JPH09130452A - Telephone line switching device with erroneous connection prevention function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform display and alarm to prevent an erroneous connection when a device is used by having connectors for two-wire type telephone connection of two systems, connecting the one connector with a telephone set and connecting the other connector with an exchange side circuit. SOLUTION: When two connectors (Jack A and Jack B) are connected with an equipment and line acquisition instruction signals S3 are imparted to a line detection and an SW control part 1, SW 1A and SW 1B are opened, whether the connected equipment is a telephone set or an exchange side circuit is detected, SW2, SW3A and SW3B are controlled, notification signals S4 and S5 showing connection states are imparted to a state analyzing part 2, the connection states are decided and the display on a state display part 3 is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telephone line switching device which is used by being added to a connecting device between a telephone and an exchange and has a function of recognizing a switching connection state of a telephone line and preventing an erroneous connection.

[0002]

2. Description of the Related Art As seen in telephone line modems,
When a new device is added between the already installed telephone and the circuit on the exchange side, such a device is usually provided with two connectors for connecting a telephone, etc. The circuit from the telephone office or the exchange (hereinafter referred to as the exchange side circuit) is connected and used.

[0003]

In many cases, these two connectors are the same standard products called modular jacks, and it is distinguished whether the connector is to be connected to a telephone or the circuit on the exchange side. It has a mechanical structure that does not stick. Therefore, in many cases, an incorrect connection is easily made, which leads to a state in which the device does not operate normally. Replacing this connector is not an easy task for unfamiliar people. Also, in an environment with many phones,
There is a possibility of erroneous connection between completely different devices or exchange side circuits, and in some cases the connected device may be damaged. In addition, re-wiring when an incorrect connection is made not only lowers work efficiency, but may cause a new connection error.

The object of the present invention is to eliminate the problem of the prior art (A) the possibility of malfunction or damage of the device due to the incorrect connection of the connector, and (B) and inform the user of the device of the contents of the incorrect connection. Another object of the present invention is to provide a telephone line switching device capable of eliminating unnecessary trial work.

[0005]

A telephone line switching device according to a first aspect of the present invention is provided with two lines of two-wire telephone connector, one of which is connected to a telephone and the other is an exchange. In the circuit used by connecting the side circuit, when a line acquisition instruction signal is given, it is detected whether the connection destination of the two-system connector is a telephone or an exchange side circuit, and four connection states are identified. And a telephone line switching unit for controlling a switch for connecting to a public line and a switch between two systems of connectors, and a state of judging a connection state by the identification signal output from the telephone line switching unit. A connection state notification unit including an analysis unit and a state display unit that lights and displays four LEDs according to the state number output from the state analysis unit is provided, and the connection destinations of the connectors of the two systems are common. When the exchange side circuit to display the critical misconnection and is characterized by being configured so as to occupy perform corresponding respectively displayed for other connection state.

[0006]

1 is a schematic diagram for explaining the erroneous connection prevention function of the present invention. In the figure, reference numeral 1 is a line detection and switch control unit which is an essential part of the present invention. SW1A,
SW1B, SW2, SW3A, and SW3B are switches controlled by the line detection and switch control unit 1.
S1 to S9 represent signals. T1 is a transformer. It is assumed that one of the two telephone lines is connected by jack A and the other is connected by jack B. The gist of the operation of the present invention will be described with reference to FIG.

When a device using this method is in a state where the telephone line is not used, including a power-off state, the switch S is used.
W1A, SW1B, SW3A, SW3B open, SW2
The line detection and SW control unit 1 is configured so that only the one is closed, and the jack A and the jack B are simply connected. For simplification, one of the two lines of the two lines is made common, but it is better to switch simultaneously with the two-line switch. When a device is connected to a telephone line and tries to communicate, if a line acquisition instruction signal S3 is given to the line detection and SW control unit 1, line detection and SW are detected.
The control unit 1 opens SW2 and closes SW3A and SW3B to check the state of the telephone line, and based on the result, SW1A,
Control AW1B.

The control logic is as follows. a) When the exchange side circuit is connected to the jack A (signals S6 and S7), the SW1B is always opened, and when the other line (for example, telephone) is connected, the SW1B is closed. b) When the switch side circuit is connected to the jack B (signals S8 and S9), SW1A is always opened, and when other lines are connected, SW1A is closed.
Therefore, the connection is made according to the contents of Table 1 depending on the line connection state.

[0009]

[Table 1]

According to Table 1, when the exchange side circuit is connected to both jacks A and B as in the state number 0, the SW
Both 1A and SW1B are opened to prevent the two exchange side circuits from colliding. Connector connection status notification signal S at this time
Both 4 and S5 are "0". If it is considered that neither jack A nor jack B is a circuit on the exchange side as in the state number 3, both SW1A and SW1B are closed and both lines are connected to the transformer T1. Normally, only the circuit on the exchange side supplies power to the line, so this connection does not damage the equipment on the line. The four states shown in Table 1 are reflected in the 2-bit line connection state notification signals S4 and S5 of FIG. 1 and given to the device side using this system. As shown in Table 1, by referring to the line connection status notification signals S4 and S5 on the device side using this system, the connection status can be known, and therefore it is possible to recognize whether or not communication is possible.

Next, the line connection status notifying unit shown in FIG. 2 will be described. In the figure, reference numeral 2 is a state analysis unit, which receives connector connection state notification signals S4 and S5 when a line acquisition instruction signal S3 is given, and analyzes the line connection state. A state display unit 3 displays the alarm display signals S10 to S13 from the state analysis unit 2. The state analysis unit 2 receives the line acquisition instruction signal S3 and the line connection state notification signals S4, S5 and classifies them according to Table 1, and the results thereof are displayed as alarm display signals S10, S11, S12, S13.
Then, the status display section 3 displays the connection status and the alarm. Note that the connection status display and the alarm do not necessarily have to be displayed, and may be combined with an alarm (sound or the like) other than the display.

[0012]

FIG. 3 is a circuit diagram showing an embodiment of the telephone line switching apparatus of the present invention, which is a concrete example of FIG. However, illustration of parts not directly related to the present invention is omitted. Signal TEL / L
INE_A1 corresponds to S6 in FIG. Similarly the signal TE
LCOM sends signals TEL / LINE_B1 to S7 and S9.
To S8, photocoupler PC1 to SW1A, PC2 to SW1B, PC3 to SW2, PC4 to SW3A,
PC5 to SW3B, LINEST0 to S4, LIN
EST1 corresponds to S5 and DT / _TK corresponds to S3.

Although a timing signal called SENSE for detecting the line connection state is inputted from the outside for simplification of the drawing, this signal can be generated based on the DT / _TK signal. PC1, PC2, PC4 and PC5 are normally open MOS photocouplers.
These may be relays having the same function. The PC 3 is a normally closed type MOS photocoupler, which may be a relay or the like having an equivalent function. PC6 and PC7 are bidirectional photocouplers for AC input, which may also be relays having the same function.

When the power of the equipment using this system is turned off, or when the equipment is not using the telephone line (DT /
_TK and SENSE are 0), PC1, PC2
PC4 and PC5 are open, no line is connected to R1, R2 and T1, and TEL / LINE_A1 is TEL.
TEL / LINE_A2 is TEL in / LINE_B1
Connected to / LINE_B2, these optocouplers only serve as relays.

When the exchange side circuit is connected to the jack A (TEL / LINE_A1, TEL / LINE_
The operation of the circuit of FIG. 3 (when a DC voltage exists between A2) will be described with reference to FIG. ON / OFF of each switch
The change in F is shown in Table 2.

[0016]

[Table 2]

In the state shown in FIG. 5, when the device using this system uses the telephone line for communication, DT /
Set _TK to 1. At this time, PC3 becomes open. Next, in the state, SENSE is set to 1. PC at this time
4, PC5 is closed, current flows to PC6 via R1, and ST1 becomes 0. In the state, SENS
The value of ST0 and ST1 when E changes from 1 to 0 is LINE
It becomes the value of ST0 and LINEST1. In this case LINE
Since ST0 is 1 and LINEST1 is 0, _DRV_
A is 0 and _DRV_B is 1. Therefore, PC1 is closed and jack A is connected to transformer T1. When DT / _TK is set to 0 at the end of communication, jack A is disconnected from transformer T1.

The same operation is realized when the exchange side circuit is connected to the jack B. In the present embodiment, the logic of the drive signals of PC1 and PC2 is shown by hardware, but it may be controlled by software for the convenience of the system.

FIG. 4 shows an embodiment of the line connection status notifying unit of the present invention, which is a concrete example of FIG. In the figure, U1A is a 2-input 4-output decoder (2-4 decoder).
Corresponds to the state analysis unit 2 of. D1 to D4 are LEDs, to which the direct current voltage Vcc is applied via resistors, and correspond to the state display unit 3 in FIG. When DT / _TK is 1 (that is, when a device using this method attempts to use a telephone line), the outputs S10 to S1 of the 2-4 decoder U1A
Since 3 is obtained corresponding to the four states shown in Table 1,
LEDs connected to each (D1, D2, D3, D4)
, D1 emits light in the state number 0 in Table 1, D2 emits the state number 1, D3 emits the state number 2 and D4 emits the state number 3 respectively. It becomes a warning means that can be fully used by changing the color of the light emitted from the LED, the number of emitted light, or the like. For example, it is effective to set the state number 0 to a large red color because it can be determined to be a serious misconnection, and to set the D4 orange color and D2 and D3 to a green color because it can be determined that the status number 3 is not serious but an incorrect connection.

Although the 74AC series is used as the logic element in the embodiments of FIGS. 3 and 4, the invention is not limited to this as long as the circuit has an equivalent function. The 74AC series is used because the driving current is large and the LED or the like can be directly driven.

[0021]

EFFECTS OF THE INVENTION (1) By implementing the present invention, it is possible to eliminate the possibility of equipment malfunction or damage due to connector misconnection. (2) By implementing the present invention, it is possible to notify the user of the device of the contents of incorrect connection of the connector. (3) By carrying out the present invention, it is possible to omit the replacement work when the connector is erroneously connected.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an erroneous connection prevention function of the present invention.

FIG. 2 is a schematic block diagram of a connection status notification unit of the present invention.

FIG. 3 is a circuit diagram of a telephone line switching device of the present invention.

FIG. 4 is a circuit diagram of a connection status notification unit of the present invention.

FIG. 5 is an example timing diagram of connection detection of the present invention.

[Explanation of symbols]

 1 Line detection and switch controller 2 State analysis unit 3 State display unit

Claims (1)

[Claims] 1. A line acquisition instruction signal is provided in a circuit in which two lines of two-wire telephone connection connectors are provided, one of which is connected to a telephone and the other is connected to an exchange side circuit. At this time, it detects whether the connection destination of the two-system connector is a telephone or an exchange side circuit and outputs an identification signal for identifying four connection states, and a switch for connecting to a public line and a two-system connector. A telephone line switching unit for controlling the switch between the two, a state analysis unit for determining the connection state by the identification signal output from the telephone line switching unit, and four LEDs according to the state number output from the state analysis unit. A connection status notification section including a status display section that lights up is displayed, and when both of the connectors of the two systems are on the exchange side circuit, a seriously incorrect connection is displayed and other connection statuses are displayed. A telephone line switching device with a misconnection prevention function, characterized in that it is configured so as to display each corresponding.