void usbDevices_DeviceRemoved(object sender, EventArgs e)
{
Console.WriteLine("USB Remove");
SystemLogBox.AppendText("USB Remove" + "\r\n");
//when device is removed, rd/rw thread will be shutdown.
tXfers_Read.Abort();
tXfers_Read.Join();
tXfers_Read = null;
outEndpoint.Reset();
tXfers_Write.Abort();
tXfers_Write.Join();
tXfers_Write = null;
inEndpoint.Reset();
setDevice();
}