... the receiver relay is off, the same as B/C/D.Extend function:(When jumper is off position) press ... on 2 seconds, then goes off automatically, same of B/C/D.2) Non lock modelPress remote button A, the ... A; the receiver relay is off, the same as B/C/D.3) Interlock modelPress remote button A, the receiver ... , the relay A/B/D is offPress remote button D, the receiver relay D is on, the relay A/B/C is off.