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ķ̿ԿCANߵKWP2000Эֶ֧ݴ䣬ҶݵĹ֯ɵģӦò㲻عݵĴͽ̡ 3.2 SAE J1850
SAE J1850 Э֣J1850Ʊ뷽ʽPWM - Pulse Width Modulation J1850ɱƱ뷽ʽVPM - Variable Pulse Width Modulationõı뷽ʽͬŲͬ㣬Ӧò·ͬ
SAE J1850 PWM: ع˾õı˫ߴ䣬ͨΪ 41.6Kbps[1]
pin 2: Bus+pin 10: Bus?CߵѹΪ+5VijΪ12ֽڣCRC
÷ƻٲõز·ʣCSMA/NDAĶٲû
SAE J1850VPW:ͨù˾õıõߴ䣬ͨΪ10.4Kbps[1]
pin 2:Bus+߿״̬Ϊ͵ƽߵѹΪ+7 Vߵ+3.5VijΪ12ֽڣCRC÷ƻٲõز·ʣCSMA/NDAĶٲû J1850Э涨ڵΪ32 ECU ͳ豸ڵ糤Ϊ40ף
糤Ϊ5ס豸СЧΪ 10.6K ŷЧΪ 500pF
J1850ݴеͨǰ¸ʽģμͼ4
Idle, SOF, DATA_0, ..., DATA_N, CRC, EOD, NB, IFR_1, ..., IFR_N, EOF, IFS,Idle иԪصĶ
Idle߿Уߴڿ״̬ʱκνڵ㶼ռݡ
SOF֡ʼ־ CRC 롣 DATA_Nݡ
EODݽ־֡ͷ EOD ʾݷͽ
NBλ VPW 뷽ʽЧ EOF֡־IFR֡ڿӦ IFS֡ڷָ־ CRCCRC Уλ 3.3 CAN
CAN 2080ſʼγɺͷչһBOSCH˾2090CAN߱ύΪʱ
CANЭһֿϵͳеͨ
ͨЭ飬ڳܺͳʹܵĹͬϸߵҲ㳵ڲϵͳܹ CANΪӸͨϵͳΪĿзģصԪߣ˽ṹӡCAN ܹʹöʣ˫ߡ˵ȣõ˫ߡCANĴٶɴ 1Mbit/s
CANֲͬ֡ʽ֡ʽչ֡ʽ֮ͬΪ֡Ϊ11λʶչ֡29λʶͼ5ͼ6 ʾ
CANֲͬ͵֡֡Զ֡֡֡֡Զ֡ʹñչָʽ
CANЭص[3]
1߿ʱӵϵĸԪԿʼϢһʼϢĵԪ÷ȨԪͬʱʼͣȼĵԪ÷Ȩ 2Ĵ䣺еĶԤĸʽ䡣 3ϵͳԣӵϵĵԪûڵַʶϢˣһԪӵϻʱҪıκ豸ӲӦò㡣
4ͨٶȣ趨ΪͨٶԿʺĴСһУеԪʹͳһͨٶȡ
5ԶԪ͡Զ֡ݴ䡣
6д⡢֪ͨʹָܡ 7룺CANʱϺͳϵĹܣڽ׳ϵĵԪȼԷֹ谭Ԫͨš
8ӣCANͬʱӶԪȻʵʿߵĵԪܵɺӳʱơ УJ2480ISO15765Э鶼ǻCANġKWP2000SAE J1850綼CAN档
4ϵͳй
200545գһַܾȾŷֵйIIIIVΣGB18352.3-2005ΪȾŷűOBDΪǿҪ״γҹķС
ͨIJŷˣEU70/220/EECָ98/69/EC ָԼֹ2003/76/ECĸָйؼݲġҪݰM1M2͵ķ顢ȼϵļҪ5棬OBDֻհŷ˵ıEOBD 5ϼչ
5.1 չеOBD-III
OBD-IIȻϳŷعϣ֤ʻ߽MILľ沢ԳϼʱһOBDϵͳҪص⡣OBD-IIIߴϢΪҪܹСͳշϵͳͨƶͨ硢ͨŻGPSϵͳVIN뼰λõϢԶϱƽ̨Ÿݸóŷĵȼ䷢ָȥδάĽ顢ŷʱȡЩϢڸطɹŷȾij߽гͷ[9]
OBD-IIIҪͨѶͷIJϳ죬OBDϵͳϹܱȷԺͿɿҲһߵҪ룬OBD-IIIijӦãϷģʽľ
5.2 µͨЭ֧