GM 2.8L V6 ALDL - Carbytes

[Dale Klein]

>Unfortunately like Carbytes, it changes $58
>to $56.  Not sure why though.

         I think I understand the reason that the $56 gets changed to 
$58.  Read the macro help and examples in carbytes v2.0 carefully.
         The second byte in a 'frame' or packet is some base value, like 
$56 in my case for 94-95 camaro 8051, plus the number of data bytes 
(everything after the first three bytes) in the message your're 
sending.  so if I'm asking for mode 1 message 0, I'd say  '$f4 $57 $01 $00' 
(and also the hex characters '$CS'  ;>)  )   the $00 is the one data byte.
         that is a 1 data byte message, so $57.  there are other messages 
you might send, like $f4 $56 $08, which is 'shut-up, stop chatter and 
listen', which has only one data byte, so there is a $56.
         To make it easier I believe, although I was confused when I tried 
it out, the program treats the first three? bytes in the macro as the 
message header.  It assumes that the first byte you send is the pcm device 
number, and that the next byte is a base length value, to which it adds the 
total number of bytes you say to send in your little macro command, but not 
counting the device#, length byte or mode (third) byte.  so for the m0m1 
request, I have to say f4 56 01 00 in the macro, and carbytes will send 
what I need:  f4 57 01 00 (and checksum)
         It might depend on how the macros were set up, but I think it 
asumes the second byte you put in the macro command is the base message length.

Here are the macro commands I was using, FWIW.  I did get it to work, ie: 
request and actually receive a few M1M0 packets, but only for short periods 
of time before it would get a checksum error and lock up carbytes on the 
laptop.  It may be the 'wait' setting on the aldl tab...?   the 
Req_m1m0_stream macro below is what would work for short periods.  It sends 
the shutup command a few times, then requests m1m0 data.

IN THE LEFT_HAND WINDOW

Header=$f4,$56

#mode1 message0
m1m0=Header,$01,$00

# Mode $08: Stop chatter
Lock=Header,$08

# Mode $09: Allow chatter
Free=Header,$09

IN THE RIGHT_HAND WINDOW

StopChatter=lock

Req_mode1_mess0=lock,m1m0,free

Req_m1m0_stream=(lock):4,(m1m0):50

ResumeChatter=free



Gather up your bytes, and Good Luck,

Dale


At 08:02 PM 9/14/00 -0500, you wrote:
>Peter Gargano wrote:
> >
> > "Shawn R. Lin" wrote:
> >
> > > I guess I need a new program to play with...
> >
> >   Did you try  ftp://ftp.diy-efi.org/incoming/Scantool.zip
> >
> > I have not played with it yet, so I'd be interested in
> > how you find it - Paul mentioned this program very recently.
>
>Yeah, I tried that one too.  Unfortunately like Carbytes, it changes $58
>to $56.  Not sure why though.  I couldn't get into Mode 1 with Scantool
>by sending any other string either.
>Thanks for the suggestion though.
>
>Shawn

_______________________________________________
Why pay for something you could get for free?
NetZero provides FREE Internet Access and Email
http://www.netzero.net/download/index.html
----------------------------------------------------------------------------
To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org