Dear all,

not sure if this is a problem, a bug or what, and also not sure if this is the correct section on where to post this.

Yesterday I noted a strange behaviour in my KTP 900 comfort with my glorious D425-2 controller.

System is: TIA 13.1. Scout has the latest HF (8 if I rememer correctly, the one that fixed the bad problem of the HMI misalignment). Wincc is the professional or advanced ( i do not remember exactly sorry).

I was visualizing in HMI some DWORD that are contained in Simotion. The DWORD were not "basic variables", but they were contained in an array of structures like in this example:

Myarrayofstruct[1].mydwordvar

Myarrayofstruct[2].mydwordvar

Myarrayofstruct[...].mydwordvar

THe strange thing is this: I download the simotion program (passing by a stop run sequence) and the modifications did not involve these Dword variables but other insignificant parts of the software.

I do not download the HMI.

I go in the KTP900 and see the pages where these mydwordvars are read and I see crazy values, 21000 or ###### or often "0", randomly. They all should be zero because my scout tia , in the watch table, shows me that they are all zero.

So I "force" one of them to, example: "44", but I do not see changing NOTHING, value remains (i.e.) 21000.

I compile HMI, download and everything remain the same (so nothing solved).

I make a recompile ALL of the HMI and all my values are brilliantly zero, and they react when I change them from Scout.

Problem is also that I must do this procedure "almost" all the times I download anything in the SImotion, not sure about the word "all", so I said "almost".

Obviously with other datatypes this does not happen (real, bools, int, dint, ecc ecc). Only with DWORD, and used in an array of structures....

Any idea, guys ? No urgency, but just a question.

Danke

I'll have a D435 to play with tomorrow, I'll see if I can duplicate it.  I avoid arrays since they always confuse me.

Thanks Jeff,

I cannot play tomorrow but only in 6 days...

Remember : array of structure containing a DWORD :)

Please paste the tag declaration of the structure. I will test because I'm curious either.

pigroplc

I hacked together this little bit of test code and I'm not seeing any issues.

INTERFACE
    USES HMI_Variables;
    PROGRAM pDWORDArray;
END_INTERFACE

IMPLEMENTATION
    PROGRAM pDWORDArray
        TYPE
            a: ARRAY[1..4] OF DWORD;
            S1: STRUCT
                    var2: a;
             END_STRUCT;
        END_TYPE
       
        VAR
            MyStruc : s1;
            i : INT;
        END_VAR
       
        FOR i := 1 TO 32000 BY 1 DO
            HMI_Array2 := mystruc.var2[2];
            MyStruc.var2[2] := MyStruc.var2[2] +2;
        END_FOR;
        ;
    END_PROGRAM
END_IMPLEMENTATION

Thanks Jeff,

but it is not what I am using...

I am using an array of datatypes, not one datatype with one array inside:

Mydatatype{

                                 mydwordvar : DWORD;

                                 mybool         : BOOL

                    }

Myvar : ARRAY [1..30] OF Mydatatype;

On HMI I try to show the Myvar[1].mydwordvar (1,2,ecc)

Array of datatypes?  Way beyond my feeble programming skills.  I defer to anyone with more experience than I have.  My formal programming training ended with FORTRAN.

If you can write me some simple sample code, I can test it on my C240/KTP700 test system.

Hi Jeff, I take ur piece of code and I modify it:

In HMI you point with the I/O field (output mode) at MyArrayOfStrut[1].a, which is clearly a DWORD.

or [2] or [3]...

What I noted is that, for example here, if you 'd point at
MyArrayOfStrut[9].a (which is not written by my code), you find spurious values (i.e.: 21000). If you do a recompile all of HMI you get 0, which is correct. But if you change ur Simotion code and DL it, you will obtain again a spurious value. If you rebuild all in HMI all returns back ok (showing zero in [9.].a)

INTERFACE
    USES HMI_Variables;
    PROGRAM pDWORDArray;
END_INTERFACE

IMPLEMENTATION
    PROGRAM pDWORDArray
        TYPE

        MyStruct : STRUCT
            a:  DWORD;
            b:  BOOL;
             END_STRUCT;
        END_TYPE
       
        VAR
            MyArrayOfStruct : ARRAY[1..30] OF MyStruct ;
        END_VAR
       

        MyArrayOfStrut[1].a:=410;

        MyArrayOfStrut[2].a:=1090;

       
        MyArrayOfStrut[3].a:=717;

        ;
    END_PROGRAM
END_IMPLEMENTATION

Thanks both Davinator and ChristophD.  I'm still trying to grasp the concept.  Let me play with this and see what happens.

BTW, that is a useful structure.  I keep this is mind for the future.