D-sub

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Conectores de tamaño DA, DB, DC, DD, y DE

Conector DB13W3

Conector macho DB13W3

Los conectores D-sub (del inglés D-subminiature) se utilizan generalmente para conectar ordenadores con distintos periféricos. Aunque cuando se crearon eran realmente pequeños —de ahí su nombre— hoy están entre los conectores más grandes.

Descripción y nomenclatura

Un D-sub son dos o más filas paralelas de contactos (pines), por lo general rodeados por un escudo metálico en forma de "D", que proporciona el apoyo mecánico y protección contra las interferencias electromagnéticas. La forma de "D" garantiza la orientación correcta en la conexión. A la parte que contiene los pines se le llama conector macho, mientras que a la que contiene los orificios se le llama conector hembra. El conector macho se ajusta firmemente en el conector hembra. Los escudos metálicos se conectan a los blindajes de los cables (cuando se utilizan cables de este tipo), creando una barrera eléctrica continua que cubre el cable entero y el sistema de conexión, evitando que los ruidos electromagnéticos interfieran en la comunicación.

El número que incluye la nomenclatura de los D-sub hace referencia a la cantidad de pines de cada conector.

Los conectores D-subminiatura fueron inventados por ITT Cannon, (una compañía de ITT Corporation) en 1952.^[1] El sistema de numeración de las piezas utilizado por Cannon hace uso un prefijo D para todas las series, seguido por una letra que indica el tamaño de la "D" (A=15 pines, B=25 pines, C=37 pines, D=50 pines, E=9 pines), seguido por el número de contactos que lleva el conector, seguido por el "sexo" conector (M=macho, F=hembra). Por ejemplo, DE15M indica un conector D-sub con un conector tamaño 9 pines y 15 contactos macho (típico conector VGA). Los pines de estos conectores tienen una separación aproximada de 0,108 pulgadas (2,74 mm) con las filas separadas 0,112 pulgadas (2,84 mm).

Cannon también fabricó D-subs con contactos más grandes para llevar corriente de alta intensidad o señales coaxiales. La variante DB13W3 se emplea para conexiones de vídeo de alto rendimiento; consta de 10 contactos de tamaño estándar y tres conectores coaxiales para las señales de vídeo RGB (rojo, verde, azul). Se fabrican conectores D-SUB híbridos en una amplia gama de configuraciones por otras compañías, incluyendo Amphenol, Conec, Reynolds Teledyne, Electrónica Assmann, Norcomp, Cinch, 3M, y Tyco. Las variaciones incluyen valores de corriente de hasta 40A, voltajes operativos de hasta 13.500 V, y variantes a prueba de agua que están certificados con las normas IP67.

Debido a que los primeros compatible IBM PC utilizaron conectores DB-25 para sus puertos serie y paralelo, cuando el puerto serie del PC comenzó a utilizar conectores de 9 pines, fueron llamados a menudo DB-9 en lugar de DE-9, debido al desconocimiento de que la B representa un tamaño de carcasa. Ahora es común ver hoy vender conectores DE-9 como DB-9. DB-9 hace siempre referencia a un conector de 9 pines con una carcasa de tamaño E.

Los conectores no estándar D-sub de 23 pines utilizados para unidades de disco externas y salida de vídeo en la mayoría de los ordenadores Commodore Amiga suelen llamarse DB-23, a pesar de que el tamaño de su carcasa es dos pines menor que los conectores DB ordinarios.

En la actualidad hay conectores D-sub que tienen el tamaño de carcasa original, pero más pines, y los nombres siguen el mismo patrón. Por ejemplo, el DE-15, por lo general se encuentran en cables VGA cables, dispone de 15 pines, en tres filas, en una carcasa de tamaño E. Los pines están espaciados 0.090 pulgadas en sentido horizontal y 0.078 pulgadas en el vertical.^[2]) La lista completa de conectores con este espaciado de pin es: DE15, DA26, DB44, DC62, y DD78. Además, siguiendo con la misma confusión mencionada antes estos conectores se llaman también DB, DB15HD, DB26HD, DB44HD, DB62HD, y DB78HD, donde HD es sinónimo de alta densidad. Todos ellos tienen tres filas de pines, excepto el DD78, que tiene 4.

Una serie de conectores D-sub con pine aún más densos se llaman doble densidad, y consiste en DE19, DA31, DB52, DC79 y DD100. Cuentan con 4 filas de pines.

Hay otra familia de conectores similares que es fácil de confundir con la familia D-sub, pero no es parte de ella. Estos conectores tienen nombres como "HD50" y "HD68", y tienen una cubierta en forma de D, pero la carcasa es de aproximadamente la mitad del ancho de un DB25. Son comunes en conectores SCSI.

Los sufijos M y F (masculino y femenino) se utilizan a veces en lugar del original P y S (macho y hembra).

Los conectores D-subminiatura originales se definen ahora por una norma internacional, DIN 41652. El ejército de Estados Unidos también especifica conectores tipo D-subminiatura con el estándar MIL-DTL-24308.^[2]

Typical applications

Communications ports

The widest application of D-subs is for RS-232 serial communications, though the standard did not make this connector mandatory. RS-232 devices originally used the DB25 25-pin D-sub, but for many applications the less common signals were omitted, allowing a DE9 9-pin D-sub to be used. The standard indicates a male connector for terminal equipment and a female connector for modems, but many variations exist. IBM PC compatible computers tend to have male connectors at the device, while modems have female connectors. Early Apple Macintosh models used DE9 connectors for RS-422 serial interfaces (which can operate as RS-232). Later Macintosh models used 8 pin miniature DIN connectors instead.

On PCs, 25-pin and (beginning with the IBM-PC/AT) 9-pin plugs are used for the RS-232 serial ports; and 25-pin sockets are used for the parallel printer ports (instead of the Centronics socket found on the printer itself).

Many uninterruptible power supply units have a DE9F connector on them, in order to signal to the attached computer via an RS-232 interface. Often these do not send data serially to the computer but instead use the handshaking control lines to indicate low battery, power failure or other conditions. Such usage is not standardized between manufacturers and may require special cables to be supplied.

Network ports

DE-9 connectors were used for some token ring and other computer networks.

The Attachment Unit Interfaces that were used with 10BASE5 "thicknet" in the 1980s and 1990s used DA-15 connectors for connectivity between the Medium Attachment Units and (Ethernet) network interface cards, albeit with a sliding latch to lock the connectors together instead of the usual hex studs with threaded holes. (The sliding latch was intended to be quicker to engage and disengage and to work in places where jack-screws could not be used for reasons of component shape.

Computer video output

A female 9-pin connector on an IBM compatible personal computer may be a video display output: MDA, Hercules, CGA, or EGA (rarely VGA or others). Even though these all use the same DE-9 connector, the displays cannot all be interchanged and monitors or video interfaces may even be damaged if connected to an incompatible device using the same connector.

Later analog video (VGA and later) adapters generally replaced these connectors with DE-15 high-density sockets (though some early VGA devices still used DE-9 connectors). DE-15 connectors are similar to DE-9 connectors, but have three rows of five contacts each in the space that in DE-9 connectors is occupied by two rows of contacts. Other common names for DE-15 connectors are HD15, where HD stands for High Density, and (less accurately) DB15 and DB15HD.

Many Apple Macintosh models (beginning with the Macintosh II) used DA-15 sockets for analogue RGB video out. Just prior to this, the Apple IIgs used the same connector for the same purpose, but in a non-compatible way. A digital (and thus also incompatible) RGB adapter for the Apple IIe also used a DA15F. And the Apple IIc used a DA15F for an auxiliary video port which was not RGB, but provided the necessary signals to derive RGB.

Game controller ports

Starting in the late 1970s the Atari 2600 game console used DE9 connectors without the pair of fastening screws (male on the system, female on the controller) for its game controller connectors. In the years following, various video game consoles and home computers adopted the connector for their own game ports, though they were not all interoperable. The common wirings supported digital connections for up, down, left, right, and one or two buttons. Some systems supported connecting a pair of analog potentiometers, or paddles, and on some computers a computer mouse or a light pen was also supported via the game port. These devices were much like joysticks in that they were not typically interchangeable between different systems.

Systems utilizing the DE9 connector for their game port included the Atari 8-bit and ST lines; the Commodore VIC-20, 64, 128, and Amiga; the Amstrad CPC (which employed daisy-chaining when connecting two Amstrad-specific joysticks); the MSX, Sharp X68000, and FM-Towns, predominantly used in Japan; the Sega Master System and Sega Genesis; and the Panasonic 3DO. The Sinclair ZX Spectrum lacked a built in joystick connector of any kind but aftermarket interfaces provided the ability to connect DE9 joysticks.

Many Apple II computers also used DE9 connectors for joysticks, but they had a female port on the computer and a male on the controller, used analog rather than digital sticks, and the pin-out was completely unlike that used on the aforementioned systems. DE9 connectors were not used for game ports on the Apple Macintosh, Apple III, IBM PC systems, or most newer game consoles.

DA15S connectors are used for PC joystick connectors, where each DA15 connector supports two joysticks each with two analog axes and two buttons. In other words, one DA15S "game adapter" connector has 4 analog potentiometer inputs and 4 digital switch inputs. This interface is strictly input-only, though it does provide +5V DC power. Some joysticks with more than two axes and/or more than two buttons use the signals designated for both joysticks. Conversely, Y-adapter cables are available that allow two separate joysticks to be connected to a single DA15 game adapter port; if a joystick connected to one of these Y-adapters has more than two axes or buttons, only the first two of each will work.

The IBM DA15 PC game connector has been modified to add a (usually MPU-401 compatible) MIDI interface, and this is often implemented in the game connectors on third-party sound cards, particularly the Sound Blaster line from Creative Labs. The "standard" straight game adapter connector (introduced by IBM) has three ground pins and four +5V power pins, and the MIDI adaptation replaces one of the grounds and one of the +5V pins, both on the bottom row of pins, with MIDI In and MIDI Out signal pins. (There is no MIDI Thru provided.) Creative Labs introduced this adaptation.

Other

25-pin sockets on Macintosh computers are typically SCSI connectors (again in contrast to the Centronics C50 connector typically found on the peripheral), while older Sun hardware uses DD50 connectors for FastSCSI equipment.

The complete range of D-sub connectors also includes 15-pin DA15s (one row of 7 and one of 8); 37-pin DC37s (one row of 18 and one of 19); and 50-pin DD50s (two rows of 17 and one of 16), these are often used in industrial products, the 15 way version being commonly used on rotary and linear encoders.

The early Macintosh, and late Apple II computers used an obscure 19 pin D-sub for connecting to external floppy disk drives. And the Commodore Amiga used an equally unusual 23-pin version for both its video output and for connecting an external floppy disk drive.

TASCAM used DB25 connectors for their multi-track recording audio equipment (TDIF), and Logitek Audio later did the same for its broadcast consoles, though with different pinouts.^[3] A few patch panels have been made which have the DB25 connectors on the back with phone jacks (or even TRS jacks) on the front, however these are normally wired for TASCAM, which is more common outside of broadcasting.

In broadcast and professional video, "parallel digital" is a digital video interface that utilizes DB25 connectors, per the SMPTE 274M specification adopted in the late 1990s. The more common SMPTE 259M "serial digital interface" (SDI) utilizes BNC connectors for digital video signal transfer.

Tipos y variantes

D-sub connectors exist in at least five types, differentiated by the method used to attach wires to the contacts. These are solder-cup or solder-bucket, insulation displacement, crimp, PCB pins, and wire wrap.

• Solder-bucket contacts have a cavity into which the stripped wire is inserted and hand-soldered.
• Insulation displacement contacts (IDC) allow a ribbon cable to be forced onto sharp tines on the back of the contacts; this action pierces the insulation of all the wires simultaneously. This is a very quick means of assembly whether done by hand or automatically.
• Crimp contacts are assembled by inserting a stripped wire end into a cavity in the rear of the contact, then crushing the cavity using a crimp tool causing it to grip the wire tightly at many points. The crimped contact is then inserted into the connector where it locks into place. Individual crimped pins can be removed later with a tool inserted into the rear of the connector.
• PCB pins as the name suggests are intended to be soldered directly to a printed circuit board and not to a wire. These connectors are frequently mounted at a right-angle to the PCB allowing a cable to be plugged into the edge of the PCB assembly.
• Wire wrap connections are made by wrapping solid wire around a square post with a wire wrap tool. This type of connection is usually used in prototyping.

A smaller type of connector derived from the D-subminiature, and about half the linear size, is called the microminiature D, or micro-D, which is a trademark of ITT Cannon.

Uso

The 25 pin D-sub connector is occasionally used in the recording studio industry for multi-channel analog audio and AES Digital audio.

The D-sub connector family is now in decline for general usage in the computer industry, due to size and cost. For portable devices such as PDAs, MP3 players or mobile phones, the D-sub connector is usually too large to fit. In the laptop computer sector, where weight and size are crucial, many models no longer include D-subs. Even small form factor desktop PCs may find D-sub connectors too large for their value.

Because of the relatively complex shapes and assembly, especially the shaped metal D shield, and screws and nuts for physical securing, D-sub connectors are now quite expensive compared to other, mostly simpler, common connectors. In the retail PC world where margins are very thin, these connectors are a natural target for removal.

The physical design is not friendly to consumer plug-and-play applications. Thin metal pins, especially in higher-density connectors, are easily bent or broken, especially when frequently plugged in "blind" behind equipment. The need to tighten screws for a secure connection is cumbersome. Although ESD and EMI resistant D-sub connectors exist, the fundamental design was never intended to protect from electrostatic discharge or electromagnetic interference or facilitate very high frequency interconnections. Plantilla:Citation needed

For video purposes, the DE15HD connector is in the process of being replaced by DVI and HDMI connectors. A notable exception to this replacement is on the many analog CRT monitors still in use - the analog version of the DVI connector is similar in price and more complex than the D-sub, so adoption in this field is slow.

For the majority of other consumer applications, D-sub serial and parallel connectors have been replaced by the physically much simpler and cheaper IEEE 1394 (FireWire), SATA, USB or Ethernet connectors.

Ver también

• Micro ribbon

Referencias

Enlaces externos

• Conectores D-sub usados en computación
• D-subminiature nomenclature
• A list of common computer connectors, including most D-SUB

Atribución

Este artículo proviene originalmente de Wikipedia que lo licencia simultáneamente bajo las licencias Creative Commons Reconocimiento - CompartirIgual 3.0 y la licencia de documentación libre GNU v.1.2 y posteriores El Museo de los 8 bits lo integra en su wiki bajo cc-by-sa-3.0