String to Word Conversion (Codesys)

[EnterDownload]

Hello All

Im using a FESTO PLC with Codesys.

I have a string, named "Program1", which Im trying to convert to a datatype of Word.

Im not sure if the convert function WString_To_Word is the correct function I should be using. When I use WString_to_Word function,

e.g. myTestWord := WString_to_Word("Program1"), I get an output of "0" for myTestWord

myTestWord is a Word data type.

Can someone tell me what Im doing wrong? and how to fix this so that I may get the Word representation of the String ("Program1")?


thanks very much

J

 

[danatomega]

See this thread for some hints:
http://www.plctalk.net/qanda/archive/index.php/t-63488.html

May not be exactly what you want but check it out.

 

[EnterDownload]

hmmm ok danatomega Ill give this a try and re-post if I get a solution

thanks

J

 

[EnterDownload]

SOLVED : String to Word Conversion

Thanks for pointing me in the right direction danatomega!


VAR
text : STRING[5]:='hello';
char : ARRAY[0..5] OF BYTE;
PT : POINTER TO BYTE;
i : INT;
WordIndex: INT;
ProgramWord: ARRAY[1..5] OF Word;
characterbyteindex: INT;
ProgramWordIndex: INT;
END_VAR


(* This program will take a String and convert it to a Word Data type *)
(* Start by separating the characters from the string into an array *)

pt:=ADR(text); // Get the Address of the text variable named 'hello'
FOR i:=0 TO 4 DO
char:=pt^; // Assign the value of the pointer to a Character
pt:=pt+1; // Advance to the next pointer
END_FOR

characterbyteindex:=1;

(* "hello" has 5 characters...2 characters per word, 3 Words *)
FOR ProgramWordIndex:=1 TO 3 DO // The program name can take up to 3 words

//Get 2 bytes at a time, and store the 2 bytes into a word array,
//e.g. BYTE_TO_WORD char[1], BYTE_TO_WORD char[0], BYTE_TO_WORD char[3], BYTE_TO_WORD char[2], ect.

ProgramWord[ProgramWordIndex]:= SHL(BYTE_TO_WORD(char[characterbyteindex]),8)+BYTE_TO_WORD(char[characterbyteindex-1]);

//Advance the index, to get the next 2 bytes
characterbyteindex:=characterbyteindex+2;

END_FOR // ProgramWord will be a collection of words representing the original string

 

[danatomega]

You're welcome - Glad you got it working.