May be used in two different ways; as an OPEN only control (all LiftMaster operators) or as an OPEN/CLOSE control (only LiftMaster operators with types B2 and S2 control wiring). In the latter case pulling the cord will open a fully closed door close a fully opened door and reverse a closing door.
Pulling the cord whlie the door is opening will either have no effect (type B2 wiring) or will stop the door (Solid State Logic Control Board).
WARNING: When used on most industrial operators this control will not stop the door. Use another control that has a STOP button in conjunction with this control.
OPEN only (all LiftMaster operators) or SAFETY only (LiftMaster operators with type B2 C2 L2 T T1 or TS control wiring) after vehicle passes over treadle.
The weight of the vehicle compresses an electric switch which sends an open signal to the door.
Requires a 2-wire connection to the operator but does not require power to function