The LiftMaster 323LM Coaxial Receiver is a Security+ 315 MHz external radio receiver designed to add reliable remote control to gate operators and commercial or residential door openers that accept a dry-contact input. Used as a replacement part or an upgrade, this coaxial receiver interfaces with the operator’s wall-station/step input and uses a rolling-code Security+ signal for enhanced access control. Its coaxial antenna connection supports flexible antenna placement to improve reception in challenging installations, helping extend range when the receiver is mounted inside metal cabinets or near interference sources.
This receiver is intended for use with LiftMaster/Chamberlain Security+ 315 MHz transmitters and wireless keypads, including common models such as 371LM, 372LM, and 373LM. It is not for Security+ 2.0 or MyQ remotes. Installation typically involves wiring the receiver’s relay output to the opener’s control terminals, providing accessory power per the operator’s manual, mounting the antenna vertically, and enrolling transmitters with the receiver’s Learn function. Suitable for retrofit and universal applications, the 323LM is used in residential and commercial settings to restore remote capability to older systems or to standardize multiple operators to the Security+ 315 MHz platform. For safe operation, follow the opener manufacturer’s instructions and applicable UL 325/ASTM entrapment protection requirements.
