Flash operation on 550D in 'motion detect'.

[Ragman]

The 'motion detect' feature works very well on my 550D but will not work my hot-shoe rf controller...Yongnuo Rf 603c II.
The Yongnuo 603c triggers my YN560 III flash unit by rf signal when the shutter release button is used . the Rf 603c sits on the 550D hot-shoe connector.
I'm aware that flash on the 550D was discussed in 2013 but at that time there seemed to be no useful conclusion.
I would be very pleased to know that this function already exists (hopefully)