LabWindows/CVI
unsigned char array to callbackdata problem with memset
Solved!
Never used in this way 
now my callbackdata isn't working because when the LoadAlarmPage() finish the byte_all became freed so i think i will do something like this.
using static unsigned char byte_all[16] in the timer callback and doing memset when discarding the timer, or do you think there is a better option?
void LoadAlarmPage(void)
{
int panelAHandle = {0};
panelAHandle = LoadPanel(0, "allarmi.uir", PANEL_ALL);
if (panelAHandle < 0)
{
return;
}
// do something
if (InstallPopup(panelAHandle) < 0)
{
DiscardPanel(panelAHandle);
}
return;
}
int CVICALLBACK PanelAllarmiCallback(int panel, int event, void *callbackData, int eventData1, int eventData2)
{
switch(event)
{
case EVENT_CLOSE:
DiscardPanel(panel);
break;
}
return 0;
}
int CVICALLBACK Gest_All(int panel, int control, int event, void *callbackData, int eventData1, int eventData2)
{
static unsigned char byte_all[16] = {0};
union S_DB10 *DB10 = {0};
int i = {0};
switch (event)
{
case EVENT_TIMER_TICK:
switch (control)
{
case PANEL_ALL_TIMER: //
DB10 = GetPointerToDB10();
if(memcmp(DB10->byte_all, byte_all, sizeof(byte_all)/sizeof(unsigned char)) != 0)
{
memcpy (byte_all, DB10->byte_all, sizeof(byte_all)/sizeof(unsigned char));
DebugPrintf ("%s: 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x\n", __FUNCTION__, byte_all[0], byte_all[1], byte_all[2], byte_all[3], byte_all[4], byte_all[5], byte_all[6], byte_all[7], byte_all[8], byte_all[9], byte_all[10], byte_all[11], byte_all[12], byte_all[13], byte_all[14], byte_all[15]);
}
ReleasePointerToDB10();
break;
}
break;
case EVENT_DISCARD:
memset(byte_all, 0, sizeof(byte_all)/sizeof(unsigned char));
break;
}
return 0;
}
and 
i think this will be too hard to debug in case of problem but thanks a lot!
Fmt (msg, "%s: 0x%*d[zb1w2p0r16j1] \n", __FUNCTION__, 16, byte_all); DebugPrintf (msg);
P.S. i think Mr Robert developing level is over 9000 
Define the variable as static in LoadAlarmPage instead, so it is retained and will be valid for other functions as well.
I made up a little example for you to see, more or less in the line of what you already developed.
With reference to that little tip about displaying in hex values, I suggest you to read Fmt documentation: Fmt is a powerful instruction that can do a lot of things. In my line I told the command to read a string, elaborate it as a byte array, consider individual bytes and write each of them in hex format in 2-characters fields padded with zeroes, separated by a space, passing the actual string lenght as a parameter to make it universal Nice job for a single instruction, isn't it? 
There may be a misunderstandinf on my part. YOU were using the callbackData mechanism so I answered considering to address that scenario and giving you some hints on how to make it work.
If you were using a global variable, then using callbackData is not needed any more: simply manipulate variable value where appropriate.
When passing to use globals, though, please consider that they are listed among bad programming practices since they increase program complexity exactly for them being potentially modifiable everywhere in the code: you need to protect yourself from multiple unwanted access and you may find the variable has been modified unexpectedly. All these events need to be considered in developing the application so the use of locals may be preferrable since they are more limited in scope and more controllable.
