Multiplexing NACAT 2005Multiplexing NACAT 2005

Sean BennettSean Bennett

Centennial CollegeCentennial College

TorontoToronto

Definitions:Definitions:

• Transmitting of digital signals Transmitting of digital signals between electronic componentsbetween electronic components

• In-vehicle networkingIn-vehicle networking

• Sharing of system hardwareSharing of system hardware

• Reduction in system hardwareReduction in system hardware

• Message Identifiers - MIDsMessage Identifiers - MIDs

Historical PerspectiveHistorical Perspective

• Used by U.S. Military since 1970sUsed by U.S. Military since 1970s

• MIL-STD-1553 Class A Serial busMIL-STD-1553 Class A Serial bus

• 1980s: most auto OEMs: at least 1 1980s: most auto OEMs: at least 1 busbus

• 1980s: truck OEMs using proprietary 1980s: truck OEMs using proprietary busbus

• 1990s: truck OEMs using full network 1990s: truck OEMs using full network serial busserial bus

Historical perspective cont.Historical perspective cont.

• Automobile OEMs slower to adopt bus Automobile OEMs slower to adopt bus networks because: networks because: – Not cost effective: eliminates some wires but:Not cost effective: eliminates some wires but:– Replaces them with protocol handling circuitsReplaces them with protocol handling circuits– Increases competition: in U.S. limited number Increases competition: in U.S. limited number

of ECM suppliers compared with EU & Asiaof ECM suppliers compared with EU & Asia– Concerns over non-proprietary access to Concerns over non-proprietary access to

vehicle networkvehicle network

Truck, transit bus, & HE OEMs Truck, transit bus, & HE OEMs

• Reduction of wiring harness massReduction of wiring harness mass

• Networking of parametric hardware: TPSNetworking of parametric hardware: TPS

• Increased flexibility of subsystem optionsIncreased flexibility of subsystem options

• Reduced factory line assembly costsReduced factory line assembly costs

• Telemetric access to data busTelemetric access to data bus

• Ability to synergize MID operation:Ability to synergize MID operation:– example: engine/ trans/ ABS/ATC/ CWSexample: engine/ trans/ ABS/ATC/ CWS

Multiplexing StandardizationMultiplexing Standardization

• Power line carrierPower line carrier

• J1587/1708 J1587/1708

• CAN 2.0 architecture: Intel and BoschCAN 2.0 architecture: Intel and Bosch

• J1850 automotiveJ1850 automotive

• J1939 heavy-equipment on/off J1939 heavy-equipment on/off highwayhighway

• Lockheed Martin aircraft – transit busLockheed Martin aircraft – transit bus

J1939 and J1850 data busJ1939 and J1850 data bus

• CAN 2.0 platform – serial busCAN 2.0 platform – serial bus

• Class C bus (relates to transaction speeds)Class C bus (relates to transaction speeds)

• Speed rated in K/bits per second (b/s)Speed rated in K/bits per second (b/s)

• Speed window: 125 Kb/s up to 1 Mb/sSpeed window: 125 Kb/s up to 1 Mb/s

• Actual example: V-MAC III module to EUP Actual example: V-MAC III module to EUP module = 500 Kb/smodule = 500 Kb/s

• High transfer rates = mean that ‘real High transfer rates = mean that ‘real time’ responses are mettime’ responses are met

MID requirementsMID requirements

• MID is any controller networked to the busMID is any controller networked to the bus

• Clock speed rated in MHzClock speed rated in MHz

• 1 MHz = 1 million bit decisions per second1 MHz = 1 million bit decisions per second

• J1939 MID clock speeds must be min 16 MHzJ1939 MID clock speeds must be min 16 MHz

• Engine controller clock speeds higher:Engine controller clock speeds higher:– FTL-MB 900 module clock speed = 24 MHzFTL-MB 900 module clock speed = 24 MHz– Cat ADEM 2000 clock speed = 32 MHzCat ADEM 2000 clock speed = 32 MHz

Non-serial bus topologyNon-serial bus topology

Fuel Injection ECM

Transmission ECM

ABS/ATCECM

Engine ECM

Chassis Management

ECM

Collision Warning

ECM

Dash DisplayECM

Serial bus topologySerial bus topology

EngineECM

TransmissionECU

Chassis Management

ECM

Instrument Cluster

Unit (ICU)

ABS/ATCModule

Twisted Wire PairTwisted Wire PairYellow: CAN High +Yellow: CAN High +Green: CAN Low -Green: CAN Low -

J1939 network MIDsJ1939 network MIDs

• Engine controller – fuel injection controllerEngine controller – fuel injection controller

• Bulkhead (BHM)/Chassis (CHM)/Dash ICUBulkhead (BHM)/Chassis (CHM)/Dash ICU

• CWS VORAD – Night vision InfraredCWS VORAD – Night vision Infrared

• Transmission Transmission

• ABS/ ATC/ RPE/ Directional stability ABS/ ATC/ RPE/ Directional stability

• Climate controlClimate control

• Telemetry: GPS and Satellite 2-wayTelemetry: GPS and Satellite 2-way

Data packet architectureData packet architecture

FET used as ‘relay’ in MPlx FET used as ‘relay’ in MPlx circuitcircuit

J1939 data bus connectorsJ1939 data bus connectors

FTL-M2 Module locationFTL-M2 Module location

AcknowledgementsAcknowledgements

• Freightliner Service TrainingFreightliner Service Training

• Pat Leitner - Freightliner MB, New JerseyPat Leitner - Freightliner MB, New Jersey

• Joe Bell - Navistar International, Chicago Joe Bell - Navistar International, Chicago

• Chris Lupini – SAE - Delphi DelcoChris Lupini – SAE - Delphi Delco

• Artwork from Heavy Duty Truck Systems, Artwork from Heavy Duty Truck Systems, 44thth Edition Delmar Thomson, pub: 12/05 Edition Delmar Thomson, pub: 12/05

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