JPH02228825A - Fault diagnostic device in changeover device for communication line - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a communication line switching device, and more particularly to a failure diagnosis device that self-diagnoses whether or not there is a failure in a switching element inside the switching device.

"Prior Art" The applicant of this invention previously filed Japanese Patent Application No. 117935/1986 as a switching device for switching a metal multi-pair cable used in a communication line to a newly installed line without interrupting the line.
An application was filed for the title of the invention: ``Communication line switching device.'' Hereinafter, first, this switching device will be explained.

Figure 2 is a block diagram showing the schematic configuration of the switching device;
The figure 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, fiber switching adapters Aa, Ab#
(The wires are connected to each other and have electrical continuity to the outside. The core wire switching adapter Ac is also connected to the pair of wires Lla and L2a of the newly installed wire 20 at the scheduled switching position.These adapters A a , A b , and A c mechanisms and connection switching methods using these are disclosed in Japanese Patent Application No. 1983-145.
Since it is described in No. 087 above, a detailed explanation will be omitted. Connection lines are output from each of the adapters mentioned above to the switching device 30.

The configuration of the switching device 30 is as follows: "Relay circuit section 3", switching section 3
2, a wire number confirmation section 33, a transmission section 34, a CPU section 3, and 5. The relay circuit section 31 includes a plurality of contact relays, and the switching section 32 includes a photocoupler type variable resistance element, a static characteristic measurement unit for measuring the current-resistance characteristic of the variable resistance element, and a static characteristic measurement unit for measuring the current-resistance characteristic of the variable resistance element. Based on the discrete wire-resistance characteristics obtained from the unit, when the resistance changes are realized finely and smoothly under the calculation of the CPU, and at the same speed as the actual switching, it becomes a pair. It consists of an unbalance measuring unit for checking whether the variation in the reproduced resistance value of the variable resistance element is within a permissible range. 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 has an empty circuit 37
Communication is carried out between stations at the other end for line number comparison.

CPU section 3 This unit controls the switching operations mentioned above in an integrated manner, and performs static characteristic measurements, unbalance measurements, and data processing necessary for these measurements, and also sequentially performs core wire switching connections by switching relay contacts. It has the function of

Next, this switching device will be explained in more detail based on FIG. In this figure, numeral 1 is a CPU (central processing unit), 2 is a memory consisting of an l'tOM in which programs for control function calculations and a series of sequential operations are stored, and a RAM mainly for storing static characteristic data. be. 3 is a photocoupler unit, which has a D/A (D/A) for capturing voltage data corresponding to the resistance value of the variable resistance element.
A V/[(voltage/current) conversion circuit 5 that outputs a current corresponding to the output voltage of this D/A converter 4, and a V/I conversion circuit 5 that is driven by a It is composed of a photocoupler 6 (variable resistance element). The photocoupler 6 is composed of an LED 6a through which the above-described current I flows, and a CdS 6b that receives light from the LED 6a. 7 is a photocoupler unit having the same configuration and function as the photocoupler unit 3, and includes a D/A converter 8 and a V/f conversion circuit 9.7J.
- Consists of Tocoupler IO.

SW l ~ SW 7 , S L l , S L 2
, Sai, Sbi, Sei, S Ni, S ci(
However, the switching core pair 1) is a switch that is sequentially driven on/off by the CPU 1.
The connection state shown by the solid line indicates the case of non-excitation. 12 is a static characteristic measuring unit, which includes a resistor 12a and this resistor +
A/D (
(analog/digital) converter 12b. Also, in this unit 12, terminals T,...
, T , are terminals to which voltages +V 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 comparison W13b compares the output of the amplifier 13a and the constant voltage Vk, and the absolute value of the output of the amplifier 13a is the voltage Vk.
If it is smaller than k, a "0" signal is output, and if it is larger, a "l" signal is output. The output of this comparator 13b is outputted to the pass line la of CPol via the interface circuit 14. Note that Vk is a value determined experimentally. The unit 13 also has +V and -V power supplies, and terminals T13. From T to the connecting wires, voltage +V, -V, respectively.
is applied.

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, SW 1.5ai (1≦j≦10)
is turned ON, the wire number comparison unit is connected to the existing core wire via the adapter Aa, and minute signals are transmitted and received between the stations at the other end to perform wire number comparison.

When the incense stick comparison is completed, write the notes sws, sw1, Sa.
i is set to OFF', and the characteristics of the photocoupler type variable resistance element are measured.

That is, before actual switching, this switching device goes through two modes: (1) static characteristic measurement mode and (2) dynamic characteristic measurement mode, and then shifts to cable switching mode. Each mode will be explained in turn below.

■Static characteristic measurement mode This mode is a mode for measuring each static characteristic of the photocoupler 6.10. In this mode, CPUt first turns on each of the switches 5W2-1 and 5W2-2 (dotted line state). As a result, one end of the CdS 6b is connected to the switches 5W2-1 and SW5-1.

to the terminal 'r of the static characteristic unit 12 via SW7-1,
CdS・61) other end is switch 5W2-2゜9W6-
Resistor 1 in static characteristic unit 12 via 1,5W7-2
It is connected to one end of 2a. That is, the CdS 6b and the resistor 12a are connected in series, and the voltage +V,
-V are applied respectively.

Next, CP[Jl sequentially outputs specific discrete data to the D/A converter 4, thereby causing a current of, for example, 0.05A, 01IA, 0.15A, etc., to flow through the LED 6a. The output data of the A/D converter 12b at this time is taken into the memory 2. 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, the CPU turns off the switches 5W2-1, 5W2-2, and then switches 5W3-1, 5W3-2. SW
? -1 and 5W7-2 are each turned on (dotted line state). This connects Cd5-10b to the static characteristic unit 12. Next, the CPUI measures the static characteristics of the photocoupler 10 in the same manner as described above.

■Dynamic characteristic measurement mode In this mode, the CPU first selects the switch 5W2-
1.2-2.8W3-1.3-2, 5W5-1.5-2
, 5W6-1, 6-2 are each turned on, and the other switches are turned off. This results in CdS・6b.

10b are connected in series, and one end of CdS/6b is an unbalance measurement unit! C to the terminal Tlff of 3.
The connection point of dS.6b and tOb is connected to the input end of the amplifier 13a in the unit hair 3, and the other end of CdS.10b is connected to the terminal T I4 of the unbalance measuring unit [3]. With this connection, a voltage +V is applied to both ends of the CdS 6b and 1Ob leakage circuits.

(2) is applied, and the voltage at the connection point between CdS 6b and 10b is applied to the comparator 13b via the amplifier 13a. Next, the CPU 1 changes the resistance values of CdS 6b and 10b with the speed and smoothness required when switching cables. This resistance value change is performed while calculating a control function based on static characteristic data. That is, first, C
Set the 1 degree resistance value of dS・6b and 10b to the maximum value. Specifically, data such that the resistance values of CdS·6b and tab 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 CclS·6b, 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 job are sequentially decreased. Next, the resistance values of CdS·6b and IOb are sequentially increased.

In the above process, each resistance value of CdS, .6b, and job must be sequentially decreased/increased while taking 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, due to reasons such as the fact that the current-resistance characteristic of the photocoupler is actually non-linear, the static characteristic is obtained using linear interpolation, and the response speed of the photocoupler 6 and IO are different. A difference (imbalance) occurs in the resistance values of CdS·6b and lOb. If this unbalance increases beyond a certain level, it disturbs the transmission characteristics of the core wires 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, when the output of the comparator 13b becomes an "L" signal, the CPU t displays this on the display (path shown in the diagram) and at the same time stops the measurement, or restarts the static characteristic. Return to measurement.

As a result of the above measurements, if the resistance unbalance amount does not fall within a predetermined value, measures such as replacing the photocoupler 6 and IO are finally taken. Note that the resistance unbalance amount is determined by data on the communication line, and is more likely to be 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 to verify the resistance value itself achieved by the control function during this mode.

■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, switches SWI and SW2 are OFF and Sai.

With S bi S ci and s Xi turned OFF, the switch 5ei (i=l ~I O
) are turned on simultaneously. As a result, a switch Sei is inserted in parallel at each switching point of each existing core wire. In this state, at time t, the switching points P of all the core wires are cut at the same time. Then, the pairs of wires from No. 1 to No. IO are sequentially switched to new core wires.

Note that normally, switching connections are made every 10 pairs, so 1=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 t, switch Sal and switches Scl, SLI, and SL2 of pair lines No. 1 and 1 are turned on. As a result, a variable resistance element is installed between the adapters Aa and Ac of each core wire E, I, and L2 of pair No. 1, that is, between the remaining side of the existing core wire 10 and one end of the new core wire 20. CdS 6b and 10b are respectively inserted. 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 t3 to t4. If the realized resistance values are not always equal, line balance will be disturbed.

(3) Time when the resistance value of each variable resistance element becomes low resistance (
4, turn on the switch SNI to short-circuit between adapters Aa and Ac. As a result, the existing core 1O and the new core 2
0 is connected.

(4) Switch Scl is turned off at time t, while switch Scl is turned off at time 1. switch Sbl ON SLt SL,
2 is turned OFF. As a result, by switching the switch SLI from the newly installed side to the existing side, CdS-6b and I Ob are inserted between adapters Aa and Ab.

(5) In this state, turn off the switch Set at time L
In this case, the CdS 6b and job are inserted in series between the remaining side and the discarded side of the existing core wire 10.

(6) Increase the resistance value of the variable resistance element from time t7 to time t.

(7) At time to when the resistance value of the variable resistance element becomes high,
Turn off switches Sat and Sbl. As a result, CdS 6b and lOb are separated from the existing core wire to 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, the adapter Aa and AC, that is, the remaining side of the existing core wire 10 and one end of the newly installed core wire 20 are maintained in a connected state by the switch SN.

In this way, once the switching of the pair wire No. 1 has been completed, the switching of the pair wire No. 2 and subsequent ones is performed by the same operation. Then, at time tlo 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 above core wires are connected. The switch SNt~・SN,,
Turn off. When the switching is completed in this way, the time tit
CPLI unit 35 and the like return to the initial state and end the operation.

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 lOb as minutely (smoothly) as possible.

"Problem to be Solved by the Invention" By the way, in the above-mentioned switching device, the configuration for sequentially changing the resistance value of the variable resistor, that is, the photocoupler 6.10. D/A converters 4, 5, V/I conversion circuit 5
. It becomes necessary. In this case, it is usually considered to use a semiconductor switching element as the switching means, but there is no semiconductor element that can easily obtain a sufficient ON resistance against the minute current for communication, and as a result, it is difficult to use a semiconductor switching element as the switching means. Only mechanical contacts can be used. However, mechanical contacts can only be used repeatedly a limited number of times, and contact abnormalities often occur, resulting in extremely low reliability.

In particular, in the case of the communication line switching device described above, the number of contacts is extremely large. That is, in the case of a switching device used for a 10-pair cable, switches S ai, S bi, S ci
There are 20 contacts each for Sai and SNi,
The total number of contacts is 100. For this reason, it is particularly important to immediately discover contact abnormalities.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a failure diagnosis device for a communication line switching device that can self-diagnose the quality of switching elements (contacts).

"Means for Solving the Problems" This invention uses a switching element to select a pair of core wires to be switched from among an existing line and a newly installed line, and between the selected core wires and between the remaining side and the removed side of the existing line. A communication line switching device that switches lines while changing the resistance value of each variable resistance element, including a constant current circuit and a switching device that supplies the output current of the constant current circuit to the switching element. and a detection means for detecting whether or not a voltage drop across the switching element is equal to or less than a certain value when a constant current is caused to flow through the switching element by the switching means.

"Operation" According to the present invention, the output current of the constant current circuit is supplied to the switching element via the switching means. Then, it is checked whether the voltage drop across the switching element at that time is below a certain value. If the switching element or ON resistance is defective,
The voltage drop becomes less than a certain value, so that the detection means can detect a failure of the switching element.

"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 41 provided with a failure diagnosis device 40 according to an embodiment of the present invention. Note that the switching device 4I shown in this figure has almost the same configuration as the switching device shown in FIG. 3, except for the fact that the failure diagnosis device 40 is provided, and the parts corresponding to the parts in FIG. The same symbols are attached. Also, in this diagram,
Only the switch corresponding to one core wire Ll of the pair is described, and the switches Sai, Sbi, Sci, Sei, S Ni corresponding to the i-th (i-1 to 10) pair are described.
and switch SLI only.

Next, in the failure diagnosis device 40, 42, 43°, 44.
45 is a mechanical switch, 46 is a constant current circuit, 47 is a comparator, and 48 is a base for supplying a reference voltage to the comparator 47 +1! This is an IT4 pressure generation circuit. However, switch 4
2 is a contact newly inserted in the vicinity of the switch Sai, and next to this switch 42 is a switch SW on the variable resistance side.
l-i are connected.

The reference voltage generation circuit 48 includes switches S ai and S b
Reference voltage for measuring ON resistance of i, Sci, Sei, S N i [and reference voltage V for measuring 0FFi resistance]
2 is generated and output to the comparator 47.

Next, the operation of the above-mentioned failure diagnosis device 40 will be explained. First, when switching the communication line by the switching device 41, turn on the switches 42 and 44 of the fault diagnosis device 40, and
．． 45 is designated as OF'F'. In this case, communication lines are switched in the process described above.

Next, a case in which failure diagnosis is performed will be explained.

First, switch SLI is connected to normally closed contact NC, and switches S3i, Sei, and Sbi are turned to O.
In addition, the switches 42 and 44 are turned OFF, the switches 43 and 45 are turned ON, and the constant current circuit 46 is turned ON.
shall be. When the constant current circuit 46 is turned on, a constant current flows through the switches 43, S ai, S ei, S bi, S
L! , 45, thereby generating a voltage Cv at one end of the constant current circuit 46. When the ON resistance of the contacts of the switches 43 and 45 is O, this voltage CV is the O of each contact of the switches Sai, Sei, Sbi, and S L l.
The value corresponds to the sum of N resistances. On the other hand, at this time, the reference voltage generation circuit 48 outputs the reference voltage Vl and supplies it to the comparator 47. Comparator 47 connects voltage Cv and reference voltage V! The voltage C is the reference voltage V.
When it is smaller than l, it outputs a "0" signal, and when it is larger, it outputs a "l" signal. Here, the switches S ai, S ei
, S bi, and S L I are all good products, the ON resistance of each switch contact is below a certain value, therefore, the voltage Cv becomes below the reference voltage Vl, and the output of the comparator 47 becomes a "0" signal. becomes. On the other hand, the switches S ai, S ei, and S bi.

If any of the SLIs has an abnormal ON resistance, the voltage C becomes larger than the reference voltage Vl, and the output of the comparator 47 becomes a "1" signal. That is, based on the output signal of the comparator 47, the switches 5aiSei, Sbi, S L
It is possible to detect an abnormality in the ON resistance of each contact of 1.

Next, the reference voltage v2 is applied from the reference voltage generation circuit 48 to the comparator 47, and the switches S ai and S
Turn ei and Sbi off in sequence and then turn them back on. When switch Sai is turned off, switch Sa
If there is no abnormality in i, the voltage CV becomes the maximum value (power supply voltage), and the output of the comparator 47 becomes a "1" signal. On the other hand, if the switch Sai is defective and the OFF resistance is below a certain value, the voltage CV will not reach the maximum voltage and the language voltage V
2 or less, and as a result, the output of the comparator 47 becomes “
O” signal.

That is, based on the output of the comparator 47, an abnormality in the OFF resistance of the switch Sai can be detected. The same applies to the switches S ei and S bi.

Switch S ai, S ei, S b
It is possible to detect abnormal ON resistance and abnormal OFF resistance.

Next, the switch SLI is put into the normal oven contact NO, the switches Sei and Sbi are turned OFF', and the switches Sai, sNi, and Sci are turned ON. below,
Switch Sai SNi Sci in exactly the same way as above
Abnormalities in ON resistance and OFF resistance can be detected.

In addition, in FIG. 1, L is used as the failure diagnosis circuit 4o.
Although only the circuit for i is shown, it goes without saying that a fault diagnosis circuit for L2 having the same configuration as circuit 40 is provided.

"Effects of the Invention" As explained above, according to the present invention, there is provided a constant current circuit, a switching means for supplying an output current of the constant current circuit to the switching element, and a constant current flowing to the switching element by the switching means. Since the present invention is provided with a detection means for detecting whether the voltage drop across the switching element is below a certain value when the switching element (contact) is caused to flow, it is possible to self-diagnose the quality of the switching element (contact).

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing the configuration of an embodiment of the present invention, and FIG.
The figure is a block diagram showing the general configuration of a communication line switching device,
FIG. 3 is a circuit diagram showing details of the switching device, and FIG. 4 is a timing diagram for explaining the operation of the switching device. 42-45... Switch, 46... Constant current circuit, 47... Comparator, 48...
・Reference voltage generation circuit.

Claims (1)

[Claims] A switching element selects the pair of core wires to be switched from among the existing line and the new line, and a variable resistance element is interposed between the selected core wires and between the remaining side and the removed side of the existing line. In a communication line switching device that switches lines while changing the resistance value,
a constant current circuit, a switching means for supplying an output current of the constant current circuit to the switching element, and a voltage drop across the switching element when a constant current is passed through the switching element by the switching means; What is claimed is: 1. A failure diagnosis device for a communication line switching device, comprising a detection means for detecting whether