You need to install it as an ActiveX component. Then it will appear on your tool pallet and you can drop it on your project form. You probably want to make it invisible. Then it's as simple as:
procedure TForm1.DoPower(Address: string; PwrOn: boolean);
var
s: string;
begin
If PwrOn then s := Address + ' on' else s := Address + ' off';
ActiveHome1.SendAction('sendplc', s);
end;
The receive function that shows in the components event list is problematic, however.