Door and gate glossary, A to Z
Plain-language definitions of the terms you hear when buying, using and servicing automatic doors and gates.
What this glossary is
A reference of the terms used with automatic doors, gates, shutters, barriers and access control, each defined in one sentence. Use the letters to jump, or the search box to find a word.
- Written for owners and managers, not engineers
- Cross-references show related terms
- Safety terms say who should handle the part
Updated
A
- Access control
- A system that decides who may pass a door, gate or barrier, using cards, codes, biometrics or other credentials. See also: Card reader
- AMC
- Annual maintenance contract: a written agreement for planned visits to check and service equipment.
- ANPR
- Automatic number plate recognition: a camera reads a vehicle plate so a barrier can open for registered vehicles. See also: Boom barrier
- Anti-tailgating
- A feature or layout that stops a second person following someone through a door on a single valid credential. See also: Tailgating
- Arm
- The bar of a boom barrier that lifts and lowers across a lane. See also: Boom barrier
B
- Balance
- The state in which a garage door's springs carry its weight, so it stays put at half height and is light to lift. See also: Torsion spring
- Barrel
- The roller above a rolling shutter that winds the slats up. See also: Rolling shutter
- Bi-parting door
- A sliding door with two leaves that open from the centre in opposite directions. See also: Leaf
- Bollard
- A short post used to block, guide or protect vehicles and people, fixed, removable or automatic. See also: Boom barrier
- Boom barrier
- A barrier with a pivoting arm that lifts to let a vehicle pass and lowers to stop the next. See also: Arm
- Breakout panel
- A door leaf or panel that can be pushed open sideways in an emergency so people can leave. See also: Leaf
C
- Cantilever gate
- A sliding gate carried on rollers at one end, so no track crosses the opening. See also: Sliding gate
- Capacitor
- A small component that helps start some single-phase motors; a failed one is a common cause of a humming motor. See also: Operator
- Card reader
- A device that reads a card or tag and sends the result to a controller. See also: Access control, Proximity card
- Clear opening
- The usable width and height of a doorway after the frame, leaf and hardware are accounted for. See also: Opening
- Control board
- The electronic unit that receives commands and signals and drives the motor. See also: Operator, Limit switch
- Curtain
- The flexible or slatted sheet of a rolling door or high speed door. See also: Rolling shutter, High speed door
D
- Dock leveler
- A plate at a loading dock that bridges the gap between the dock and a truck bed. See also: Dock shelter
- Dock shelter
- A frame with cushions or a curtain that seals around a truck at a loading bay. See also: Dock leveler
- Double-skin panel
- An insulated panel with a metal face on each side and insulation between. See also: Sectional door
- Duty cycle
- The number of openings per hour or day an operator is built to do without overheating. See also: Operator
E
- Emergency release
- A means of opening a door or gate without power; see manual release. See also: Manual release
- Encoder
- A sensor that tells the control board the position and speed of the motor. See also: Limit switch
F
- Fail-safe
- A lock that releases when power is lost. See also: Fail-secure
- Fail-secure
- A lock that stays locked when power is lost. See also: Fail-safe
- Flap barrier
- A pedestrian lane with flaps that retract to let a validated person pass. See also: Speed gate, Turnstile
- Force limiting
- A setting that stops or reverses a moving leaf when the push needed to move it rises above a set level. See also: Obstruction detection
- Full-height turnstile
- A floor-to-ceiling rotating cage that admits one person at a time. See also: Turnstile
G
- Gearbox
- The set of gears between a motor and the part it moves. See also: Operator
- Guide rail
- The vertical channel at each side of a rolling shutter or high speed door that holds the curtain. See also: Rolling shutter
H
- Header
- The housing above a sliding door that holds the track, drive and controls. See also: Sliding door
- High speed door
- A fast roll-up door, usually with a flexible curtain, for busy openings. See also: Curtain
- Hinge pillar
- The post on which a swing gate hangs; it carries the weight and the operator's force. See also: Swing gate
- Hydraulic operator
- A drive that uses oil pressure to move a gate or barrier arm. See also: Operator
I
- Inductive loop
- A wire loop cut into the ground that senses a vehicle above it. See also: Loop detector
- Intercom
- A voice or video unit that lets a visitor speak to someone inside before entry. See also: Access control
- Interlock
- A control that lets one door open only when another is closed, as in a mantrap. See also: Mantrap
- Isolator
- A switch that cuts power to equipment so it can be worked on safely. See also: Control board
K
- Key switch
- A switch operated by a key, often used to open or lock a shutter or gate. See also: Manual release
L
- Leaf
- One moving panel of a door or gate. See also: Swing gate
- Limit switch
- A device that tells the operator where the fully open and fully closed positions are. See also: Control board
- Lintel
- The beam across the top of an opening. See also: Clear opening
- Loop detector
- An electronic unit that reads an inductive loop and signals that a vehicle is present. See also: Inductive loop
M
- Magnetic lock
- An electromagnet that holds a door shut and releases when power is removed. See also: Fail-safe
- Mantrap
- A small chamber with two interlocked doors so that only one can be open at a time. See also: Interlock
- Manual release
- A way to disconnect the motor so a door or gate can be moved by hand. See also: Emergency release
- Microwave sensor
- A motion sensor that uses reflected radio waves to detect movement near a door. See also: Presence sensor
O
- Obstruction detection
- A feature that stops or reverses a moving door or gate when it meets something. See also: Safety edge, Photocell
- Opening
- The space in a wall or fence that a door or gate closes. See also: Clear opening
- Operator
- The motor and drive unit that moves a door or gate. See also: Control board
P
- Photocell
- A light-beam sensor across an opening; breaking the beam stops or reverses the door. See also: Safety edge
- Pinch point
- A place where moving parts or a leaf and a fixed part can trap a hand or body. See also: Safety edge
- PIR sensor
- A passive infrared sensor that detects the heat of a moving person. See also: Presence sensor
- Presence sensor
- A sensor that detects a person or object standing in a zone, not only moving. See also: Radar sensor
- Proximity card
- A card read by holding it near a reader, without insertion. See also: Card reader
R
- Rack and pinion
- A toothed rail and a gear wheel that drive many sliding gates. See also: Cantilever gate
- Radar sensor
- A sensor that detects an approaching person or vehicle by reflected radio waves. See also: Microwave sensor
- Receiver
- The unit that picks up signals from remote controls. See also: Remote control
- Remote control
- A handheld transmitter that opens a door or gate. See also: Rolling code, Receiver
- Revolving door
- A door with wings that rotate around a central axis inside a drum. See also: Sliding door
- Rolling code
- A remote security method in which the code changes every time the button is pressed. See also: Remote control
- Rolling shutter
- A door made of horizontal slats that wind around a barrel above the opening. See also: Barrel, Slat
S
- Safety edge
- A sensitive strip along the leading edge of a leaf that reverses or stops it on contact. See also: Obstruction detection
- Sectional door
- A garage or industrial door made of horizontal panels hinged together that lifts on tracks. See also: Torsion spring
- Slat
- One horizontal strip of a rolling shutter. See also: Rolling shutter
- Sliding door
- A door whose leaves move sideways on a track. See also: Header
- Sliding gate
- A gate that moves sideways along a fence or wall. See also: Cantilever gate
- Soft start and stop
- A control that ramps the speed up and down so a leaf starts and stops gently. See also: Operator
- Speed gate
- A pedestrian lane with glass or metal wings that open quickly for a validated person. See also: Flap barrier
- Swing gate
- A gate whose leaves pivot on hinges. See also: Hinge pillar
T
- Tailgating
- Following someone through a controlled door without your own credential. See also: Anti-tailgating
- Torsion spring
- A wound spring above a sectional door that balances its weight; it holds heavy tension and is for trained hands only. See also: Balance
- Tripod turnstile
- A pedestrian turnstile with three arms that rotate to admit one person. See also: Turnstile
- Turnstile
- A rotating or barrier device that admits one person at a time. See also: Tripod turnstile, Full-height turnstile
U
- Underground operator
- A swing gate drive buried in the ground beside the hinge. See also: Swing gate
W
- Wicket gate
- A small pedestrian door set in or beside a larger gate. See also: Swing gate
- Wiegand
- A common signal format between access readers and controllers. See also: Card reader
No term matches.
Parts for trained hands only
- Torsion spring
- Control board and isolator
- Gearbox and hydraulic operator
- Force limiting settings
Owners can wipe sensor lenses and test the reverse with a soft object. Everything else is a technician's job.
Questions people ask
What is a photocell on a gate?
A photocell is a light-beam sensor across the opening. If something breaks the beam while the gate is closing, the gate stops or reverses.
What is duty cycle?
The number of openings per hour or day an operator is built to handle without overheating.
What is the manual release?
A way to disconnect the motor so a door or gate can be moved by hand when power fails.
What is a mantrap?
A small chamber with two interlocked doors, so only one can be open at a time.
What is rolling code?
A remote security method in which the code changes with every press, so a copied signal cannot be reused.
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