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stringcharasciistcodesys

How to get ASCII code of char in Codesys?

I need to get a byte code of char in Codesys (using ST language). Is there a way to do it?

For example, in c++ it is quiet straightforward:

int c = 'h';
Solution

  • There are few ways to do that but concept is the same. You convert it to BYTE.

    VAR
    sTest: STRING(1) := 'h';
    bChar: BYTE;
END_VAR

bChar := STRING_TO_BYTE(sTest);

    But I like most use pointers. Here is example of function that return ASCII code of given character in a string.

    FUNCTION STRING_TO_ASCII: BYTE
    VAR_INPUT
        pbIn: POINTER TO BYTE;
        bCharNum: BYTE; (* Character number in a string start with 0 *)
    END_VAR
    pbIn := pbIn + bCharNum;
    STRING_TO_ASCII := pbIn^;
END_FUNCTION

    Now you can use it in program

    VAR
    sTest: STRING(250) := 'Hello Wold!';
    bChar: BYTE;
END_VAR

bChar := STRING_TO_ASCII(sTest, 0); (* Character H *)
bChar := STRING_TO_ASCII(sTest, 1); (* Character e *)