A keystone module is a standardized snap-in package for mounting a variety of low-voltage electrical jacks or optical connectors into a keystone wall plate, face plate, surface-mount box, or a

patch panel A patch panel is a device or unit featuring a number of jacks, usually of the same or similar type, for the use of connecting and routing circuits for monitoring, interconnecting, and testing circuits in a convenient, flexible manner. Patch ...

. Keystone modules have a rectangular face of 14.5 mm wide by 16.0 mm high and are held in place with flexible tabs. This allows them to be snapped into a mounting plate with correspondingly-sized rectangular holes, called ports. Most keystones are interchangeable and replaceable. This provides much flexibility in arranging and mounting many different types of electrical jacks in one plate or panel without requiring customized manufacturing. Some keystones use a pass-through type connector, where there is a jack on both the front face and the rear side. Others only have a jack on the front and employ a different mechanism for hard-wiring signal cables to the rear, such as a mini 110 block, an

insulation-displacement connector An insulation-displacement contact (IDC), also known as insulation-piercing contact (IPC), is an electrical connector designed to be connected to the conductor(s) of an insulated cable by a connection process which forces a selectively sharpe ...

, or a crimp or

solder Solder (; NA: ) is a fusible metal alloy used to create a permanent bond between metal workpieces. Solder is melted in order to wet the parts of the joint, where it adheres to and connects the pieces after cooling. Metals or alloys suitable ...

connection.

Types

Many types of jacks are available in the keystone module format, limited mainly by their physical size, including: *

6P6C A modular connector is a type of electrical connector for cords and cables of electronic devices and appliances, such as in computer networking, telecommunication equipment, and audio headsets. Modular connectors were originally developed for ...

( RJ-11) modular jacks (telephone) *

8P8C A modular connector is a type of electrical connector for cords and cables of electronic devices and appliances, such as in computer networking, telecommunication equipment, and audio headsets. Modular connectors were originally developed for ...

(

RJ-45 A registered jack (RJ) is a standardized telecommunication network interface for connecting voice and data equipment to a service provided by a local exchange carrier or long distance carrier. Registration interfaces were first defined in t ...

) modular jacks (computer networking), unshielded for UTP cable and shielded for STP. *

F connector The F connector (also F-type connector) is a coaxial RF connector commonly used for "over the air" terrestrial television, cable television and universally for satellite television and cable modems, usually with RG-6/U cable or with RG-59/U c ...

(TV antenna/cable/satellite), 75 ohm coaxial *

RCA jack The RCA connector is a type of electrical connector commonly used to carry audio and video signals. The name ''RCA'' derives from the company Radio Corporation of America, which introduced the design in the 1930s. The connectors male plug an ...

s (audio/video) * 4-pin mini-DIN (

S-Video S-Video (also known as separate video, Y/C, and erroneously Super-Video ) is an analog video signal format that carries standard-definition video, typically at 525 lines or 625 lines. It encodes video luma and chrominance on two separate channe ...

jacks) *

HDMI High-Definition Multimedia Interface (HDMI) is a proprietary audio/video interface for transmitting uncompressed video data and compressed or uncompressed digital audio data from an HDMI-compliant source device, such as a display controller, ...

jacks (high-definition video and audio) *

Optical fiber connector An optical fiber connector joins optical fibers, and enables quicker connection and disconnection than splicing. The connectors mechanically couple and align the cores of fibers so light can pass. Better connectors lose very little light due ...

s *

BNC connector The BNC connector (initialism of "Bayonet Neill–Concelman") is a miniature quick connect/disconnect radio frequency connector used for coaxial cable. It is designed to maintain the same characteristic impedance of the cable, with 50 ohm and ...

(50 ohm coaxial) *

USB Universal Serial Bus (USB) is an industry standard that establishes specifications for cables, connectors and protocols for connection, communication and power supply (interfacing) between computers, peripherals and other computers. A broad ...

jacks *

Speaker terminal A speaker terminal is a type of electrical connector often used for interconnecting speakers and audio power amplifiers. The terminals are used in pairs with each of the speaker cable's two wires being connected to one terminal in the pair. S ...

s *

Banana connector A banana connector (commonly banana plug for the male, banana socket or banana jack for the female) is a single-wire (one conductor) electrical connector used for joining wires to equipment. The term 4 mm connector is also used, especiall ...

s *

Binding post A binding post is a connector commonly used on electronic test equipment to terminate (attach) a single wire or test lead. They are also found on loudspeakers and audio amplifiers as well as other electrical equipment. History A binding post ...

s * 3.5 mm TRS connector (miniature stereo headphone jack) *

British telephone socket British telephone sockets were introduced in their current plug and socket form on 19 November 1981 by British Telecom to allow subscribers to connect their own telephones. The connectors are specified in British Standard BS 6312. Electrical chara ...

either as a master socket or a secondary socket Assortment of keystone modules

History

The origin of the "Keystone" module may be traced back to US Patent 4261633 of Aug 27, 1979 for a "Wiring module for telephone jack" - by Amp Incorporated. The module referred to in that patent was affixed by "A pair of diagonally inclined mounting flanges (which) include stepped, panel bearing surfaces .. at the outer free ends thereof." The unit was "inserted through the panel opening, with the sides of the opening resiliently deflecting the (mounting flanges), until they pass through the opening and spring outwardly away from the remainder of the housing, with the panel bearing surfaces .. thereof seated against the front surface of the panel". However, the current design (now called "Keystone") is first referenced in US Patent US 5624274 of Nov 7, 1995 for a "Telephone connector with contact protection block" - by International Connectors And Cable Corporation. In this design the module is affixed by a single diagonally inclined mounting flange, together with a protuberance (ramp) on the opposite side. In the patent description, it is stated that "the jack assembly may be mounted to a face plate by first inserting the bottom of the jack assembly into a jack opening until the ramp of the housing engages a mounting surface of the face plate. The jack assembly is then rotated and snapped into place due to deflection of the cantilever latch of the housing."

References

External links

{{Commons category inline, Keystone modules Electrical signal connectors