JPS61284138A - Switching device for communication line - Google Patents

Abstract

PURPOSE:To facilitate multiplexing a communication line by switching a switching circuit so that a communication signal passes between the first and the second terminals if an OR circuit has the OR output but switching the switching circuit so that the communication signal passes between the first and the third terminals if it has not the OR output. CONSTITUTION:Switching devices TSWa and TSWb are installed in a telephone station A and a subscriber's home B respectively. Devices TSWa and TSWb are connected to telemetering device TMR of lower priority level when communication is not performed, and a telephone call signal is transmitted only when telephone service is performed. Each of signal detectors DETa and DETa' of devices TSWa and TSWb detect the call signal of, for example, 16Hz to switch the connection between terminals alpha and beta. Each of signal detectors DETb and DETb' of devices TSWa and TSWb detects a DC loop of a line closed by a telephone TE to switch terminals to the connection between terminals alpha and beta.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a communication line switching device for time-division multiplexing of a plurality of types of communication signals onto one communication line.

〔overview〕

The present invention provides a communication line switching device for time-divisionally multiplexing multiple types of communication signals on one communication line installed between two points, in which a communication line is connected to a first terminal,
Connect the communication line of the communication signal with high priority to the second terminal,
Connect the communication line of the lower priority communication signal to the third terminal,
When there is a logical sum output of each output of the first and second signal detectors that detect communication signals arriving at the first and second terminals, the first terminal and the second terminal are connected, and the logical sum of each output is output. By configuring the first and third terminals to be connected when there is no output, there is no need for a special switching signal.
Switching is performed by detecting a signal transmitted along with a normal communication signal, making it easy to interrupt a high-priority communication signal.

[Conventional technology]

Conventionally, multiplexing of communication lines has been performed using a frequency multiplexing method or a time division multiplexing method. In such a multiplexing method, the multiplexing equipment is complicated and expensive.

Furthermore, since multiplexing is performed by assigning frequencies and time slots, it is not possible to freely set the frequency band and dynamic range given to each communication line.

Recently, devices have come into use that read the values of meters installed in each home using telemetering signals using telephone lines and automatically calculate, for example, the amount of electricity used.

In addition, a method has also been put into practical use in which safety monitoring equipment from a security company or the like is similarly connected to safety monitoring equipment in each home through a telephone line to centrally monitor safety.

[Problem that the invention seeks to solve]

However, with such conventional communication line multiplexing methods, when multiplexing telemetering signals, safety monitoring signals, etc. as in the example above, the signals have different frequency bands and dynamic ranges as described above. However, there were problems in that it was not necessarily economical considering the frequency of use.

Therefore, in the prior art, in such a case, a method is used that includes a switching device that switches signals each time and multiplexes them in a time-division manner. That is, the signal is normally connected to the main communication signal and switched to the slave communication signal when a switching signal arrives, thereby performing time-division multiplexing.

However, when the number of communication signals to be multiplexed increases, the switching signal detection by the switching device becomes complicated, and the switching control cannot be performed easily, resulting in a significant cost increase depending on the number of communication signals to be captured. This has the disadvantage that the switching device is also large in size.

The present invention solves these conventional drawbacks by providing a switching device that is inexpensive, has few electrical limitations, can be easily switched to multiplex multiple communication signals, and is further compact. The purpose is to

[Means for solving problems]

The present invention provides a switching circuit that switches between a state in which a communication signal passes between a first terminal and a second terminal and a state in which a communication signal passes between a first terminal and a third terminal; In the communication line switching device, the control circuit includes a first signal detector that detects when a communication signal arrives at the first terminal, and a control circuit that controls the switching circuit. a second signal detector that detects the arrival of the signal; and an OR circuit that receives each detection output of the first and second signal detectors as input, and when the OR circuit has an OR output; The switching circuit is set so that a communication signal passes between the first terminal and the second terminal, and when the logical sum circuit does not have a logical sum output, the switching circuit is set between the first terminal and the third terminal. It is characterized by a configuration in which the communication signal is set in a state through which a communication signal passes.

[For production]

The present invention prioritizes communication signals taken into each of two points, constantly connects lower priority communication signals to a communication line that is multiplexed via a switching device, and when a higher priority communication signal arrives. Furthermore, multiplexing of a large number of communication signals can be easily performed by detecting a signal transmitted along with the communication signal and switching to a communication signal with a higher priority.

That is, the signal detector of the switching device only needs to detect a specific signal of the communication signal, which simplifies the structure and makes the control method extremely easy.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a communication line multiplexing device in which a switching device of the present invention is used.

Point A is telephone office A, and point B is subscriber premises B. A subscriber line SL is connected to the terminal α of the switching device T S W a of the telephone office A via a signal detector DETb'.
A switch SW is connected to the terminal β via a signal detector DETa. A telemetering device TMRa is connected to the terminal γ. Terminal α of switching device TSWb in subscriber premises B
A subscriber line SL is connected to the terminal β via a signal detector DETa′, a telephone TE is connected to the terminal β via the signal detector ];) ETb, and a telemetering device TMRb is connected to the terminal γ. Ru. Telemetering device TMR
b takes in the data of the electric meter M and transmits it to the communication line.

Here, telephone call signals are given higher priority than telemetering signals.

This multiplexer is characterized by switching devices T and S.
Wa and TSWb are connected to the lower priority telemetering device TMR side when no communication is taking place, and the telephone call signal is transmitted only when a telephone call is made. It is in. This is fundamentally different from the conventional method, which connects to the higher priority side when no communication occurs.

The signal detectors DETa and DETa' of the switching devices TSWa and TSWb detect the 16Hz ringing signal (
TR) is detected and the connection is switched to terminal α and terminal β. In addition, the signal detectors DF, Tb, and DETb' of the switching devices T S W a and Tswb detect the direct current loop (DCL) of the line closed by the telephone TE and switch the terminal α
and terminal β.

Therefore, when a ringing signal (TR) arrives from the exchange SW and the telephone TE answers, the exchange SW and the telephone TE are connected until the call ends and the DC loop (D CL) disappears.
is connected. When the call ends, the switching device automatically activates and switches to the telemetering side.

This configuration greatly simplifies the switching device TSW. That is, in order to perform telemetering, there is no need for any signal or control circuit to previously switch the communication line to the telemetering side. When making a telephone call, the call signal (T
R) and the closure of the DC loop (D CL),
The communication line can be preferentially and automatically used for telephone calls. The switching device for this purpose is simple and inexpensive.

FIG. 2 is a block diagram showing an embodiment of the switching device of the present invention. In FIG. 2, the switching device T SW
a corresponds to the switching device T S W a shown in FIG.

The lines L1, L2, and L3 are each in pairs, and one of the lines L1 is connected to the terminals α1 and α2, and the other is connected to the subscriber line SL. One side of line L2 is terminal β1, β
2, and the other is connected to exchange SW. Line L
One of the terminals 3 is connected to the terminals γ1 and γ2, and the other is connected to the telemetering device TMR. Signal detector DETa
is connected to line L2, and signal detector DETb' is connected to line L2.
Connected to 1. When the signal detector DET does not detect a switching signal, the terminals α and γ are connected. The switching output of each signal detector DET is input to an OR circuit OR, and when a switching signal is detected by any of the signal detectors DET, the connection is switched between terminal α and terminal β.

The example shown here is a 168z ringing signal (TR) for a telephone call.
This configuration detects DC loops and direct current loops (D CL), but the targets of signals to be detected are not limited to these, but include carrier frequencies of data communication signals, specific dial signals of push button dial signals, and other signals accompanying communication signals. It is possible to target various types of signals that are generated.

Next, an implementation example of the communication line switching device of the present invention will be described.

FIG. 3 is a diagram showing an example of the configuration of a main distribution board MDF that connects subscriber line SL at a telephone office to exchange SW.

The subscriber line SL is connected to one terminal pair 11. of the terminal board 10. ．． 1
1□, terminal pair 11. ．． 11□ is the disconnection contact pair t
3+, the other terminal pair 151.15□ via 132
The terminal pair 151.15□ is connected to one terminal pair 21t, 21□ of the terminal board 20 via jumper cotton J, and the terminal pair 211.212 is connected to the other terminal pair 25+.
, 25□, and the terminal pair 25. ．． Exchange machine S on 25□
W is connected. A trunk line TL is connected to the exchange SW.

Disconnection contact pair 13. ．． 13□ is for disconnecting the subscriber port %SL from the exchange SW for the purpose of testing and inspection, etc., and this disconnection contact pair 13. ．． Insert the switching device TSW of the present invention into 13□.

FIG. 4 is a diagram showing an overview of the main parts of the pair of disconnecting contacts and the switching device. FIG. 4(a) shows a pair of disconnecting contacts, and FIG.
b) is a switching device, and FIG. 4 (C1 is a partial sectional view of the pair of disconnecting contacts and the switching device).

In FIG. 4, reference number 10 is a terminal board, reference number IL, 11□ is a contact piece of one terminal pair, reference number 15+, i5g is a contact piece of the other terminal pair,
Reference number 131.13□ indicates an insertion hole for a pair of disconnection contacts.

Reference numbers 31+ and 31g are terminal α8 of the switching device TSW.
, a contact piece connected to α2, reference number 32+ −
32z is a contact piece connected to the terminal β. Reference number 3
3. ．． 33□ is a protrusion for insulating the contact pieces 31 and 32 and inserting them into the separation contact pair 13. Reference number 34+
, 34g are contact pieces connected to terminals γ8 and T2.

In this way, the switching device TSW can be easily mounted by having a structure that allows it to be inserted into the pair of disconnecting contacts 13. That is, by inserting the protrusion 33 into the pair of disconnecting contacts 13, the contact piece 11 and the contact piece 31, and the contact piece 15 and the contact piece 3 are separated.
2 electrical continuity is measured, and the subscriber line SL and the exchange S
The switching device of the present invention can be electrically inserted between the W and W, and mechanically fixed at the same time. Subscriber line SL and contact piece 15. soldered to contact piece 11.12.
Mounting can be easily performed without any modification to the jumper wire J soldered to 16.

FIG. 5 is a diagram showing an example of the arrangement of the switching device of the present invention mounted on the distribution board of a private branch exchange, FIG. 5(a) shows an example of the configuration of the distribution board, and FIG. 5(b) shows the switching device An example of the arrangement is shown below.

In FIG. 5, reference number 40 is a drop line, reference number 50 is a premises line, and reference number 60 is a drop line 4.
0 is terminal pair 61. ．． 61□, reference number 70 indicates that the local line 50 is connected to the terminal pair 71. ．． 71
It is a terminal board connected by □. Terminal pair 62. connected to terminal pair 611.61□ of terminal board 60. ．． 622 and
Terminal pair 71 of terminal board 70. ．． Terminal pair connected to 71□? 2. ．． 722 is connected by jumper wire J.

In the switching device TSW of the present invention disposed in this private branch exchange, the terminal pieces 811.81□ connected to the terminals β1 and β2 are connected to the terminal pair 62. ．． 62□, and the jumper wire J is connected to the terminal piece 82.182□ which is connected to the terminals α1 and α2. Reference number 83. ．． 83□
is a branched terminal piece connected to terminals γ0 and γ2.

In this way, the terminal pair 62. to which the jumper wire J is screwed. ．． 62□ is the terminal piece 81 of the switching device TSW 81□
By screwing the jumper wire J to the terminal pieces 821 and 822, the switching device TSW can be electrically inserted between the jumper wire J and the terminal board 60, and mechanically fixed at the same time. can.

That is, the switching device TSW can be easily mounted without removing the lead-in line 40 that is normally soldered to the terminal board 60.

Here, the driver insertion hole 84 is the terminal 62□ of the terminal board 60.
This is a hole for turning the screw of the terminal piece 81. when inserting a metal screwdriver if necessary. ．． 81□ may be insulated inside the hole to prevent conduction.

In this implementation example, the switching device TSW is inserted between the terminal board 60 and the jumper 'ftfAJ, but the same effect can be achieved even if the switching device TSW is inserted between the jumper iJ and the terminal board 70.

〔Effect of the invention〕

As explained above, the present invention is a method in which a communication signal with the lowest priority is normally transmitted between two points, and when a communication signal with a higher priority arrives, it can be automatically interrupted. Therefore, the signal detection means only needs to detect the signal transmitted along with the communication signal, which simplifies the structure of the switching device and also greatly simplifies the control method.

Therefore, communication lines can be multiplexed easily and inexpensively, and the slave communication signal can be easily used by utilizing the idle time of transmission of the main communication signal. services (telemetry, safety monitoring,
It has the excellent effect of being able to provide low-cost services (such as data communications).

Furthermore, the switching device can be easily installed by having a structure that allows it to be inserted into a pair of disconnecting contacts on a terminal board in a telephone office, and a structure that allows it to be inserted between a jumper wire and a terminal board in a private branch exchange.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a communication line multiplexing device in which a switching device of the present invention is used. FIG. 2 is a block diagram showing an embodiment of the switching device of the present invention. FIG. 3 is a diagram showing an example of the configuration of a main distribution board MDF that connects subscriber line SL at a telephone office to exchange SW. FIG. 4 is a diagram showing an overview of the main parts of the pair of disconnecting contacts and the switching device. FIG. 5 is a diagram showing an example of the arrangement of the switching device of the present invention mounted on a distribution board of a private branch exchange. A... Telephone office, B... Subscriber's premises, TSWa, TS
wb...Switching device of the present invention, TMRa, TMRB.
・・Telemetering device, SW・・Switching equipment, SL・
・・Subscriber line, TE・Telephone, DETaSDETb
...Signal detector.

Claims (5)

[Claims] (1) A switching circuit that switches and connects a state in which a communication signal passes between a first terminal and a second terminal and a state in which a communication signal passes between a first terminal and a third terminal, and this switching circuit. A communication line switching device comprising a control circuit that controls the circuit, the control circuit comprising: a first signal detector that detects when a communication signal arrives at a first terminal; a second signal detector that detects that The switching circuit is set so that a communication signal passes between the first terminal and the second terminal, and when the above-mentioned OR circuit does not have an OR output, the switching circuit is set to pass between the first terminal and the third terminal. A communication line switching device configured to allow communication signals to pass through. (2) Either the first signal detector or the second signal detector includes a circuit that detects the arrival of a telephone call signal at the first terminal; 2. The communication line switching device according to claim 1, wherein the other of the signal detectors includes a circuit for detecting that the DC loop of the second terminal is closed. (3) The communication line switching device according to claim (1), wherein the first and second signal detectors include a circuit for detecting a carrier wave of a data transmission signal. (4) The first terminal and the second terminal are formed of metal plates on both sides of one terminal board separated by an insulator, and this terminal board has a structure that allows it to be inserted into the main distribution frame (MDF) test terminal of the subscriber line. A communication line switching device according to claim (1). (5) The communication line switching device according to claim (1), wherein the first terminal and the second terminal have a structure that can be connected to a main distribution frame (MDF) of the subscriber line by screwing.