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Discussion Starter · #1 ·
Has anyone got a usb-->serial converter working reliably with VAG-COM???

I can't believe the 12MB/s USB link is the bottle-neck. Sounds like the converter

between USB/Serial. I'm guessing different converters may be able to handle

the transfer rates required by VAG-COM.

Any ideas???

Malc
 

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I haven't used it before but I thought I heard that it didn't work that well through convertors. Maybe Uwe Ross will pick up on this thread.

The company I work for make PC Apps that use COM1 at a highish speed. Some of our recent customers have bought Laptops with no port and they try to use a USB->Com1 and they just don't seem to work very well.

Be interested to see the setup tomorrow Liquorice.

Mr Benn
 

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Discussion Starter · #7 ·
What to do is log some info using the measuring block option in the engine section. This will test out the performance of the convertor to the maxmimum. You should get about 3-3.5 samples per second on one measuring block. This will decrease as you log more blocks.

I'm going to try getting the convertors from a couple of high street shops, as I can always take them back if they don't work!!!

Will be interested to know what your one is though!!

Malcolm
 

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Discussion Starter · #10 ·

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Discussion Starter · #11 ·
BTW, you can alter the delays in VAG-COM to improve the sample rate. I got mine up to 4.5/second.

Posted Image


Try changing Blk Int to 25 and Char Int to 1

This should speed it up. Covered in the FAQ on the VAG-COM website
 

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USB<->Serial converters are plenty fast when you're moving big chunks of data, but the old VAG protocol (KW1281) doesn't move big chunks, it moves one byte at a time. The problem with USB<->Serial converters in this application is latency. The "turn-around" time can be as much as 16mS, which is too long for many control modules.

In addition, many USB<->Serial converters do not properly support some of the non-standard baud rates that the control modules want (example 10,400 baud is a MUST for modern cars).

If you find a USBM<->Serial converter that works with everything in your car, fine, use it. Just understand we don't recommend or support them because of the above issues.

-Uwe-
 

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Discussion Starter · #13 ·
Well, bought another usb-serial converter at the weekend, which worked straight away and can sample at about 4.5 samples a second on one measuring block. Superb...

Will post a piccy, but again, no manufacturing info on it! Bought from a local computer spares shop.

Malcolm
 

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Yeh im after one as well. Went to PC world and they done sell them. They passed me on to www.partsmaster.co.uk but cant find nothing on their website. Keep meaning to try a local PC shop by me but keeps forgetting.

Malky, if i cant get no joy gettin one, fancy making a few quid and picking me up one. That would be spot on cos at least then i know it will def work.
 

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ah feck, dunno wot to do now. Is there any kind of thing im looking for or is it just pot luck???

Edit - found a few on www.maplin.co.uk. Any look familar. i want to connect up my new VAG COM so badly

  • USB to Serial & Parallel - 24.99http://www.maplin.co.uk/media/mediumimages/37209i0.jpg]
  • USB to Serial Adaptor -19.98
    Posted Image

  • USB to Serial 9 Pin Male - 24.98
    Posted Image

 
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