Corona Virus Self Isolation Puzzle

[L D[AR2P#0.0]]

For anyone stuck in self isolation, here's a puzzle to keep you occupied.



Attached is a structured text function block that I wrote and used recently (in an S7-1500 plc), the puzzle is to determine what the function block would be used for.....

 

[drbitboy]

well-tempered clavier tuner?


or maybe chromatic tuner?

 

[PLCnovice61]

word to the wise, you normally PM him so people can keep guessing, but then again he never said to PM

 

[drbitboy]

realized that after I posted, but then that guess is more for humour than seriousness ...

 

[ndzied1]

Not familiar with S7 Structured Text. What does the pound sign (#) before the variable names mean? I have never seen this with CoDeSys.

 

[Lare]

Not familiar with S7 Structured Text. What does the pound sign (#) before the variable names mean? I have never seen this with CoDeSys.

It tells that variable is inside of FC / FB block. On this it is located to STAT variables of FB.
Without # it would point outside from FB (like MW20 or DBWxx address directly which could be bad programming on FB if FB is multiused)

 

[L D[AR2P#0.0]]

well-tempered clavier tuner?


or maybe chromatic tuner?

No, neither of these.

 

[L D[AR2P#0.0]]

For codesys, replace all #'s with nothing:

 

[drbitboy]

Is it considered bad practice to write to the outputs* at any point in the FB other than just before a RETURN**?


* Numerator and Denominator, in this case
** whether such RETURN is explicit or implicit

 

[padees]

No experience with Siemens, nor have the software. I guess I'm stuck with Rockwell puzzles, and that will take a lifetime... Well, except when I'm dead, no more puzzles.

 

[L D[AR2P#0.0]]

Can't you copy/paste the structured text?

 

[drbitboy]

Hmmm ....

 

[kalabdel]

Is it considered bad practice to write to the outputs* at any point in the FB other than just before a RETURN**?


* Numerator and Denominator, in this case
** whether such RETURN is explicit or implicit

My answer to your question is no. I prefer to address the outputs at the bottom but I would not consider it bad practice.

But I think you meant addressing the outputs more than once and in this case I would agree.

 

[drbitboy]

possible typo in fb1002.txt: should DINT_TO_REAL be DINT_TO_LREAL, or vice versa?

 

[L D[AR2P#0.0]]

Yes, typo: it should be DINT_TO_LREAL