I have a quick question... what does the 12v socket at the top left corner of the A-164-1 Manual Gate module do The instructions just say " Gate 1 is a bit different: provided that no plug is connected to the input socket it behaves like the other two manual gates (the socket is normalled to +12V via a protection resistor). " Does this just mean that it's a handy 12 volt source If so, is it always on or is it supplied/interrupted by pressing the Gate 1 button

Thanks