JPS6230592B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention sends line number information from the slave unit to the base unit via a cable, and based on this line number information, there is no need to separately provide a common current return path between the base unit and the slave unit. This invention relates to a non-polar cable line number search method that can select the line number of a cable core.

Conventionally, this type of wire number search method includes a continuity method in which wire numbers are sequentially selected by measuring the continuity between both terminals of a core wire using a circuit tester, etc. An analog method is known in which an analog signal with a different current value is given at the receiving end, and a wire number is digitally displayed via an A-D converter based on this analog signal on the receiving end, and a digital method using pulses is also known. There is. However, in the conduction method, in the case of a long cable that has been laid, it is difficult for one worker to search for the cable because the cable is long. In the analog method, if contact occurs between the core wires of the cable, a line number other than the one to be searched is displayed, and it is impossible to detect whether or not contact occurs between the lines. Not only that, but if noise due to electromagnetic induction from other equipment or cables enters the cable, it is impossible to separate it from the line number information, resulting in an incorrect line number being displayed. Also, in the digital system, if there is contact between lines, pulses with widths corresponding to the respective line numbers will overlap with each other, resulting in a false alarm being transmitted to the receiving device. It is also not easy to detect.

Therefore, in order to solve this problem, the present applicant has already proposed a cable line number search method as disclosed in Japanese Patent Application No. 55-98937. In this cable line number search method, each line number information output from a slave device has a width of logic "1" corresponding to each line number, occurs within the same time without duplication, and is identical. Each wire number information has a certain period of time in which the logic "0" is shown for each logic "1", and the base unit receives the periodic pulse train of this wire number information to search for the cable wire number,
This prevents so-called false alarms in which a completely different line number is searched even if there is contact between lines in the middle of the cable, and it is not only possible to detect the presence or absence of this line-to-line contact, but also to distinguish between line number information and noise. This allows for easy separation and extremely high search accuracy. However, even in this search method, it is necessary to select in advance a core wire to be used as a common current return wire, or to separately install a common current return wire.

The present invention has been made in view of the above circumstances, and includes a base unit and a slave unit, and the base unit receives line number information from the slave unit via a cable, and the base unit receives line number information from the slave unit via a cable. In the cable line number search method for searching line numbers, a switching circuit is provided between the child unit and the cable, and this switching circuit transmits line number information via the cable under potential control from the base unit. is possible, and one input terminal of the base unit performs a switching operation to appropriately set the core wire of the connected cable to a common current return wire, and as a result, the wire number from the slave unit is To provide a non-polarity cable line number search method in which a base unit searches for a cable line number based on information, and also eliminates the need to prepare a core wire of a cable to be used as a common current return path separately from this cable in advance. It is something.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the non-polar cable line number search method according to the present invention will be described below with reference to the drawings. Reference numeral 1 denotes a slave unit equipped with a signal generator 2, and numeral 3 denotes a master unit equipped with a line number identification display 4. A multicore cable 5 to be searched is connected between the slave unit 1 and the base unit 3. Handset 1
can be connected to each core wire of the cable 5 via a switching circuit 6 to the output terminals OUT ₁ to _{OUT o} of the signal generator 2, and can be connected to the switching circuit 6 via a resistor R ₁ and a charging capacitor C ₁ . A switching regulator 7 is connected to the switching regulator 7, and a wire number signal is sent to each core wire of the cable by power transmission from the base unit 3 via the cable 5, as described later. A logic signal generator LS that can send out is connected. The switching circuit 6 connects the output terminals OUT ₁ to OUT _o of the signal generator 2 and the core wires l ₁ to _{l o} of the cable 5.
The anodes of diodes D _{1-1 to D 1-o are inserted between the collectors of transistors Q 1} to Qn to make the output of the logic signal generator LS a constant current, and the anodes of diodes D _1-1 to _{D 1-o} are inserted _between A resistor R ₁ is connected to the cathode of _-1 to D _1-o , respectively, and a diode D _2-1 to _{D 2} is connected to the collector of each transistor Q ₁ to Qn.
_-o cathode is connected. The resistance R ₁ is l ₁ ~ l
This is to limit the maximum current of D _1-1 to _{D 1-o} with respect to line-to-line induced noise of _o , and is selected to be a small value. The anodes of the diodes _D2-1 to D2 _-o are each grounded, and the emitters of the transistors _Q1 to _Qo are also grounded via a resistor _R2 . On the other hand, the slave unit 1 has input terminals IN ₁ and IN ₂ which are arbitrarily connected to any one of the core wires l ₁ to _{l o} of the cable, and this input terminal IN ₁ has one input terminal of the operational amplifier 8 ( −)
However, the cathode of the DC power supply B is also connected to the input terminal _IN2 . The other input terminal (+) of this operational amplifier 8 is connected to the anode of the DC power supply B via a resistor _R3 , and to the cathode of the DC power supply B via a resistor _R4 and an electronic switch _SWp . Further, the output terminal of the operational amplifier 8 is connected to the base of the transistor Q ₀ . The collector of this transistor _Q0 is connected to the anode of the DC power supply B via resistor _R2 , and the emitter is grounded to one end of the input of the line number identification display 4 whose other end is grounded. It is also connected to the input terminal (-) of the operational amplifier 8 via a resistor _R0 . The opening and closing operations of the electronic switch SW _p are controlled by a system controller (not shown).

In the above configuration, the electronic switch SW _p is opened and closed under the control of a system controller (not shown), and this opening and closing operation causes the voltage Em applied to one input terminal (+) of the operational amplifier 8 to change to the second
As shown in figure a, the electronic switch changes.
When SW _p is opened, the cable 5 transmits power to the handset 1 (power refresh) via it, and when it is closed, wire number information is transmitted from the handset 1 to the base unit 3 in order to search for the wire number of the cable 5. do. Now, suppose that the main unit 3
Assuming that input terminal IN ₁ of is connected to core wire l ₁ of cable 5, and input terminal IN ₂ is connected to core wire l ₃ of cable 5,
When the electronic switch SW _p is opened, a voltage approximately equal to the power supply voltage of the DC power supply B is applied to the input terminal (+) of the operational amplifier 8, so that the transistor Q ₀
The emitter current of resistor R ₀ , input terminal IN ₁ , diode D _1-1 and resistor R ₁ increases.
to capacitor C ₁ , thereby charging capacitor C ₁ as shown in FIG. 2b.
After this charge voltage Ec is made constant to a predetermined value by the switching regulator 7, it is supplied to the signal generator 2 as an operating power source. On the other hand, when the electronic switch SW _p is closed, a voltage divided by both resistors R ₃ and R ₄ is applied to the input terminal (+) of the operational amplifier 8, and therefore the voltage of the transistor Q ₀ is applied to the input terminal (+) of the operational amplifier 8. As a result of the decrease in the emitter current, the terminal voltage E _p at the input terminal IN ₁ becomes lower than the terminal voltage E c between the capacitor C ₁ and the resistor R ₁ as shown in FIG _. It is reverse biased and operates off. When diode D _1-1 turns off, the core wire
The capacitor _{C1 ,} that is, the switching regulator 7, is electrically disconnected from l1, and at this time, the signal generator 2 generates a pulse width T as shown in FIG.
The wire number information with _t is transistor Q ₁ , core wire l ₁
and is transmitted to the wire number identification display 4 via the resistor R ₀ , and the wire number identification display ₄ searches for the core wire l 1 of the cable 5 . Input terminal for the core wire l ₂ ~ _{l o}
Switch the connection of IN ₁ arbitrarily and repeat the above operation.
Thereby, the wire numbers of the core wires l ₁ to _{l o} are searched.

By the way, in this embodiment, in the line number information, _an information signal having a pulse width T _t as shown in _FIG . Width T _t+1
An information signal with a pulse width corresponding to the line number that similarly occurs sequentially after _a Toff period, that is, a period of logic "0" is output to the corresponding output terminal OUT ₁ to OUT. supplied to _o . That is, the line number information output from the output terminals OUT ₁ to OUT _o is generated without duplication, and as described above, there is a period of logic "0" between each information signal of logic "1". , and occurs cyclically with a predetermined period while maintaining such a relationship. The line number identification display 4 receives the above-mentioned information signal and identifies and displays the line number based on its pulse width. By using such wire number information, contact between wires in the middle of the cable can be detected, noise induced in the cable can be separated, and extremely high search accuracy can be obtained.

The common current return path during the above power transmission and wire number information transmission is from ground to diode D _2-3 and the core wire.
It flows through _l3 to the cathode of DC power supply B. In this case, a current return path is formed no matter which of the core wires l ₁ to _lo is connected to the input terminal IN ₂ .

In short, in the above embodiment, the electronic switch SW _p
When opened, power refresh is performed from base unit 3 to slave unit 1, and when closed, line number information is transmitted from slave unit 1 to base unit 3. When transmitting line number information, diode D Since _{diodes 1-1} to D _1-o are turned off and the directions are opposite to diodes D _2-1 to _{D 2-o} , the information signal can be transmitted without being harmed by the diodes. Moreover, the diodes D _1-1 to _{D 1-o} , D _2-1 are also effective against external noise.
Since ~ _D2-o is clamped, the signal transmission characteristics are good, and it also functions as a protection for internal elements.

In the above embodiment, an example was explained in which a cable line number is searched, but it goes without saying that the method can also be used as is when searching a connector terminal number.

In addition, in a system where it is possible to easily place a power source (such as a battery) in circuit 1, the capacitor C ₁ is removed and the power source is reconnected to the connection point of this capacitor C ₁ . Power is supplied from the power source to the handset 1 via the regulator 7. In this case, the electronic switch SW _p of the base unit 3 is left in the closed state.

As described above, according to the non-polar cable line number search method according to the present invention, the switching circuit performs a switching operation under potential control from the parent unit and performs line number information as appropriate, so that the connection between the parent unit and the slave unit is There is no need to install a common current return path separately from the core cable, and wire number information can be detected by one worker's potential control operation on the base unit side.
Furthermore, since the switching element provided in the slave device can form a positive or negative current path, it can also be used to clamp noise and protect internal elements, which has important practical effects.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing an embodiment of the non-polar cable line number search method according to the present invention, Fig. 2 a, b, c
is a diagram showing the voltage values of each part in FIG. 1, and FIG. 3 is a time chart showing line number information. 1...Slave unit, 2...Signal generator, 3...Main unit, 4...Line number identification display, 5...Multi-core cable, 6...Switching circuit, 7...Switching regulator, 8
...Operational amplifier, l ₁ - l _o ... Core wire, Q ₀ - Q _o ... Transistor, R ₀ - _{R 4} ... Resistor, D _1-1 - D _1-o , D _2-1 - _{D 2
-o} ...diode, C ₁ ...capacitor, OUT ₁ ,
OUT ₂ ...output terminal, IN ₁ , IN ₂ ...input terminal, B...DC power supply, SW _p ...electronic switch.

Claims (1)

[Claims] 1. In a device in which a signal generating device is provided on the child device side to send a wire number or connector terminal number signal to each cable core wire, and a line number identification display device is provided on the parent device side, the output terminal of the signal generating device A switching element is connected which automatically determines the direction of the search signal current based on the signal sent from the base unit and which controls the potential of any two search terminals. A non-polar cable line number search method characterized in that it is performed without determining a special common current return line.