Twincat 3 - dynamic matrix size

Hello guys
I have an object actually FB. Inside my FB i got matrix which size I want to be declared once you create instance of my object in Main program. I have done like this: Input parameter of my FB is ppMymatrixPointer : Pointer to Pointer to Lreal; but inside program Iam not sure how to use it this pointer to pointer since this is not working ppMymatrixPointer[x, y].

naturephoenix said:

Hello guys
I have an object actually FB. Inside my FB i got matrix which size I want to be declared once you create instance of my object in Main program. I have done like this: Input parameter of my FB is ppMymatrixPointer : Pointer to Pointer to Lreal;

Ialso have pPointer : Pointer to Real; but inside my FB program Iam not sure how to use it this pointer to pointer since this is not working ppMymatrixPointer[x, y].

Click to expand...

I put
pPointer := __NEW(pointer to real, x) ;
ppMymatrixPointer :=__NEW(pointer to pointerto real, y) ;

a pointer from a pointer is not working good, as you are talking about memoryplaces of memoryplaces. and that is no good.

Admittedly, I have never used TwinCat, but I have never seen a PLC that allowed for dynamic array declaration. What I have seen the ability to pass an array in as a type of pointer, and then use whatever operations I want. The actions aren't stored in a local version of the array, they go straight back to the original.

Wherever the array is declared, it is fixed at compile time, but you can process it dynamically. This prevents things like memory leaks, but still allowed a lot of flexibility.

My goal is to pass size of matrix so just INT to a FB where I make matrix. Operafor __NEW allows that. ITS like mallic in C.

In my example pPointer[] works but ppMymatrixPointer [x,x] does not