labviewbeginner

thanks for the big explaining.

Yes i tried it also with memcpy(pointer, datatable, sizeof(datatable));

But all the time labview crashes (just close without warning) when i start labview.

I made me a test.vi: in this i just want to get the data from c to an array in labview.

I did this:    constant uint16 - bundle 7 times to get a cluster with 7 uint16 - then i made "initialize array" and wired the cluster in the above input and by the dimension size i made  "constant int32" (this data type came automatically) then i wired it to the CFN. In the CFN i made "return type = numeric, signed 32-bit Integer" "arg1 = Adapt to type -> Handles by value".

My C code is this:

struct{ 7xuint16_t Integer}table;

table datatable[16];

int32_t LV_DLL_EXPORT func(struct *pointer)  

{

     copy_to_datatable();

    memcpy(pointer, datatable, sizeof(datatable));

    return 1;

}

in the CFN the prototype is this : "int32_t func(void *arg1);

And then i wired the CFN with an indicator array. This array i build like this in the FP : i took array. Then i took a cluster and put this into the array. In this cluster i put 7 numeric constant of the data type uin16.

So now i have an 1D array with one cluster with 7 numeric constants. now i just raise the size of the array that i have 16 clusters in line.

But still if i want to start the vi. it crashes without saying anything. So i think that i write or copy something into a position in the memory where something is written so that it should not be copied there.

Or can you explain me what i make wrong?

thanks anyway for the big help to understand it better.

regards.

labviewbeginner

ps: i put labview screenshots attached

Thanks for the answer,

1) yes you are right. But at least i have to try it .

2) But the memory usage of the C file should be fitting to the labview vi. Am i right? So i need to know how i can solve this difference between the C 224-Bytes and the labview 224+x Bytes for the dataspace management. How can i do this?

3) ok thanks. So am i right that i need to use the CFN not the CIN?

4) ok if i have the struct and the function like above:

struct{ 7xuint16_t Integer}table;

table datatable[16];  (here is C allocating the memory for the array with struct of integers if i am right)

int32_t func (struct *pointer)

{

     copy_in_table();  (this copies my data into the table)

    pointer = datatable;  (did you mean it like this? that i can give the pointer the data of the table, because C is using arrays as pointers as i read somewhere)

 return 1;

}

Is this correct? Because if you say yes i dont know why my Labview all the time crashes without any error warning. it just closes itself.

Yes sorry for this i will stick to this forum.

Thanks.

LabviewBeginner

Hello,

i have a problem.

I am writing a C code and i have to edit an existing Labview code.

My big problem is with the CFN that i dont know how to get the data from the array of structs with integer (array of 16 structs with 7 integer elements) into an array of cluster of 7 integers.

I tried it with struct {..7 integer (each uint16_t)..}table;  struct table[16];

"int32 func (struct *pointer)" and memcpy( pointer, table, sizeof(struct)*16); , and then my labview crashes without any error warning. And i found out via debugger from visual studio, that i think memcpy is saving his data into the memory of labview where it isnt allowed to save it.

so my first question is:

1) if i make a numeric constant and bundle 7 types of it to one cluster and use "build array" and make all of this before the CFN, is the memory for this allocated and the value is "0"?

Second:

2) how much bytes are allocated for this? How can i look how much bytes does an array of 16 cluster with each 7 uint16-integers need?

3) What is the difference between Call Library Function node and "call interface node" exactly?

4) If i have another three function in C which copies some data into the C array "table" how can i get the data from this "table" into Labview when i only have the possibility to return void, numeric or string??

Because as far as i know i need in Ansi C for the array of 16 structs with 7 uint16_t-Integers  224 Bytes (16*7*2Bytes) . Am i correct by this?

I think the most problem is about the memory handling here.

About help i am very grateful.

Sincerly

Labviewbeginner