WO1988003653A1

WO1988003653A1 - Wire tester

Info

Publication number: WO1988003653A1
Application number: PCT/AU1987/000384
Authority: WO
Inventors: Cornel Paul Nemeth
Original assignee: Cornel Paul Nemeth
Priority date: 1986-11-13
Filing date: 1987-11-13
Publication date: 1988-05-19

Abstract

A sequential wire pair testing unit suitable for use for testing wire pair terminations in new or existing telephone line and/or data line installations. The hand held tester (200) incorporates a sequential, visual display (41) comprising an aligned group of individual display devices (151, 152 ...) for reporting the status of each wire pair termination under test, each display device being allotted to individual ones of the wire pairs under test. Preferably the visual indication means (41) lie in a physical, sequential relation which corresponds with the desired sequential relation of the wire pairs under test. Each individual display device (151, 152 ...) is actuated immediately following a test of the wire pair to which that display device has been assigned. The unit is suited for quickly and efficiently testing groups of pairs of wires for open circuit, short circuit, split leg, out of sequence pair and leakage to earth.

Description

WIRE TESTER TECHNICAL FIELD The present invention relates to an automatic wiring tester, and in particular, to a tester suited to sequentially test parallel connections of wires.

BACKGROUND ART Telecommunications installations, worldwide, utilise varying types of mass-termination connectors as a means of connecting telecommunication cables. Typically, these telecommunication cables are presently wired in a polarity conscious manner and testing of such networks must include this as well as testing for open and short-circuits and earth faults. These mass-termination connectors are arranged such that each connection block presently typically caters for connecting ten wire-pairs.

In the past, particularly in the telecommunications industry, testing of installed wire pairs has required the use of bulky equipment, the equipment itself requiring connection to the cables under test by means of alligator clips or equivalent. Furthermore, not all of the common tests can be carried out by the same piece of test equipment. Also, communications between personnel operating the test equipment have required independent communication apparatus separate from the test equipment. It is an object of the present invention to provide a wire pair testing system which provides a quick and efficient means for testing wire-pairs connected in banks, at both ends. An alternative embodiment allows efficient testing of multiple pairs whose physically separated pair terminations feed to a central block.

Typical test requirements for wire pairs include continuity, correct sequence of termination, split pairs, short circuits and "loss betweens".

Other preferred test requirements include earth leakage and, in certain circumstances, a "megger" (insulation) test.

DISCLOSURE OF INVENTION In one broad form there is provided a sequential wire pair testing system, said system having a master test unit connected at a first end of a plurality of pairs under test, said system having a slave test unit connected at a second end of said plurality of pairs under test, said system utilising said master unit and said slave unit to sequentially test said plurality of pairs, pair by pair in sequence; said system providing an interim report after each pair is tested before moving on to the next wire pair test. Preferably said interim report for each pair tested includes a visual indication specifically allotted to each pair under test.

Preferably said visual indication is provided on an outer surface of at least said master unit.

Preferably said visual indication means lie in a physical, sequential relation which corresponds with the desired sequential relation of the wire pairs under test.

In one preferred form said system halts testing when a fault is found and requires intervention by an operator to continue testing.

In an alternative preferred form said system halts for a predetermined period of time upon detection of a fault and displays the appropriate fault message during said predetermined period of time before automatically continuing on with sequential testing.

In yet a further preferred form upon initial connection of said master and said slave units to said wire pairs under test said master unit performs an initial scan of all wire pairs to which it is connected in order to determine which of said wire pairs are also connected at a second end to said slave unit. In this preferred form said master unit performs tests only upon those pairs to which said' slave unit is connected.

Preferably, in addition to visual indication of said faults, fault information is remembered by said master unit for subsequent transmission to a central processor.

Preferably said master unit and said slave unit are identical units with switch means incorporated to allow a user to select operation of the one unit as either a master unit or a slave unit.

Preferably said central processor provides a diagram of all circuits detected and tested and reports in hard copy form as to any corrective action which needs to be taken in respect of those circuits.

Preferably each said unit is small, hand-held and compact.

In yet a further preferred form a subset of said system is incorporated into a hand set as a single pair wire tester and intercom system in combination with existing test telephone circuitry, sa.id hand set having an internal power source such that no external test power source is required for said test system.

Preferably said system incorporates a "phantom" carrier signal whereby testing is carried out in such a manner that normal operation of the wire pairs under test is not affected.

In yet a further broad form there is provided a sequential wire-pair testing system comprising a master unit and a slave unit, each said unit having a connector block means arranged to connect into an on-site connector block, said connector block connecting a predetermined plurality of pairs of wires; said master unit adapted to supply a test current sequentially through individual ones of said plurality of pairs whilst said slave unit is connected via its connector block to the same said pairs at a distant location via its said connector block; said main unit having display means for indicating the conduction condition and conduction direction within each individual ones of said plurality of pairs of wires; said slave unit having corresponding indication means for indicating the state of conduction of and direction of conduction of corresponding wire pairs at a distant location.

Preferably said main unit and said slave unit each have an individual indicator for each and every one of said plurality of wire-pairs under test, said indicators physically arranged sequentially adjacent to each other, preferably in a straight line.

In this specification a "phantom" carrier signal is a test signal or audio intercom signal which is superimposed upon the signals (if any) which are normally present upon the wire pair when the wire pair is in use. The superimposed "phantom" signal does not interfere with the normally present signals.

A "Batinsky" unit, as referenced in this application, is a portable telephone handset unit including decadic and/or tone dialling means and suitable for a technician's use for communication in the field.

In this specification a "master" unit is a primary testing unit which initiates testing procedures and which receives all available test information resulting from a test. A "slave" unit in this specification is a unit which receives signals from a "master" unit and, in conjuction with the master unit, tests wire pairs and otherwise aids the master unit to obtain all relevant test information concerning the wire pairs under test

"Polarity" as used in this specification refers to a desired order of the two wires making up a wire pair.

BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the present invention will now be shown with reference to the drawings wherein:

Fig. 1 is a block schematic diagram of an individual pair manual tester,

Fig. 2 is a block schematic diagram of a multiple wire pair tester, Fig. 3(a) and (b) is a combined wiring and schematic diagram of a ten wire pair manual cable tester,

Fig. 4(a) and (b) is a block diagram of an automatic multi-pair, multi-block tester arrangement,

Fig. 5(a) and (b) is a diagram of the external arrangement and connections of an automatic multiple pair tester following the concept of Fig. 4,

Fig. 6(a) and (b) is a wiring diagram of the automatic multiple pair tester of Fig. 5,

Fig. 7 is a diagram of the external features of a handheld automatic one, two or three pair tester incorporated into a telephone handset.

Fig. 8 shows a fifth embodiment of the test unit,

Fig. 9(a) and (b) shows a sixth embodiment of the present invention incorporated into "Batinsky" type units, Fig. 10 shows a seventh embodiment of the present invention incorporating advanced features including an alpha-numeric display,

Fig. 11 shows a block circuit diagram suitable for implementation of either the fifth embodiment of Fig. 8 or the seventh embodiment of Fig. 10.

Fig. 12 is a ttlock diagram of an eighth embodiment utilizing some embodiments of the invention in conjunction with data processing means to produce building telephone and data netv/ork circuit diagrams, and

Fig. 13(a) and (b) shows an example of a circuit diagram output capable of being generated by the unit of Fig. 12.

MODES OF CARRYING-OUT THE INVENTION:

In the following description at least eight embodiments of the invention are described. A common integer of at least parts of each embodiment is a hand held test unit which is arranged to test wire pairs and report the results of the wire pair tests by means of, at least, visual indication on an external surface of the unit. Furthermore there is a physical relation between the reporting visual indication on the external surface of each unit which corresponds with the desired physical sequential arrangement of the wire pairs under test. These units therefore provide a quick and convenient means of indicating to even an unskilled technician in the field the ongoing status of a wire pair test whilst the test is bei ng carri ed out .

FIRST EMBODIMENT

Fi g . 1 di scloses a basi c ci rcui t for testi ng an i nter-connected wire-pai r (1 ) of a s imp l e manual nature . Wi re-pai r ( 1 ) i s termi nated at each end with mass-termination connectors (2) and (3), (only one wire pair is shown for simplicity). The apparatus, constituting assembly 10, consists of red LED 5 and 6, green LED 4 and 7, and two current limiting resistors 8 in each assembly, connected as depicted at each end of the wire-pair to be tested. At one end of the wire pair, battery 9 is connected as depicted while at the opposite end of the wire pair the apparatus is connected directly across the wire pair, without a battery. If the wire pair is connected correctly LEDS 5 and 6 will light. If the wire pair is open circuit no LEDS will light. If the wire pair is short circuit LED 5 will light but not LEDS 6 and 7. If the wire pair is reverse connected LEDS 5 and 7 will light.

Thus each type of fault may be indicated for a wire pair, (excluding short circuit to earth faults). A standard communications handset 11 is connected at each end of the wire pair to allow the test personnel to communicate when testing. It will be clearly seen from Fig. 1 that the manual testing method requires transferring the apparatus connected at each end of the wire pair to successive wire pairs via verbal dialogue, to test other wire pairs.

The manual method of testing and the apparatus outlined above can be extended to include the testing of multiple wire pairs at the one time, as depicted within Fig. 2. Mass-termination connectors 2 and 3 are shown as four wire for simplicity. However, a multiplicity of pairs can be tested using the basic circuit, one for each pair. The apparatus outlined previously is connected to both ends of the wire pairs using an M-way mass termination connector block, (not shown for clarity but plugs into mass termination connectors 2 and 3 to make connection from each apparatus to mass termination connectors 2 and 3. Each apparatus includes a double pole M-way switch. At the end where the apparatus has battery 9 installed this switch is 12 while at the other end-the switch is 13. Standard communication hand sets 11 are fitted to each apparatus as shown. Using verbal communication, each test operator successively operates switches 12 and 13 to test each wire pair, the faults being indicated on the LEDS as outlined previously.

SECOND EMBODIMENT Fig. 3 shows details of a ten pair manual tester as a specific group utilisation of the circuits of Figs. 1 and 2.

The basic unit consists of two telephone type hand sets and two multi wire connection plugs with 10 switches, one for each pair of wires in a 10 pair cable. The two handsets are specifically adapted to preferably test three wire-pairs and consist of a main unit 31 containing the power supply 32 (9VDC) and a tone generator 33. The slave unit 34 consists of an ordinary hand set without a power supply. It has a Bl colour LED in the plug and a 6 way switch.

On the main unit 31 is a switch 35 and LED 36 to activate and indicate the test tone is on. There is also a switch and battery level indicator 38.

To obtain an intercom path both units (handsets) must be plugged into the same pair of wires to complete a circuit so current can be drawn .

As most poi nt to poi nt tel ephone cabl es cons i st of 3 pai rs of wires the switch in the plug of the headset enables each pair to be tested in turn.

When both handsets are plugged in, a LED 37 on the main handset and plug light up indicating the slave unit is on line. If the pair of wires are if the correct polarity the Ted in the plug of the slave unit will light green and red if the polarity is reversed.

If the pair of wires are short circuit the LEDs on the main unit light up but not on the slave unit and no speech path is available.

If the pair is open circuit nothing will work.

Should the three pairs be on the wrong combination of terminals, they can be identified by switching through the pairs at either end.

Spl i t pai rs are i nd i cated by i nducti on of the test tone wh i ch can be heard faintly in the handsets.

To operate the 10 pair cable tester the two hand sets as above descri bed are plugged i nto the 10 pai r manual tester blocks 40, 41 respectively. The switches on both hand set plugs are put into the first position, then through verbal instruction a progression through the cable pairs is performed. The test is carried out as for a 3 pair ordinary telephone cable as described above.

The multi pair plug has a short probe lead for testing the earth wire with one of the cable pairs for continuity. A summary of fault, conditions detectable by this unit and their means of diagnosis are tabulated below. Main Unit Slave Unit

Pa i r OK Red Led Green Led

Tone/Speech OK Tone/Speech OK

Pair Reversed Red Led Red Led

Tone/Speech OK Tone/Speech OK

Pair O/C No Led No Led

No Speech/Tone No Speech/Tone

Pair S/C Red Led No Led

No Speech No Speech/Tone

Tone On

Split Pairs No Led No Led

Induction Tone Induction Tone

No Speech No Speech

Out of Sequence Pairs No Led/Tone No Led/Tone

Until Slave Unit Until Pair is

Switches onto Pair Found

THIRD EMBODIMENT The manual tester of Figs. 1, 2 and 3 can be replaced by a fully automatic multiple pair tester embodiment. Figs. 4a and 4b provide a block diagram of such a system.

In this embodiment the switches in connector block 41 are deleted and replaced with dual light assemblies, one for each wire-pair. The main multi pair connector 40 includes a similar dual light pair for each wire pair and the switches for connecting the wire pairs to the test circuit are replaced by an automatic sequence switching system. The generalized form of the device is shown in Fig. 4a.

Fig. 4b shows a single bank embodiment. (i.e. for M = 10 and N = 1).

In this embodiment the dual light assemblies 151, 161 are arranged in a straight line. Light pair 51 and 61 designate the condition of wire-pair 171. Light pair 152, 162 designate the condition of wire-pair 172. For the 10 wire-pair embodiment there are 10 light pairs arranged sequentially in the respective master 181 and slave 182 test blocks. The dual light assemblies are connected sequentially into a test circuit as shown in Fig. 1 or Fig. 2. The single test circuit is sequentially switched so as to test each wire pair in sequence.

Under test a sequence is triggered whilst observers watch the main unit light display and the slave unit light display respectively. The sequencing lights will immediately indicate to the observer whether there is any fault condition. If there is a fault condition the sequence can be repeated or all circuits tested simultaneously in order to isolate the fault circuit.

The light pair can be either a dual red/green diode pair or separate differently coloured light sources.

It is simply necessary that two states for any given circuit can be represented sequentially on the test block. Further specific embodiments will now be shown with reference to Figs. 5 and 6.

The automatic multiple pair tester of Figs. 5 and 6 is as follows:-

This unit consists of two small plug in units that have a head set transmitter and receiver unit attached to each unit.

The handset testers (Fig. 7) can also be used with these units via an adapter.

As with the manual version these units can be adapted to any type of cable connectors.

There are two units. The main unit contains the circuitry for testing and for communications. The second or slave unit contains only a display unit and headset (or hand set) and an earth indicator.

The main unit contains a visual display that steps automatically through the cable pairs displaying their states. It also contains the power supply, on/off switch, line select switch, power to intercom or test unit, signal switch, earth test switch and a repeat test sequence switch.

The two test units with their headsets will take a 100 pair connector module that enables a block of 100 pairs to be tested in sequence from pair 1 to 100.

The testing circuit consists of a 3914 chip with associated components and a visual display. The LM 3914 chip is a dot/bar display driver described in manufacturer's data manuals. Such description is incorporated herein by cross reference.

When the 100 pair adapter is used the circuitry is stepped up by cascading 3914 IC chips to enable the display to be extended over the range.

The 100 pair slave unit consists of 10 ten pair slave units connected together to form the 100 pair slave unit. The test units are operated by plugging them into corresponding modules at each end of the cable. With the switches in the intercom position conversation can take place. To test the 10 pair block the control switches are placed into the test mode. At this time the unit will automatically step through the cable pairs from left to right in sequence. If the cable pairs are OK the unit will display from left to right on both units with the slave unit indicating the polarity state "green" if OK, "red" if polarity is reversed.

Should the display not progress from left to right, in sequence, but jump to random positions, there is a fault in that 10 pair block of wires. These test units can be made to operate on any number of different terminal blocks.

By switching to intercom the results can be discussed and the fault isolated by switching back to test and pressing the retest button A. Retest can be called up every time the button (switch) is pressed.

While in the test position the earth continuity can be checked. Should the earth connection be remote from the connection block the remote earth test probe is used.

When the connection block with the 10 pairs of wires connected is tested both units are moved to the next pair of connection blocks, thus progressing through the installation.

When testing individual telephone outlets back to the connection point a handset unit is used at the phone point in conjunction with the automatic tester main. The manual C.I.T. units are compatable with the automatic C.I.T. units (not the 10 pair manual switching unit) (the hand sets).

OPERATION OF AUTO C.I.T. UNIT CONDITION MAIN UNIT SLAVE UNIT

Al l pai rs of wi res OK Di spl ay l i ghts from Same as main unit left to right in with all green sequence LEDS on

Some pairs of wires Display lights from Same as main unit with reversed polarity left to right in with reversed pairs sequence glow red, the rest green OPERATI0N OF AUTO C.I.T . UNIT (Cont'd)

CONDITION MAIN UNIT SLAVE UNIT

Open circuit pairs or Pairs of open circuit Same as main unit wires no display showing for them

Short circuit pairs All lights on from Pairs or wires short or wires left to right in circuited not lit up sequence (the rest OK)

A or + leg of pair split Display runs out of Normal display from at main end or slave end sequence for the left to right split pairs

B or - leg of pair split Display runs out of Same display as for at main end or slave end sequence for the main unit split pai rs

Wire pairs terminated out Display runs normal Display runs out of of sequence at main end from left to right sequence for cable or slave end pairs out of sequence

Earth continuity test Light position Earth test LED lights 1 and 2 light

Earth onto cable pairs Corresponding LEDS in Earth test LED lights display light up when and corresponding earth test is done LED shorting to earth. If a leg short to earth red LED lights only.

FOURTH EMBODIMENT Referring to Fig.7, the automatic testing assembly can be incorporated within a standard handset.

Standard communication handset 14, which is standard to the country where the automatic multi pair tester is destined, has standard to the country voice communications circuitry, together with an intelligent liquid crystal display 18 integrated within to give a clear indication of status and fault conditions.

Keyboard 19 is also integrated within the device to allow control of the test functions.

The keyboard 19 can be expanded to the full standard to the country dialling keyboard and dialling electronics, and integrated within the handset if so desired. Multipair cable 15 connects the handset 14 to the mass termination connector under test via mass termination connector 16, of opposite polarity. There is no limit to the size of cable 15 and connector 16 since both could be of the order of 200 wire capability (ie. a hundred pair connector block array consisting of ten by ten pair standard mass termination blocks) allowing automatic testing of large arrays of mass termination blocks. The size and style of connector 16 will be determined by the country of destination of the automatic multipair tester. LCD 18 is depicted facially in 17 showing a typical message displayed during a test sequence.

Testing is performed in the following manner.

Two automatic multi-pair testers are required: One is connected to one end of the system to be tested, by plugging in connector 16 to the mass termination assembly to be tested. The other one is connected to the corresponding other end of the system under test. The test personnel can be in constant verbal communication via integration of the standard voice communications circuitry, adopted by the country of use, within the device, and either one places his tester in the "slave" mode as previously outlined. Upon initiating testing, the faults discovered, if any, are displayed on the LCD and memorised by the internal electronics to allow recall under operator control for correction.

An advantage of this type of test unit is its ability to allow entry of installation tested identification code numbers and retention of test data for automatic entry into a large computer back at base installation, by plugging the connector 16 into a suitable interface the large computer.

Modifications to the invention, obvious to those skilled in the art, can be made without departing from the scope and spirit of the present invention.

For example, rather than actually having an observer for the slave test unit to interpret the light display appearing thereon it is possible to install telemetery within the slave unit in order to transmit condition information back to the main unit. In this situation a helper will still be required to physically relocate the slave unit into the different wire pair blocks under test. However, the helper will not need the expertise to interpret any light display. Rather, a central processor within the main unit can interpret status information received from both ends of the pairs under test and consequentially perform the task previously performed by the human interpreters. In this form of the invention a computer can be used to perform all test logic and fault information can be directly displayed on the main unit, ie. the display would indicate in alphanumeric form the type of fault and which wire pairs were involved.

FIFTH EMBODIMENT

A fifth embodiment of the invention is shown in Fig. 8. The device 200 of Fig. 8 is a hand held unit designed to plug directly into typical ten pair telephone wire connection frames found in many installations throughout the world. If necessary physical adaptors can be used in order to ensure compatibility.

The unit of Fig. 8 comprises fault status lamps 40 for indicating open circuit, short circuit, reverse polarity, transposed wire, split pair and earth faults respectively. Lamp series 41 comprise a group of individual display devices 151, 152 ... which are dedicated to each individual wire pair under test. These lamps 151, 152 ... indicate which pair is presently undergoing tests and provide distinguishing indications to indicate whether each sequential test is successful or otherwise.

A master/slave switch (not shown) allows the user to set the unit as either a master or slave unit. Loud speaker 42 is used to receive voice communication from the remote test unit. The loud speaker can also be used to provide audible fault or other indications.

A test/scan switch 43 allows initiation of the test sequence at will by the user. This switch is also used to allow the test sequence to continue when halted at a fault indication.

A remote handset 44 or remote headset 45 can be connected via jack 46. Volume control 47 allows adjustment of received communication volume. Where single terminal testing is to be carried out an adaptor cord 48 is arranged to have a first end connected into the line socket 49 of the test unit with its further end 50 connected into the telephone socket under test.

The device of Fig. 8 is used as follows:

TEST MODE

Test mode is used where multi wire connection blocks are located at both ends of a cable under test. In this situation a first operator is responsible for the master unit plugged in at a first end of the cable under test. A second operator is responsible for and is physically located with the slave unit plugged in at the second (remote) end of the cable under test. The master unit is designated as such by appropriate adjustment of the slide switch on the unit. Similarly the slave unit is designated as such. Once both units are connected to the line under test the test is initiated by a short push on test button 43 on the master unit. The test is done automatically on the first wire pair with the mas ter and slave units communicating along the first wire pair under test. If a fault is found testing stops and the fault is indicated via the display device 40. If no fault is located the units will automatically continue on to the second wire pair and test them. If a fault was located on the first wire pair then, to initiate testing of a second wire pair, it is necessary to press the test button 43 again. The test continues in this way until all wire pairs have been tested.

During the test the operator of the master unit and the operator of the slave unit can communicate by means of the handset 44 or headset 45 as necessary. If the environment does not warrant this, communication can be carried out via loudspeaker 42 which is used as both a loudspeaker and microphone. This "intercom" arrangement utilises a "phantom" circuit which works even if the line under test is short-circuited or open circuit (1 leg only). The "phantom" circuit does not affect the lines under test, even if they are in service. This is an advantage particularly where it is desired not to interfere with a customer's telephone service or otherwise give an indication to the customer that his telephone lines are under test.

Preferably an audible indication is given when each test sequence is completed. During a test an operator can observe the test proceeding sequentially by observation of the indication lights 41. By this visual indication the operator obtains a visual, physical understanding of the progress of the test and the physical location of faulty wire pairs (if any). Even an unskilled operator, therefore, becomes competent and confident in the use of the device in a short period of time.

SCAN MODE Scan mode is used where testing is to be carried out between a central distribution frame and individual telephone sockets scattered, for example, throughout one floor in a building. In this mode a master unit is plugged into a multiple pair termination point in a distribution frame. A unit designated as a slave unit is physically carried by the slave un i t operator to each te l ephone socket on the f l oor under te s t . The s l ave unit is plugged into each telephone socket under test by means of the adaptor cord 48. Testing is initiated by the operator of the master unit providing a long push on test button 43. In this mode the master unit, upon initiation, firstly searches for a wire pair having the slave unit attached. Upon location (by impedence test) the master and slave units communicate so as to perform a test on the wire pair. On completion of the test the master and slave units provide an audible beep for the operators. The operator of the slave unit then proceeds to the next telephone socket and, once again, connects the slave unit via cord 48. The master unit searches for and locates the new wire pair to which the slave unit is now connected and commences the test of this second wire pair. This search and test procedure continues until all wire pairs connected to that particular connector block have been tested.

SIXTH EMBODIMENT

Referring to Fig. 9(a) and (b) there is shown a further embodiment of the present invention incorporated into and used as a substitute for the commonly known "Batinsky" units presently commonly used. In this embodiment the unit has an internal power supply allowing it to operate as a normal intercom unit and also to operate as a test unit without the need for any external power source. Each unit comprises a power source (battery) 50 which supplies power to an intercom and cable testing circuit 51 and to a telephone test circuit 52. Test circuit 52 performs all the functions of the commonly available "Batinsky" unit. The circuitry of cable testing circuit 51 is equivalent to and performs the function of the circuits of Fig. 1 and Fig. 2. "Phantom" circuitry can also be included. Select circuitry 53 allows either telephone test (Batinsky) mode or intercom/cable test mode to be selected on each unit.

In use the embodiment of Fig. 9 is initially connected to one end of a wire pair under test with a corresponding, identical unit being connected to the other end of the pair under test. Either a voice path is established to allow communication between the operators of both units or the mode can be switched over to cable test mode and testing, generally as per the example of the first and/or fifth embodiments, can be carried out.

SEVENTH EMBODIMENT

Referring to Fig. 10 a further, more advanced, embodiment of the present invention is shown. In this embodiment the sequential test indicators 41 remain. In place of the individual fault lamps an alpha-numeric display 61 is utilised. The LCD display 61 can display programmed words such as "short circuit", "open circuit", "split", "A-leg", "8-leg", "reverse", "pair", "out of sequence", "earth", "test OK", "meg ohm" and various digits as appropriate. Messages relating to the status of each pair under test can be composed from the above available words and numerals. The unit also incorporates a dot/bar mode switch 62, an on/off switch 63, a test switch 64, an insulation resistance test switch 65, an earth test switch 66, an intercom on/off switch 67, a master/slave switch 68 and a headset/handset jack for connection of sets 44, 45. In block diagram form the unit comprises LCD displays 61 and sequential status display leds 41 driven by processor circuitry 70 which itself receives information from a polarity generator/receiver circuit 71. The circuit 71 directly interfaces with the wire pairs under test as shown. The processor 70 can also drive an intercom circuit 72.

Referring to Fig. 11 there is shown a block circuit diagram suitable for implementation of either the fifth or seventh embodiments of the invention. Referring to Fig. 11 there is shown a multi-wire connection block 73 which is designed to connect to the wire pairs under test. The block 73 communicates with a line isolating and filtering circuit 74 which interfaces via switching circuitry 75 with a microprocessor 76. The processor 76 interfaces with and coordinates the visual status indicator 77, remote test jack 78, master/slave switch 68, test mode switch 64, data dump port 79, remote earth test jack 80, headset/handset socket 69, loudspeaker 42 and on/off switch 65. Also shown interconnected on the diagram are power supply source (battery) 81, voltage regulator circuit 82, intercom circuitry 83, "power on" indicator 84 and speaker volume/talk control 85.

EIGHTH EMBODIMENT Referring to Fig. 13 there is shown an example of a schematic diagram output which is possible utilising the present invention. To obtain such a djagram the results of the tests, say for a whole building, having been carried out using a combination of the test mode and the scan mode as appropriate for these units is fed via a data port located on the master unit to a central processor (if necessary via intermediate storage means). The processor, utilising stored information regarding standard connection techniques and procedures for telephone installations is able to construct a diagram of the telephone interconnections of the building under test. The output can appear as shown in Fig. 13.

Referring to Fig. 12 there is shown a block diagram of an implementation utilizing either the fifth or seventh embodiments of the invention in conjuction with data processing means to produce the desired building circuit diagram. Specifically test units as previously described are utilized in the field as previously described. Additionally, these units have associated with them means for identifying whether the wire connector system which they are presently, attached to and are testing is an MDF, IDF, FDP, SKT or other standard known connection device. During tests the appropriate nomination is made. This nomination together with the test results is communicated indirectly via data storage means or directly via cable or telemetry to data processing means 90. Data processing means 90 is also loaded with information relating to the design drawings of the telephone/data network installation under test. Using appropriate software a comparison is made between the designed telephone/data system and the "as installed" system as identified and tested by the field units (embodiments 5 and/or 7). The resultant circuit diagram showing the "as installed" system together with any fault information if necessary is printed on printer 92 and/or display and on VDU 93.

The above describes only some embodiments of the present invention and modifications, obvious to those skilled in the art can be made thereto wi thout departi ng from the scope and sp i ri t of the present i nventi o .

Claims

HIRE TESTER CLAIMS 1. A sequential wire pair testing system for testing a plurality of wire pairs under test, said system having a master test unit connected at a first end of said plurality of pairs under test, said system having a slave test unit connected at a second end of said plurality of pairs under test, said system utilising said master unit and said slave unit to sequentially test said plurality of pairs, pair by pair, in sequence; said system providing an interim report for each pair tested immediately after each said pair is tested before testing the next wire pair under test.

2. The system of claim 1 wherein said report for each pair tested includes a visual status indication specifically allotted to each pair under test.

3. The system of claim 2 wherein said visual status indication is provided on an outer surface of at least said master unit.

4. The system of claim 3 wherein each said visual status indication lies in a physical, sequential relation which corresponds with the desired sequential relation of the wire pairs under test.

5. The system of any previous claim wherein said plurality of pairs comprises from 2 - 20 pairs.

6. The system of any of claims 1-4 wherein said system halts testing when a fault is found and requires intervention by an operator to continue testing.

7. The system of any one of claims 1-4 wherein said system halts for a predetermined period of time upon detection of a fault and displays the appropriate fault message during said predetermined period of time before automatically continuing on with sequential testing.

8. The system of any previous claim wherein upon initial connection of said master and said slave units to said wire pairs under test said master unit performs an initial scan of all wire pairs to which it is connected in order to determine which of said wire pairs are also connected at a second end to said slave unit; said master unit thereupon performing tests only upon those pairs to which said slave unit is connected.

9. The system of any one of claims 2-8 wherein, in addition to visual indication of said faults, fault information is remembered by said master unit for subsequent transmission to a central processor.

10. The system of claim 9 wherein said central processor provides a diagram of all circuits detected and tested and reports in hard copy form as to any corrective action which needs to be taken in respect of those ci rcui ts .

11. The system of any previous claims wherein said master unit and said slave unit are identical units with switch means incorporated to allow a user to select operation of the one unit as either a master unit or a slave unit.

12. The system of any previous claim wherein each said unit is small, hand-held and compact.

13. The system of any previous claim wherein said system incorporates a "phantom" carrier signal whereby testing is carried out in such a manner that normal operation of the wire pairs under test is not affected.

14. A sequential wire-pair testing system comprising a master unit and a slave unit, each said unit having a connector block means arranged to connect into an on-site connector block, said connector block connecting a predetermined plurality of pairs of wires; said master unit adapted to supply a test current sequentially through individual ones of said plurality of pairs whilst said slave unit is connected via its connector block to the same said pairs at a distant location via its said connector block; said main unit having display means for indicating the conduction condi tion and conducti on di recti on wi thi n each i ndivi dual ones of sai d plurality of pairs of wires; said slave unit having corresponding indication means for indicating the state of conduction of and direction of conduction of corresponding wire pairs at a distant location.

15. The testing system of claim 1 wherein said main unit and said slave unit each have an individual indicator for each and every one of said plurality of wire-pairs, said indicators being physically arranged sequentially adjacent to each other.

16. The testing system of claim 2 wherein said indicators are arranged in a straight line.

17. The testing system of any previous claim wherein said main unit and said slave unit incorporate voice communication means which allows users to communicate by voice between the main unit and the slave unit.

18. The testing system of any previous claim wherein said plurality of pairs comprises ten pairs.

19. The testing system of c l aim 18 wherei n sai d p l ural i ty of pai rs compri ses fi ve pai rs .

20. The testing system of claim 18 wherein said plurality of pairs comprises eight pairs.

21. The testing system of claim 13 wherein said plurality of pairs comprises ten pairs.

23. A handset testing unit incorporating a subset of the system of any preceding claim; said handset testing unit comprising a hand set as a single pair wire tester and intercom system in combination with existing test telephone circuitry, said hand set having an internal power source such that no external test power source is required for said test system.