SAVES POWER!
`
`
`
`Voc
`
`_ WARN
`
`$0T23-6
`
`
`
`POWER(max)
`
`“=
`
`SOLUTION
`
`“Voc
`= TI
`
`¢—— TLOWae
`
`COMPETITOR’S
`SOLUTION
`
`MAXIN’S
`MAX6505
`
`COMPETITOR’S
`
`MAXIM'S
`MAX6505
`
`¢ $0123 Package
`
`¢ Low Power (30pA @ 2.5V)
`
`@ Two Temperature Comparator
`Outputs
`
`¢ Factory-Set Trip Temperatures from
`-40°C to +125°C in 5°C Increments
`
`The MAX6505/MAX6506/MAX6507/MAX6508 family of products combines
`two temperature comparators on a single chip, making control, warning,
`and protection functions even easier to build into your system.
`The MAX6505 and MAX6506 have twologic outputs, each corresponding to
`a different temperature. The outputs become active when temperature rises
`above factory-programmed thresholds. The difference beiween the two
`temperature thresholdsis pin-selectable to 5°C, 10°C, 20°C, or 30°C.
`The MAX6507 and MAX6508are ideal for maintaining a precise window of
`temperature to ensure optimum system performance. One logic output
`indicates when the system is within the desired operating temperature range.
`A second outputindicates that the upperlimit of the temperature window has
`been exceeded. Hysteresis for the two outputs is pin selectable to 2°C or
`10°C. Available with open-drain or push-pull outputs, these temperature
`switches operate from 2.5V to 5.5V supplies and are available in a 6-pin
`SOT23 package.
`
`¢ +0.5°C (typ) Threshold Accuracy,
`+3°C (max), +5.5°C (max) over
`Specified Temperature Ranges
`@ 2.5V to 5.5V Operation
`FREE Temp Sensors Design Guide—Sent Within24Hours!
`includes: Reply Cards for Free Samples and Data Sheets
`CALL TOLL-FREE 1-800-998-8800 for a Design Guide or Free Sample 9
`6:00 a.m. — 6:00 p.m. Pacific Time
`MAKIM
`www.maxim-ic.com
`Inline at www.maxim-ic.ce
`
` et Price, Delivery, and Place (
`
`o..cy:cineathoxtA10s
`ON CD-ROM
`
`Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086, (408) 737-7600, FAX(408) 737-7194.
`Distributed by Maxim Distribution, Arrow, Avnet Electronics Marketing, CAM APC,Digi-Key, Elmo, Nu Horizons, and Zeus.
`.
`Distributed in Canada by Arrow and AvnetElectronics Marketing.
`MAAXILAA is a registered trademark of Maxim Integrated Products. © 2000 Maxim Integrated Products.
`Circle 81 on Sensors RS Card
`
`oe
`1
`“ye
`:
`Petitioner's Exhibit 1006
`Page 2 of 16
`
`Petitioner's Exhibit 1006
`Page 2 of 16
`
`

`

`
`
`
`Getting Control Through CAN thecan
`| has gainedwidespread popularity not only in the
`jomotive
`industrybut also in the industrial automation arena.
`
`
`
`
`
`Fa
`
`OCTOBER 2000 VOL.17 NO. 10ieos
`
`36 Noncontact Displacement Sensors in Automotive
`Manufacture Advances in noncontact displacement sensors are bringing
`newlevels of quality andefficiency to the research labs and assemblylines of
`automakers worldwide. Bryan Manning and Robert Foster
`
`42 AShort Guide to MeasurementUncertainty. No
`measurementdevice produces perfect results. Uncertainty analysisis onewayto
`define how confidentyou are of your measurements. Stephen Humpage
`
`48 Uncertainty Analysisin Pitot Static Pneumatic
`Mass Flow Measurements: The integrity ofa mass flow rate
`measurementusing a Pitot static technique should bea primary concern for
`low-flow applications becauseerror in oneofthe calibration constants has an
`exaggerated effect whenthedifference betweenthe totalpressure and the
`static pressure is small. Don Ersland
`
`52 Anlnnovative Passive Solid-State Magnetic Sensor
`Anew magnetic sensortechnology is based on the magnetostrictive andthe
`piezoelectric effects. Yi-Qun Liand Robert O'Handley
`
`55 ThePrinciples of Level MeasurementRF capacitance,
`conductance, hydrostatic tank gauging, radar, and ultrasonics are theleading
`sensor technologiesin liquid level tank measurement and control operations.
`Making the wisestselection for your ownapplication requires a basic
`understanding ofhow these devices work. Gabor Vass
`
`z
`
`7]
`
`@ a
`
`wh
`
`~
`wi
`=
`a)
`@
`
`-
`@
`
`65 Measuring Individual Wheel Noise How do you determine
`ifyour new wheeldesign is quieter, ifthe rest of the clanging, squealing train
`drownsit out? With a phased microphonearray andintensivecalculations.
`
`Johan.Van Keymeuten
`
`,
`
`68 Acoustic Wave Technology Sensors Acoustic wave sensors
`are extremely versatile devices that arejust beginning torealize their
`commercial potential. This tutorial addresses acoustic wave sensor physics and
`materials, and the various types ofacoustic wave Sensors andtheir industrial
`applications. Bill Drafts
`
`SENSORS EPO”
`Sensors magazineis the official sponsor ofSensorsExpo Conferences and Expositions.
`
`PetiaQetSFRAB1806
`Page 3 of 16
`
`DEPARTMENTS
`
`6 Business Sense
`
`10 WebPicks
`
`14 Research & Developments
`
`
`72 Advertiser Index/ReaderService Card
`
`
`79 Product News
`
`88 WishList
`
`ABOUT THE COVER
`Whatstarted as a bustailored for the automotive industry is now a
`protocol that has been adopted by the industrial automation, test
`and measurement, and medical communities. The robust Control
`Area Network (CAN)is optimized with sophisticated error checking
`and handling that guarantees that the system will continue to run
`even whenerrors andfailures occur. To see just how this bus works,
`read the article that begins on page 18. (Cover image courtesy of
`Microchip Technology Inc.)
`
`Petitioner's Exhibit 1006
`Page 3 of 16
`
`

`

`Bruce Negley,
`
`DA SYSTEMS
`
`CONTROL Microchip TechnologyInc.
`
`Getting Control Through
`
`
`
`The CAN protocol has gained widespread popularity not only in the automotive industry but also
`in the industrial automation arena. Take a look at what it can do, and see how you can extendyour
`
`control capabilities.
`
`_erman automotive system supplier Robert Bosch created the Controller ik aNetwo
`(CAN)to enable robust serial communications while decreasing wiring harnesswei
`.and complexity. The currentversion ofthe protocol, 2.0B, provides transmission speeds
`
`up to 1 Mbps.
`Since its inception, CAN has moved from automotive applications to industial
`
`trol. Now technicians and engineersarestartingto use it in medical andtest equipmen
`
`‘Thetest, measurement, and control community is discovering just whatthis bus can do
`when itis coupled with smart sensing technology.
`
`How isCAN Used?
`
`‘The CAN protocolcreates a communications path thatlinks all the nodes wonnecied
`to the busand enables them totalk to one another. Depending on how the designerhas
`_ configured thesystem, there mayor may not be a central, or main, node. The protocol
`
`defines aspects of howeachnodecan respond,butit leaves tremendousflexibilitytoth
`system designerto implement the nodes in ways thatsuit the particular applicatic
`Wgigure | (page 20) showsan automotive application inwhich several nodesi
`‘tioned before, the network need nothavea controller node; each node canjust a easi
`be connectedtothe main bus. Applying the concept shown in Figure| to asens
`
`work isaseasy as changing the‘type and description ofthe ede: (see Figure
`
`20).
`
`What Makes Up a Node?
`The term node describes a portion of the overall system or network, Eachnode ean
`have onefunction,or it can have manyfunctions. Depending onthe system configura-
`
`tion, different nodes may transmit messagesat different times based on the func:)
`
`_ ofeachnode.For example:
`© Anode maytransmit a message only whena system failure occurs.
`
`Petitioner’Ss Exhibit1006
`
`‘Page4 of16
`
`18
`
`www.sensorsmag.com OCTOBER 2000
`
`.
`
`Petitioner's Exhibit 1006
`Page 4 of 16
`
`

`

`Page 5 of 16
`
`BENSORINeHOBER2b0tbiTS 006
`
`Petitioner's Exhibit 1006
`Page 5 of 16
`
`

`

`<<
`
`_ TA & TBSeries
`Accelerometers
`
`* Piezoresistive Technology
`
`* Amplified & Unamplified
`
`* Automotive Test Applications
`
`These low noise and DC
`to 1000Hz bandwidth
`
`accelerometers are ideal
`for test and measurement
`
`applications. 25 G to
`100 G ranges are now
`available.
`
`DA CONTROL
`
`
`
`CAN Bus
`implementation
`
`DoorNode
`Controller
`
`CAN Bus
`Implementation
`
`Figure 1. In this auto-
`motive application,
`the CAN busis used to
`interconnect the indi-
`vidual nodes that de-
`tect button presses
`and control motors or
`solenoids in a door.
`Each node can com-
`municate with any
`other node.
`
`Figure 2. CAN is a
`robust protocol, which
`makesit well suited to
`interconnect sensor
`and motor control
`nodes in industrial
`environments.
`
`° A node may transmit messages continu-
`ally, such as whenit is monitoring the flow
`rate from a pumpin a controlloop.
`e A node maytake action or transmit a
`message only wheninstructed. by another
`node, such as when a fan controller is in-
`structed to turn a fan on when the tempera-
`ture-monitoring node has detected an ele-
`vated temperature.
`
`immediately pass the information on to the
`bus for other nodesto use, or it may wait for
`a value higher than a set point before trans-
`mitting any data. The bus transceiver con-
`verts the standardlogic signals from the
`microcontroller to the signal levels used on
`the physical CAN bus.
`
`CAN Messages
`The CANprotocol uses a message-based
`data format in which informationis trans-
`ferred from onelocation to another by
`sending a group ofbytes at onetime.
`Unlike address-based systems, every
`node in this system listens to every
`message on the bus (and will
`acknowledgeif the message was prop-
`erly received) to determineif it needs to take
`action.
`
`Figure 3 (page 21) outlines the com-
`ponents of a generic node. In this
`node, a signal from a sensorpasses
`throughsignal conditioning cir-
`cuitry and theninto the A/D con-
`verter. The node feeds the data
`from the converter into the micro-
`controller for analysis. Based on the func-
`tion of the node, the microcontroller may
`
`
`
`We wrote the book on
`silicon sensing solutions.
`
`Call: 408/965-3300
`email: info@xbow.com
`online: www.xbow.com
`
`Crossb¢w’
`
`41 E. Daggett, San Jose CA 95134
`408/965-3300 + FAX 408/324-4840
`
`|
`|
`
`|
`|
`
`Bp
`
`_ V
`
`v
`Cc
`(@))
`14)
`
`‘é
`‘e)
`te
`>
`oy)
`ea
`ase
`
`a_ (
`
`aD)
`Cc
`
`le
`Ee
`‘e)
`
`=m
`
`eae
`Se
`Ie
`
`€ c
`
`e.
`Oo
`
`_ (
`
`4)7
`ge
`Vv
`WU
`U
`
`20
`
`www.sensorsmag.com OCTOBER 2000 Circle 51 on Sensors RS Card
`
`Petitioner's Exhibit 1006
`Page 6 of 16
`
`Petitioner's Exhibit 1006
`Page 6 of 16
`
`

`

`node applications.
`
`
`well), are based on the CAN protocol. Fiber-Optic
`
`Temperature Sensor
`Sense
`aaa
`Savings
`( $3,995" >
`
`* Includes a 4-channel fiber-optic
`thermometer and 4 two-meter probes
`(TP-11 and TP-21) Limited Time Offer
`
`The ReFlex
`
`e Reliable performance, robust
`construction, configurable
`design
`© Temperature range from -200°C
`to +250°C
`
`For Microwave/RF/High Voltage
`used in educational, industrial,
`and lab environments:
`
`- Bonding, curing, and drying
`of various components and
`substances
`
`Organic chemistry
`Biological processes
`Chemical industries
`
`Biomedical applications
`RFI/EMI-polluted environments
`Electronic industries
`
`Food industries (packaging,
`pasteurization, etc.)
`
`Nortech Fibronic, your number one
`source of reliable technology and
`premium quality products
`
`Figure 3. A typical smart
`sensor node is made up of
`both digital and analog
`components, which allow
`the sensor data to be cap-
`tured, transformed, ana-
`lyzed, and transmitted to
`other nodes in the system.
`System designers often
`create generic node hard-
`ware, which can be easily
`configured for different
`
`Every other node captures the message and
`Every message has an identifier field con-
`examinesit to see if it is required to take
`sisting of either 1] or 29 bits. The message
`some action. A single node mayact on the
`can also contain data, butit’s not required.
`message, or many nodes may accept the
`The nodeuses the identifier to determineif
`message and act on it. For example, a tem-
`the incoming message should be accepted
`perature-monitoring node may send out
`and acted onordiscarded.
`temperature data that are acted on only by a
`When one node wants to send data to any
`node that displays the current temperature.
`other node(s), it assembles a message with
`But if the temperature sensor detects an
`the proper identifier and data,
`
`overtemperature situation, then many nodes
`checksto see if the busis free, and
`mightact on the information.
`then transmits the message.
`
`ISO/OSI Reference Model
`
`Figure 4. The ISO/OSI reference model defines seven layers of system implementation for net-
`work applications, which allows standardization of network components from different manufac-
`turers, making them interchangeable. The CAN protocol defines the lower two layers of the model
`with the exception of the medium-dependent interface (MDI) in the physical layer. The upper lay-
`ers were left undefined by CAN so that users could create interfaces that met their specific
`requirements. Some upper-level protocols, such as DeviceNet (Allen-Bradley) and SDS (Honey-
`
`41 800 290-7244 (Canada & USA)
`(418) 872-4686
`Visit our Website at www.nortech.ca
`sales@nortech.ca
`
`Circle 90 on Sensors RS Card Petsaixaoas' odmekrinno 1206
`Page 7 of 16
`
`Petitioner's Exhibit 1006
`Page 7 of 16
`
`

`

`DA (CONTROL
`
`
`
`Figure 5. Many CAN sys-
`tems use a transceiver to
`implement the physical
`layer of the protocol. A
`typical transceiver oper-
`ates from a 5 V supply and
`delivers a differential sig-
`nal of 0-3 V for the actual
`data transmission. The
`transceiver also provides
`protection against tran-
`sient voltages on the data.
`
`With the message-based format, you can
`add nodesto the bus without reprogram-
`ming the other nodes to recognize the addi-
`tion. The new nodewill start receiving mes-
`sages from the network immediately.
`Another useful feature built into the CAN
`protocolis the ability of a node to request
`information from other nodes. Thisis called
`a remote transmit request, or RTR. This is
`different from the previous example because
`instead of waiting for information to be sent
`to it, the node specifically requests that the
`data be transmitted.
`
`CAN Protocol Layers
`Most network applications follow a layered
`approachto system implementation. This
`enables interoperability among products
`from different manufacturers. The Inter-
`national Standards Organization (ISO) cre-
`ated the Open Systems Interconnection
`(OSI) Network Layering Reference Model
`to serve as a template for this approach (see
`Figure 4, page 21).
`
`The CAN protocol implements most of
`the features of the lower twolayersof the ref-
`erence model. But Bosch did not include
`the communications medium portion of the
`model in the CAN specification because he
`
`wanted to give system designers the freedo1
`to adapt and optimize the protocol on mult
`ple media(e.g., twisted pair, single wir
`optically isolated, RF, and IR) for maximut
`flexibility. A common method of impli
`
`Magic Sold Here.
`
`_ Add alittle prox magic with QProx™ Charge-TransferICs...
`OProx ICs can transform your product in ways you won't believe. Use our chips and modules to create some of the most
`stunning sensing effects, at astonishingly low prices. OProx ICs can be used to sense everything from fluid level to
`transducer displacement to proximity and touch. Since we just make the chips, not the whole sensor package, you save
`tremendously on cost. To ease development, we offer several EM-series dev kits to help you kick-start yourefforts.
`_ OProx is already usedin industries like appliances, biomedical, computing, instrumentation, and machine
`_ controls. It's also undergoing advanced developmentin the automotive industry. Uses include fluid level sensing,
`| airbag controls, lighting controls, distance gauging, safety sensing, and humaninterfaceslike thru-glass touch
`| keyboards. Users range from Formula Oneracing teamsto industrial giants like GE and Perkin Elmer.
`EM kits quickly help you to understand the OProx system,
`QProx ICs cost aslittle as $1 and includeall the signal processing
`to let you develop applications fast. You can magically
`| you're everlikely to need, including digitalfiltering, threshold comparison
`turn almost any surface or objectinto a sensor, even plants!
`logic, drift compensation, auto-calibration, and more.
`If we don’t have
`| what you want, OProx can be readily customized for your application. In
`high volume OProx can even belicensed to drive down costs even more.
`Discover the incredible ways that OProx technology can add
`magic to your products - check our website for in-depth technical
`| details and a fulllist of products.
`
`
`
`
`
`
`
`sales@qprox.com
`
`
`
`
`http://www.qprox.com
`QUANTUM Research Group Ltd.
`Prox made simple.
`
`651 Holiday Drive, Pittsburgh PA 15220
`Tel: (412) 391-7367 Fax: (412) 291-1015
`
`||
`
`|| |
`
`|
`
`Petitioner's Exhibit 1006
`Page 8 of 16
`
`

`

`DA CONTROL
`
`inter-Frame Space
`
`&
`Bus Idie
`
`
`
`Lo)StareFrame
`
`Arbitration Ficld
`
`a=
`a
`
`ii
`
`n
`a
`
`a a
`ad Od
`
`4
`
`4
`5
`
`Identifier
`
`3B] Dats
`
`Message
`Filtering
`Stored in Buffers
`
`Data Frame (number ofbits = 44 + 8N}
`§N (0SN<&)
`Data Field
`
`8
`
`-
`
`x
`
`Stored in TransmitReeeive Bulters
`
`Bit Smiling
`
`
`
`16
`CRC Ficld
`
`15
`cRC
`
`tLendAckSlotBit
`
`iy
`
`<4
`
`Inter-Frame Space
`
`Figure 6. The standard data frame is one of several frame types used in
`the CAN protocol. The data frame is made up of several fields, which
`include 11 bits for the identifier, up to 8 data bytes, and 16 bits of cyclical
`redundancy check sum error checking. The nodes use the identifier field to
`determine if a message should be acted on. It is also used in the bus arbi-
`tration scheme to prevent bus collisions if more than one node begins
`transmitting at the same time.
`
`menting the physical layeris
`by specifying a 5 V differen-
`tial electrical bus as the physi-
`cal interface (see Figure 5, page
`22). Such an implementation is fully
`defined in ISO-11898.
`Therest of the layers of the OSI protocol
`stack are left to be implemented by the sys-
`tem software developer. Higher Layer
`Protocols (HLPs) are generally used to
`implement the upperfive layers of the OSI
`reference model. Two of the most notable
`industrial control HLPs are Allen-Bradley’s
`DeviceNet and Honeywell’s Smart Distrib-
`uted System (SDS).
`Higher Layer Protocols are used to:
`® standardize startup procedures, including
`the bit rates used
`® distribute addresses among participating
`nodesortypes of messages
`® determinethestructure of the messages
`* provide system-level error handling
`
`24 www.sensorsmag.com OCTOBER 2000
`
`This is by no means a full list of the func-
`tions that HLPsperform, butit does describe
`someoftheir basic functionality.
`Most CAN systems implement the physi-
`cal layer of the protocol by using somekind
`of transceiver (see Figure 5). This device
`connects the CAN High (CANH) and CAN
`Low (CANL)pins to the CAN bus with a
`differential signal of 0-3 V. A trans-
`ceiver also provides transient protec-
`tion of +200 Vandfault protection
`by acting as a barrier that can with-
`stand voltages of +40 V.
`
`CAN Message Frames
`The CANprotocol defines four types of
`messages, or frames. Thefirst and most com-
`mon is a data frame, which is used when a
`node transmits information to anyor all
`other nodesin the system. The second most
`common,a remote frame, is used when one
`node requests data from another node. The
`
`other two frame types are used to handle
`errors. A nodegenerates an error frame when
`it detects one of the many protocol errors
`defined by CAN, And the protocolcalls for
`an overload frame whenit requires more
`time to process messages already received.
`Standard and Extended Data Frames.
`Data frames consist of fields that provide
`additional information about the mes-
`sage. Embedded in the data frames
`are arbitration fields, control fields,
`data fields, cyclic redundancy
`check sum (CRC) fields, a 2 bit
`acknowledge field, and an end of
`frame.
`The arbitration field prioritizes messages
`on the bus. Because the CAN protocol
`defines a logical 0 as the dominantstate, the
`lower the numberin the arbitration field,
`the higherthe priority of the message on the
`bus. For a standard data frame, the arbitra-
`tion field consists of 12 bits—1] identifier
`
`
`
`Petitioner's Exhibit 1006
`Page 9 of 16
`
`Petitioner's Exhibit 1006
`Page 9 of 16
`
`

`

`tocol. Carrier sense means that before any
`node sends a message, it must monitor the
`bus for a period ofinactivity before trying to
`send a message. Multiple access indicates
`that once the period of inactivity occurs,
`every node on the bus has an equal opportu-
`nity to transmit a message. The CD stands
`for collision detection. If two nodes on the
`
`network start transmitting at the sametime,
`the nodeswill detect the collision, and one
`of the nodeswill stop transmitting.
`CAN uses a nondestructive bitwise arbitra-
`tion, which means that messages remain
`intact after arbitration is completed even if
`collisions are detected. All the arbitration
`
`takes place without corruption or delay of > to 50 KHz to 1000°F
`easure engine
`dynamic
`
`to <1 micron
`
`.M
`
`Dy Wra eh nasty e
`
`controller
`
`(loaded) by the CAN
`
` These are generated
` The protocol engineis
`
`troller hardware
`
`part of the CAN con-
`
` CAN Bus
`
` Figure 7. To transmit a message, the node
`
`first must load the message identifier, data
`
`bytes, and control bits into the transmit
`
`
`message assembly registers. The node then
`
`
`transfers the data to the CAN protocol
`engine. The protocol engine creates the
`
`
`actual frame by inserting the frame ele-
`
`
`ments, such start and stop bits and inter-
`
`
`frame space bits. The protocol engine also
`
`
`handles bus arbitration, cyclical redundancy
`
`
`check sum calculations, and looks for trans-
`mission errors.
`
`
`
`
`
` HORLAIN
`
`bits and 1 RTR bit—(see Figure 6,
`page 24). Extended data frames are
`
`identical to the standard data frames
`exceptthat the arbitration field is 32 bits (29
`identifier bits, 1 bit to define the message as
`an extended data frame, 1 unused bit, and
`an RTRbit).
`Remote Frames. As described in the pre-
`OUR NONCONTACT EDDY CURRENT SENSORS MEASURE:
`ceding section, the RTR is used when a
`node requests information from another
`© Rocker arm movementilifter leak-down
`node. This might be used whenasensoris
`© Axial camshaft/crankshaft run-out/balancing
`monitoring the temperature but transmits a
`© Push-rod deflection
`signal only when an overtemperature condi-
`@ Valvelift and valve float investigation
`tion exists or when another node requests
`the sensor to transmit the current tempera-
`@ Piston slap and skirt clearance
`ture. A remote frame is sent as a command
`© Static bearing clearance on crank journal
`and has nodatafield.
`@ Engine mount deflection
`| Error Frames. Whena node detects one of
`© Dynamic TDC/headgasket clearance
`the errors defined by the CAN protocol, an
`error frameis automatically sent by the con-
`© Fuelinjection needlelift (not shown)
`troller.
`| Overload Frames. These framestell the
`network that a node is busy andis not ready
`to receive additional messagesat the time.
`| Bus Arbitration. CAN is based on the car-
`rier sense multiple access (CSMA/CD)pro-
`
`see what's happening ©
`
`www.kamaninstrumentation.com
`
`800-552-6267
`
`Circle 74 on Sensors RS Card
`
`SENSORS OCTOBER 2000 25
`Petitioner's Exhibit 1006
`
`age
`
`100
`
`Petitioner's Exhibit 1006
`Page 10 of 16
`
`

`

`most devices. A message is typically it
`the message that winsthe arbitration.
`There are a couple of things required to
`in the controller byfilling registers with the
`support nondestructive bitwise arbitration.
`properinformation. This includesthe identi:
`First, logic states must be defined as domi-
`fier information that determines which
`nodesreceive the message and the data ee
`nant or recessive. Second, the transmitting
`node must determineif the logicstateit is
`Many CAN controllers have multiple ‘and
`trying to send actually appears on the bus.
`CAN defines a logic bit 0 as a dominantbit
`mit buffers so that messages can b
`and a logic bit 1 as a recessive bit. A domi-
`preloaded in preparation for a particulay
`event.
`nantbitstate will always win arbitration
`over a recessivebit state.
`After the data have been loaded,,
`the controller can be given tha
`For example, suppose two nodes
`are trying to transmit a message at
`command to transmit the message,
`the same time. Each nodewill
`When the controller receives the
`monitor the bus to make sure the bit
`command,it checks to see if the bus
`type U05
`is busy before beginningthe transmis:
`that it is trying to send actually appears
`and S05
`sion. As transmission of the message id
`on the bus. The lowerpriority message will
`1-1 ¢oWt{o8]
`to new
`occurring, the controller checks for bus col-
`at some pointtry to sendarecessive bit (a
`(eyaigcliitetcy
`logic high), and the monitored state on the
`lisions and other transmission errors, Othet
`buswill be a dominantbit(a logic low). At
`than loading the buffers and giving the com:
`mandto transmit, all the details of this procs.
`that point, the node sendingthe lowerprior-
`ity message loses arbitration and immedi-
`ess are handled in hardware by the CA
`ately stops transmitting. The higher priority
`protocol engine. The controller automati+
`cally checks for the bus-free state and per!
`message will continue until completion, and
`the nodethatlost arbitration will wait for the
`—
`formsbit arbitration and error checking)
`Most CAN controllers maintainaseries of
`next period ofinactivity on the bus andtry to
`transmitits message again.
`status bits that can be used to determine ifa.
`transmission is complete and if any errors _
`occurred during the transmission.
`:
`
`multiNCDT
`Displacement
`and Position
`yeatst0)eee
`
`Our sub-
`Plialelallaes
`eddy
`Colegali
`sensors
`
`wwwmicro-epsiton.com
`
`Eddy Current Sensors
`i Non-Contact * Wear-free
`_ 0 14 Sensor models
`for ranges 0-0.02in ... 0-3.2 in
`4 Compact single-channel systems
`© Modular multi-channel systems
`0 Linearity + 0.2% FSO
`0 Resolution downto0.002 mils
`Temp.Stability +0.01 %FSO/*°F
`o Frequency response100 kHz
`Displacement online
`
`
`
`that are required (see Figure 7, page 25
`
`
`
`Creating and Sending a Message
`Every CAN controller handles the details
`of message transmission and reception differ-
`ently, but the overall conceptis the samefor
`
`Receiving and Processing a Message
`As mentioned previously, the CAN proto-
`
`;
`
`received message
`into the microcontroller
`
`CAN Bus
`
`The Receive Assembly
`Register attempts to capture
`every message
`
`CAN Protocol Engine
`- Error Checking
`- CRC Checking
`
`Filter and Mask values
`are typically programmed
`
`The microcontroller
`can now act on the
`
`Figure 8. Every active node
`reads every message transmitted
`on the bus. When a node
`receives a message and deter-
`mines that there are no errors
`with the message, the identifier
`field of the message is checked
`against filter and mask registers
`to determine if the message
`should be acted on. Different
`CAN controllers implementtil-
`ters and masksin different ways,
`and most controllers have multi-
`ple receive registers to increase
`the throughput of message
`reception. The system designer _
`is free to determine how to use
`_
`the receive buffers andfilters to
`manage messages in a way that
`suits their needs.
`
`©
`
`|
`
`
`
`26 www.sensorsmag.com OCTOBER 2000 Circle 86 on Sensors RS Card
`
`Petitioner's Exhibit 1006
`Page 11 of 16
`
`Petitioner's Exhibit 1006
`Page 11 of 16
`
`

`

`
`
`
`
`By Brevi ne yel
`
`
`
`
`col is a messaged-based system that requires
`is a match.If the identifier bits match one or
`every nodeto listen to every message on the
`moreofthefilters, then some action will be
`bus. Each node must determineif it should
`taken by the node.
`discard the message or take some action. A
`The system designer determines how the
`node determinesif it should accept a mes-
`filters and masks are used. Most CAN con-
`sage by examining the identifierbits. Inside
`trollers have multiple receive buffers, which
`the controller, filters and masks are com-
`increase the ability of the controller to han-
`pared againstthe identifierbits to seeif there
`dle higher transmission rates and reduce the
`
`
`
`chanceofan overload condition, where the
`controlleris still busy processing one mes-
`sage when another message is being trans-
`mitted. Most CAN controllers have sophisti-
`cated methods of using masks, filters, and
`interrupts to minimize message processing
`requirements (see Figure 8, page 26).
`
`Whatis
`small,
`reliable,
`inexpensive,
`durable,
`generates a consistent 5-6 volt, 10us pulse,
`requires no external power,
`has no moving parts,
`operates in temperatures from -40°C to +200°C,
`is capable of zero speed detection, and
`ideal for
`Motor Control applications?
`
`
`
`(actual size)
`
`The $2000 Series Sensor.
`Questions?
`At HID Corporation we have the answersforall your sensor needs.
`From design and development to manufacturing and assembly, we can
`help you find the perfectsolution for your application.
`For more information giveusa callor visit our Website today.
`
`LD)
`
`HID CORPORATION
`
`800.243.2563 www.hidcorp.com
`
`28 www.sensorsmag.com OCTOBER 2000
`
`Circle 66 on Sensors RS Card
`
`Error Handling
`Because CAN wasinitially designed for use
`in automobiles, the protocol hadtoefficiently
`handle errors if it was to gain market accep-
`tance. With therelease ofversion 2.0B of the
`CAN specification, the maximum communi-
`cation rate was increased eight times overthat
`of version 1.0 to 1 Mbps. Atthis rate, even the
`most time-critical parameters can be transmit
`ted serially without latency concerns, In addi-
`tion, the CAN protocol has a comprehensive
`list of errors that it can detect, which ensures
`the integrity of messages,
`CAN nodescan determinefault conditions
`and transition to different modes based on
`the severity of the problems encountered.
`They can also differentiate between short
`disturbances and permanentfailures and
`modify their functionality accordingly. CAN
`nodes can transition from functioning as a
`normalnode(i.e., being able to transmit and
`receive messages normally) to shutting down
`completely (bus off) based on the severity of
`the errors detected. This feature is called
`fault confinement.
`A faulty node cannot monopolize the
`bandwidth of the network because the fault
`is confined to that one node, whichshuts off
`before bringing the network down. This fea-
`ture guarantees bandwidthforcritical system
`information.
`Errors Detected. The CAN protocol
`definesfive errors.
`ae.
`CRC Error. The transmit-
`E>,
`ting node calculates a CRC 4
`value and then transmits the
`value in the CRCfield, All
`‘W e_
`nodes on the network receive
`the message, calculate a CRC,
`andverify that the CRC values match. If the
`values do not match, a CRC error occurs,
`and the node generates an error frame.
`Acknowledge Error. In the acknowledge
`field of a message, the transmitting node
`checksif the acknowledgeslot (which it has
`sent as a recessive bit) contains a dominant B
`
`
`
`Petitioner's Exhibit 1006
`Page.12 of 16
`
`_—
`
`Petitioner's Exhibit 1006
`Page 12 of 16
`
`

`

`
`
`
`
`Drain tel
`
`
`
`
`
`
`
`
`
`Accelerometers
`
`Built-in Signal Conditioning
`Wide Temperature Range
`A force-balanced design minimizes
`variations due to temperature and
`aging effects, resulting in a sensor that
`is more stable over temperature than
`piezoelectric or piezoresisitive devices.
`Built-in Custom Filtering
`Small & Rugged
`Will survive 500 g powered.
`DC-coupled Ranges
`£1, +1.5, +2, 22.5, +3, +5, +7.5 g,
`+10, +15, +20, +25, +30, +50, +75 g
`and custom
`
`Bi-Axial
`Models 23200A & 23203A
`
`
`
`Built-in Temperature Sensor
`Single +5 to 30 Volt Supply
`Built-in reverse & transient protection
`
`Tri-Axial
`Models 34100A & 34103A
`
`FY 391034
`
`ioe at
`
`Precision Aligned
`Less than 0.5° deviation from ideal
`Less than 0.25% transverse sensitivity
`Single +5 Volt Supply
`
`Call or FAX today!
`(330) 659-3312
`FAX: (330) 659-3286
`
`www.summitinstruments.com
`
`Summit Instrumenis, Inc.
`P=
`ju 2236 N. Cleveland-Massillon Rd
`Akron, Ohio 44333-1255 USA
`
`MAMET: AAme meee eee TANAAA om
`
`
`Takes temperature data every
`mits 2 bytes ofdata with identifier as 0x200
`
`Takes pressure data everysecond and transmits 2
`bytes ofdata with identifier as 0x100
`
`Figure 9. A typical smart sensor network is made up of nodes that have different functions.
`Some nodeswill only transmit data, somewill receive data, and some may have multiple func-
`tions, The CAN bus provides a robust means of intereonnecting nodes and allows each node to
`communicate with any other node. If the system has many nodes and thereis a lot of traffic on
`the bus, message identifiers can be organized to include a schemethat ensures that priority
`messages are processed first.
`
`
`
`
`
`bit. Such a bit acknowledgesthatat least one
`receiving nodes to synchronize by recover-
`node correctly received the message. If the
`ing clock information from the data stream.
`bit is recessive, then no node received the
`Receiving nodes synchronize on recessive-
`message properly. If an acknowledge error
`to-dominant