Lift gates and related control systems and methods

A method for operating a gate in a manual mode by a user, said method comprising:

• initiating the manual mode to manually open or close the gate;
• determining that the user has pressed a gate close input button;
• closing the gate in response to the gate close input button being pressed;
• periodically determining whether the gate has reached a fully closed position;
• determining whether the gate close input button is still being pressed if the gate has not reached the fully closed position;
• and
• stopping closing the gate if the gate close input button is not being pressed or the gate has reached the fully closed position.

A fail-safe programmable logic controller (PLC) circuit for controlling a gate, said PLC circuit comprising:

• a PLC including a first input terminal and a second input terminal;
• a light curtain switch electrically coupled to the first and second input terminals, said light curtain switch configured to be responsive to a signal from an optical light curtain device that is configured to detect an object in a light curtain, wherein the light curtain switch transmits a stop signal to stop movement of the gate in response to the signal from the optical light curtain device;
• a bump strip switch electrically coupled to the first and second input terminals, said bump strip switch being responsive to a signal from a bump strip positioned on a bottom edge of the gate that indicates that the gate has hit an object to stop movement of the gate;
• [[and]] a laser camera switch electrically coupled to the first and second input terminals, said laser camera switch being responsive to a signal from a laser camera that indicates that an item is in a travel area of the gate to stop movement of the gate;
• and
• a floor loop detection switch electrically coupled to the first and second input terminals, said floor loop detection switch configured to be closed when a floor loop detector detects metal, wherein the floor loop detection switch is separate from the bump strip switch is responsive to the floor loop detector that detects metal and the bump strip switch is responsive to the bump strip on the bottom edge of the gate hitting the object.