ebook correction: ladder logic, Digital logic functions

Thread Starter

kintzlr

Joined Jun 26, 2012
8
Hi,

Minor spelling issue on first line of this page:
http://www.allaboutcircuits.com/vol_4/chpt_6/2.html

>We can construct simply logic functions for our...

I think the author meant to say "simple" not simply.

Second issue on the same page....
The discussion of control relay or CR1 is a bit confusing/ambiguous.
Specifically, this line:
"When the coil of CR1 (symbolized with the pair of parentheses on the first rung) is energized."

Which is the first rung? The top wire is labeled 1. However, the lowest wire could also be considered the first rung since the first rung is the lowest rung on a real ladder.

Hope that helps! Thanks for the excellent web site.
- Randy
 

Georacer

Joined Nov 25, 2009
5,154
To be honest, I find all of the ladder logic diagrams extremely confusing myself. Maybe that's because I was never taught ladder logic.
Whenever I see them in the e-book, I just skip them. :p
 

Wendy

Joined Mar 24, 2008
21,848
It is an industrial control diagramming system. I was taught it, but haven't used it for many moons/orbits. I'll eventually review this, unless we can find a more competent volunteer to yea/nay it.
 

BSomer

Joined Dec 28, 2011
433
Hi,

Minor spelling issue on first line of this page:
http://www.allaboutcircuits.com/vol_4/chpt_6/2.html

>We can construct simply logic functions for our...

I think the author meant to say "simple" not simply.
I can agree with this point...

Second issue on the same page....
The discussion of control relay or CR1 is a bit confusing/ambiguous.
Specifically, this line:
"When the coil of CR1 (symbolized with the pair of parentheses on the first rung) is energized."

Which is the first rung? The top wire is labeled 1. However, the lowest wire could also be considered the first rung since the first rung is the lowest rung on a real ladder.

Hope that helps! Thanks for the excellent web site.
- Randy
Ladder logic is read from top to bottom. So the e-book is correct in that the first rung is as labeled "1". Perhaps a clarification in this aspect is needed in the book.
 
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