On Wednesday, December 4, 2019 at 1:13:59 PM UTC-5, three_jeeps wrote:
On Thursday, November 21, 2019 at 9:33:26 PM UTC-5, Fox's Mercantile wrote:
On 11/21/19 8:09 PM, Clifford Heath wrote:
On 22/11/19 12:35 pm, wrote:
Â*Â*Â* I'm pretty bsure this is a real long shot. I have looked online but
have not yet found something that will help. So I ask here.
Â*Â*Â* The EPROM reader/programmer arrived yesterday and it works fine.
The UV EPROM eraser should be here in a day or two. Amazon apologized
for the delay. So I can copy the EPROMs just fine but I would really
like the ladder programs so that I can make some changes to the
machine.
Â*Â*Â* I understand that the decompiled ladder will noit have mnemonics
but maybe I can decipher it anyway.
Â*Â*Â* The control in question is a FANUC 3T.
Thanks,
Eric
How in heck do yu expect help with a decompiler when you haven't told
anyone what type of CPU it is?
Please try to pay attention.
"The control in question is a FANUC 3T."
--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com
In this case, the 'river to the ppl' took a wrong turn.
with all due respect, FANUC 3T tells you almost nothing wrt what the OP is trying to do. One needs to open the box and find out what CPU is on the main board e.g. intel iX, ARM X, Atmel, etc. etc.
Knowing the CPU defines the ISA of the machine, and one can begin to figure out how to set up a logic analyzer to look at the machine instructions and execution. Configuring a small, simple ladder logic example or 5 and observing the instruction and address trace will provide some insight into what is being R/W to memory, EPROMS, etc. which can then be used to identify and decode the ladder login mnemonics used by the mfg.
From what I know, the approach taken to codify and execute ladder logic mnemonics is unique to the mfg. There are some general schemes/patterns used to execute the ladder program but again, every mfg has their own way of doing things.
If you really need to do things at this level, it is a LOT of work and a fair amount of guessing.
There have been a number of academic papers looking at various issues wrt Ladder Logic in general and in some cases, manufacturer specific details are sometimes contained in the paper. Perhaps googling may help you.
A JTAG connection and associated diagnostic software may be helpful as well.
Good luck
J
I just saw the reference to the 8086 processor. the good news is that there is lots of knowledge about this processor, including how to use a logic analyizer with it. I believe that looking at a static ROM dump of contents may not provide you with the insight for what you want to do. Looking at execution of the system would be more beneficial. But again, a LOT of work
J