Probably a silly question, any help appreciated

ijm51000

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• Nov 14, 2009

• #1

Hi,

I am just doing an assignment for my college course and I have just one silly question.

On an Allen-Bradley PLC5 what exactly is forced I/O?

I have searched but not found a good answer.

Cheers

 

jrwb4gbm

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• Nov 14, 2009

• #2

How it works. An input or output is forced when it is commanded to either remain true or false with the force instruction. Any normal logic or inputs within the program will have no effect. I'm sure there is a classic textbook answer that is somewhat different.

 

milldrone

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• Nov 14, 2009

• #3

ijm51000 said:

Hi,

I am just doing an assignment for my college course and I have just one silly question.

Click to expand...

This cannot be, any one trying to learn has several.

Welcome to the forum!

 

ijm51000

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• Nov 14, 2009

• #4

Hi jrwb4gbm, That makes sense, thank you a very much for the quick reply

Milldrone, Only one I will waste the forums time with The rest I will keep to myself.

 

Mickey

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• Nov 14, 2009

• #5

See exert from the manual below.

And link below

http://www.plctalk.net/qanda/showpost.php?p=80533&postcount=9

 

Last edited: Nov 14, 2009

ijm51000

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• Nov 14, 2009

• #6

Hi Mickey,

Thank you for the info it explains everything.

what had me confused was the AB documents make such a big deal of saying x amounts of the I/O is forcible making it sound specific to their equipment.

Thanks to all for great information.

Ian

 

Mickey

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• Nov 14, 2009

• #7

Your welcome. And welcome to the forum.

 

shoelesscraig

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• Nov 14, 2009

• #8

Asking stupid questions is how you learn....take it from someone who has asked plenty of them. You want my advice?? Don't stop asking them. The more you ask, the more you learn.