WO1995027379A1

WO1995027379A1 - Cable management system with remote line testing

Info

Publication number: WO1995027379A1
Application number: PCT/US1995/002271
Authority: WO
Inventors: James Henry Wise
Original assignee: The Whitaker Corporation
Priority date: 1994-04-05
Filing date: 1995-02-22
Publication date: 1995-10-12

Abstract

A cable management system which provides routing of wired services between service lines (16) and user lines (18). Each service line enters the cable system at a service termination unit circuit card (22) which also holds a portion of a crosspoint switch matrix (126). Each user line enters the system at a line termination unit circuit card (20). The service termination unit circuit cards are all mounted to connectors (36) on a first side of a centerplane board (24) and the line termination unit circuit cards are mounted to connectors (36) on the other side of the centerplane board. Pins (37) extending through the centerplane board interconnect the connectors on the opposed sides of the centerplane board so that any service line can be connected to any user line. A system controller card (26) mounted to the centerplane board communicates with the circuit cards via a bus (38) on the centerplane board. Each of the termination unit circuit cards has a test port connector (204) for communication with a line tester (228), and a switch bank (206) for selectively connecting each of the lines on that card to the test port connector. The line tester may either be a handheld unit or be permanently installed as part of the cable management system. An active termination device (300) is provided at the end of each line remote from the cable management system. Each active termination device is arranged to respond to instructions received over the line for providing a desired termination of the line to assist in line testing.

Description

CABLE MANAGEMENT SYSTEM WITH REMOTE LINE TESTING
This invention relates to a cable management system which provides routing of telephony, low and high speed data, power and video, between service lines and user lines under computer control and, more particularly, to such a system wherein testing of each of the lines can be effected in a single-ended manner from the cable management system by utilizing a remote active termination device.

When wiring a commercial building, it is conventional that all of the services carried by wire, such as telephony, low and high speed data, power and video, enter the building for termination at respective patch panels. The patch panels are typically located within wiring closets and each includes a first array of terminations for the service lines which enter the building and a second array of terminations for the user lines which extend within the building to various user stations. Within each patch panel, the connections between the service lines and the user lines are made manually via jumper wires extending between the first array of terminations and the second array of terminations. In an ideal situation, records would be maintained as to where each wire goes within the building and to what it is connected.

However, since the real world is not ideal, such records are not always properly maintained. In addition, wires are often tagged at the patch panels and the tags are lost or become outdated because of lack of updating. Therefore, when a technician is given a service order to add, move or change a connection, the technician must first determine exactly which physical wires are involved.

This has proven to be a very time consuming and labor intensive chore. It has therefore been proposed to provide a cable management system with automatic record keeping capability.

The proposed cable management system is interposed between a plurality of service lines and a plurality of user lines and includes a plurality of line termination unit circuit cards which provide connections to the user lines and a plurality of service termination unit circuit cards which provide connections to the service lines. Controllable switching means are coupled between the terminations to the user lines and the service lines for selectively providing physical electrical connections between selected ones of the service lines and selected ones of the user lines. A controller is provided to control the switching means to selectively make and open connections between the service lines and the user lines in accordance with received commands, the controller having a memory in which is stored a map of the connections made through the switching means.

A management station is provided for issuing commands to the controller, the commands including a connect command to make a physical electrical connection through the switching means between a specified service line and a specified user line, and a disconnect command to open a physical electrical connection through the switching means between one or more specified service lines and one or more specified user lines.

In this cable management system, there is a centerplane board which has a first plurality of card edge connectors on a first side arranged in a first parallel array and a second plurality of card edge connectors on the other side arranged in a second parallel array orthogonal to the first parallel array.

The first and second pluralities of card edge connectors are electrically interconnected through the centerplane board. The switching means are mounted on the service termination unit circuit cards and these cards are installed in the card edge connectors on the first side of the centerplane board. The line termination unit circuit cards are installed in the card edge connectors on the other side of the centerplane board.

Accordingly, any one or more of the plurality of service lines can be connected to any one or more of the plurality of user lines through the switching means.

The controller is mounted on a circuit card and installed in one of the card edge connectors on the first side of the centerplane board. A plurality of conductive bus lines are disposed on the centerplane board and are electrically interconnected to all the card edge connectors on both sides of the centerplane board. A respective transceiver coupled to the bus lines is provided on each of the controller circuit card, the service termination unit circuit cards and the line termination unit circuit cards for effecting communications therebetween over the bus lines.

In such a system, if the system operator is notified of a problem on a particular line, the first determination should be whether the problem is with the line itself or with equipment connected to the line.

Various tests have been devised to isolate the problem.

These tests include opening the line, shorting the line, terminating the line with a known resistance or load, and injecting a tone on the line. Each of these tests is performed independently and each requires that appropriate measurements be made on the line. Until now, such testing has required that a technician go to the end of the line remote from the cable management system and, while communicating with another technician located at the termination of the line at the cable management system, provide the various line terminations. It would be desirable to control the establishment of the various terminations to the line without requiring the presence of a technician at the remote end. It is therefore an object of the present invention to provide an arrangement whereby such remote control of line termination can be effected.

As is conventional, each user line is terminated in an outlet, typically wall mounted, by means of which the user can couple a desired peripheral user device, such as a telephone or computer, to the user line. Such outlets are generally passive, that is, they only provide a fixed mechanical connection. It is therefore another object of this invention to provide an active outlet for selectively terminating the line in response to appropriate control signals issued from the cable management system.

It is yet another object of this invention to provide an active termination device for the cable connecting the peripheral user device to the outlet in order to effect testing of that cable.

In a commercial building, the system operator, rather than the service provider, is responsible for maintaining all the wiring which is on the user side of where the service provider terminates its wiring at the building (i.e., at the line of demarcation). It would be desirable for the system operator to have the ability to test the service lines between the line of demarcation and the cable management system. It would also be desirable for such testing to be effected remotely under the control of the management station.

It is therefore a further object of the present invention to provide an active line termination device by means of which tests can be performed on the service lines connected to a cable management system of the type described under the control of the management station.

SUMMARY OF THE INVENTION
The foregoing and additional objects of the present invention are attained in accordance with the principles of this invention in combination with a cable management system interposed between a plurality of service lines and a plurality of user lines. The cable management system includes a plurality of service termination unit circuit cards each connectable to a first predetermined number of respective ones of the plurality of service lines, a plurality of line termination unit circuit cards each connectable to a second predetermined number of respective ones of the plurality of user lines and connecting means for connecting each of the plurality of service termination unit circuit cards to all of the plurality of line termination unit circuit cards.

Each of the plurality of service termination unit circuit cards includes switching means for selectively connecting one of the plurality of service lines connected to that service termination unit circuit card to one of the plurality of user lines. The present invention provides an active termination device connectable to a line at a location remote from the cable management system. The active termination device comprises a set of input terminals for providing a connection to the line, a set of output terminals and at least one auxiliary line termination.

The active termination device further includes controllable switching means for selectively connecting the set of input terminals to the set of output terminals or to the at least one auxiliary line termination, and control means connected to the set of input terminals and adapted to receive instructions over the line from the cable management system for controlling the switching means.

In accordance with an aspect of this invention, the at least one auxiliary line termination may comprise either one or more of loopback means for providing a connection among the set of input terminals, a termination resistor, a tone generator, or an open circuit.

In accordance with another aspect of this invention, the control means includes control logic means responsive to instruction signals on the line for controlling the switching means and detector means coupled to the set of input terminals and responsive to an activate signal having a predetermined characteristic on the line for activating the control logic means to respond to instruction signals following the activate signal.

The foregoing will be more readily apparent upon reading the following description in conjunction with the drawings in which like elements in different figures thereof are identified by the same reference numeral and wherein:
FIGURE 1 is a conceptual drawing showing the proposed cable management system discussed above;
FIGURE 2 is a block diagram of the cable management system of FIG. 1;
FIGURE 3A schematically depicts the rear of the interior of the cable management system enclosure showing the service termination unit circuit cards, a line test card and the controller circuit cards;
FIGURE 3B schematically depicts the front of the interior of the cable management system enclosure showing the line termination unit circuit cards;

;
FIGURE 3C shows a first side of the centerplane board, which side is adapted to mount the service termination unit circuit cards, the line test card and the controller circuit cards;
FIGURE 3D shows the other side of the centerplane board, which side is adapted to mount the line termination unit circuit cards;
FIGURE 3E schematically illustrates orthogonal edge connections of a service termination unit circuit card and a line termination unit circuit card to the centerplane board;
FIGURE 4 is a block diagram of an illustrative controller for the cable management system of FIG 2;
FIGURE 5 is a block diagram showing the circuitry on an illustrative service termination unit circuit card for the cable management system of FIG. 2;
FIGURE 6 is a block diagram showing the circuitry on an illustrative line termination unit circuit card for the cable'management system of FIG. 2;

;
FIGURE 7 is a block diagram showing circuitry on an illustrative line test card for the cable management system of FIG. 2;
FIGURE 8 illustrates circuitry for the selective switching of the user lines on the line termination unit circuit card of FIG. 6;
FIGURE 9 is a block diagram of a remote active termination device according to the principles of this invention; and
FIGURE 10 schematically depicts alternative placements of the termination device shown in FIG. 9, according to this invention.

As shown in FIG. 1, the cable management system with which the present invention is concerned is contained within an enclosure 10 illustrated as having media-specific connectors on both its front surface 12 and its rear surface (not shown). The cable management system within the enclosure 10 serves as a flexible electronic patching, or cross-connecting, hub for automated cable management of communications circuits.

Various services, such as LAN'S, telephone, computer I/O channels and peripherals, and video distribution links are connected to the cable management system through media-specific connectors on the rear surface of the enclosure 10. Typically, these will be aggregated multi-pair cables or high bandwidth cables, such as coax and fiber, common in riser and horizontal distribution subsystems. As shown in FIG. 1, such services include ethernet, telephone, video and token ring.

Matrix switch modules are installed within the enclosure 10. Media-specific connectors corresponding to the media selected for each user's work station subsystem wiring are installed on the front surface 12 and have cables which are attached and then run to the user's location. Thus, as shown in FIG. 1, at the user's location there may be one or more peripheral user devices, such as telephones, computer work stations, facsimile machines, or television sets. Once wired in this fashion, each user can be electronically connected to any combination of services that is required. All future changes in each user's service complement can be accomplished electronically.

The cable management system within the enclosure 10 maintains a data base of the location, source and destination for each cable. The system is configured by a management station 14 (FIG. 2). As shown in FIG. 2, the cable management system contained within the enclosure 10 is connected to the service lines 16, which may be telephone lines, video lines, etc., which come to the system from the various service providers. The cable management system is also connected to the user lines 18 which extend to various user locations. The user lines 18 are each connected to a respective port on one of a plurality of line termination unit circuit cards 20-1,..., 20-n. Similarly, the service lines 16 are each connected to a respective port on one of a plurality of service termination unit circuit cards 22 1, . . ., 22-p.

The switching matrix for connecting the service lines 16 to the user lines 18 is distributed among the service termination unit circuit cards 22-1,..., 22-p so that each of the service termination unit circuit cards 22-1,..., 22-p includes thereon a plurality of service termination units for connection to a group of the service lines 16 and a portion of the overall switch matrix. The line termination unit circuit cards 20-1,..., 20-n and the service termination unit circuit cards 22-1,..., 22-p are installed on opposite sides of a centerplane board 24, represented schematically in
FIG. 2 by a dot-dash line, in.such a manner that every line termination unit circuit card 20-1,..., 20-n is connected to the switch matrix portion of every service termination unit circuit card 22-1,..., 22-p, as will be described in full detail hereinafter.

Within the enclosure 10, there is also provided a controller circuit card 26 which is mounted to the centerplane board 24 on the same side thereof as the service termination unit circuit cards 22-1,..., 22-p.

The controller circuit card 26 is connected to the management station 14 in a suitable manner, such as through an RS-232 link or a modem. To effect communications between the controller circuit card 26, the line termination unit circuit cards 20-1,..., 20-n, and the service termination unit circuit cards 22-1,..., 22-p, a multi-line communications bus 38 (FIG.

3C) is provided on the centerplane board 24. Each of the controller circuit card 26, the line termination unit circuit cards 20-1,..., 20-n, and the service termination unit circuit cards 22-1,..., 22-p, is provided with a respective transceiver 28, 30 and 32 which is coupled to the communications bus 38 when the respective circuit card is mounted to the centerplane board 24.

Each of the service termination unit circuit cards 22-1,..., 22-p includes a memory which contains a map of all the connections through the switch matrix portion on the respective service termination unit circuit card, and the controller circuit card 26 includes a memory which contains a map of all of the connections in the entire cable management system within the enclosure 10.

The management station 14 issues commands to the circuitry on the controller circuit card 26. These commands include a connect command to make a connection between one or more specified service lines 16 and one or more specified user lines 18, and a disconnect command to open a connection between a specified one of the service lines 16 and a specified one of the user lines 18. The circuitry on the controller circuit card 26 places each appropriate command onto the communications bus 38 on the centerplane board 24, from which it is received by the transceiver 32 on the specified one of the service termination unit circuit cards 22-1,..., 22-p, which then controls its respective switch matrix portion in accordance with the received command to either make or open the specified connection.

As shown in FIG. 3A, there are illustratively sixteen service termination unit circuit cards 22-1, .

22-16 which are installed vertically in the enclosure 10 from the rear thereof. In addition, the controller circuit card 26, which is comprised of two half-cards 26-1 and 26-2, is also installed vertically, as is a line test card 34. As shown in FIG. 3B, there are illustratively sixteen line termination unit circuit cards 20-1,..., 20-16 which are installed horizontally in the enclosure 10 from the front thereof. Each of the line termination unit circuit cards 20-1,..., 20-16 and the service termination unit circuit cards 22-1,..., 2216 has eight ports terminated by a respective mediaspecific connector on the visible edge of the circuit card away from the centerplane board 24 for connection to a respective user or service line.

FIGS. 3C and 3D illustrate opposite sides of the centerplane board 24. Specifically, FIG. 3C shows the side of the centerplane board 24 on which the service termination unit circuit cards, the controller circuit cards, and the line test card are mounted and FIG. 3D shows the side of the centerplane board 24 on which the line termination unit circuit cards are mounted. Thus, as shown in FIG. 3C, for each of the service termination unit circuit cards, the controller circuit cards and the line test card there is provided a pair of vertically oriented card edge connectors 36.

Likewise, as shown in
FIG. 3D, on the other side of the centerplane board 24 there is provided for each of the line termination unit circuit cards a pair of horizontally oriented card edge connectors 36. (The top and bottom rows of connectors 36 are not utilized.) Each of the card edge connectors 36 has within it nine fields, each of which includes thirty six pins 37 (FIG. 3E) arranged in a square 6x6 matrix. The pins 37 extend through the centerplane board 24 to a corresponding field in one of the card edge connectors 36 on the other side of the board 24, thereby interconnecting the connectors 36 on both sides of the board 24.

Illustratively, each of the service termination unit circuit cards 22-1,..., 22-16 and the line termination unit circuit cards 20-1,..., 20-16 has eight input/output ports. Each of these ports is a four wire port and each of the four wires of each port of the line termination unit circuit cards is connected to each of sixteen of the pin fields in the pair of connectors 36 to which its card is connected. This accounts for 8 x 4 = 32 of the thirty six pins of each field. The remaining four pins in each of those sixteen pin fields are reserved for power, ground and control signals.

Similarly, each of the four wires of a service termination unit circuit card port is connected to the switch matrix portion on that service termination unit circuit card. The outputs of each service termination unit circuit card's switch matrix portion are eight 4 wire bundles which are each connected to four pins of each of sixteen of the pin fields of the connector 36 associated with that service termination unit circuit card. Again, that accounts for thirty two of the thirty six pins in each of those sixteen pin fields, with the remaining four pins being reserved for the same power, ground and control signals.

Because of the orthogonal relationship of the connectors 36 on both sides of the centerplane board 24, every port of a line termination unit circuit card is connected to a pin field connected to every one of the service termination unit circuit cards on the other side of the centerplane board 24. Thus, FIG. 3E illustrates how the line termination unit circuit card 20-1 is connected to a pin field of the service termination unit circuit card 22-16, as well as to all corresponding pin fields of all the other fifteen service termination unit circuit cards. As shown in FIG. 3E, the pins 37 (a square 6x6 array) connect the card edge connectors 36 on the two sides of the centerplane board 24 at their intersections (i.e., at their common pin fields).

Illustratively, the line termination unit circuit cards 20-1,..., 20-16 take up the second through the seventeenth rows of the horizontal connectors 36 on their side-of the centerplane board 24. The top and bottom rows are vacant. Similarly, the service termination unit circuit cards 22-1,..., 22-16 take up the third through the eighteenth columns of the vertical connectors 36 on their side of the board 24. Thus, through the switch matrices on the service termination unit circuit cards, any one of the service lines 16 can be connected to any one of the user lines 18. In the illustrative embodiment, there are sixteen service termination unit circuit cards, each with eight ports, for a total of 128 service ports and there are sixteen line termination unit circuit cards, each having eight ports, for a total of 128 user ports.

Each switch matrix portion on a service termination unit circuit card is an eight port by 128 port (32 by 512 lines) matrix of crosspoints. Thus, as disclosed, each of the 128 service lines can be connected to each of the 128 user ports.

As shown schematically in FIG. 3C, there is a multi-wire communications bus 38 on the centerplane board 24. The bus 38 extends parallel to the leftmost column of the vertical connectors 36 and parallel to the upper row of the horizontal connectors 36 (not shown in
FIG. 3C) on the other side of the board 24.

In order that the transceivers 28, 30 and 32 may be interconnected, along with the transceiver on the line test card 34, the bus 38 is terminated at the pin fields in the second through seventeenth rows of the leftmost column for connection to the transceivers 30 on all of the line termination unit circuit cards 20-1,..., 20-16; at the upper pin fields in the second through eighteenth columns for connection to the transceiver on the line test card 34 and to the transceivers 32 on all of the service termination unit circuit cards 22-1,..., 22-16; and at the upper pin field of the first column for connection to the transceiver 28 on the controller circuit card 26.

FIG. 4 illustrates circuitry on the controller circuit card 26 which may be utilized in the cable management system with which the present invention is concerned. The controller 26 includes a microprocessor 102 which is associated with three different types of memory. The first type of memory is a program read only memory (ROM) 104 which has stored therein the program instructions for operating the microprocessor 102. The microprocessor 102 is also associated with a random access memory (RAM) 106 which is utilized as a temporary storage memory by the microprocessor 102. Lastly, there is a non-volatile random access memory 108 which is utilized to store a map showing all of the connections through the switch matrix portions on the service termination unit circuit cards 22-1,..., 22-16 as well as information as to what type of card is installed in each of the connectors 36.

The non-volatile RAM 108 may be an electrically erasable PROM or a "flash" PROM which saves its contents even when power is lost. Since it takes a relatively long time to write information into the non-volatile RAM 108, the RAM 106 is used to temporarily store the map until such time as it is written into the non-volatile RAM 108.

The microprocessor 102 is coupled to the management station 14 in any suitable manner, such as by an RS-232 link or a modem, or through a local area network. The microprocessor 102 receives commands from the management station 14, such as a connect command or a disconnect command as described above, and in accordance with the program stored in the ROM 104 transmits instructions over the bus lines 38 on the centerplane board 24 via the transceiver 28. Illustratively, the transceiver 28 is a Neuron chip manufactured by Echelon Corp. The microprocessor 102 addresses a specified one of the service termination unit circuit cards 22-1,..., 22-16 over the bus 38 via the transceiver 28 and provides an appropriate instruction for controlling the switch matrix portion of that service termination unit circuit card.

The microprocessor 102 receives acknowledgements of its instructions, which are returned over the bus 38 from the specified service termination unit circuit card, via the transceiver 28, and updates the map stored in the non-volatile RAM 108.

FIG. 5 illustrates the circuitry 22 on one of the service termination unit circuit cards 22-1,..., 22-16.

This circuitry includes a microprocessor 116 having associated therewith three types of memory. There is a program ROM 118, a non-volatile RAM 120 and a RAM 122.

These memories function similarly to the memories 104, 108 and 106, respectively, associated with the microprocessor 102 of the controller 26, but are specifically for the particular one of the service termination unit circuit cards 22-1,..., 22-16 with which they are associated. The microprocessor 116 is coupled to the transceiver 32, which is illustratively a
Neurons chip manufactured by Echelon Corp. The transceiver 32 is coupled to the bus lines 38 on the centerplane board 24 and is utilized for communications between the microprocessor 116 and the microprocessor 102 on the controller circuit card 26. Instructions received by the microprocessor 116 via the transceiver 32 over the bus 38 from the microprocessor 102 are utilized to control the relay drivers 124 and the switch matrix 126.

Interfacing between the service lines 16 and the switch matrix 126 is effected via service line circuit paths which include the cable drivers (amplifiers) 130. The relay drivers 124 set the control relays 128 so that the cable drivers 130 interposed between the service lines 16 and the switch matrix 126 are "pointing" in the proper directions. At system start-up, for safety reasons the cable drivers 130 are initially bypassed. The switch matrix 126 is connected to all of the line termination unit circuit cards 201,..., 20-16 mounted on the other side of the centerplane board 24, as previously described, so that any one of the service lines 16 entering that particular service termination unit circuit card may be connected to any one of the user lines 18.

In accordance with instructions received from the microprocessor 102 on the controller circuit card 26, the microprocessor 116 controls the switch matrix 126 to make an appropriate physical electrical connection therethrough between a specified one of the service lines 16 entering that card and a specified one of the user lines 18 entering any one of the line termination unit circuit cards 20-1;..., 20-16 on the other side of the centerplane board 24.

The line termination unit circuit card 20 illustrated in FIG. 6 includes the transceiver 30 coupled to the bus lines 38 on the centerplane board 24.

Illustratively, the transceiver 30 is a Neurons chip manufactured by Echelon Corp. The function of the line termination unit circuit card 20 is to provide interfaces between the user lines 18 and the switch matrices on the service termination unit circuit cards 22-1,..., 22-16 mounted on the other side of the centerplane board 24. This interfacing takes place via user line circuit paths which include the cable drivers (amplifiers) 110. The cable drivers 110 are selectively controllable to pass signals either from individual ones of the service lines 16 to individual ones of the user lines 18 or in the reverse direction from individual ones of the user lines 18 to individual ones of the service lines 16, as determined by the settings of respective ones of the control relays 112.

The control relays 112 are controlled by the relay drivers 114 which are operated on the basis of instructions received via the transceiver 30 from the microprocessor 102 of the controller 26 over the bus lines 38 on the centerplane board 24. Initially, all the cable drivers 110 are set to pass signals in the direction from the user lines 18 to the service lines 16, with the cable drivers being bypassed. This is for safety reasons so that upon system start-up dangerously high amplified signals are not inadvertently transmitted to the user lines 18, where they could damage sensitive equipment.

For use with the present invention, the equipment for testing the user lines 18 and the service lines 16 can either be incorporated in an enclosure separate from the enclosure 10 (e.g., as a handheld unit) or be permanently installed within the enclosure 10. In either case, the line testing equipment is illustratively similar to the MT350 Scanner manufactured by MicroTest of Phoenix, Arizona. Such a device is described in U.S. Patent No. 4,970,466, issued November 13, 1990, the contents of which are hereby incorporated by reference herein. This patent discloses a handheld unit, which may be modified for mounting on a circuit card when permanently installed within the enclosure 10.

The tester disclosed in the referenced patent is capable of selectively evaluating various characteristics of a line connected to its output port. For example, the tester can determine the length of a line, its capacitance and its resistance. It can also evaluate the near end crosstalk of a line, its attenuation characteristics at various frequencies and the noise on a line within various frequency bands. Further, the tester can also be controlled to automatically run a combination of these tests.

To accommodate the testing function, each of the line termination unit circuit cards 20, in addition to having eight user line connectors 202-1,..., 202-8, has a test port connector 204 for receiving a connection to the tester. In order to be able to connect a selected one of the user lines 18 to the line tester, there is provided a bank of switches 206. The switches 206 are connected to the user line port connectors 202-1,..., 202-8, the test port connector 204 and the cable drivers 110. Although single lines are shown, it is understood that each "line" includes a number of wires, illustratively four. As is shown more clearly in FIG.

8, the bank of switches 206 includes a plurality of individual switches 208 each having an armature 210.

Although individual single pole switches are shown, it is understood that these are actually multi-pole switches to accommodate multi-wire lines. The armatures 210 are each controlled by a relay coil (not shown) which is selectively energized by the relay drivers 114 (FIG. 6) which are operated on the basis of instructions received from the transceiver 30, as will be described hereinafter. As shown in FIG. 8, with the armatures 210 in the position shown by the solid line, each of the user line port connectors 202-1,..., 202-8, is connected to a respective one of the cable drivers 110. When an armature 210 is in the position shown by the broken line, the user line port connector associated with that particular one of the switches 208 is connected to the test port connector 204 so that the particular user line can be evaluated.

When the line tester is a handheld unit, as disclosed in the referenced patent, and a technician wishes to evaluate a particular one of the user lines 18, the technician connects the line tester to the test port connector 204 on that one of the line termination unit circuit cards 20 to which the user line being evaluated is connected. By means of the keyboard on the handheld line tester, the technician communicates with the controller 26 via the transceiver 30 and the bus 38, to cause the controller 26 to send an instruction to open all connections through the switch matrix 126 to the particular one of the user lines 18 which is to be evaluated.

The technician then sends a command through the transceiver 30 to the relay drivers 114 to cause the particular one of the switches 208 which is associated with the user line port connector associated with the particular user line to move its armature 210 so that that port connector is connected to the test port connector 204. After the particular user line is evaluated, the evaluation results are transmitted to the controller 26 via the transceiver 30 and the bus 38. The particular switch 208 associated with that user line is then caused to move its armature 210 so that the user line port connector 202 is connected to one of the cable drivers 110, and then any desired connection through the switch matrix 126 may be effected.

Alternatively, the line tester may be permanently installed within the enclosure 10. When this is the case, the line tester is illustratively mounted to the line test card 34 as shown in FIG. 7. Thus, the line test card 34 includes a microprocessor 220 having associated therewith a program ROM 222 and a RAM 224.

The memories 222 and 224 function similarly to the memories 104, 106, respectively, associated with the microprocessor 102 of the controller 26, but are specifically for the line test card 34. The microprocessor 220 is coupled to the transceiver 226, which is illustratively a Neurons chip manufactured by
Echelon Corp. The transceiver 226 is coupled to the bus lines 38 on the centerplane board 24 and is utilized for communications between the microprocessor 220 and the other circuit cards in the enclosure 10. Also mounted on the controller circuit card 34 is a line tester 228, which is functionally the same as the tester disclosed in the referenced patent, but is modified for mounting on the card 34 rather than within a handheld enclosure.

The line tester 228 is controlled by the microprocessor 220 in accordance with instructions received from the management station 14, to which it is coupled in any suitable manner, such as by an RS-232 link or a modem, or through a local area network. The line tester 228 has its output port 230 connected to the bank of relay switches 232, which are controlled from the microprocessor 220 through the relay drivers 234. The relay switches 232 are arranged similarly to the switches 206 shown in FIG. 8. However, there are illustratively sixteen individual switches within the switch bank 232, each of which corresponds to a respective one of the line termination units circuit cards 20-1,..., 20-16.

Each of the switches within the switch bank 232 is connected to a respective test port connector 204 on a respective line termination unit circuit card by one of the test cables 236-1,..., 236-16 which are each connected to a respective connection port 238 on the line test card 34.

So that there are no disparities when testing the user lines, all of the test cables 236 are substantially identical, at least as to length and gauge.

Alternatively, connections can be made from the line test card 34 through the centerplane board 24 and to the test port connector 204 on all of the line termination unit circuit cards 20-1,..., 20-16.

When a particular user line is to be evaluated by the line test card 34, the system operator at the management station 14 sends a command to the controller 26 to disconnect the selected user line from any service line to which it had been connected. The management station 14 then causes the microprocessor 220 on the card 34 to control the appropriate one of the relay drivers 234 to actuate the appropriate one of the switches 232 so that the line tester 228 is connected to the appropriate one of the line termination unit circuit cards 20. The microprocessor 220 also sends a command via the transceiver 226 and the bus 38 to the transceiver 30 on that line termination unit circuit card to actuate the appropriate one of the switches 206 to connect the test port connector 204 to the appropriate one of the user line port connectors 202 associated with the selected user line.

After that user line is evaluated, the line tester 228 transmits the evaluation results to the microprocessor 220 for transmission to the management station 14.

In addition to testing the user lines 18 when a problem surfaces or for routine maintenance purposes, testing of the user lines 18 can be done upon initial system installation to develop an "as built" data base of user line characteristics.

Only a single embodiment of the line termination unit circuit card 20 has been shown (FIG. 6). This embodiment is specifically for the case where the line tester is separate from the cable management system and must communicate directly with the controller 26. For the case where the line tester is mounted on the line test card 34, the wires between the test port connector 204 and the transceiver 30 on the line termination unit circuit card 20 may be eliminated or, for uniformity of card manufacture, may remain but are not utilized.

The foregoing discussion was directed to testing of the user lines 18. In order to test the service lines 16, up to the line of demarcation, each service termination unit circuit card 22 would have an additional test port connector and a bank of switches, as shown in FIGS. 6 and 8 for the line termination unit circuit cards. In addition, the line test card 34 would have an additional sixteen ports 238 and there would be an additional sixteen test cables 236 for connecting the line test card 34 with the service termination unit circuit cards 22-1,..., 22-16. Further, when a service line is to be tested, the service provider is notified (e.g., by a telephone call) so that no signals are applied to the service line which would interfere with the testing.

As discussed above, the line tester is capable of performing a variety of tests on the line to which it is connected. Each of the tests typically requires that the line being tested have a particular termination at its end remote from the tester. FIG. 9 shows an illustrative remote active termination device, designated generally by the reference numeral 300, constructed according to the present invention and which is adapted to selectively provide an appropriate termination to a line in response to control signals received over the line from the cable management system.

Thus, the active termination device 300 at one end has a set of input terminals 301 for connection to a service or user line and at the other end has a set of output terminals 302, each set of terminals being illustratively two in number. The active termination device 300 includes a multi-pole relay switch illustrated as having a pair of ganged armatures 304 selectively connectable to pairs of contacts 306, 308, 310, 312 and 314. The armatures 304 are controlled by a relay coil (not shown) which is selectively energized by the control logic 316. Preferably, the relay switch is of the type that maintains its state until instructed to change by the control logic 316.

As shown, when the relay switch is in the state where the armatures 304 engage the contacts 306, the input terminals 301 are coupled directly to the output terminals 302. This is the "normal", or "straight through", state of the active termination device 300.

When the armatures 304 engage the contacts 308, this is a loopback- state where the input terminals 301 are shorted by the wire 324. When the armatures 304 engage the contacts 310, the input terminals 301 are terminated by the resistor 318, which preferably has a value equal to the characteristic impedance of the line. When the armatures 304 engage the contacts 312, the tone generator 320 is connected to the input terminals 301.

Illustratively, the tone generator 320 applies a 2.5 volt, 20 mA sinewave of frequency 10 KHz of constant amplitude to the input terminals 301, upon receiving an appropriate command from the control logic 316. When the armatures 304 engage the contacts 314, the input terminals 301 are terminated by an open circuit.

The active termination device 300 also includes a detector 322. The detector 322 is responsive to an "activate" signal applied to the input terminals 301.

This activate signal is a signal that is not present in any of the possible signatures provided by the service provider or cable management system on a service or user line, respectively. Alternatively, dedicated wire(s) may be utilized to carry the activate signal. Thus, for example, the activate signal may comprise a unique combination of tones. When the detector 322 recognizes the activate signal, it provides a "wake up" signal to the control logic 316. The control logic 316 illustratively includes a Neurons chip manufactured by
Echelon Corp., or alternatively may include a microprocessor of the 8051 family, or some other microprocessor based chip.

The control logic 316 is normally in a quiescent state, but upon being activated in response to the wake up signal from the detector 322, it responds to a subsequent instruction received at the input terminals 301 from the cable management system to control the relay switch to move the armatures 304 so as to cause the appropriate termination to be made to the line being-tested. These instruction signals may be provided by the line tester or, alternatively, by the controller 26. After controlling the relay switch, the control logic 316 returns to its quiescent state. Thus, whenever the termination of a line being tested is to be changed, first an activate signal is provided on the line to the input terminals 301 and then an instruction signal designating the desired termination is applied to the line.

Therefore, there is no need for a technician to travel to the end of the line remote from the cable management system in order to change the termination of the line for testing purposes.

Referring now to FIG. 10, for testing of the service lines 16, the active termination device 300 is installed remote from the enclosure 10, preferably at the line of demarcation. In this case, the active termination device 300 can be incorporated as part of an in-line electrical module, often referred to as a "brick". Thus, each service line can be tested from the line of demarcation to the enclosure 10.

Each user line 18 is typically run as a "horizontal drop" from the enclosure 10 above ceilings, below floors and behind walls, where it is virtually inaccessible.

The horizontal drop is usually terminated by an outlet, indicated generally at 305, which is usually wall mounted, behind a wall 303 by means of which an appropriate peripheral user device 400 in front of the wall 303 can be coupled to the user line 18 by plugging into the outlet 305 a relatively short cable, or user drop, 402. To test the user line 18 from the enclosure 10 up to the outlet 305, the device 300 can be incorporated further in the outlet behind the wall 303.

To test the user drop 402, together with the user line 18, the device 300 can be incorporated further in a brick indicated generally at 307, in the user drop 402 remote from the outlet 305 behind the wall 303, leaving an almost negligible length of cable, or no cable, between the device 300 in the brick 307 and the peripheral user device 400. Alternatively, the device 300 can be incorporated within the peripheral user device itself, preferably with the input terminals 301 being connected directly to a socket of the peripheral user device by means of which the peripheral user device is connectable to the cable 402.

Accordingly, there has been disclosed a remote active termination device for selectively terminating a line of a cable management system to accommodate different testing functions for the line. While an illustrative embodiment of the present invention has been disclosed herein, it is understood that various modifications and adaptations to the disclosed embodiment will be apparent to those of ordinary skill in the art and it is intended that this invention be limited only by the scope of the appended claims.

The details of the LTU cards schematics for a fixed .Ethernet version and the STU cards schematics for a fixed Ethernet version and the Controller A card schematics and a 15 Volt power supply schematics are attached in microfiche Appendix I. The details for a universal version, i.e. non-Ethernet version, are in additional drawings and a bill of materials, which are attached in microfiche Appendix II.

Claims

WHAT IS CLAIMED IS:

1. In combination with a cable management system interposed between a plurality of service lines (16) and a plurality of user lines (18), the cable management system including a plurality of service termination unit circuit cards (22) each connectable to a first predetermined number of respective ones of said plurality of service lines, a plurality of line termination unit circuit cards (20) each connectable to a second predetermined number of respective ones of said plurality of user lines, connecting means (24, 36, 37) for connecting each of said plurality of service termination unit circuit cards to all of said plurality of line termination unit circuit cards,

and each of said plurality of service termination unit circuit cards including switching means (126) for selectively connecting one of the plurality of service lines connected to that service termination unit circuit card to one of said plurality of user lines, an active termination device connectable to a line at a location remote from the cable management system, the active termination device comprising: a set of input terminals for providing a connection to the line; a set of output terminals; at least one auxiliary user line termination; controllable switching means for selectively connecting said set of input terminals to said set of output terminals or to said at least one auxiliary line termination;

and control means connected to said set of input terminals and adapted to receive instructions over said line from said cable management system for controlling said switching means.

2. The active termination device according to Claim 1 wherein said at least one auxiliary line termination comprises loopback means for providing a connection among said set of input terminals.

3. The active termination device according to Claim 1 wherein said at least one auxiliary line termination comprises a termination resistor.

4. The active termination device according to Claim 1 wherein said at least one auxiliary line termination comprises a tone generator.

5. The active termination device according to Claim 1 wherein said at least one auxiliary line termination comprises an open circuit.

6. The active termination device according to Claim 1 wherein said control means includes: detector means coupled to said set of input terminals and responsive to an activate signal having a predetermined characteristic on said line for generating an output signal; and control logic means responsive to said output signal for thereafter controlling said switching means in response to an instruction signal on said line.

7. The active termination device according to Claim 1 incorporated in a wall outlet wherein: said set of input terminals is connectable to a user line; and said set of output terminals is connected to a socket of said wall outlet by means of which a peripheral user device is connectable to said user line.

8. The active termination device according to Claim 1 incorporated in a peripheral user device wherein: said set of input terminals is connected to a socket of said peripheral user device by means of which said peripheral user device is connectable to a user line.

9. The active termination device according to Claim 1 wherein said active termination device is incorporated as part of an in-line electrical module.

10. In a cable management system interposed between a plurality of service lines (16) and a plurality of user lines (18) and including a plurality of service termination unit cards (22) each connectable to a first predetermined number of respective ones of said plurality of service lines, a plurality of line termination unit cards (20) each connectable to a second predetermined number of respective ones of said plurality of user lines, connecting means (24, 36, 37) for connecting each of said plurality of service termination unit cards to all of said plurality of line termination unit cards, and each of said plurality of service termination unit cards including switching means (126) for selectively connecting one of the plurality of service lines connected to that service termination unit card to one of said plurality of user lines,

an outlet connectable to a user line at a location remote from the respective line termination unit card, the outlet adapted for providing a connection between the user line and a peripheral user device, the outlet comprising: a first set of terminals for providing a connection to the user line; a second set of terminals for providing a connection to a selected peripheral user device; at least one auxiliary user line termination; controllable switching means for selectively connecting said first set of terminals to said second set of terminals or to said at least one auxiliary user line termination; and control means connected to said first set of terminals and adapted to receive instructions over said user line from said cable management system for controlling said switching means.