OE 20 C1 OE20C VCC RxD RST LED1 LED2. TxD XTAL2 XTAL1 NC. TxK TxL. RxK GND. v /05/2004. Features

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1 Features Low cost Compatible with ISO & KWP000.7 to 6V operating range Direct LED drive for status display 000 baud communication Auto fast init process Auto slow init process Multiple response from multiple ECU Physical and fonctional addressing Description KWP000 & ISO9- to RS gateway OE0C000 ISO0 is an international standard for communication between automobiles and diagnostic testers.it specifies a serial data communication bus between ECUs and diagnostic test SAE OBDII Scan Tool ( SAE j97 ). The OE0C000 provides an inteligent interface between a Host and the vehicle s Electronic control units. Both LEDs display the current communication status and connected information. K and L lines can be connected to ISO BUS eighter via transistor or transceiver chip. The logic level on K and L lines can be inverted. The ISO baud rate is 000. RST 0 RxD 9 TxD XTAL XTAL OE 0 C LED LED TxK TxL 9 RxK GND 0

2 Pin description Pin Pin Name Type Description RST I A high level on this pin during machine cycles while the oscillator is running resets the device RxD I RS data input TxD O RS data output XTAL I MHz crystal input 5 XTAL I MHz crystal input GND I Ground RxK I ISO9- K-Line input TxL O ISO9- L-Line output 5 TxK O ISO9- K-Line output 6 7 LED O LED for communication K-Line LED O LED for connected info 9 0 I Power supply ( + 5V )

3 Application notes DB uF 0uF + + 0uF uF 6 RIN RIN TIN TIN C+ C- C+ C- V+ V- GND 5 MAX ROUT ROUT pf TOUT TOUT 9 7 pf M TXD RXD XTAL XTAL RST LED LED TXL TXK RXK GND TxL TxK k RxK k k OE0C000 uf + the both LEDs are low current If < 5 ma. Don t change the value of crystal. LED yellow ( PİN 7 ) indicates everytime a frame exchange occurs. LED green is on if a valid protocol is found.

4 VBAT R5 50 Q VBAT TXL TXK RXK R R K7 K7 VBAT + - R7 0K N VBAT R 0K R6 50 Q N JP OBD CONNECTOR UA LM9 R9 0K U6 LM705C/TO0 OUT IN C 00nF GND VBAT D N00 C9 00nF typical KWP000 to RS interface

5 PC Serial Port Parameters The Rs parameters are : 9600 Baud, bits, no parity. The PC is Master and the Adapter is slave. Software There are types of commands for communication with the interface adapter. High Level Commands When sending to the adapter the service Nr. and the PID a response of 7 data bytes as specified in ISO 50-5 is received. For exemple: <STX> <0> service and no pid to get the stored error codes. <STX> <0><frame> gets the freeze frame stored in ECU. <STX> <0> clears the DTC stored. <STX> <0><00> gets the PID supported and <STX><0><0> gets the coolant temperatur in.byte in response Bytes. Low Level Commands In this mode the adapter can speak to ECU directly. We must first request the found protocol. For in ISO 0- to speak to ECU for exemple we send <length> <0X><0x7A><0xf><service Nr><PID> to mobydic. the checksum is calculated by adapter. As a response we obtain <length> <0x0><0Xf><0x7a><0x><PID> ( for service ) 5

6 Software driver The Host software must wait at power on until a valid protocol is found. It is normally max 6 sec. The protocol can be requested with Command. 0x05. Is this number zero than is no protocol found. The host can search a valid protocol itself too. The Host must set a time out of 6 sec. for a response. The Fonction numbers are all decimal. But 0x0 means hexadecimal. The Mobydic has a timeout of 000mS for a incoming Message.The unused commands return <Command-Nr> <nack> first let the mobydic search a valid protocol with default parameters ( ECU Address is 0x) even if no protocol is found ( protocol = 0), use the command 0 to search with different ECU address and with auto detect of ISO baudrate generic command is only used when the mobydic finds a valid protocol at power on. 6

7 Low Level Command Listing Command : 0 Generic commands Host sends Mobydic sends Host sends Mobydic sends : <stx> : <ack> or <nack> : <service><pid> : <stx><length><user data> Stx = 0x0 Ack = 0x06 Nack = 0x5 Length = all byte inc. CS Service = ( request current powertrain diagnostic data ) ( read freeze Frame data ) ( read DTCs) ( clear DTCs) PID = only used in service and 9. Set to 0 if not used <User Data> = <priority/type><target add><source add><data byte..7 ><CS> CS = summe of bytes mod 56 according to diagnostic message format of ISO page Example : suppose that Mobydic found an ISO9 protocol Host sends <Stx> Mobidic sends <ack> Host sends <0><05> read coolant temperatur ( service PID 5 ) Mobydic sends <stx><07><0x><0x6b><ecuadd><0x><0x05> <0x6><CS> coolant temp is 0x6 60 C ( 00 0 ) 7

8 Command : 0 Read serial number of mobydic Host sends : <0> Mobydic sends : <0><High Byte serial><low Byte Serial> Serial number = 0 for beta chip Command : 0 Read version number of mobydic Host sends : <0> Mobydic sends : <0><High Byte version><low Byte version> Version.00 => 00 decimal Command : 05 Read protocol Nr. Host sends : <05> Mobydic sends : <05>< protocol HB><protocol LB> Protocol 0x0000 = no protocol 0x0 = ISO9-0x0 = ISO9-0x0 = KWP000 slow init 0x0 = KWP000 fast init 0xFF = protocol found by user Command : 06 Tester present Host sends : <06> Mobydic sends : <06><ACK> Command : 07 Set KWP000 parameter Host sends : <7> Mobydic sends : <ack> Host sends : <init pattern><interbyte time><keep alive> Mobydic sends : <07><ack> Slow Init pattern = normally 0x but user can send another pattern. Interbyte =..0 ms default is 0mS Keep alive = default is. sending a 0 stops the auto keep alive fonction

9 Command : 0 Get Keywords Host sends : <> Mobydic sends : <><kw><kw> Kw = detected Keyword Kw = detected Keyword Command : 09 seek protocol Host sends : <9> Mobydic sends : <ack> or <nack> If mobydic doesnt find any protocol, user can try to change the Headers and search again for a valid protocol using this command. The Green LED indicates a succesfully connection to ECU. 9

10 Command : direct access to ECU via KWP000 Host sends : <> Mobydic sends : <ack> Host sends : <length><kwp000 string> Mobydic sends : <><length><kwp000 response string> Or <> <00> for no response Or <><0x> format error checksum error Functional addressing : KWP000 string = <0xC><0x><0xf><0x0><0x0d> Service PID 0d ( vehicle speed request ) CS is calculated by Mobydic KWP000 response string: <0x><0xf><ECUadd><0x><0x0d><speed><CS> Pysical addressing : ECU address = 0x7a KWP000 string = <0xC><0x7a><0xf><0x0><0x0d> Service PID 0d ( vehicle speed request ) CS is calculated by Mobydic KWP000 response string: <0x><0xf><0x7a><0x><0x0d><speed><CS> All timeout for communication is according to ISO

11 Command : 5 Send KWP000 Keep alive message to ECU Host sends : <5> Mobydic sends : <5><ack> Once the Mobydic is connected to ECU by a Init ISO slow init command ( 9 ) or Init KWP000 fast init command ( ) there is a timeout of 5 sec. if during this timeout no activity is detected by ECU the communication is interrupted and a init sequence must begin by tester. Normally we don t need to send this command for ISO 0- because mobydic connects automatically to ECU and a keep alive message is performed by mobydic automatically every sec..