if(connect(deviceIquiry,SIGNAL(sendStatus(QString) ),this,SLOT(displayStatusMessage(QString))))
std::cout <<"SUCCESS SIGNALS / SLOTS CONNECTED "<< std::endl;
Do you see this message? Note that connect() does not return a bool, it returns an object of type QMetaObject::Connection. However, this class does have a bool() cast operator, which does return true if the connection was made. So you lucked out with this.

#ifdef TRACE
std::cout <<"TRACE START emit sendStatus \nFunction "<< __FUNCTION__ << "\nFile " << __FILE__<< "\n@Line # "<< __LINE__<< std::endl;
#endif

emit sendStatus( "Status from SomeMethod" );

#ifdef TRACE
std::cout <<"TRACE END emit sendStatus \nFunction "<< __FUNCTION__ << "\nFile " << __FILE__<< "\n@Line # "<< __LINE__<< std::endl;
#endif
This isn't really testing for anything. The "emit" will happen even if there are no slots connected to the signal. If no slots are connected, there is no error, Qt just eats the signal and does nothing.

Change your connect() statement to this and see if that helps:

Qt Code: 
  1. connect( deviceIquiry, SIGNAL( sendStatus( const QString & ) ), this, SLOT( displayStatusMessage(const QString & ) ) )
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Your original code does not really match the function signatures for either the signal or the slot.

Qt Code: 
  1. /*
  2.     QStatusBar * pStatusBar = statusBar();
  3.     pStatusBar->showMessage( message, 5000 );  // A 5 second timeout
  4.     */
  5.  
  6.     ui->statusbar->showMessage(message,5000);
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And have you verified that the pointer returned by QMainWindow::statusBar() is the same as your ui->statusbar? If not, maybe you should consider implementing that part of the slot in the same way as I did in my example.