Converting String to Bits

PLCnext Engineer
1

Hallo, I´m having a hard time programming with the PCWorx Engineer.

There are a lot of basic FunctionBlocks/Functions meantioned in the help center and/or selectable in the programming interface, which are not implemented for the PLCnext. Examples: WORD_TO_BITS
When I type this in ST-Code there is a quick help (showing the function arguments order) for it but it is not working. PULSE_GEN
German error msg:
“Die ausgewählte Ressource axcf2152:OLC unterstützt die Programmorganisationseinheit ACTF nicht”
“Die ausgewählte Ressource axcf2152:OLC unterstützt die Programmorganisationseinheit PULSE_GEN nicht” I could add more examples…
Could you help me to find an efficient way to convert a String containing a HEX number to Bits? The String could look like this “input;00C3” and I need to split this into Bits. Converting the String into a Number always converts it from DEZ to whatever. I don´t know how to Handle it as HEX Numbers.
My Workarround in ST is not really efficient:

/*parse string: input:0000KOMISCHESZEICHEN*/  
>    
>  //cut number from String  
>  str_tmp:= str_in;  
>  str_tmp:= DELETE(str_tmp,6,1);  
>    
>  //number String to Buf (takes number as DEZ but is really HEX)  
>  b_cpyRdy:= STRING_COPY(str_tmp,buf_tmp,0,4);  
>  r_tmp:= 0;  
>    
>  //reconvert false DEZ to real DEZ  
>  (* Variable und alle Werte müssen vom Typ INT sein *)  
>  FOR int_i := 0 TO 4 BY 1 DO  
>      int_x:= int_x+1;  
>      CASE TO_INT(buf_tmp[int_i])(* Ausdruck (muss einen INT Wert zurückgeben*) OF  
>          48: ;//0 -> muss nicht berechnet werden!  
>          49: r_tmp := r_tmp + 1*EXPT(anyreal16,3-int_i);//1  
>          50: r_tmp := r_tmp + 2*EXPT(anyreal16,3-int_i);//2  
>          51: r_tmp := r_tmp + 3*EXPT(anyreal16,3-int_i);//3  
>          52: r_tmp := r_tmp + 4*EXPT(anyreal16,3-int_i);//4  
>          53: r_tmp := r_tmp + 5*EXPT(anyreal16,3-int_i);//5  
>          54: r_tmp := r_tmp + 6*EXPT(anyreal16,3-int_i);//6  
>          55: r_tmp := r_tmp + 7*EXPT(anyreal16,3-int_i);//7  
>          56: r_tmp := r_tmp + 8*EXPT(anyreal16,3-int_i);//8  
>          57: r_tmp := r_tmp + 9*EXPT(anyreal16,3-int_i);//9  
>          65: r_tmp := r_tmp + 10*EXPT(anyreal16,3-int_i);//A  
>          66: r_tmp := r_tmp + 11*EXPT(anyreal16,3-int_i);//B  
>          67: r_tmp := r_tmp + 12*EXPT(anyreal16,3-int_i);//C  
>          68: r_tmp := r_tmp + 13*EXPT(anyreal16,3-int_i);//D  
>          69: r_tmp := r_tmp + 14*EXPT(anyreal16,3-int_i);//E  
>          70: r_tmp := r_tmp + 15*EXPT(anyreal16,3-int_i);//F  
>          //usw A,B,C...F  
>      END_CASE  
>  END_FOR  
>    
>  int_x:= TO_INT(r_tmp);  
>  w_out:= TO_WORD(int_x);

Thanks for your help, Jimmy Pesto

2

Hello Jummy, If you can tell me the version of PC Worx Engineer you are using, I can look into this further. The next version of software (now called PLCnext Engineer) should be available in the coming weeks, and I hope that you will not have the same issues with the new version. For the string conversion, I suggest the following:

                                               1. Prepend the text "WORD#16#" to the string that represents the hexadecimal number. So the text "**00C3** " will become "**WORD#16#00C3** "
                                               2. Use the TO_WORD function to convert the text to a 16 bit number.

Note that you can use different prefixes and conversion functions, depending on the number of hexadecimal digits you need to convert at once.
* 2 digits = BYTE
* 4 digits = WORD
* 8 digits = DWORD
* 16 digits = LWORD
You can then refer to the individual bits in the BYTE, WORD etc. using dot notation - e.g. MyVar.X0 to refer to bit 0 in the variable MyVar. Hope this helps. - Martin.

3

Hey Martin, thanks for your quick response. I´m currently using PC Worx Engineer 7.2.2. Nice, I wasn´t aware of the possibility to specify the number system within the string. It works like acharm. Is there also a way to set Bits in a Word more efficiently then in my solution? w_out:= w_out AND NOT SHL(bitOne,n_0);

w_out:= w_out OR SHL(b_0,n_0);

w_out:= w_out AND NOT SHL(bitOne,n_1);
w_out:= w_out OR SHL(b_1,n_1); This helped a lot, greetings, Jimmy

4

Hi Jimmy, Re. software version: You can download a later version (7.2.3) from our website, maybe give this a try and see if the problems remain? If so, perhaps you can send a small project showing the problem(s). Re. setting bits in a word: You can do this a few ways: 1. Use dot notation, so to set the first (least significant) bit in a word: w_out.X0 := TRUE; With this notation, you can’t use a variable to specify the bit number. 2. Use the “bit manipulation functions” - e.g. GET_BIT(), SET_BIT(), RESET_BIT(), INVERT_BIT(). Using these functions, you can use a variable to specify the bit number. Hope this helps. - Martin.