WinCC C-script Raw data operation.

[AdamF]

Hello.
I have a db which is 1000 INT, and this db is represented in WinCC as a raw data type set of 5x 400 Bytes.
This set is read with a script to form an INT inside, which is working ok.
What i have to do is to multiply the INTs * 1000 and write them back.
I have to do inside wincc because I can't touch db structure.

With the following code:

GetTagRawWait(Kurve1, &Yb[0],    400);
GetTagRawWait(Kurve2, &Yb[400],  400);
GetTagRawWait(Kurve3, &Yb[800],  400);
GetTagRawWait(Kurve4, &Yb[1200], 400);
GetTagRawWait(Kurve5, &Yb[1600], 400);


 for (i=0; i < 1000; i++)
 {
  
    Y = (Yb[2 * i] << 8) + Yb[2 * i +1];        // -- Read 2 bytes, form INT
            Ymul =(unsigned int) Y*100;        // -- Multiply

    printf("Before: %d", Y);
    printf("After: %d", Ymul);
    printf("\n");

    if (Ymul >= 32768) Ymul = Ymul - 65536;
  
    Yb[2*i] =  (Ymul <<8);            // -- Write back INT to 2 bytes
    Yb[2 * i +1] = Ymul &0xFF;
}

I can read my values, i see correct result, but I have trouble writing it back.
It doesnt really matter if i swap bytes or not - my data written back is totally something else.

Do You have any suggestion what I'm doing wrong?
Thank You for any help and suggestions.

EDIT: IF i write them back without changing (Write3 image), my DB remains the same... Now I'm really confused.

 

[AdamF]

Ok I figured it out by myself.

Yb[2*i] =  (Ymul /256)&0xFF;            // -- Write back INT to 2 bytes
Yb[2 * i +1] = Ymul &0xFF;