I just tested on the bench and both my Futaba 9C with the XPS-F1 transmitter module and my Taranis with the XPS-J1 transmitter module show a rapidly flickering green led when in normal operation connected to a receiver.
When I press the range test (prog) button on the transmitter module, the led turns solid red. when I release the button it goes back to flickering green.
When I press the range test (prog) button on the transmitter module, the led turns solid red. when I release the button it goes back to flickering green.