Hello,

I have CAN Dll program for my application,which was separately used.Now I have included the Drivers program into my application Program and I am having this error System Access Violation Exception:Attempted to read or write protected memory.Please help me what is error for.i am attaching the Dll code and Application code which is throwing this error.

[CODE]

The CAN Dll Code

int receive_data(unsigned char *data_output, int *MsgId, XLportHandle g_xlPortHandle){
XLstatus xlStatus, xlStatus_new;
XLevent xlEvent;
unsigned int msgsrx=RECEIVE_EVENT_SIZE;
char *local_data ="11111111";
DWORD status;

xlStatus_new = xlSetNotification(g_xlPortHandle, &h, 1);

WaitForSingleObject(h,1);
xlStatus = XL_SUCCESS;

while(!xlStatus){
msgsrx = RECEIVE_EVENT_SIZE;
xlStatus = xlReceive(g_xlPortHandle, &msgsrx, &xlEvent);---------->Here is the error
if ( xlStatus!=XL_ERR_QUEUE_IS_EMPTY ) {

memcpy(data_output,xlEvent.tagData.msg.data,8);
*MsgId = xlEvent.tagData.msg.id;
return 0;
}

else{
return XL_ERR_QUEUE_IS_EMPTY;
}
}
}

My Application Code which is the receiver thread for accessing the messages got onto the CAN bus.

DWORD WINAPI Rcv_Msg(LPVOID param){
int *MsgId = new int; //msg id from CAN
int RcvVal; //0 = there is data in the queue; 1 = there is no data
unsigned int uMsgId;
*MsgId = 0;
unsigned char CanData[8];
unsigned int i = 0;
unsigned int j = 0;
unsigned int Startbit = 0;
unsigned int Endbit = 0;
float Offset = 0;
float Resolution = 0;
try {
while(vThread_exit.Rcv_Msg){
RcvVal = receive_data(CanData, MsgId,g_xlPortHandle_global);-------->Here is the error

memcpy(&uMsgId,MsgId,4);
UI64 RawCanData;
if(RcvVal == 0){ //there is data in the queue
switch(uMsgId){ //switch statement that parses the incoming message based ON the message id.


So this program builded successfully and while executing it I am getting the error as

Receive thread quit Unexpectedly
system Access violation Exception:Attempted to read or write protected memory.This is often an indication that other memory is corrupt at
xlreceive(int32,Uint32*,s_xl_event*)
at receive_data(Byte*data_output,int32*MsgId,Int32 g_xlPortHandle).


Please help me with this.

Thanks in Advance.

[CODE\]