CN1694474A - Test method for line equipment including hybrid circuits and line equipment therefor - Google Patents

Abstract

The present invention relates to a method for testing analog telephone line equipment, in particular to a method for detecting faults in its mixed resistance array. The method includes isolating the device from the telephone line and applying a standard ring signal to the device. If the resistor array is defective, the output logic signal of the off-hook/on-hook detector circuit consists of a series of 0's and 1's at the frequency of the AC component of the ringing signal, which indicates the presence of a fault. This makes it possible to omit the usual device test repeater.

Description

Be used to comprise the method for testing and the line facility thereof of the line facility of hybrid circuit

The cross reference of related application

Present patent application is based on the french patent application No.0404 785 that submitted on May 4th, 2004, in these whole disclosures of quoting this patent application for your guidance, and requires the priority of this patent application.

Technical field

The present invention relates to a kind of method of test telephone line facility, relate in particular to and comprise the particularly equipment of hybrid resistor array of electric resistance array, it is used to realize the multiple function such as for described telephone line power supply and restricting ringing current.The invention still further relates to the line facility that is configured to realize described method.

Background technology

United States Patent (USP) 6,219,417 have described the analog of telephone line pipeline equipment that comprises a hybrid resistor array and a signal processor that also is used for particularly carrying out test when sending bell signal on the telephone line.Yet this patent is not described any test that is used to check the integrality of described hybrid resistor array.

European patent document EP 0 808 053 has described and also has been used to carry out analog of telephone line pipeline equipment test, that comprise a hybrid resistor array and a signal processor.The document described when do not use repeater and being used to check described hybrid resistor array integrality test and when testing described equipment, how isolated described equipment and telephone line.Described signal processor is to the digital test signal that conversion of signals is provided 1kHz for the codec of the analog signal of importing described hybrid resistor array.Amplifier by the telephone signal receiver amplifies the signal that described hybrid resistor array reflects, and measures the amplitude of this signal then by described signal processor.The amplitude of this signal depends on the load of every wire of described telephone line and the state of described hybrid resistor array.If described array comprises an offresistance, then the amplitude of reflected signal is higher than fixing threshold value, and processor triggers alarm.The shortcoming of above-mentioned method of testing is its equipment that can only be applied to comprise signal processor.Yet signal processor has increased the cost of telephone line equipment significantly.

Fig. 1 has shown conventional line facility, for example with opposite such as the so new system of ISDN or ADSL, it is designed to be connected to plain old telephone by telephone wire 101, promptly works in the phone on the common analog line.Be configured between described equipment and local office to send and the circuit of received speech signal and unit be known in the art,, also, so do not show them in the drawings because these circuits and unit have nothing to do with the present invention in order to simplify accompanying drawing.

At the input of described line facility, described telephone wire is connected to a class overvoltage protection 102 well known in the art.Described device 102 is connected to line test repeater 103, and it is used for described telephone line equipment and described telephone line isolated, so that this telephone line equipment is connected to line test bus 104.

Second line test repeater 105 is used to test the work of described line facility, especially on-hook/handoff functionality, and be used for more specifically by the input of hybrid resistor array 107 is isolated so that this array is connected to the integrality that line test bus 106 is tested this array.Therefore, outside these test periods, described repeater 105 is connected to circuit the input of described hybrid resistor array 107 from described repeater 103.

The detailed structure of described hybrid resistor array 107 will be described later, and by ringdown repeater 108, this array is connected to power supply circuits 109 or ringing circuit 111.In the present embodiment, described circuit 109 is connected to two switching circuits of described repeater, and for one of them switching circuit, described circuit 109 is corresponding to the negative pole of power supply (Vbat), and for another switching circuit, with the positive pole of described circuit 109 corresponding to power supply.Yet as known in the art, negative pole is hot end (hot side), and positive pole is connected to common ground connection 110.

The control circuit that is used for these different repeaters is known in the art, and does not therefore show in the drawings.

The output of described hybrid resistor array 107 is connected to circuit 112, and it is used to detect the off-hook or the hook state of the phone that is connected to described line facility.Be applied to the bias voltage that the voltage vcc on the described hybrid resistor array 107 provides described circuit 112 to use by connecting 114.If detect hook state, then described circuit 112 connects 113 to output and sends a logical signal.If detect off hook state, then described circuit 112 connects 113 to output and sends a logical signal (complementary logic signal) of mending mutually.

Because used repeater 105 and line facility are as many, thus use test repeater 105 to test the cost that described hybrid resistor array 107 causes be the highest, and also be the highest therefore by the cost of the phone of this system service.

Summary of the invention

In order to reduce above-mentioned cost by omitting described TSTTRK test trunk device, the present invention proposes a kind of also method of testing of undesired signal processor of described TSTTRK test trunk device 105 that neither needs.It is characterized in that in order to test described electric resistance array, this method comprises:

Described equipment and described telephone line is isolated;

Apply described bell signal; And

Analyze described logical signal, if described electric resistance array defectiveness, then described logical signal by the frequency of the alternating current component that adopts described bell signal a series of 1 and 0 constitute.

The invention allows for the analog of telephone line pipeline equipment that is used to realize said method, this equipment comprises:

Be configured to the electric resistance array of described device coupled to the analog of telephone line pipeline equipment;

Between described electric resistance array and described telephone line, be used for described equipment and the isolated device of described telephone line;

Be used to isolate the device of described telephone line equipment;

Be used for applying the device of the bell signal that comprises the low-frequency ac component to this equipment; And

Send the off-hook/on-hook detector circuit of off-hook/on-hook logical signal, in order to test described hybrid resistor array, described circuit comprises and is used to detect described logical signal whether by a series of 1 and 0 device that is constituted of the frequency of the alternating current component that adopts described bell signal.

According to another feature of the present invention, described off-hook/on-hook detector circuit comprises comparator, it has two inputs, be connected respectively to each output of described electric resistance array, described electric resistance array comprises two biasing resistors of the described input that is connected to described comparator, to apply bias voltage, if described electric resistance array is intact, then the value of described bias voltage is much larger than from the residual alternating voltage of the low amplitude of described bell signal.

Following with reference to the description of the drawings in, it is obvious that other features and advantages of the present invention will become.

Description of drawings

Fig. 1 is the sketch of the line facility of prior art;

Fig. 2 shows the diagrammatic sketch of the Fig. 1 that revises according to the present invention;

Fig. 3 is the diagrammatic sketch of the assembly in the frame of broken lines 115 among Fig. 2.

Embodiment

Fig. 2 has shown a kind of line facility that is used to realize method of the present invention.Notice that except omitting described detection repeater 105, this line facility is not different significantly with line facility shown in Figure 1.

More detailed diagrammatic sketch with reference to the assembly in the frame of broken lines among Fig. 3 115 is explained method of the present invention.

By by described ringdown repeater 108 two the flow restricter resistance R A 201 and the RB 211 of power supply in turn, thereby described hybrid circuit 107 be described repeater 103 power supplies and powers for described telephone line.In order to simplify diagrammatic sketch, do not show power supply circuits 109.

Determined the direction of bias current at the bridge circuit that forms by two resistance R B1A 202 and RB2B 212 series connection between the output of the input of resistance R A and resistance R B and between the input of the output of resistance R A and resistance R B by the connect bridge circuit that forms of two resistance R B2A 203 and RB1B 213, in this area, as everyone knows, bias current has been indicated the off hook state and the hook state of the phone that is connected to described line facility.For reaching this purpose, the intermediate point of two branches of described bridge circuit is connected to the positive and negative input of comparator, this comparator has formed the basic module of offhooking detector circuit 112, when the input voltage Ve of this comparator suitably changed direction corresponding to 1 or 0 logical signal that is sending, the output 113 of this circuit was transmitted in the voltage Vs that switches between 0V and the X volt.And the first biasing resistor RAb 204 is connected to the mid point of resistor R B2A and RB1B with power Vcc, and the second biasing resistor RBb 214 makes the neutral earthing of RB1A and RB2B.Like this voltage Ve is fixed on minimum value and sentences the unsteadiness of avoiding comparator 112.

In order to make described system operate as normal, the resistance value of different resistance must meet the following conditions:

RA＝RB＜＜RAb＝RBb＜＜RB1A＝RB1B＝RB2A＝RB2B

In order to test especially its hybrid circuit of described line facility, the present invention proposes by described repeater 103, described equipment and described circuit is disconnected, and then by described repeater 108, apply bell signal from ringing signal generator 205 to this equipment.Programme by the control computer of local office that described line facility is connected simply, just can carry out aforesaid operations.

The bell signal that is applied is preferably well known in the art to be comprised-signal without direct current component of 52V, and 80V has superposeed on this DC component _RmsThe low-frequency ac component.

When the resistance of described hybrid circuit had nominal value, at the input of described circuit 112, described low-frequency ac component only produced several millivolts the residual alternating voltage of low amplitude.This component is far below bias voltage Ve, and this will prevent that the comparator in the described circuit 112 from changing state.

On the other hand, if any one among resistance R B1A, RB2A, RB1B or the RB2B in the described hybrid circuit 107 is defective, if promptly this resistance be open circuit or short circuit, if perhaps the value of this resistance changes significantly, then be superimposed upon the value of the value of the described alternating current component on the Ve greater than initial bias voltage, this causes the comparator in the described circuit 112 to come the change state with the frequency of the alternating current component of described bell signal.Therefore, a series of 1 and 0 logical signal that is constituted that described circuit 112 sends by the frequency that adopts this alternating current component detects mistake with indication.Described system can also detect the remarkable increase of the resistance value of open circuit or RA and RB.

Above-mentioned logical signal is with different fully corresponding to the logical signal of off-hook or on-hook operation, and the latter is in case generation is exactly the stabilization signal that no longer changes.Therefore, by detecting above-mentioned sequence, whether the hybrid circuit that the control computer of the described local office that described line facility connects can be easy to determine described line facility defectiveness.Similar to above-mentioned situation, this detection can realize by computer is programmed simply.

Therefore, the present invention has omitted described TSTTRK test trunk device 105 and the described bus and relevant electronic component of each line facility, and its cost is to increase several line codes in the program of the computer of the described local office that all line facilities connect.

The present invention also is applicable to the line facility that has replaced described repeater with semiconductor switch circuit.

Claims (4)

1. A method of testing for analog telephone line equipment, said equipment comprising: a resistor array configured to couple the device to an analog telephone line; means between said resistive array and said telephone line for isolating said device from said telephone line; means for applying a ringing signal comprising a low frequency AC component to said device; and An off-hook/on-hook detector circuit that sends an off-hook/on-hook logic signal; For testing the resistor array, the method includes: isolating said equipment from said telephone line; applying said ringing signal; and The logic signal is analyzed and, if the resistor array is defective, the logic signal consists of a series of 1s and 0s at the frequency of the AC component of the ringing signal. 2. An analog telephone line device comprising: a resistor array configured to couple the device to an analog telephone line; means between said resistive array and said telephone line for isolating said device from said telephone line; means for applying a ringing signal comprising a low frequency AC component to said device; and an off-hook/on-hook detector circuit sending an off-hook/on-hook logic signal, for testing said hybrid resistor array, said circuit comprising a frequency for detecting whether said logic signal is composed of said ac component of said ringing signal A device consisting of a series of 1s and 0s. 3. The apparatus of claim 2, wherein the isolating means connects the telephone line directly to the resistive array. 4. The device of claim 2, wherein the off-hook/on-hook detector circuit includes a comparator having two inputs connected to respective outputs of the resistor array, the resistor array including connections two bias resistors to the input of the comparator to apply a bias voltage, if the resistor array is intact, the value of the bias voltage is much greater than the low amplitude from the ringing signal residual AC voltage.

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