SE Modicon M221 SHORT Instruction

[KristienP]

Hi All,
I'm looking for some insight into what the SHORT instruction does. The help file wasn't very useful, as I found the explanation to be confusing.

So far, I've only seen them at the beginning of a rung, and not all rungs have them, so I'm confused why some do and some don't. The logic appears to act the same with or without the SHORT instruction.

Pics attached of the Help File & a rung of code.

Thanks in advance!

 

[Lare]

It don't do nothing. It is same than line, but compiler wants to add it before paraller contacts.



Also line is not allowed on paraller with contact and lead to error. But you can use short to bypasss (shorting) contact on program if you make online edits.

 

[KristienP]

Thank you, I'll continue with assuming I don't need it. It seems to be something from really old versions of the SE programming software.

 

[Lare]

I think that it comes from Schneider Twido series as M221 is sussersor for that. Twido series was new around 20 years ago.


Compiler adds short commands sometimes and if you upload from PLC there is sometimes extra short commands which wasn't on original code.



Short and open are allways true and allways false commands. This is from twidos manual and explains them much better.

 

[KristienP]

Much better explanation. Thank you for taking the time to share.