Good Evening William.
I ordered the RG-11 Hydreon rain detector yesterday and today it was delivered. The pulsar dome relay opens the shutter when there is no current and closes when a 12 volt supply is connected. This implies that I will need have the relay to be off when there is no rain and on when raining.
Switches nos 5 only for very sensitive and 1 and 5 for sensitive and switch 3 on to hold the output for 15 minutes.
I need to get a mounting bracket to fix to the wall and some wires to connect and let you know how I get on.
Thank you for your very comprehensive reply