Abstract: This invention discloses an electronic control system for an Industrial Motor Operator that uses standard steady state logic to improve reliability in rough service wet and dirty environments. It includes means of providing electronic snow limit to close limit sensing removing the need for two switches and radically improving its accuracy. A low voltage switch reverses the high voltage motor wires and at the same time reverses the open limit, close limit, and snow limit sensors mechanical positions. It discloses a system using lamps to indicate that the power wiring is connecting to three-phase motors in the correct sequence or that single-phase motors have their windings correctly phased.

Abstract: A one wire interface for optical emitter-detectors is disclosed that is fail-safe, simple, and includes diagnostics, noise and static protection. Two indicator lamps are used for diagnostics indicating four conditions; a) Ready, b) Not Connected, c) Blocked Beam, d) No power. This allows single or two conductor systems to have the same troubleshooting information as the 4-wire systems.