Mode 3 Issue

toliphint · Post by **toliphint** » Mon Jul 28, 2014 7:52 am

TPro RT 5.08.8144.00, AUJP $8D

Sorry for long post, but necessary to explain. Have been working on this for some time now and believe there is a bug in the Mode 3 logic if, in a Mode 3 ADX, a request is made for more than one, 2-byte variable in the 0x3000-0x6fff range. Here's why.

Have a simple Mode 3 ADX that requests only 2 items: Spark-TDC (0x3128/29) and Spark-REF(0x30BD/BE). Weirdly, only the first item in the xmit string is reported back correctly. The second is not converted according to the conversion formula but is reported raw. Swap the items in the xmit string, reorder their offsets and same thing. This would be easier to understand if I could send ADX files and logs to an email address.

Example:
Send Request for Spark-TDC(0x3128/29) and Spark-REF(0x30BD/BE)
0xF4 0x5E 0x03 0x31 0x28 0x31 0x29 0x30 0xBD 0x30 0xBE 0x1D

Reply:
timeout: 400
payload offset: 3
payload size: 4
body size: 7 (Also used 8, no difference)

Results:
looking at one sample

Code: Select all

            Spark- TDC &#40;1st item&#41;     Spark-REF &#40;2nd item&#41;
Returned    22.15                     5670.01
Conversion  divide by 0.351563        divide by 0.351563
Result Dec  63.00                     16128.00
Result Hex  3F                        3F00

And thus the MSB of the 2nd item Spark-REF &#40;3F&#41; is same as the LSB of 1st item Spark-TDC &#40;3F&#41;. Every sample this way.

If swap the order of TDC and REF in the ADX file, get same results = TDC, the 2nd item, reported incorrectly.

Additionally, if insert a 1-byte value between the 2 Sparks (eg RPM) the 2nd spark is reported incorrectly as above.

I'm fixated on this because I need to have both Sparks in the same Mode 3 ADX., but as long as both are in there, regardless of what else is in the xmit string, the 2nd transmitted spark reports errantly as above.

again, it appears the problem lies in having more than one 16 bit item in the transmit string.

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EDIT -- And the conversion is the same for both Sparks in the ADX: X * 0.351563
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Help please & thanks in advance!

toliphint · Post by **toliphint** » Wed Jul 30, 2014 5:58 am

Bump, please

Post by **Mangus** » Thu Jul 31, 2014 2:11 pm

Tom, email me the ADX. How are you inspecting the reply? Are you looking at the raw data coming back from the ECM on the ALDL line (through a port monitoring program), or just relying on the data shown in the data list? If the latter, you'd need to provide information on how the ADX Values are configured for the spark values.

-Mark

Post by **Mangus** » Thu Jul 31, 2014 7:13 pm

Thanks for sending the files. That problem is with the ADX Values in your ADX. The first value is at offset 0. The second should start at offset 2 (16-bit values), but you have it/them set to offset 1.

Set the second value to offset 2 and give that a try.