Originally Posted by
toyinhawaii
Thanks Steveo...i'm hoping this is my problem and sorry for the elementary question but jus want to confirm that only
"M" D29 (serial data) and "A"(ground) is what is needed. What is “B” (D20 output field service enable) used for?
I can offer some limited information taken from the '97 LT1 code. The FSE input is an analog with value set using an external resistor to ground. There are a few different settings depending on the value of resistor used. Here are my comments from the code:
Code:
*************************************************
* A/D CH6, INPUT 0: ALDL FIELD SERVICE ENABLE
*
* A/D CONVERTER HAS A 10K PULLUP TO +5V
*
* NORMAL MODE R > 40K0 OHM TO GROUND: USE OPEN
* ALDL MODE R < 40K0 OHM TO GROUND: USE 15K0
* R > 6K7 OHM TO GROUND
* BACKUP MODE R < 6K7 OHM TO GROUND: USE 3K9
* R > 2K0 OHM TO GROUND
* FIELD SERVICE R < 2K0 OHM TO GROUND: USE 0K0
*************************************************
The named definition of the modes was taken from info someone else provided (can't remember where I got it...)
I have seen in the code where the FSE when grounded (that is in Field Service Mode) no longer checks the checksum/reset on invalid checksum.
On my board there is an unused connector that was used during development for connection of a test board. FSE is also involved with that operation.
I believe some of the modes have a timeout.
Don't think this answers your question, but for the moment it's what I have.
-Tom
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