EDDI (Error Diagnostics Dynamically Indicated)

Do you have a link on the web to share?

The only EDDI I could find in 3 minutes of searching was for "Error Detection by Duplicated Instructions", which has duplicate programs running concurrently and comparing the results to the core program, to verify that no bits are accidently flipped during the program execution due to bad memory locations.

Not suitable for PLCs (although it makes you wonder just how immune to corruption the little beasties are. I take it as gospel that a -( )- instruction sets a memory location to the value I expect it to be when I do a -| |-. Or, for that matter, when the PLC is executiong its program, that it doesn't accidently read -|/|- for one scan when I wrote -| |-.

But you've got to believe in something.... I believe I'll have another drink... (-Groucho Marx)
 
Hello, Stantheman;
Siemens used to have a specialized version of their SFC programming software for the S5 PLCs called Graph5-EDDI. You could find the manual on the Siemens website as Graph5_V3, or by doing a search on EDDI. I'm don't remember how far they went to explain the EDDI theory, but you would find an actual implementation of dynamic error diagnostics.
Hope trhis helps,
Daniel Chartier
 
I managed to find a book with a short (very short) chapter on the subject. I should have it in a couple of days & I'll let you know if there is any usable information. The books title is "Programmable Controllers: An Engineer's Guide". Most likely useless, but I'll let you know.

Darren
 

Similar Topics

Further to my request for some help on the explanation of EDDI and its concept. I have found out that this was possibly first implemented by ford...
Replies
1
Views
2,388
I've recently started a new job where all the machines are controlled by mitsubishi PLCs using EDDI logic. I'm trying to find a web site that can...
Replies
0
Views
1,436
In our factory, we use several PLC's from AllenBradly (PLC5/20). In programs are written using the "EDDI"-standard. I'm not very familiar with...
Replies
2
Views
3,847
I have a Sinumerik 828D control panel and its for a CNC machine, the problem is that it gives an error state 700027 tool turret state :S4...
Replies
0
Views
11
I am having a problem communicating my PLC with Drive via Modbus connection. I start by opening the port and there is no problem, but then when I...
Replies
5
Views
64
Back
Top Bottom