Help required

[Dave1971]

Dave,

You give us the four functions and your description, then we will give you ours...

two reasons...

1st, homework
2nd, I have no idea what you are talking about, but if you give me a better description then we may be able to help.

"give less then greater then"?? is that two of the functions?

Okay here`s the question.

Modern plcs often come with a number of advanced functions, four such functions are less than, greater than, binary to BCD and PID controls.

I need to evaluate each of these functions in turn by giving examples on how would it be used in a ladderw logic program.

State typical applications for each function.

 

[geniusintraining]

Okay here`s the question.

Modern plcs often come with a number of advanced functions, four such functions are less than, greater than, binary to BCD and PID controls.

BCD... look here on this thread with help from CroCrop and Bernie, I have taken a BCD number converted it to a floating point integer, then done some math then converted it back to a BCD, BCD is limited to 4 numbers max 9999

0000000000000000 this is 16 bit format binary
 
0000 0000 0000 0000 
this word(16 bits) is broken into sections, each section forms a byte or nibble ?? 
 
Each section (byte) can make any number 0-9 the LSB being
0 the MSB (in each byte) is 8, so the value of 1001=9

so in a nutshell, Binary Coded Decimal is another way the a plc will store data and use it so we can view is easier


Greater then and Less then, you can figure out that one, its just as its stated "if A is geater than B"

PID is a book in its own...
But PID is a control, we can use this as a way to make reactions to our needs, if we have a PID 'loop' on a temperature controller we would us P, I and D to help achieve the SP without excessive over or under ramping, but still be able to react fast enough for our needs and changing PV, for more info on PID's read here http://www.controlguru.com/pages/table.html

Hope this helps, as my name states im still in training myself

 

[geniusintraining]

Dave,

I found you a friend... he has the same questions as you, and it looks like all his questions have been answered...

http://forums.mrplc.com/index.php?showtopic=10777

 

[Dave1971]

Dave,

I found you a friend... he has the same questions as you, and it looks like all his questions have been answered...

http://forums.mrplc.com/index.php?showtopic=10777

That is me.