Patent Publication Number: US-6217228-B1

Title: Fiber channel drive adapter

Description:
TECHNICAL FIELD 
     The present invention relates to a fibre channel drive, and in particular, to the pluggability of that drive. 
     BACKGROUND 
     Fibre Channel is the name of an integrated set of standards developed by the American National Standards Institute (ANSI) which defines new protocols for flexible information transfer. Fibre channel is an open industry standard serial interface for high speed systems. One can view fibre channel simply as a transport vehicle for the supported command set (usually SCSI commands). In fact, fibre channel is unaware of the content of the information being transported. It simply packs data in frames, transports them to the appropriate devices, and provides error checking. It is also called Fibre Channel-Arbitrated Loop (FC-AL). 
     One popular connector interface is a single connector attachment SCA. The SCA interface was designed to provide a standard connection for systems using hot-swappable drives. The original SCA was followed by a second version called the SCA2, which includes alignment posts for grounding on the SCA2 plug and cavities on the SCA2 receptacle for receiving those posts. Unless otherwise specified, the use of the term SCA2 here includes both the original SCA as well as its descendant, the SCA2. Small Computer Systems Interface (SCSI) is the current high end CPU-to-drive interface. SCA2 interface drives connect to a SCSI backplane that provides power, configuration settings such as SCSI ID, and termination of the SCSI bus. An SCA2 adapter is necessary to attach an SCA2 interface drive to a standard SCSI host adapter. An SCA2 adapter should provide power and termination as well as jumper settings for SCSI ID and other drive features. Some drive models may offer configuration options on the drive. 
     State-of-the-art fibre channel drives come with a single connector adapter. This SCA2 has 40 connections. Other numbers of contacts are also common: 80, 120, etc. 
     There is no adapter which allows one to connect a fibre channel drive to anything but an SCA2 receptacle. 
     SUMMARY OF THE INVENTION 
     Objects of the present invention include providing an interface to a fibre channel drive, the interface having at least two form factors—one for interfacing to a connector on a fibre channel drive and one or more others for interfacing to one or more other styles of connectors. 
     Another object is to provide an interface having a first form factor on a first side of a printed circuit board and one or more other form factors on an opposite side of the printed circuit board for allowing the first to interface to a connector on a fibre channel drive and the others to interface to other styles of connector. 
     Another object is to provide an interface between a DB9 receptacle and a fibre channel drive. 
     Another object is to provide an interface having an SCA style form factor on a first part of a printed circuit board which can mate to a fibre channel drive and a DB9 style receptacle on another part of said printed circuit board for connecting to a DB9 connector on a fibre channel cable. 
     According to the present invention, an interface is provided, the interface having at least two form factors—one for interfacing to a connector on a fibre channel drive and one or more other form factors for interfacing to one or more other styles of connectors. In further accord with the present invention, the first form factor is on a first part of the printed circuit board and the others are on a second part of the printed circuit board. In further accord with the present invention, the first part of the printed circuit board is on one side of the printed circuit board and the other part of the printed circuit board is on an opposite side. In further accord with the present invention, one or more non-SCA connectors are mounted on a front side of a substrate for receiving one or more non-SCA style connectors and an SCA2 receptacle is mounted on the back side of the substrate for interfacing the non-SCA connector an SCA connector on a fibre channel drive. In still further accord with the present invention, the non-SCA2 connector is a DB9 receptacle. In still further accord with the present invention, that non-SCA2 connector is a high speed serial data connector (HSSDC). In still further accord with the present invention, that fibre channel drive of the present invention receives a media interface adapter (MIA). In still further accord with the present invention, the non-SCA connector is an RJ-45 connector. 
     An advantage is that fibre channel drives are no longer restricted to interfacing to SCA style receptacles. 
     Another advantage is that fibre channel drives, normally adapted to interfacing to copper media, can interface to optical media without using an SCA receptacle. 
     Another advantage of the present invention is that an SCA style connector on a fibre channel drive can use a single interface to mate with one or more connectors having form factors other than an SCA style form factor including high speed serial data connectors (HSSDC), media interface adapter (MIA) style connectors, RJ-45 style connectors or DB9 style connectors. 
     Other advantages include a direct interface from a copper link to a fibre channel drive, a direct interface from an optical link to a fibre channel drive, configurability by means of the programmable header of the interface between the drive and non-SCA2 receptacle, and the provision of power to the fibre channel drive through a power plug. 
     These and other objects, features and advantages will become more apparent in light of the drawings and accompanying text. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an isometric view of a prior art electrical connector assembly comprising an electrical connector and a mating electrical connector, with ground contacts extending along guide posts of the first electrical connector, and with ground contacts along channels in the mating electrical connector. 
     FIG. 2 is a top view of the fibre channel adapter according to the present invention having an SCA2 receptacle and DB9 receptacle. 
     FIG. 3 is a front view of the fibre channel adapter according to the present invention having an SCA2 receptacle and DB9 receptacle for receiving an MIA. 
     FIG. 4 is a back view of the fibre channel adapter according to the present invention having an SCA2 receptacle and DB9 receptacle. 
     FIG. 5 is a front view of the fibre channel adapter according to the present invention having an SCA2 receptacle and DB9 receptacle. 
     FIG. 6 is a top view of the fibre channel adapter according to the present invention having an SCA2 receptacle and RJ-45 receptacle. 
     FIG. 7 is a front view of the fibre channel adapter according to the present invention having an SCA2 receptacle and HSSDC receptacle. 
    
    
     DETAILED WRITTEN DESCRIPTION OF A PRESENTLY PREFERRED EMBODIMENT 
     With reference to FIG. 1, a prior art SCA2 electrical connector assembly  1  that is presently used with Fibre Channel Disk drives and is mounted to the adapter of the present invention. The connector comprises an electrical connector  2  and another, mating electrical connector  3 ; each of which connectors  2 ,  3  comprises an insulating housing  4  having a rear face  5  and a mating face  6 ; and electrical signal contacts  7 , in and extending through contact receiving cavities through the housing  4  extend from the rear face  5  toward and to the mating face  6 . 
     Each electrical connector  2 ,  3  further comprises electrical terminals on rear ends of the electrical contacts  7  that project from the rear face  5  for connection to a circuit board, not shown. Each connector  2 ,  3  further comprises electrical ground contacts  10  extending in and through ground contact receiving cavities  11  in end portions  18  of the housing  4 . 
     Each electrical connector  2  comprises insulative posts  12  and the conductive ground contacts  10  extending along the posts  12 . The ground contacts  10 , together with the electrical contacts  7 , extend through the housing  4  and through the rear face  5 . Electrical terminals  13  on the ground contacts  10  project from the rear face  5  of the housing  4  for connection to a circuit board, not shown. The connector  2  in FIG. 1 that uses the bifurcated terminal  13  is a straddle mount version of the connector  2 . The posts  12  and the ground contacts  10  project in the same direction as the mating face  6  to establish a ground connection of the ground contacts  10  when the connectors  2 ,  3  are mated. A shroud  14  on the housing  4  encircles the signal contacts  7  at the mating face  6 . The ground contacts  10  engage the mating ground contacts  10  in the mating electrical connector  3  while the posts  12  engage the mating electrical connector  3 . The shrouds  14  of the connectors overlap, with the shroud  14  on the connector  2  encircling the shroud  14  on the connector  3 . For example, the connector  2  is a plug connector, and the connector  3  is a receptacle connector. 
     In the mating electrical connector  3 , the cavities  11  define post receiving cavities to receive the posts  12  and are in the form of channels on the mating electrical connector  3 . The ground contacts  10  are in grooved recesses of the channels, and face opposite open sides of the channels. Open ends  16  of the channels are spaced apart to correspond with the spacing between tips  17  of the posts  12 . The ground contacts  10  in the channels receive and engage the ground contacts  10  along the posts  12  upon receipt of the posts  12  along the channels. The posts  12  project so as to align the mating face  6  of the connector  2  with that of the mating electrical connector  3  while the mating faces  6  are spaced apart, and posts  12  and the channels are at opposite ends  18  of connectors  2 , 3 . 
     With reference to FIGS. 1 and 2, alignment of the respective connectors  2 ,  3 , end  18  to end  18 , is accomplished by viewing along the posts  12  as sights to target where the posts  12  will align to assure insertion of the posts  12  into the open ends  16  of the channels. The mating connector  3  is often hidden from view inside a chassis, not shown, requiring the posts  12  to enter the chassis through an opening in the chassis. The posts  12  permit alignment of the connectors  2 ,  3  when the mating connector  3  is hidden from view. The posts  12  thereby facilitate blind mating connection of the connectors  2 ,  3 . An exterior surface  19  of each post  12  is flat for a major portion of its length from back to front, and is tapered with a rounded taper forwardly and inwardly along its length, the taper merging with the tip  17  of the post  12 . The surfaces  19  face outwardly away from each other. The ground contacts  10  extend along the surfaces  19 . An inward facing surface  20  of the post  12  merges with the surface  19  at the tip  17 . The surfaces  20  of the posts  12  face each other. The ground contact receiving cavity  11  is a closed end channel in the surface  19  that communicates with one of the ground contact receiving cavities in the housing  4 . The closed end is adjacent to the tip  17 . A ground contact  10  extends within the channel and along the surface  19  at the tip  17 . The post  12  partially surrounds the portion of the ground contact  10  within the channel. 
     The ground contacts  10  are stamped and formed from a blank of metal and are unitary with a carrier strip, not shown. Each ground contact  10  is separated from the carrier strip. An outwardly curved contact surface on the ground contact  10  in the connector  2  projects outwardly of the channel to engage a ground contact  10  on the mating electrical connector  3 , when the posts  12  and the ground contacts  10  along the posts  12  are received along the cavities  11  of the mating connector  3  for connection with the ground contacts  10  in the recessed groove portion of the cavities  11  of the mating connector  3 . 
     With reference to FIG. 1, the electrical connector  3  is an electrical receptacle connector having the cavities  11  and the ground contacts  10  projecting outwardly beyond the mating face  6  to align the mating faces of connectors  2  and  3  and to establish a ground connection of the ground contacts  10  to the ground contacts  10  in the posts  12 , while the mating faces  6  of connectors  2 , 3  are spaced apart. 
     With reference to FIG. 1, the ground contact receiving cavities  11  on the connector  3  project beyond the mating face  6  to receive the posts  12  prior to mating of the connectors  2 ,  3 . The ground contacts  10  in the cavities  11  project beyond the mating face  6  of the connector  3  to engage the ground contacts  10  in the posts  12  prior to mating of the connectors  2  and  3 . An insulating funnel  22  is on the open end of each of the ground contact receiving cavities  11  in the mating connector  3 . The ground contact  10  in each of the cavities  11  is recessed from the open end. Because the ground contacts  10  of both connectors  2 ,  3  are positioned rearwardly, when the posts  12  are inserted along the cavities  11  of the mating connector  3 , the open ends of the cavities  11  will be covered by the posts  12  before the ground contacts  10  of the connectors  2 ,  3  become engaged. Thereby, the ground contacts and the cavities  11  will be covered safely in the event that electrical arcing might occur when the ground contacts  10  of the connectors  2 ,  3  approach one another during mating connection. 
     Prior to connecting the signal contacts along the mating face  6  of the connector  2  with those of the mating electrical connector  3 , the ground contacts  10  on the alignment posts  12  engage the ground contacts  10  in the mating electrical connector  3 . The ground contacts  10  of the mating connector  3  are connected to chassis ground electrical potential. When the ground contacts  10  of the connectors  2 ,  3  are engaged, the ground connections of the connector  2  to chassis ground potential are established before the contacts  7  of the connector  2  engage the contacts  7  of the mating connector  3 . It can be said of the invention that the subsequent contacts  7 , combined with the prior connection of the longer ground contacts  10 , provide at least two levels of sequenced electrical connections with the mating electrical connector  3 . The contacts  7  are protected from electrostatic charges when such charges discharge to chassis ground. In addition, the connection of the contacts  7  in the respective connectors  2 ,  3  can be accomplished when the contacts  7  of the mating connector are part of an activated electrical circuit, not shown. 
     This feature discharges electrostatic charges through the engaged ground contacts  10  to isolate the electrical contacts  7  from such charges during connection and disconnection of the connector  2  and the mating electrical connector  3 , especially useful when the contacts  7  of one of the connectors  2 ,  3  is part of an activated electrical circuit, not shown. 
     Each connector  2  is capable of being modified to provide a desirable feature wherein mating connection of the electrical contacts  7  themselves of the connectors  2 ,  3  will occur in sequence. Selected electrical contacts  7  in the connector  2  are positioned forward and closer to the mating face  6  than are the remainder of the electrical contacts  7  when the connector  2  is being viewed from the mating face  6 . As the connectors  2 ,  3  are moved toward each other for mating connection, the forward contacts  7  will engage respective contacts  7  of the other mating connector  3  before the remainder of the contacts  7  in the connector  2  become engaged with the remainder of the contacts  7  of the mating connector  3 . This feature provides another level of sequenced electrical connection when the connectors  2 ,  3  are urged toward one another for mating connection. 
     FIG. 2 is a top view of the fibre channel adapter  40  according to the present invention. FIG. 2 shows a fibre channel adapter  40  including a substrate  42  having a front  44  and a back  46 . The front  44  has two DB9 receptacles  48  having input sides  50  for receiving a fibre channel cable DB9 plug. The DB9 plug which connects into the DB9 receptacle  48  of the fibre channel adapter  40  typically has four active pins. Two of those four pins are for transmitting and two are for receiving. Each of the DB9 receptacles  48  include holes  52  for receiving attachment means which can pass through holes in the substrate  42  and then into, for example, a motherboard. Also shown on the front  44  of substrate  42  are sixteen pins  56  of a programmable pin header  57 . FIG. 2 shows eight pins  56  and these eight hide a second set of eight that stand behind the first set of eight which are visible in FIG.  2 . Placing a removable shunting member  55  across corresponding pairs of pins  56  of the first and second sets establishes an electrical connection which can be disconnected simply by removing the removable shunting member  55 . 
     On the back  46  of substrate  42 , is a forty pin SCA 2 receptacle  3  like that shown in FIG. 1 for mating to an SCA2 plug  2  (FIG.  1 ). The SCA2 plug is the state of the art interface for fibre channel drives. An SCA2 receptacle  3  includes two cavities  11  for receiving grounding alignment posts  12  (FIG. 1) while the male pins of an SCA2 fit into a central D-shell  26 . 
     FIG. 3 is a front view of the fibre channel adapter  40  according to the present invention. DB9 receptacles  48  are attached by connection means  64  to substrate  42 . Adjacent one of the DB9 receptacles  48  is a power jack  66  having four power terminals  77 , two grounded, one at plus twelve volts and the other at plus five volts. Adjacent the power jack  66  is the SCA2 receptacle  3 . Its pins  69  are shown emerging from the front  44  of substrate  42 . Located between the DB9 receptacles  48  is a pin header  57  for configuring the connection of the SCA2 receptacle  58  to the DB9 receptacles  48 . 
     FIG. 4 is a view of the back  46  of the fibre channel adapter  40  according to the present invention. Pins  71  from the DB9 receptacles  48  are shown as well as pins  56  from the pin header  57 , and pins  77  of the power jack  66 . SCA2 receptacle  3  includes a D-shell  26  that receives an SCA2 plug  2  on a fibre channel drive. The PCB is formed with circuitry to allow for the signals in a fibre channel drive to be coupled through the SCA2 connector  3  to the pair of DB-1 connectors  48 . The PCB provides power, termination and jumper circuitry for SCS1 ID and other features. 
     FIG. 5 is a top view of the fibre channel adapter  40  according to the present invention adapted to receive a media interface adapter (MIA). A media interface adapter, as is known in the art, is attached to an optical fiber for providing a signal from that optical fiber to a DB9 plug (or sometimes a DB 9 receptacle) which, in turn, allows the optical fiber to be provided to a copper medium using fibre channel. FIG. 5 shows a fibre channel adapter  40  having the substrate  42  and front  44  and back  46 . The front  44  has two DB9 receptacles  48  are for receiving not a fibre channel cable DB9 as in FIGS. 2-4, but rather an MIA. Therefore, FIG. 5 appears generally the same as FIG. 3 although electrically the two are a little different in that the substrate  42  provides power and ground to the DB9 receptacle  48 , causing two more contacts out of nine of the DB9 receptacle to be active. FIG. 5 is a front view of the fibre channel adapter  40  according to the present invention. DB9 receptacles  48  are attached by connection means  64  to substrate  42 . Adjacent one of the DB9 receptacles  48  is power jack  66  having four power terminals  77 , two grounded, one at plus twelve volts and the other at plus five volts. Adjacent the power jack  66  is the SCA2 receptacle  3 . Its pins  69  are shown emerging from the front  44  of substrate  42 . Located between the DB9 receptacles  48  is a pin header  57  for configuring the connection of the SCA2 receptacle  3  to the DB9 receptacles  48 . 
     FIG. 6 is a top view of the fibre channel adapter  40  according to the present invention adapted to receive an RJ-45 jack. Thus, in each of FIGS. 2-5, a different non-SCA2 receptacle is substituted on either side of the pin header  57 . FIG. 6 shows a fibre channel adapter  40  having substrate  42 , front  44 , and back  46 . The front  44  has two RJ-45 receptacles  88  for receiving not a fibre channel cable DB9 as in FIGS. 1-3, but rather an RJ-45 plug (not shown). Therefore, FIG. 6 appears generally the same as FIG. 2 except that RJ-45 receptacle  88  replaces the DB9 receptacle  48  shown in FIG.  1 . The RJ-45 receptacles  88  are attached by any suitable means to substrate  42  and are mounted so that the direction of plugging is at a right angle to the substrate  42 . Each RJ-45 receptacle  88  includes mating contacts  90  for mating an RJ-45 to a fibre channel drive. Located between the RJ-45 receptacles  88  is a pin header  57  for configuring the connection of the SCA2 receptacle  3  to the RJ-45 receptacles  88 . 
     FIG. 7 shows the fibre channel adapter  40 . The non-SCA2 receptacle can be an RJ-45 receptacle as in FIG. 6 or HSSDC receptacles  98  as shown in FIG.  7 . HSSDC receptacles  98  include mating contacts  100  for receiving an HSSDC plug (not shown). As known in the art, flanges  102  in the HSSDC receptacles  98  are pushed aside by a head portion of the HSSDC plug when inserted into the HSSDC receptacle  98  and spring back around a neck portion of an HSSDC plug when further inserted into an HSSDC receptacle  98 . 
     It should be understood that the basic concept described here is an SCA2 attached to one side of a substrate that has on its other side a non-SCA2 receptacle. That non-SCA2 receptacle can include an RJ-45, a DB9, an HSSDC receptacle, an MIA receptacle and others without departing from the spirit and scope of the invention. 
     Furthermore, it should be understood that various changes and modifications to the presently preferred embodiments described herein would be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the present invention and without diminishing its attendant advantages. It is, therefore, intended that such changes and