how can i program a usb interface using ni-visa

[MXI Master]

I have a feeling that FF6 has some nulls in the middle of it. Is that character in the [1] index a 0? 

This Discussion Forum discusses has some suggestions, this is a basic tenant of C programing.

[siul82mx]

Thanks a lot that was the problem and i did not notice before, the 2nd byte on the string is a cero, so that´s why it only shows the 1st byte fo the string. Your support have been excellent.

[siul82mx]

Hi Marshall now i have another problem with respect the data Type.I read some attributes from my device but the problem comes when I want to show them on the pront panel of the user interface because the commands need a diferente type of values. For example when i use this function:  viGetAttribute (instrument, VI_ATTR_USB_BULK_OUT_PIPE, &bulkoutpipe); i can only put the name of the variable that i will use to save the value of the data, and by default this variable is an integer (teh program uses ViInt16) and till here is ok, i got the value from my device with any problem, but now the next step is display this value on the user interface using a text box and i have to use the next command:      InsertListItem (panelHandle, PANEL_CONFIG, 1, bulkoutpipe, bulkoutpipe); but here by default the variable to show is a character array and i can not select another type of variable, so when i run the program i got the message error that says: Type error in argument 4 to 'InsertListItem';found 'ViInt16' expected 'pointer to const char'

Here is the code in the function where i have the problem:

int CVICALLBACK GetConfig (int panel, int control, int event,void *callbackData, int eventData1, int eventData2)
{
// char bulkoutpipe[256];
 ViInt16 bulkoutpipe;
 ViChar name[256];
 unsigned char idnresult[72];
 ViUInt32 retcount;
 
 switch (event)
  {
  case EVENT_COMMIT:
    DeleteListItem (panelHandle, PANEL_CONFIG, 0, -1);
    viGetAttribute (instrument, VI_ATTR_RSRC_NAME, name);
       InsertListItem (panelHandle, PANEL_CONFIG, 0, name, 0);
    viGetAttribute (instrument, VI_ATTR_USB_BULK_OUT_PIPE, &bulkoutpipe);
  
  
  //  viGetAttribute (instrument, VI_ATTR_USB_BULK_IN_PIPE, &bulkinpipe);
    InsertListItem (panelHandle, PANEL_CONFIG, 1, bulkoutpipe, bulkoutpipe);
   
   
    //viGetAttribute (instrument, VI_ATTR_USB_BULK_IN_PIPE, &bulkinpipe[0]);
          
   
  //  viWrite (instrument, "*IDN?\n", 6, &retcount);
  //  viRead (instrument, idnresult, 72, &retcount);
  //  InsertListItem (panelHandle, PANEL_CONFIG, 1, idnresult, 0);
      
    SetCtrlAttribute (panelHandle, PANEL_SAVE, ATTR_DIMMED, 1); //enable the button SAVE 

   break;
  case EVENT_RIGHT_CLICK:

   break;
  }
 return 0;
}

Can you help me again please?. Thanks , bye

[MXI Master]

I believe the command you are looking for is sprintf, I will refer you to the CVI help as to how to properly use the command since there are various formats you can choose from. I would highly recommend checking this resource in the future as it is very well written and helpful for gaining a simple understanding of the commands available in CVI

[siul82mx]

Ok, thanks for all your help, your support was very good 🙂 .

Bye