JPH0410751A - Modem - Google Patents

Abstract

PURPOSE:To obtain a MODEM reducing an area occupied by a plane by using two, i.e., 1st and 2nd, metallic circuit substrate and setting up the height of a bus connector mounted on the 1st substrate to a value equal or lower to/than the mounting height of the 2nd substrate. CONSTITUTION:The MODEM is provided with structure obtained by fixing the 1st metallic circuit substrate 10 mounting functions capable of corresponding to the MODEMs of wide objective standards in common as a hybrid IC and the 2nd metallic circuit substrate 12 mounting only functions different in each standard or functions corresponding to the comparatively small number of standards as a hybrid IC through a resin-made casing 14. Two main faces are formed by the 1st and 2nd substrates 10, 12. In this case, the height of a bus connector to be an insertion terminal to a data terminal equipment(DTE) slot is set up to a value equal or lower than the mounting height of the 2nd substrate controlling the volume of the DTE slot. Consequently, the volume of the DTE slot can be minimized.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a modem, and in particular, to a modem control device and an intelligent
Regarding modems.

(Example) Conventional technical data For data communication between terminal devices, the communication speed of each communication device, data bit length, existence and type of parity dots, transmission code, synchronization method, communication method, It is necessary to match transmission control procedures, etc. Therefore,
In order to reduce the burden on data terminal devices, modems have been proposed that incorporate software for data communication and a dedicated microcomputer. Such modems are called intelligent modems because they can automatically make various connections necessary for data communication by simply inputting simple commands from a data terminal device.

In addition, voice band modems (hereinafter simply referred to as modems) that use the public telephone line as a transmission path must have functions that do not interfere with the public telephone line itself or other users. There is a demand for a function that allows highly reliable data communication even when the signal is weak.

For these reasons, modern modems are often designed with large circuits, and the most common modem today has the circuit configuration shown in FIG.

Referring to FIG. 4, such a modem is a microcomputer (60) that interprets commands manually input from a data terminal device (not shown) and performs a predetermined operation, and this microcomputer (60) and the data terminal device are connected to each other. ROM (64), which supplies program data such as communication protocols to the connected DTE interface (62) and microcomputer (60), or control data for setting various modes of the modem, etc. 200
bps PSK/FSK modulation/demodulation circuit (68), 30
0 bps FSK modulation/demodulation circuit (70), transmission amplifier (7
2), a receiving amplifier (74), a modem section consisting of a dialer (76) that generates an automatic call dial signal and a dial pulse signal; 11, 12) under predetermined electrical conditions;
Runy filter (80), dial pulse relay (
82).

The DTE interface (62) stores the parallel data of a data terminal equipment (hereinafter referred to as DTE) such as a personal computer (not shown) in its internal register, and then transfers the data to the microcomputer (62).
output to the microcomputer (60) and conversely to the microcomputer (60).
) has the function of outputting data from various P10. USART is used. DTE for modem
5TC9610 (Seiko Epson Corporation) is known as the interface (62).

The microcomputer (60) interprets the meaning of commands manually input from the DTE and causes each function within the modem to perform specific operations, and when the start code of the command is detected, the end code is detected. The manually inputted data is stored in a built-in memory called the command buffer until the input is completed, and the command decoding unit checks the validity of the contents of this buffer and sequentially converts it into specific internal commands. . For example, a micro combi coater for this modem is 5TC9B20.
(Seiko Epson Company) and others are aware of this. but,
With slight design changes, it is possible to use a general-purpose microcomputer.

The transmit amplifier (72) is connected to the tone/pulse dialer (76).
) tone signal or PSK/FSK modulation/demodulation circuit (
68) and the FSX modulation/demodulation circuit (70) are output to the network control unit (NCU), the reception amplifier (74) is output to the network control unit (NCU), and the reception amplifier (74) is the network control unit. The output of the unit (NCU) is output to either the PSK/FSX modulation/demodulation circuit (68) or the FSX modulation/demodulation circuit (70).

The operation of the modem configured as described above is as follows.

When starting data communication, the microcomputer (
ROM (60) based on the address signal specified by
4) is supplied to the microcomputer (6o), and the communication standards (BEl, L
/CCI TT standard), communication speed (300/1200b
ps), data format matching, depth switch mode switching, etc. are checked to see if they match.

If the various modes match, D on the responding side (not shown)
TE's modem phone number is entered by any appropriate means;
The telephone number is entered into the DTE interface (62). fc, it is also transferred to the microcomputer (6o) to decode the telephone number. The microcomputer (6o) decodes the tζ result as tone/
sent to the pulse dialer (76). Therefore, if the public telephone line is a push button/dial line,
A tone signal is output from the tone/pulse dialer (76), and then sent to the transmitting amplifier (72) and line transformer (78).
are transferred to public telephone lines (Il, h) via

When the responding modem automatically receives the call in response to this tone signal, the responding modem sends an answer tone for the connection procedure to the calling modem.

the calling modem detects whether the answer tone is a predetermined answer tone for the calling modem;
If it is a predetermined answer tone, the communication state is entered.

When the communication state is established, the parallel data of the DTE on the calling side is input to the DTE interface (62), and the data is further transferred to the microcomputer (60). Next, when the parallel data is output from this microcomputer (6o), it is converted into serial data and sent to the FSK modulation/demodulation circuit (70). Here, the digital signal is converted into an analog signal, frequency-modulated based on the communication standard, and transmitted to the responding modem via a transmission amplifier (72) and a line transformer (78).

On the other hand, the frequency-modulated analog signal from the DTE on the responding side is sent to the modem on the calling side.
8), FSK modulation/demodulation circuit (
70). Here, the analog signal is converted into a digital signal and sent to the calling DTE via the DTE interface (62). As a result, the calling party's D
Full-duplex communication is achieved between the TE and the responding DTE.

(c) Problems to be solved by the invention The standards for network control devices and intelligent modems with built-in modem control devices depend on the type of public telephone line, communication speed, data pit length, presence and type of parity bits, and transmission. The number of times is extremely large, determined by a combination of code, synchronization method, communication method, transmission control procedure, etc.

Therefore, in consideration of modem development efficiency, modem versatility, and practicality, conventional efforts have not been focused on developing modems that can comply with a wider range of standards.

However, for example, modems that use multi-function integrated circuits that can be used for both PSK and FSK modulation circuits, or modems that have dialers that can support both push-button dial lines and rotary dial lines, are suitable for specific applications. Not only does this result in excessive quality, but it also has the drawback of not being able to meet the demand for miniaturization of modems.

Furthermore, since there are standards that cannot be met even with such a modem, there is also the drawback that it is difficult to create a series of modems based on standards within an appropriate range.

Therefore, the first object of the present invention is to provide a modem that can meet the requirements of any modem standard with appropriate performance, and that can be easily made into a series of modem standards and that can be configured to be more compact. Our goal is to provide a modem that can

In addition, intelligent modems with built-in network control equipment and modem control equipment are line transformers,
Since it requires unusual parts such as modular jacks,
It is difficult to adopt a structure that allows the card to be inserted and attached to a DTE slot like an OM card.

Therefore, a second object of the present invention is to provide a modem structure that can be used by being inserted into a DTE slot like a ROM card.

Furthermore, conventional modems are mounted on resin printed circuit boards, and modems built into data terminal equipment require special shielding structures or Care had to be taken in the placement of the circuit elements and modem.

Therefore, a third object of the present invention is to provide a modem that does not require a special shield structure and can be placed at any position in a data terminal device.

Also, the frame ground of the network control unit (NCU) is marked separately from the signal ground of the modem section.
Moreover, it must be connected to the data terminal device's casing over the shortest distance, and in the case of a modem with a built-in network control unit (NCU), frame-ground connections are complicated.

In particular, it was difficult to connect the frame ground of modems used in laptop-type data terminal equipment.

Therefore, a fourth object of the present invention is to provide a modem in which the frame ground can be easily connected.

(d) Improving means to solve the problem The above problem can be solved by mounting the module jack and bus connector on opposite peripheral edges, and installing odd-shaped parts such as line transformers and ROMs between the connectors over a relatively large area. A first circuit board made of metal on which common functional circuit elements compatible with modem standards are mounted, and a second circuit board made of metal on which circuit elements different for each standard are mounted and equipped with leads at the peripheral edge. This is solved by the modem of the present invention, characterized in that the height of the path connector mounted on the first circuit board is equal to or lower than the mounting height of the second circuit board.

(E) The modem of the present invention, which uses two metal circuit boards, the first and second, as working circuit boards, has a reduced planar area and eliminates the need for a special shield structure. Furthermore, a simple grounding means via a metal circuit board can be employed for the frame ground of the network control unit (NCU).

Step 2: Make the height of the connector equal to or lower than the mounting height of the second circuit board that dominates the volume of the DTE slot.
The TE slot can have minimal volume.

Furthermore, the modem has a first circuit board on which common functional circuit elements are mounted that can be compatible with a relatively wide range of standards, and a first circuit board on which different circuit elements are mounted for each standard, and the mounting area is smaller than that of the first circuit board. It is possible to respond to standards such as t-components, which are divided into small second circuit boards, with appropriate performance, and there is no need to design all circuits for each standard, making it easier for development. This greatly reduces the burden on users, making it easier to create a series of modem standards.

Embodiment One embodiment of the present invention will be described with reference to FIGS. 1 to 3. Note that FIG. 1 is a plan view of the embodiment, and FIG. 2 is a side view of the embodiment partially shown in cross section.

As shown in FIGS. 1 and 2, the modem of the present invention has a metal first circuit board (10) on which functions commonly compatible with modems of a wide range of target standards are implemented as a hybrid IC. High-print ICs have different functions depending on the standard, or only functions compatible with a relatively small number of standards.
A second circuit board (12) made of metal and mounted with a metal casing (12) is fixed to the casing (14) made of resin.
(12) is formed.

The first and second circuit boards (10) and (12) are formed by forming a wiring pattern on a metal board through an insulating resin layer, and in a particularly preferred embodiment in which aluminum is used, anodizing treatment is applied. After forming an oxide film on the surface thereof, a wiring (wiring)<turn is formed via an insulating resin layer. These first and second circuit boards (10)
(12) and the resin casing (14) are usually fixed using an adhesive sheet called J-sheet (trade name).

Opposite peripheral edges of the first circuit board (10) include a modular jack (20) for connecting the modem of the present invention to the public telephone line and a T-path connector (22) for connecting to the internal path of the DTE. are placed respectively. In addition, this mojikola jack (20) and path connector (
22) on the array line of the modular jack (20)
A line transformer (24) is placed adjacent to the path
A second circuit board (12) is positioned adjacent the connector (22). Such an arrangement effectively separates the analog section and the digital section of a compact modem.

Matoko, that Hasko talented futa (22) (from the rules DTE
The modem of the present invention is suitable for use by being inserted into the slot of the path connector (22), the second circuit board (12).
), the line transformer (24), and the modular jack (20) have the same mounting height, or the mounting height decreases from the modular jack (20) toward the path connector (22).

In particular, the path located at the insertion end of the DTE into the slot.
The height of the connector (22) is made lower than the mounting height of the second circuit board (12). That is, the second circuit board (12) occupies a relatively large area as a mounted component, and the path connector (12) is inserted into the slot of the DTE first.
22) is higher than the mounting height of the second circuit board (12), the volume of the DTE slot will inevitably become large. According to the present invention, the mounting height is lower than (12), the volume of the DTE slot can be reduced, or the DTE slot volume can be reduced.
The shape of the TE slot can be made similar to that of the modem of the present invention, and its volume can be minimized.

In the area surrounded by the casing (14) on the first circuit board (10), functions commonly compatible with modems of a wide range of standards are implemented as high-print ICs. and,
These components and circuits are interconnected by grooves and wiring patterns formed on the first circuit board (10).

Note that the ROM (26) will be described later.

On the other hand, the second circuit board (12) is designed and developed for each modem standard, on which functions that differ depending on the standard or only functions that correspond to a relatively small number of standards are implemented as a hybrid IC. However, its mounting area is larger than that of the first circuit board (10
), the development burden is significantly reduced.

The figure shows these first and second circuit boards (10) (]2
) is electrically connected to the plurality of leads (+61) provided on the second circuit board (12) by soldering them to the pads (18) formed on the first circuit board (10) by means of, for example, Although an example is shown, it is also possible to use a socket, and in such a variant, the second circuit board (]2) has an R
It also becomes possible to implement OM (26).

The embodiment will be further described with reference to the circuit diagram in FIG.

The modem of the present invention includes a microcomputer (30) that decodes commands manually input from a DTE (not shown), a ROM (26) that supplies control data such as transmission control procedures and communication methods to the microcomputer (30), and a microcomputer (30) that supplies control data such as transmission control procedures and communication methods to the microcomputer (30). 30) and the internal bus of the DTE in a predetermined procedure.
It is shown by a dip switch (34) for setting the mode of the interface (32), a dip switch (40), a receiving amplifier (42), a transmitting amplifier (44), a line transformer (24), etc.

There is no need to change the function for each modem standard, or a microcomputer (30
), DTE interface (32), receiving amplifier (4
2) and the transmission amplifier (44) are mounted in chip form on the first circuit board (102), below the second circuit board (12), that is, in a position surrounded by the casing (14). be done.

In conventional modems, multi-function integrated circuits are usually used for the above-mentioned reasons. Integrated circuits with a single function or a limited range of functions are selectively used.For the same reason, the dialer (40) is also a dialer that can handle either a push-button dial line or a rotary dial line. Used selectively.

However, only a single function or limited functions are mentioned here.
The range of functions is expressed relative to all target modem standards; for example, it is possible to use a dialer that is compatible with both push-button dial lines and rotary dial lines. The first circuit is a functional circuit that differs depending on each modem standard, or a functional circuit that corresponds to a relatively small number of standards.
and second modulation/demodulation circuits (36) (38), dialer (
40) is mounted on the second circuit board (]2) in the form of a chip.

The dashed-dotted lines in the figure indicate the first and second circuit boards (10)
(12) indicates the boundary. That is, - the microcomputer (30) inside the area surrounded by the dotted chain line, DT
Circuit elements such as the E interface (32), the receiving amplifier (42), and the transmitting amplifier (44) are mounted on the first circuit board (
10), and the first and second modulation/demodulation circuits (36
038) and dialer (40) on the second circuit board (1
2).

The ROM (26) is preferably implemented using a socket if a change in user specifications is expected, and more preferably an EPROM. However, since the structure and mounting method of the ROM (26) are outside the scope of the present invention, it will simply be expressed as a ROM (26). In addition, the ROM at the time when the specifications of ROM (26) were fixed.
The arrangement of (26) is not limited to the illustrated position.

The common connection end of the capacitor C constituting the line filter (50) is connected to the first circuit board (lO), and the locking mechanism of the first circuit board (10), for example, screw or click - Connected to the DTE casing using a stop mechanism.

(1) Effects of the Invention As described above, according to the present invention, (1) the modem is constructed of two circuit boards on which circuit elements are mounted in the form of chips, and a modem with a small planar area is provided. can do.

(2) The height of the bus connector located at the insertion end of the DTE into the slot is made equal to or lower than the actual device of the second circuit board, so that the volume of the slot of the DTE is kept to a minimum. be able to.

(3) A metal circuit board is used, and the main surface of the modem is formed of the circuit board, resulting in a simple shape. Furthermore, since the modem is shielded with metal, mutual interference between internal elements of the data terminal device and the modem can be prevented by or without considering the direction of the shielding surface. Therefore, it is possible to provide a modem whose layout can be easily designed when designing a data terminal device.

(4) A first circuit board that mounts circuit elements that are commonly used in modems of a wide range of standards, and a second circuit board that mounts circuit elements that have different functions depending on the standard and that has a smaller mounting area than the first circuit board. Since the modem is constructed from a circuit board, the burden of developing modems for multiple standards is reduced.

(5) If a metal circuit board is used, the frame ground of the network control unit (NCU) can be reliably grounded by fixing the modem to the data terminal equipment or by other convenient means. can.

(6) Reliability is improved because the chip-shaped circuit element is arranged in the sealed space formed by the first circuit board, the second circuit board, and the casing.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an embodiment of the present invention, FIG. 2 is a side view of the embodiment partially in section, FIG. 3 is a circuit diagram of a modem of the present invention, and FIG. 4 is a diagram of a conventional modem. It is a circuit diagram. 10・First circuit board, 12・Second circuit board, 14
Casing, 16 leads, 18 bads,
20 modular seat, 22 bus connector, 24 line transformer, 26-ROM.

Claims (5)

[Claims] (1) A metal product that mounts a modular jack and a bus connector on opposing peripheral ends, and between them mounts unusual components such as line transformers and common functional circuit elements that can support a relatively wide range of modem standards. A second circuit board made of metal is mounted with different circuit elements depending on the standard and has leads at the peripheral edge, and the height of the bus connector mounted on the first circuit board is Saga 2nd
A modem characterized in that the mounting height of the circuit board is equal to or lower than that of the circuit board. (2) Common function circuit elements of the first circuit board and circuit elements of the second circuit board are arranged in a sealed space formed by the first and second circuit boards and the casing, and the modular jack, line transformer 2. A modem as claimed in claim 1, characterized in that irregular parts, such as bus connectors, etc., are arranged on the other plane of the first circuit board. (3) modular
Modem according to claim 1, characterized in that a jack and a bus connector are respectively arranged. (4) The modem according to claim 1, wherein a DTE interface, a microcomputer, a transmission amplifier, and a reception amplifier are mounted on the first circuit board, and a modulation/demodulation circuit and a dialer are mounted on the second circuit board. 5. The modem of claim 1, wherein the signal ground of the modem is connected to the bus connector and the frame ground of the network controller is connected to the first metal circuit board.