ALDL stream recycle time

[Ludis Langens]

Dave Zug wrote:
> 
> You mean that the stream is not simply 'completely' populated and THEN spat
> out, that it reads each location just before spitting it?

Yup.  There isn't enough RAM in the ECM to do otherwise.  Actually,
sometime in the late '80's GM started capturing both bytes of a 16 bit
variable before sending them out.  In older ECMs (like the '1227148),
you can get the high byte of the "old" value and the low byte of the
"new" value.  If the injector pulse width went from 254->258->262, it
might look like it went 254->2->262.  This problem is fixed by capturing
all 16 bits before sending the high byte.

> Putting the good stuff in the first 10 bytes and shortening the quantity
> transmitted to 10 would do it if I could have my way.. but the 63 thing
> works if like you say it changes a few times during the 63 byte transmission
> time.

Yes, it's possible to reduce the length of the 63 byte packet.  You'll
have to have custom scan tool software to handle your shortened packet though.

-- 
Ludis Langens                               ludis (at) cruzers (dot) com
Mac, Fiero, & engine controller goodies:  http://www.cruzers.com/~ludis/


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