JP3067130U - Adapter for modem connection - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a modem connection adapter for connecting a modem to a line accommodated in a private branch exchange, wherein a user sets "0".
It is possible to reliably perform communication without performing an intentional operation for “transmission”. A first connector used for electrical connection with a private branch exchange, a second connector for an extension telephone, and a third connector for detachably electrically connecting a modem. An off-hook detection circuit 15 for detecting that the modem 3 connected to the third connector 13 has transitioned to the closed state of the DC loop, and a private branch exchange when the off-hook detection circuit 15 detects the transition. A tone dial signal corresponding to a prefix number (typically “0”) for outgoing line transmission at 4 is provided on a line that electrically connects the first connector 11 and the third connector 13 to each other. Tone generation circuit 1 for sending out over a period of time
6 is provided.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a modem connection adapter for connecting a modem (modulator / demodulator) connected to a personal computer (PC) or the like to a line accommodated in a private branch exchange (PBX).

[0002]

[Prior art]

 With the spread of mobile computing, opportunities to use portable personal computers such as notebook PCs and PDAs (Personal Digital Assistants) on the go are increasing. There is an increasing demand for access to the Internet and personal computer communication services from outside the office, and remote access to company LANs (local area networks). As described above, when connecting to various types of networks while away from home, it is common to use a portable personal computer or PDA to make a dial-up connection to a target network or an access point of a communication service. When making a dial-up connection, it is conceivable to use a mobile communication network such as a mobile phone network or PHS (Personal Handy Phone System). Considering the cost, it is not suitable for large-capacity data communication or long-time connection. Therefore, when a long-time connection or a large amount of data exchange is expected, it is preferable to make a dial-up connection not through a mobile communication network but through a fixed telephone network such as an analog public network. When a dial-up connection is made via an analog public network, a modem is used to connect a personal computer or the like to a telephone line. When the portable personal computer has a PC card (PCMCIA (Personal Computer Memory Card International Association) card) slot, a card-type modem attached to this slot is preferably used as the modem. In addition to the dial-up connection, for example, a facsimile image information such as a document can be output from a portable personal computer to a desired facsimile apparatus by using a facsimile modem.

Here, a case is considered in which a guest room of a hotel where the user is staying is connected to an access point through a dial-up connection to connect to a network. In the hotel rooms, commercial power is available and there is also a telephone line that can be used for external connections. Therefore, hotel rooms are a suitable place for remote access to the Internet or corporate LAN via mobile computing. Recently, some hotels have a modular outlet for connecting modems in their rooms for the convenience of guests.

[0004]

[Problems to be solved by the invention]

 However, the telephone lines that are routed into hotel guest rooms and the like are not lines directly connected to the public network (so-called external lines), but lines that are housed in private branch exchanges (so-called internal lines). In order to make a call from an extension to an outside line, it is often necessary to add "0" which is a prefix (prefix) number for making an outside call to an original telephone number in a public network as "0 transmission". . The telephone number of the access point is usually set in advance on a personal computer, and this personal computer automatically calls the access point only by starting the communication software. , "0" is very inconvenient for the user. The same inconvenience arises when sending a facsimile document using a fax modem.

[0005] Further, since the electrical characteristics and signal characteristics of the private branch exchange are not the same as those of the public network exchange, depending on the compatibility between the modem and the private branch exchange, the modem may make a correct call. In some cases, the operation cannot be performed.

An object of the present invention is to provide a modem connection adapter for connecting a modem to a line accommodated in a private branch exchange, in which a user performs an intentional operation for “0 transmission”. Instead, it is to provide a device that can surely perform communication.

[0007]

[Means for Solving the Problems]

 The modem connection adapter of the present invention is a modem connection adapter for detachably connecting a modem to a line accommodated in a private branch exchange, and is a first connection used for electrical connection with the private branch exchange. Point, a connector for removably electrically connecting the modem, a line for electrically connecting the first connection point to the connector, and a modem connected to the connector being in a DC loop closed state. A detection circuit for detecting the transition, and transmitting a tone dial signal corresponding to an external line transmission prefix (prefix) number in the private branch exchange over a predetermined time when the transition is detected by the detection circuit. And a tone generation circuit.

[0008]

[Embodiment of the invention]

 Next, a preferred embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a modem connection adapter according to an embodiment of the present invention.

The modem connection adapter 1 is configured to connect the extension telephone 2 and the modem 3 to the private branch exchange 4. The private branch exchange 4 receives a tone dial (push button) signal (DTMF (dualtone multi-frequency) signal) as a selection signal (dial signal). It is assumed that a so-called “0 transmission” system in which a prefix number “0” is added to the head of an outside line telephone number.

The modem connection adapter 1 has a first connector 11 used for connection to the private branch exchange 4, a second connector 12 used for connection to the extension telephone 2, and a connection for the modem 3. And a third connector 13 to be used. Typically, modular jacks for telephones are used for these connectors 11 to 13. Of course, other forms of connectors, such as screwing, can be used.

Inside the modem connection adapter 1, the first connector 11 is electrically connected directly to the third connector 13, and is connected to the second connector 12 via a telephone connection circuit 14. ing. The telephone connection circuit 14 allows a call signal to the extension telephone 2 to pass therethrough, detects an off-hook (closed DC loop) of the extension telephone 2 connected to the second connector 12, and outputs the first connector 11. And the second connector 12 are connected. When the extension telephone 2 is on-hook (DC loop is open) and no call signal is transmitted from the private branch exchange 4, the telephone connection circuit 14 disconnects the second connector 12 from the first connector 11 Cut off.

In FIG. 1, for convenience, a line connecting the first connector 11 to the second connector 12 and the third connector 13 is represented by a single line. Are composed of one pair (two) or two pairs (four) of conductors. In particular, when using a private branch exchange in which the extension side is a four-wire system, the first connector 11 and the second connector 12 are paired with a pair of a communication line for transmitting a communication signal and a It is connected by a total of four control lines. In this case, the telephone connection circuit 14 may be inserted into the communication line.

Further, the modem connection adapter 1 has an off-hook detection circuit 15 for detecting an off-hook (closed DC loop) state of the modem 3 connected to the third connector 13, and the off-hook detection circuit 15 enters an off-hook state. When the transition from the first state to the second state is detected, a tone dial (push button) signal (here, a turn dial sound corresponding to “0”) for transmitting an outside line is transmitted to the first connector for a predetermined time after the off hook state. And a tone generating circuit 16 for transmitting the signal on a line between the first connector 11 and the third connector 13. In order to avoid erroneous recognition of the tone dial signal in the private branch exchange 4, the tone generation circuit 16 requires an appropriate time between the time when the transition to the off-hook state is detected and the time when the transmission of the tone dial signal is started. It is desirable to provide a guard time.

Next, the operation of the modem connection adapter 1 will be described.

Since the telephone connection circuit 14 as described above is provided between the first connector 11 and the second connector 12, transmission of a call signal from the private branch exchange 4 to the extension telephone 2, The telephone call when the telephone 2 is in the off-hook state is performed in a normal mode.

Next, when the extension telephone 2 is in the on-hook state, the modem 3 connected to the personal computer is connected to the third connector 13 and a call is made to the access point on the outside line via the modem 3. Think of the operation. In this case, by executing the communication application software on the personal computer, the modem 3 first closes the DC loop of the modem 3 (transitions to an off-hook state) as a calling operation, and executes the call using the software. A tone dial signal corresponding to a preset telephone number is transmitted, and after establishing a line connection, transmission / reception of data is started based on a predetermined protocol. Here, since the modem connection adapter 1 is used, the transition is detected by the off-hook detection circuit 15 when the DC loop of the modem 3 is closed, and as a result, the tone generation circuit 16 outputs “ The tone dial signal corresponding to “0” (two-frequency sound of 941 Hz and 1336 Hz) is transmitted to the private branch exchange 4 and the modem 3. As a result, the private branch exchange 4 enters an outside line transmission state, and the modem 3 subsequently sends a tone dial signal corresponding to the outside telephone number of the communication destination, thereby making the communication with the modem 4 via the private branch exchange 4 possible. Will be established. Depending on the settings of the modem 3, etc., the modem 3 may transmit a tone dial signal after confirming a so-called dial tone on the line. Even if the private branch exchange 4 does not transmit a dial tone that can be detected by the modem 3, the tone dial tone corresponding to "0" from the tone generating circuit 16 is regarded as the dial tone. , The connection can be established correctly.

FIG. 2 shows an example of a specific circuit configuration of the modem connection adapter 1. Here, an integrated circuit (IC), specifically, LC7363J, a dialer IC manufactured by Sanyo Electric Co., Ltd., is used as the tone generating circuit 16 (for a detailed description of LC7363J, see Sanyo Semiconductor News. No. 3199). The connection between the private branch exchange 4 and the extension telephone 2 is a four-wire system, and each connector 11 to 13 uses a 6-core modular jack. The numbers 1 to 6 attached to the connectors 11 to 13 indicate the terminal numbers of the modular jack. The line connecting the terminals 3 and 4 is a communication line (a pair of lines through which a communication signal passes), and the line connecting the terminals 2 and 5 is a control line for a control signal. The communication line from the first connector 11 for the private branch exchange 4 to the third connector 13 for the modem 3 is indicated by a bold line.

As the telephone connection circuit 14, a circuit composed of a triac TA1, a resistor R12, and zener diodes ZD2 and ZD3 is used. In addition, a diode bridge composed of diodes D1 to D4 for supplying DC power to the LC7363J, the off-hook detection circuit 15, and the like, a transistor Q2, and a resistor R7 are inserted in series into the above-mentioned modem communication line. ing. Since the resistor R8 is provided between the base of the transistor Q2 and the collector, the transistor Q2 allows the signal between the modem 3 and the private branch exchange 4 to pass, and connects the capacitor C2 from the DTMF terminal of the LC7363J. The tone dial signal supplied to the base via the modem is transmitted on the modem communication line.

The transistor Q1 activates the LC7363J with a time constant determined by the resistor R4 and the capacitor C1 after the modem 3 transitions to the off-hook state. The LC7363J is provided with a switch matrix terminal, and generates a "0" tone dial signal by short-circuiting C2 and R4. The off-hook detection circuit 15 includes a transistor Q3, a capacitor C7, and a resistor R15. The off-hook detection circuit 15 detects the closing of the DC loop in the modem 3, and when the transition to the closing of the DC loop occurs, the resistor R15 and the capacitor C7. Generates a pulse with a time constant determined by. This pulse is applied to the base of transistor Q4, which short-circuits terminals C2 and R4 of the switch matrix of LC7363J, causing LC7363J to generate a "0" tone dial signal for a predetermined time width.

Further, the modem connection adapter 1 is provided with a light emitting diode LED 1 for confirming the modem connection and an AC (alternating current) outlet 21 for service. The AC outlet 21 can be used, for example, for an AC adapter of a notebook computer.

FIG. 3 shows the appearance of the above-described modem connection adapter 1. The modem connection adapter 1 has a substantially rectangular parallelepiped casing, and a third connector 13 which is a modular jack for connecting a modem, and an AC outlet are provided on the upper right portion of the casing on the right half of the figure. 21 and a light emitting diode LED1 for displaying an operation state. In addition, a lid member 22 having a size about half of the upper surface of the housing is provided on the upper surface of the housing. The lid member 22 is held by a pair of hinge portions 24 provided at the center of a pair of opposing sides on the upper surface of the housing, respectively, as shown in FIG. It is movable between a first position covering the illustrated left half of the upper surface of the housing and a second position covering the illustrated right half of the upper surface of the housing as shown in FIG. 3 (b). When the lid member 22 is in the first position, the third connector 13, the AC outlet 21 and the light emitting diode LED1 are exposed, and the modem connection adapter 1 can be used for modem connection. Will be possible. On the other hand, when the lid member 22 is at the second position, the third connector 13, the AC outlet 21, and the light emitting diode LED 1 are covered by the lid member 22. By providing the lid member 22 in this manner, the appearance can be improved by putting the lid member 22 in the second position when the modem connection adapter 1 is not in use, and dust and the like can be improved. Adhesion to the connector 13 and the AC outlet 21 can be prevented.

FIG. 3C shows the back of the modem connection adapter 1. A first connector 11 for connection to the private branch exchange 4, a second connector 12 for connection to the extension telephone 2, and a commercial AC An AC inlet 23 for supplying a voltage is provided.

[0023]

[Effect of the invention]

 As described above, the present invention supports a detection circuit that detects that the modem has transitioned to the closed state of the DC loop, and, when the transition is detected by the detection circuit, corresponds to the prefix for transmitting an external line at the private branch exchange. And a tone generation circuit for transmitting a tone dial signal to be transmitted for a predetermined period of time so that the user can reliably perform communication without intentionally performing an operation for “0 transmission”. This has the effect of becoming

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a modem connection adapter according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing an example of a specific circuit configuration of the modem connection adapter according to the present invention.

FIGS. 3A and 3B are perspective views of the modem connection adapter shown in FIG. 1, respectively, and FIG. 3C is a rear view of the modem connection adapter shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Modem connection adapter 2 Extension telephone 3 Modem 4 Private branch exchange 11-13 Connector 14 Telephone connection circuit 15 Off-hook detection circuit 16 Tone generation circuit 21 Outlet 22 Cover member

Claims (4)

[Utility model registration claims] 1. A modem connection adapter for detachably connecting a modem to a line accommodated in a private branch exchange, comprising: a first connection point used for electrical connection with the private branch exchange; A connector for detachably electrically connecting a modem, a line for electrically connecting the first connection point to the connector, and a modem connected to the connector transitioning to a closed state of a DC loop And a detection circuit for detecting that the transition has been detected by the detection circuit, when a tone dial signal corresponding to a prefix number for outgoing line transmission in the private branch exchange is transmitted over the line for a predetermined time, a tone. And a generator circuit. 2. A second telephone which is electrically connected to an extension telephone.
The connection point of the first, when a call signal to the extension telephone is generated and when the extension telephone is in an off-hook state,
2. The modem connection adapter according to claim 1, further comprising a telephone connection circuit for connecting the connection point of (1) and the second connection point. 3. A housing, provided on one surface of the housing,
A lid member movable between a first position and a second position;
The connector is provided on the one surface, is exposed when the lid member is at the first position, and is covered by the lid member when the lid member is at the second position. The modem connection adapter according to claim 1. 4. An outlet provided on the one surface for supplying commercial power, wherein the outlet is exposed when the lid member is at the first position, and wherein the lid member is The modem connection adapter according to claim 3, wherein the adapter is covered by the cover member when the adapter is at the position of (2).