NIce Aria 400 unable to program gate open/close

[Telboy]

Just trying to complete the installation of a Nice Aria 401 kit. Problem with programming the control unit to recognise/memorise the close and open positions. I start with gate in midway position per the manual then press P3 key. Flashing warning light comes on and gate moves to close position but then stops. I expected gate to close then go to open position then close again. LED's on photocells are flashing approx once per second and the same for the Bus LED. Stop LED is on. I have checked photocells and gate stops if beam is interrupted as gate closes so appears photocells are working correctly. Checked voltage across terminals connected to motor and only 9v and power goes off once gate is closed. P3 LED is flashing which presumably indicates that the process has not been completed.