JPH0585030B2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" This invention relates to a communication line switching device, and in particular,
The present invention relates to a fiber connection inspection device for inspecting the connection state of a connection between a connector half and a core wire, a probe and a core wire, or the like.

``Prior Art'' The applicant of this invention previously proposed Japanese Patent Application No. 61-117935 as a switching device for switching a metal multi-pair cable used in a communication line to a friendly line without disconnecting the line. An application was filed for the title of the invention: ``Communication line switching device.'' Hereinafter, first, this switching device will be explained.

FIG. 2 is a block diagram showing a schematic configuration of the switching device, FIG. 3 is a circuit diagram of the device, and FIG. 4 is a time chart showing the open/close states of each switch contact when switching the core. First, the overall configuration of this switching device will be schematically explained. In FIG. 2, among the communication lines, the existing core wire 10 to be switched includes 10 pairs of wires, each pair consisting of two core wires L1,
L2 is twisted together (only one pair of wires is shown in this figure). On both sides of the switching point P planned in the middle of this existing core 10, there are connections for core switching. Children Aa and Ab are connected to provide electrical continuity to the outside. Kindness line 20
Similarly, it is composed of 10 pairs of wires, and a wire switching connector Ac is connected to the core wire L1a, L2a constituting each pair at a switching scheduled position. The mechanism of these connectors Aa, Ab, and Ac and the connection switching method using them are disclosed in Japanese Patent Application No. 145087/1987. From each connector above, switching device 3
A connection line goes out to 0.

The configuration of this switching device 30 is as follows:
1, switching section 32, wire number confirmation section 33, transmission section 34,
It consists of a CPU section 35. The relay circuit section 31 has a plurality of contact relays, and the switching section 32
is a photocoupler-type variable resistance element, a static characteristic measurement unit for measuring the current-resistance characteristics of the variable resistance element, and a CPU based on the discrete current-resistance characteristics obtained from the static characteristic measurement unit. When the resistance changes minutely and smoothly under calculation, and at the same speed as when actually switching, does the variation in the reproduced resistance values of the paired variable resistance elements fall within the allowable range? It consists of an unbalance measuring unit for checking. The line number confirmation unit 33 is connected to the existing line 10, transmits and receives a minute signal that does not affect communication to and from the station at the other end, and performs line number comparison. The transmission section 34 is connected to the empty circuit 3
7, the stations at the other end communicate with each other for line number comparison.

The CPU unit 35 controls the switching operation described above, and performs static characteristic measurement, unbalance measurement, data processing necessary for these measurements, and sequentially performs core wire switching connections by switching relay contacts. Has a function.

Next, this embodiment will be explained in more detail based on FIG. In this figure, 1 is a CPU (central processing unit), 2 is a ROM that stores programs for control function calculations and a series of sequential operations, and a ROM that is mainly used for storing static characteristic data.
Memory consists of RAM. 3 is a photocoupler unit, which includes a D/A (digital/analog) converter 4 for taking in voltage data corresponding to the resistance value of the variable resistance element;
V/I outputs a current I corresponding to the output voltage of
It is composed of a (voltage/current) conversion circuit 5 and a photocoupler 6 (variable resistance element) driven by this V/I conversion circuit 5. In addition, the photocoupler 6 is an LED 6a through which the above-mentioned current I is passed.
and a CdS 6b that receives the light from this LED 6a. 7 is photocoupler unit 3
This is a photocoupler unit having the same configuration and function as the above, and is composed of a D/A converter 8, a V/I conversion circuit 9, and a photocoupler 10.

SW1~SW7, SL1, SL2, Sai, Sbi, Sei,
SNi and Sci (where i is the number of switched core wires) are switches that are sequentially turned on and off by the CPU 1, and the connection state shown by a solid line indicates a non-excited state. 12 is a static characteristic measuring unit, which includes a resistor 12a and an A/D (analog/digital
(digital) converter 12b. In addition, in this unit 12, the terminal
T ₁₁ and T ₁₂ are terminals to which voltages +V ₁ and -V are applied, respectively. Reference numeral 13 denotes an unbalance measuring unit, which is composed of an amplifier 13a and a comparator 13b. In this case, the comparator 13b is connected to the amplifier 1
Compare the output of amplifier 1 with the constant voltage Vk,
When the absolute value of the output of 3a is smaller than the voltage Vk, a "0" signal is output, and when it is greater, a "1" signal is output. The output of this comparator 13b is sent to the bus line 1a of the CPU 1 via the interface circuit 14.
Output to. Note that Vk is a value determined experimentally. The unit 13 has +V and -V power supplies, and the voltages +V and -V are applied to the connection lines from terminals T ₁₃ and T ₁₄ , respectively.

Next, the operation of the switching device having the above configuration will be explained. Prior to cable switching, wire number comparison is performed. This is SW8, SW1, Sai (1≦i≦10)
is turned ON, the wire number comparison unit is connected to the existing core wire via the connector Aa, and a minute signal is sent and received between the stations at the other end to perform wire number comparison.

When the wire number comparison is completed, the SW8, SW
1. Turn off Sai and measure the characteristics of the photocoupler type variable resistance element.

That is, before actual switching, this switching device goes through two modes: static characteristic measurement mode and dynamic characteristic measurement mode, and then shifts to cable switching mode. Each mode will be explained in turn below.

Static Characteristics Measurement Mode This mode is a mode for measuring each static characteristic of the photocouplers 6 and 10. In this mode, CPU1 first switches SW2-1, SW2
- are each turned on (dashed line state). As a result, one end of CdS 6b is connected to switch SW2-1,
The other end of CdS 6b is connected to terminal T11 of static characteristic unit ₁₂ via SW5-1 and SW7-1.
It is connected to one end of the resistor 12a in the static characteristic unit 12 via SW2-2, SW6-1, and SW7-2. In other words, CdS 6b and resistor 12a are connected in series, and voltages +V and - are applied across them.
V is applied to each. Next, CPU1 uses D/A
By sequentially outputting specific discrete data to the converter 4, for example, 0.05A,
A current of 0.1 A, 0.15 A, . Here, each data taken into the memory 2 indicates the resistance value of the CdS 6b when each of the above currents is passed through the LED 6a. The above is the process of measuring the static characteristics of the photocoupler 6.

Next, CPU1 switches SW2-1, SW2-
After turning 2 off, switch SW3-1,
SW3-2, SW7-1, and SW7-2 are each turned on (dotted line state). This allows CdS・10b
is connected to the static characteristic unit 12. then
CPU1 is connected to photocoupler 1 in the same way as above.
Measure the static characteristics of 0.

Dynamic characteristic measurement mode In this mode, CPU1 first switches SW2-1, 2-2, SW3-1, 3-2,
SW5-1, 5-2, SW6-1, 6-2 are each turned on, and the other switches are turned off. As a result, CdS 6b, 10b are connected in series, and one end of CdS 6b is connected to terminal T 13 of the unbalance measurement unit ₁₃ .
The connection point of 0b is the amplifier 13 in the same unit 13.
The input end of CdS.a and the other end of CdS 10b are connected to the terminal _T14 of the unbalance measurement unit 13, respectively. With this connection, CdS・6b,1
Voltages +V and -V are applied to both ends of the series circuit 0b, and the voltage at the connection point of CdS·6b and 10b is applied to the comparator 13b via the amplifier 13a. Next, CPU 1 uses CdS 6 with the speed and smoothness required when switching cables.
The resistance values of b and 10b are changed. This resistance value change is performed while calculating a control function based on static characteristic data. That is, first, CdS・6
Set the resistance values of b and 10b to the maximum value. Specifically, data such that the resistance values of CdS 6b and 10b become maximum values are output to the D/A converters 4 and 8, respectively. Next, a drive current value is calculated so that the resistance value of CdS 6b and 10b is slightly lower than the maximum value, and the resistance value is set based on this value. Similarly, the resistance values of CdS 6b and 10b are sequentially decreased. Next, the resistance values of CdS 6b and 10b are sequentially increased.

In the above process, the resistance values of CdS 6b and 10b must be sequentially decreased/increased while maintaining the same value. When the values are sequentially decreased/increased while maintaining the same value, the output of the amplifier 13a is always 0 because the balance is maintained, and therefore the output of the comparator 13b is always a "0" signal. However, in reality, the current-resistance characteristics of photocouplers are nonlinear, but static characteristics are obtained using linear interpolation, and the response speeds of photocouplers 6 and 10 are different. 6b,1
A difference (unbalance) occurs in the resistance value of 0b.
If this unbalance increases beyond a certain level, it disturbs the transmission characteristics of the core wire when switching cables, resulting in adverse effects such as bit errors.

Therefore, in the switching devices shown in FIGS. 2 and 3, the comparator 13b constantly compares the absolute value of the output of the amplifier 13a and the constant voltage VK, and when the absolute value of the amplifier 13a is larger than the voltage VK, the absolute value of the output of the amplifier 13a is larger than the voltage VK. In other words, if the output of the comparator 13b becomes a "1" signal, the CPU 1 displays this on the display (not shown) and simultaneously stops the measurement, or
Or return to measuring static characteristics again.

As a result of the above measurements, if the resistance unbalance amount does not fall within a predetermined value, measures such as replacing the photocouplers 6 and 10 are finally taken. Note that the resistance unbalance amount is determined based on communication line data, and is largely determined experimentally.

The above is the process of measuring dynamic characteristics. Note that, although a detailed explanation will be omitted, a function may be added during this mode to verify the resistance value itself achieved by the control function.

Cable Switching Mode This mode is an operation mode for actually performing cable switching, and is performed after the above-mentioned static characteristic measurement and dynamic characteristic measurement are completed.

The actual switching operation will be explained with reference to the time chart shown in FIG.

First, switch SW1 and SW2 are OFF, Sai,
With Sbi, Sci, and SNi turned OFF, switch Sei (i = 1 to 10) is turned ON all at once at time t ₁ in Figure 4.
shall be. As a result, the switches Sei are inserted in parallel at each switching point of each existing core wire.
In this state, at time t ₂ , all core wire switching points P
cut all at once. Then, pairs of wires No. 1 to No. 10 are sequentially switched to newly installed core wires.

Note that normally the connection is switched every 10 pairs, so i
=10.

Note that these operations are performed under the control of the CPU section 35 while being synchronized on the A side and B side in FIG. That is, a switching device similar to that on the A side is prepared on the B side so that the same resistance change can be made.

(1) At time _t3 , switch Sal of pair No. 1 and switches Sc1, SL1, and SL2 are turned ON. As a result, between the connectors Aa and Ac of each core wire L1, L2 of pair No. 1, that is, the existing core wire 1
CdS 6b and 10b, which are variable resistance elements, are inserted between the remaining side of 0 and one end of the newly installed core wire 20, respectively. The values of these variable resistance values are both set to the maximum value in advance.

(2) The resistance value of each variable resistance element is decreased from time t ₃ to t ₄ . If the realized resistance values are not always equal, line equilibrium will be disturbed.

(3) At time _t4 when the resistance value of each variable resistance element becomes low resistance, turn on switch SN1 and
Short-circuit between and AC. As a result, the existing core wire 10 and the newly installed core wire 20 are connected.

(4) Switch Scl is turned off at time t ₅ , while switches Sb1, ON, SL1, and SL2 are turned off at time t ₆ .
shall be. As a result, switch SL1 is switched from the newly installed side to the existing side. connector
CdS 6b and 10b are inserted between Aa and Ab.

(5) In this state, switch Se1 is turned off at time t ₇ .
, CdS 6b, 10b is the existing core 1
It is inserted in series between the 0 remaining side and the discard side.

(6) Increase the resistance value of the variable resistance element from time _t7 to _t8 .

(7) Time t ₈ when the resistance value of the variable resistance element becomes high
Then, turn off switches Sa1 and Sa1.
As a result, CdS・6b, 10b is the existing core 1
0 and the newly installed core wire 20, and the remaining side and the discarded side of the existing core wire 10 are separated.
On the other hand, connectors Aa and Ac, that is, existing core wire 1
The remaining side of 0 and one end of the newly installed core wire 20 are maintained in a connected state by the switch _SN1 .

In this way, once the switching of pair No. 1 is complete,
Thereafter, similar operations are performed to switch the pair No. 2 and subsequent lines. Then, at time _t10 in FIG. 4, each core wire on the existing side and the newly installed side is connected (this connection is made by connecting connector halves (not shown) all at once), and at time _t11 , the core wires are connected. Turn off the connected switches SN ₁ to SN ₁₀ . When the switching is completed in this way, the CPU section 35 and the like return to the initial state at time _t12 , and the operation ends.

The above are the details of this switching device. It goes without saying that in the cable switching process, it is desirable to change the resistance values of CdS 6b and 10b as minutely (smoothly) as possible.

"Problems to be Solved by the Invention" In the switching device described above, the connector Aa is composed of a connector half Ca and a connector probe Cp, as shown in the upper part of FIG. In this figure, only the one corresponding to one fiber is shown. The connector half Ca is provided with a pressure contact K that is pressed into contact with the core wire, a joint contact J that is coupled to another connector half, and a conductor D that connects these contacts. In addition, the connector probe Cp is the connector half Ca
When the connector half Ca is connected, the lead wire RD is connected to the conductor D.
Further, the connector Ab is constituted by a core wire probe Sp (FIG. 1). This core wire probe SP is
When the contact part Ss is brought into contact with the core wire, the lead wire RD
and the core wire are electrically connected.

By the way, when line switching is performed by the above-mentioned switching device, the pressure contact K of the connector half Ca and the contact portion Ss of the core wire probe Sp must each be reliably electrically connected to the core wire.

SUMMARY OF THE INVENTION Accordingly, the present invention provides an inspection device for a core wire connection portion in a communication line switching device, which is capable of inspecting the contact state of the connection portion between the insulation displacement contact K and the contact portion Ss and the core wire prior to switching connection. It is an object.

"Means for Solving the Problem" The present invention includes an operational amplifier, voltage output means for supplying a constant voltage to a first input terminal of the operational amplifier, one end of which is grounded, and the other end of which is connected to a second input terminal of the operational amplifier.
a first resistor connected to an input terminal, a second resistor one end connected to a second input terminal of the operational amplifier, and a third resistor one end connected to an output terminal of the operational amplifier. The other end of each of the second and third resistors is connected to an end of a lead wire connected to one core wire of an existing line via a switching means and a switching element.

"Operation" According to the present invention, the second resistor, the lead wire, the core wire connection section, the core wire, the core wire connection section, the lead wire, and the third resistor are arranged in series in the feedback loop of the operational amplifier. Interposed. As a result, if there is a contact failure in the core wire connection portion, the gain of the operational amplifier changes significantly, and therefore, a contact failure in the core wire connection portion can be detected from the output of the operational amplifier.

"Embodiment" Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a circuit diagram showing a communication line switching device equipped with a fiber connection inspection device 40 according to an embodiment of the present invention. The switching device shown in this figure has exactly the same configuration as the switching device shown in FIGS. 3
Portions corresponding to those in the figure are given the same reference numerals. In addition, in this figure, only the switch corresponding to one of the wire pairs, L1, is shown, and only the switches Sai, Sbi and switch SL1 corresponding to the i-th wire pair are shown. It is listed. Also, in this figure, one core wire L1
Although only the fiber connection inspection device 40 for processing the fiber connection portion side is shown, in reality, the inspection device 40 for processing the fiber L2 side is provided. That is, two sets of inspection devices 40 are provided within one switching device.

In the fiber connection inspection device 40, 41, 42
is a changeover switch that operates in conjunction with each other, and when performing core switching processing, common terminal c and terminal b are connected,
When inspecting the core wire connection portion, the common terminal c and the terminal a are connected. 44 and 45 are resistors connected in series, one end of the resistor 44 is connected to the terminal a of the changeover switch 41, a connection point between the resistors 44 and 45 is connected to the inverting input terminal of the operational amplifier 46, and The end is grounded. 47 is a resistor, one end of which is connected to the other end a of the changeover switch 42, and the other end connected to the output end of the operational amplifier 46. The above-mentioned resistors 44, 45, and 47 all have the same high resistance value (for example, 100KΩ). 48 is a capacitor inserted between the input and output terminals of the operational amplifier 46. 49 and 50 are voltage dividing resistors that divide the constant DC voltage +V, and a voltage Va (for example, 100 mV) obtained by this voltage division is supplied to the non-inverting input terminal of the operational amplifier 46. Further, 51 and 52 are power supplies for the operational amplifier 46.

Next, the operation of the circuit described above will be explained. When inspecting the core wire connections, first turn on the selector switch 4.
1 and 42, each common terminal c and terminal a are connected.
Next, only the switches Sa1 and Sb1 are turned on, and the output of the operational amplifier 46 is checked. Now, the core wire connection part, that is, the connector half Ca
If the connection between the insulation displacement contact K and the core wire and the connection between the contact section Ss of the core wire probe Sp and the core wire both maintain a good connection state, there is no resistance in the feedback loop of the operational amplifier 46. A series circuit of 44 and 47 is inserted. As a result, operational amplifier 4
The output V ₀ of 6 becomes V ₀ = Vs (1 + R ₄₄ + R ₄₇ / R ₄₅ ) (However, R ₄₄ , R ₄₅ , R ₄₇ are resistors 44,
45, 47 values). Here, as mentioned above, since R ₄₄ =R ₄₅ =R ₄₇ , V ₀ =3Vs. On the other hand, if there is a poor contact in the core wire connection part, the gain of the operational amplifier 46 becomes ∞, and its output V ₀ becomes equal to the positive power supply voltage. That is, by checking the output V ₀ of the operational amplifier 46, it is possible to detect a contact failure at the core wire connection portion. Incidentally, by the above check, it is of course possible to discover a connection failure between the connector half Ca and the connector probe Cp.

Next, only switches Sa2 and Sb2 are turned on, and the output _V0 of the operational amplifier 46 is checked.
Thereafter, the contact state between each core wire, the connector half, and the core wire probe is inspected by repeating the same process.

In the embodiment described above, when the contact state is normal, the current i flowing through the core wire is as follows: i=Vs/R ₄₅ =100 mV/100 KΩ=1 μA, which is an extremely small current. Further, when a contact failure occurs, the current i becomes 0. Furthermore, since the inspection device 40 is provided corresponding to each of the two core wires that make up the pair, no voltage is applied between the two core wires that make up the pair. As a result of the above, even if the above-mentioned inspection device 40 inspects the core wire connection portion while the data transmission line is in use, there will be no adverse effects such as occurrence of bit errors on the data transmission line.

In addition, the data transmission line (MODEM: 300~
9600, DSU: 3.2K to 64Kbit/sec), we were able to inspect the connections without any bit errors.

In addition, in the above embodiment, the core wire probe
Sp is used, but when switching again, a connector probe is used in place of this core wire probe Sp.

"Effects of the Invention" As explained above, according to the present invention, the connection state between the connector half, core wire probe, etc. and the core wire in a communication line switching device can be accurately inspected in a short time. As a result, the effect of improving the reliability of switching processing can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a block diagram showing the schematic configuration of a conventional communication line switching device, and FIG. 3 is a circuit diagram showing details of the switching device. FIG. 4 is a timing chart for explaining the operation of the switching device. 6b, 10b...CdS (variable resistance element), 41,
42...Switch switch, 44, 45, 47, 4
9, 50...Resistor, 46...Operation amplifier, Sai,
Sbi...Switch.

Claims (1)

[Claims] 1. Connect lead wires to each of the core wires on the remaining side of the existing line, on the removed side of the existing line, and on the new line, respectively, via pressure connection means, and connect switching elements to the other ends of these lead wires, respectively. A switching element is used to select the core wire to be switched, and between the core wire on the remaining side of the selected existing line and the core wire on the new line, and between the core wire on the remaining side and the core wire on the removed side of the existing line. each with a variable resistance element interposed,
This communication line switching device that switches lines while changing the resistance value of a variable resistance element includes an operational amplifier, a voltage output means for supplying a constant voltage to a first input terminal of the operational amplifier, one end of which is grounded, and the other end of which is grounded. a first end connected to a second input end of the operational amplifier;
a second resistor having one end connected to the second input terminal of the operational amplifier, and a third resistor having one end connected to the output terminal of the operational amplifier, the second resistor having one end connected to the second input terminal of the operational amplifier. , each other end of the third resistor is connected to an end of a lead wire connected to one conductor of the existing line via the switching means and the switching element. Line connection inspection device.