V_ARMED not automatically enabled...
Having just got V_ARMED working as I want I notice that when a node presents itself and children that the V_ARMED setting seems to be disabled by default.
So a node with child sensor V_TRIPPED and V_ARMED will only display V_TRIPPED as default. You have to go through the menus to enable V_ARMED and that could be an issue for many people who are new to this.
Once found and enabled though, it does do what I want