Laurence Gibbs

Doug
I have an iso9141 to rs 232 convertor as per the article in elecktor magazine. I would love the software to go with it that would work on my 964. I am prepared to be a bit of a guinea pig. I have yet to try the scantool.net software which I suspect might work(though is designed for obd11) though I'm sorely tempted. but Porsche specific software would be great. K & L and Gnd & Pwr ain't exactly rocket science to connect up with or without the correct connector. If you would like to supply me with the software i would be most greatfull.

KirkF

What was this article in elecktor magazine about?

Kirk

DougB

If you send me an e-mail I'll send you the software as an attachment.

I'm not positive it will work with your converter. Is there a schematic I could look at?

doug.boyce@hummingbird.com

Laurence Gibbs

I will try and get a copy uploaded. it is the same as the elm scan devices(see www.scantool.net ). Give me a few minutes and I'll dig the magazine out. There may be a back issue section on there website.

Laurence Gibbs

Found mag it's the November 2002 edition of the Elektor electronics magazine. www.elektor-electronics.co.uk the chip is an elm 323 designed to convert iso 9141 to rs 232 levels. try www.elmelectronics.com for the datasheet on this chip.

Laurence Gibbs

Sorry to answer your question Kirk the article was on a vehicle diagnostics adapter. with software desgned for obd11 compliant vehicles.

Gregg-K

I'm the person who has gotten Doug's ScanTool working, using an interface of my own design. It works well.

Regarding the 3rd party 19pin diangostic plug, there is a fellow in the UK who has tooled one up, but he wants $150US for one, inlcuding pins.

That's pretty steep by any measure, so Doug's idea of using a second connector to intercept the K, L, and Power & ground leads is the way to go. A simple DB-9 connecor is inexpensive and well suited to the task.

John Speake

That was me, the $150 is for the complete lead, from KTS 8 way to 19 pin "Porsche special".

Can you read all the control units with your device ?

Regards,

Laurence Gibbs

Hi Gregg
have not yet got round to building the circuit too many other things getting in the way like le mans for instance. I will let you know how I get on.

Colin 90 C2

Ok you've now lured me in. Where can I get the schematics for the converter and who will email me the software?

Colin
chinaloy@yahoo.com

richardheggie

And rather like "Lord Lucan riding Shergar to a third consecutive Derby win" being used as an indication of an improbable event....English....what a wonderful language...try getting a German similarity....still not going to change my 964 for a Rover 75

Richard

Gregg-K

Colin,

I didn't seee your request for my interface schematic until tonight, because I normally read the digests.

I'll email you a pdf of my schemtic privately, so you can build one for your own use.

.. Gregg

Lorenfb

The solution to reading data from the Porsche 964 DME is not as simple as impied
on this thread.

ISO 9141 is the OBDII spec defining the data format and uses the RS232 serial
data protocol which provides ASCII characters. A standard PC with an RS232
port can talk to the K & L lines of an OBDII port or the 964 port. No external
level or electronic circuits are required.

The problem with reading the 964 data is developing the proper command codes
and interpreting the data. This is a form of ODBI which was not standardized as
is OBDII for all '96 and later cars.

The electronic circuits generally available only "strip out" the ASCII characters
from the data stream which can be used by non-PC type scanners to access
the K & L data. The signal level of the K & L lines of OBDII can be 0 to 5 volts.

DougB

"ISO 9141 is the OBDII spec defining the data format and uses the RS232 serial
data protocol which provides ASCII characters. A standard PC with an RS232
port can talk to the K & L lines of an OBDII port or the 964 port. No external
level or electronic circuits are required. "

The 964 diagnostics is based around ISO 9141-1. ISO 9141-2 is the updated ODBII protocol. A level converter IS requires as the logic/voltage levels on the K & L lines are different than rs-232.

"The problem with reading the 964 data is developing the proper command codes
and interpreting the data. This is a form of ODBI which was not standardized as
is OBDII for all '96 and later cars."

The 964 protocol belongs to a group of older "keyword" protocols that were used in many European autos. It's very simalar to VAG's KW 71 protocol. In fact, you can reconfigure the 964 software to connect to an older VW that uses the KW 71 protocol and many of the basic functions will work. The 964's "command codes" were discovered by reverse engineering the Motronic ECU software.

"The electronic circuits generally available only "strip out" the ASCII characters
from the data stream which can be used by non-PC type scanners to access
the K & L data. The signal level of the K & L lines is 0 to 5 volts."

Not sure what you're saying here but the K & L lines operated at 0 to 12 volts.

If you would like a copy of the 964 diag software send me an e-mail.

-doug

doug.boyce@hummingbird.com

Lorenfb

As I said;

"The problem with reading the 964 data is developing the proper command codes
and interpreting the data. This is a form of ODBI which was not standardized as
is OBDII for all '96 and later cars."

No level shifting is required for 0 to 5 volts or 0 to 12 volts, most scanners handle
either. That's the easy part of reading the 964 data. ISO 9141 is MORE than just
the electrical interface. The software interface is the hard part of any scanner
interface. The reverse engineering needs to be done on the Hammer & not on
the DME.

You should be able to hookup a PC via the Comm1 port, if you have the 964
diagnostic software and you've converted it to run on a PC. Because the software
is "easily available", that's why we have so many scanners available for the 964
on the market now, right?