JPH03139036A - Connector for simple lan and its connection method - Google Patents

Abstract

PURPOSE:To facilitate inter-communication of plural data terminal equipments by keeping pins other than a frame ground pin, a transmission data pin, a reception data pin, and a logic ground pin in idle state or in self-loop state so as to keep them in the transmission reception enable state at all times. CONSTITUTION:Eight pins as 1st-7th pins and 20th pin are used and other pins are not used. The 1st pin is for frame ground and is connected to a shield of a cable 101 and a frame ground wire of stereo mini-jacks 103a, 103b. The 2nd pin is connected to a transmission data wire of the cable 101 via a jack 103b and the 3rd pin is connected to a signal wire for the jack 103a. The 4th pin is a transmission request pin for a computer and the 5th pin is a pin returning an acknowledge of reception enable state. Moreover, the 6th pin and the 20th pin are pins for receiving notice of the ready state of transmission and reception, and the 7th pin is used for logic ground.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a simple LAN connector device that connects a plurality of data terminal devices such as computers and word processors and realizes mutual communication over short distances within a premises, and the same. Regarding the connection method, in particular, a simple LAN that can easily connect multiple data terminal devices without adding an R3-232-C port, and connects using only the R3-232-C port without going through a node. The present invention relates to a connector device and its connection method.

[Conventional technology]

Local area networks (so-called LANs), which perform mutual communication over short distances within a company's premises, are being widely constructed and used not only within the premises of companies but also in various other places as society becomes more information-oriented and computer technology develops. It's starting to look like this. Also, as a form of LAN, one data terminal device (master station) and N data terminal devices (dependent stations) are connected, and communication is performed between the main station and the dependent stations. There are various forms of communication, such as N:N communication form, in which N data terminal devices act as a master station and a slave station, and each data terminal device can communicate with N plural data terminal devices. It is taken.

In full-scale NUN communication, one data terminal device corresponds to one node, and the nodes are sequentially connected to form a network. Since each node performs communication control so that only the data related to the connected data terminal device is transmitted (taken in) to the data terminal device, each data terminal device does not need to receive all data (inefficient used for many purposes.

Furthermore, in a LAN, when each data terminal device starts communication at an inopportune time, information overflow or fjj collision occurs, so various systems have been proposed and put into practical use to prevent this.

Generally, in constructing a LAN, the N:N
For full-scale communication or when high-speed transmission is required due to a large amount of communication, network hardware such as nodes is installed and the network is configured, for example, in a star-like loop shape or a bus-like shape.

On the other hand, when the amount of communication is small, a method of simply constructing a predetermined communication form using the R3-2320 port is adopted. The R3-232-C port is originally a modem connection for communication using a telephone line with outside the premises.
As shown in Figure 4(a), a computer (data terminal device), R3232-C port, straight cable,
Modem telephone line, switch, telephone line, modem, straight cable, RS-232-C port Computer (
data terminal equipment) to perform communication. Therefore, in order to use this R3-232-C port for a LAN network, a jumper box that functions as a modem, telephone line, exchange, telephone line, and modem is installed as shown in Figure (b). Or use the same figure (
As shown in C), a method is adopted in which data terminal devices are connected using a jumper box and a cross cable instead of a pair of straight cables. R3-
The method of simply constructing a predetermined communication form using the 232-C port does not require the installation of network hardware such as nodes, and it is only necessary to connect with a cross cable, etc. Communication formats can be constructed at low cost.

[Problem to be solved by the invention]

However, in the conventional method using a cross cable, only one R3-232-C port is connected to one data terminal device, so it is difficult to communicate with N data terminal devices. Nx (N-1) R3-2
There was a problem that a 32-C port and NX (N-1)/2 cables were required. Further, data terminal devices such as ordinary personal computers and word processors have only one R3-232--C port, and in order to connect to multiple data terminal devices, R3-232--
Another problem was that an expansion board was required to add more C ports. Furthermore, assuming that there are three expansion slots and seven ports, mutual communication between eight data terminal devices is possible, but in reality it is practically difficult to use all seven ports. In other words, it was difficult to connect to eight or more data terminal devices.

The present invention has been made in view of the above, and an object of the present invention is to provide a LAN with an inexpensive and simple configuration, and to enable mutual communication between multiple data terminal devices without expanding the R3-232-C port. With the goal.

Another object of the present invention is to enable mutual communication without fear of data collision.

Means for Solving Problem C] In order to achieve the above object, the present invention includes a cable including a signal line for transmission data, and a cable attached to one end of the cable,
A plug for connecting the transmission data signal line, a first jack attached to the other end of the cable to input external data, and a bypass for external data to the transmission data signal line of the cable. pin 1 (frame ground pin), pin 2 (pin for transmission data), pin 3 (pin for reception data), and pin 7 (pin for logic ground). The present invention provides a simple LAN connector device equipped with a 25-pin plug-in connector in which pins other than the 25-pin plug-in connector are unused or self-looped.

In addition, it is a simple LAN connector that has a transmission-only cable that transmits only the signal (transmission data) on the 2nd pin of the R3-232-C port, and an input port that receives the signal (reception data) on the 3rd pin. Data transmission is performed by connecting multiple data terminal devices equipped with the device to the input port of the other data terminal device, and by connecting the transmission cable of one data terminal device to the input port of the other data terminal device, and connecting the multiple data terminal devices in a loop. The present invention provides a connection method for a simple LAN connector device that performs the following.

[Function] The simplified LAN connector device and its connection method of the present invention are provided by the following: pin 1 (frame ground pin), pin 22 (pin for transmission data), pin 3 of a 25-pin plug-in connector;
No. pin (receive data pin).

Also, pins other than pin 7 (logic ground pin) are left unused or in a self-loop to maintain a state in which transmission and reception are possible at all times. In addition, data from the outside (reception data) is input to the third pin by the first jack of the 25-pin plug-in connector, and data (transmission data) from the second pin is output to the transmission data signal line of the cable. Furthermore,
The data (received data) input from the second jack is directly bypassed to the transmission data signal line and output as transmission data. When configuring a LAN, connect this 25-pin plug-in connector to the R5-232-C port of a data terminal device, connect the plug to the first jack (25-pin plug-in connector) of another data terminal device, By repeating this process, a plurality of data terminal devices are connected in a loop to form a network.

〔Example〕

Hereinafter, the simplified LAN connector device and the connection method thereof according to the present invention will be explained in detail.

FIGS. 1(a) and 1(b) show the configuration of an embodiment of a simple LAN connector device of the present invention, in which a first core wire for logic ground, a second core wire for a signal line for transmission data, and , a two-core shielded wire cable 101 consisting of a frame ground shield, and a stereo mini plug 10 attached to one end of the cable 101 and connected from its tip to a rosin ground, a signal line, and a frame ground in this order.
2, a stereo mini-jack 103a that is attached to the other end of the cable 101 and inputs data from the outside, and a stereo mini-jack 103b that bypasses data from the outside to the second core wire. frame ground pin), pin 2 (transmission data pin),
It consists of a 25-pin plug-in connector 103 in which pins other than pin 3 (receive data pin) and pin 7 (logic ground pin) are unused or self-looped. In addition, the stereo mini jack 103a.

103b is a structure that fits into the stereo mini plug 102, and three wires for a logic ground, a signal line, and a frame ground are arranged. In this embodiment, of the 25 pins of the 25-pin plug-in connector 103, the 1st pin, 2nd pin, 3rd pin, 4th pin, 5th pin, and 6th pin are shown in FIG. , 7th pin, and 20th pin are used, and the other pins are not used. Pin 1 is a pin for frame ground, shield for cable 101 and stereo mini jack 103a.

A frame ground line 103b is connected. 2
The number pin is a pin for transmission data, and a signal line for transmission data of the cable 101 is connected via the stereo mini jack 103b.

The third pin is a receive data pin, and is connected to the signal line of the stereo mini jack 103a.

Pin 4 is the computer (data terminal device in this example)
This is a transmission request pin used to notify the destination that data will be sent when the sender sends data. On the other hand, the No. 5 pin is a transmission enable pin for returning a response from the destination computer indicating that the computer is in a state in which it can receive transmissions (in other words, in a state in which it can receive data).

In this embodiment, pin No. 6 is a destination preparation pin for inputting a notification from another computer that preparations for transmission and reception have been completed. On the other hand, the 20th pin is a preparation pin that notifies the user that preparations for transmitting and receiving data are complete. Also,
By connecting the 4th pin and the 5th pin, when the computer makes a transmission request, a notification that the transmission is possible is immediately input. In other words, it constitutes a state in which transmission is possible at any time. In this example, pin 6 and pin 2
By connecting the No. 0 pin, when a notification indicating that preparations for transmitting and receiving data are completed is outputted, a notification indicating that preparations for transmitting and receiving data are completed is immediately inputted. In other words, it constitutes a state in which transmission and reception are possible at any time. Pin 7 is a logic ground pin,
The logic ground core wire of the cable 101 and the logic ground wire of the stereo mini jack 103a are connected. Although the details will be described later, the cable 101 and the stereo mini jack 103a are each connected to a pin, and the cable 101 and the stereo mini jack 103a
3b is connected in series, and stereo mini jack 1
By inserting the stereo mini plug 102 into the stereo mini jack 103b, the transmission data signal line of the cable 101 and the signal line of the stereo mini jack 103b are connected.

In the above configuration, l5O (International Organization for Standardization: In
ternationl organization
Based on the 7 layers (physical layer, data link layer, network layer, transport layer, session layer, presentation layer, and application layer) of the O3I basic reference model of Standardization),
A simple LAN connector device and a LAN to which the connection method is applied will be described in detail.

It should be noted that the O3 basic reference model is well known, so a description thereof will be omitted.

■Physical layer The physical layer provides mechanical, electrical, functional, and procedural means for data transfer (bit transfer) between data terminal devices (in this example, between computers) in a network. It is the one that makes the physical connection of the network. In other words, it includes how to connect the cables forming the network, the shape of the connector, the pin arrangement of the connector, etc., that is, the simple LAN of the present invention
The connector device and its connection method belong to the scope of this physical layer.

In this embodiment, a computer is used as the data terminal device, and as shown in FIG. 3(a), a plurality of computers (
In this embodiment, six computers (A to F) were arranged in a loop and connected using the simple LAN connector device of the present invention.

Specifically, R3-23, which is standard equipment on computers.
A 25-pin plug-in connector 103 is inserted into the 2-C port, and the stereo mini plug 102 provided at the other end of the cable 101 connected to the 25-pin plug-in connector 103 is shown in FIG. 3(a). Stereo mini jack 103 of 25 pin plug-in connector 103 inserted into the computer next to the positional relationship arranged in a loop shape
a (or 103b), and this process was repeated to construct a loop-like network. Here, the stereo mini plug 102 is connected to the stereo mini jacks 103a and 10.
3b, the connection status of the signal line within the 25-pin plug-in connector 103 changes depending on which one of the 25-pin plug-in connectors 103 is inserted. For example, stereo mini plug 102 is connected to stereo mini jack 1.
03a, the 25-pin plug-in connector 10
The connections in 3 are as shown in FIG. 3(b), and the data sent from the computer A side is connected to the stereo mini plug 102 (comviator A side) and the stereo mini jack 1.
03a (computer B side), and is manually input (received) to computer B via the third pin of the 25-pin plug-in connector 103.

Further, data transmitted from the computer B side is sent to the cable 101 via the second pin of the 25-pin plug-in connector 103, and is sent to the computer C side via the stereo mini plug 102. On the other hand, when the stereo mini plug 102 is inserted into the stereo mini jack 103b, the connection within the 25-pin plug-in connector 103 becomes as shown in FIG. 102 (computer A side) is directly connected to cable 101 via stereo mini jack l03b (computer B side). Therefore, in this case, the data transmitted from computer A is transmitted to computer C side without passing through computer B, and no data is actually input (received) into computer B. In other words, the stereo mini plug 102 is connected to the stereo mini jack 10.
For example, by selecting either 3a or 103b,
It becomes possible to physically select whether or not to connect computer B to the network. Therefore, if a specific computer is unable to communicate, by changing the connection of the stereo mini plug 102 on the upstream side (the direction in which the transmitted data flows in the network loop), the transmitted data can be directly transmitted downstream. .

Here, the computer (data terminal device) inspects the input received data at the subsequent network layer, and the destination (destination) and source transmit data other than their own data downstream, thereby allowing the computer (data terminal device) to connection is running.

As shown in FIGS. 2(a) and 2(b), in this embodiment, the 4th pin and the 5th pin are connected to form a self-loop, and the 6th pin and the 20th pin are connected to form a self-loop. These 4.5, 6.20 pins (signal names: R3, C3, DR
, ER) are signal lines for handshaking with the modem, and are not used because they are not suitable for computer interconnection.

This allows the sending side to send data at any time, regardless of downstream circumstances.

In this embodiment, the following transmission method is used.

Line Full-duplex transmission speed Maximum 9600 bps Synchronization method
Number of asynchronous data bits: 7 Parity: Even number of stop bits: 1 Data for which 1, parity, overrun, or framing errors are detected in the physical layer is passed to the next layer (upper layer) with an error mark (2') attached.

■Data link layer Here, for the purpose of identifying control characters and data characters and ensuring error checking, 1 byte of data is divided into 4 bits each and expressed as hexadecimal numbers, in JI37 units. Convert to code and transmit. Although this reduces the transmission speed to 4/7, it is possible to improve the reliability of data transmission.

Characters used STX (G”): Text start ETX (“H”゛): Text end Text format STX+data+ETX+bcc STX and ETX are generally specified by JIS.
02H", "03H" are used, but "03H'"
has the disadvantage that it is difficult to use because it is a code that is used too frequently.In this example, G"l, I
Use I H11.

data is O~9 (30H~39H), A-F
The data (41H to 46H) is divided into 4 pints and expressed in hexadecimal notation, and converted into a JIS 71-place code.

bcc ()゛ronkuche tsuku character) is dat
The result of XORing a and ETX in byte units (actually 7 bits) is shown, and all data is 4xH, 3
It is made up of two characters xH, so XOR is OxH, 7
xH, and ETX (48H) together becomes 4xH or 3χH, which is an easy-to-read code. That is, all codes from STX to bcc are 4xH3xH.

The communication procedure of this embodiment is as follows.

The sending computer converts the sent data into text (STX + hexadecimal JIS code conversion data + ETX
+bcc)L, transmit continuously.

Since this is a so-called non-procedural process, data will be lost unless the receiving computer (communication program) is started in advance.

There is a CR (return: Carri) between ETX and the next 5 TXO.
age Return), LP (Line break: Lin
Control characters such as e Feed) may also be inserted.

The receiving side ignores all data before STX. ST
When a code other than a hexadecimal code comes between X and ETX, all data after STX is ignored. Also, bc
If c does not match, all data after STX is ignored.

Only data that passes the above inspection is sent to the upper layer.

■The first 3 bytes of network layer data (hexadecimal JISD-code transformation data) are used in the network layer.

The 1st byte is used for the receiving side address (destination), the 2nd byte is used for the sending side address (sender), and the 3rd byte is used for the net data length information, and the address is expressed as a number from 0 to 254. . When the receiving side address is 255 (OFFH), it indicates that the data is BC (broadcasting) and is destined for all data terminal devices on the network, and therefore, all computers receive the data. The following checks are performed on the received data at the network layer:

i, data whose total data length is within 3 bytes, and data whose net length is not total length -3 are discarded as defective data.

11. Check the sender address range, and if it is 255, discard it as bad data.

iii. Of the data that passed, if it was not generated by yourself, it will be transferred downstream.

+v, %Debt address is addressed to me or BC
Data that corresponds to any of the above is sent to the upper layer.

■If the sender's address matches your address,
In other words, self-generated data is transmitted downstream and sent to upper layers.

■Transport layer Discard your own data here.

In this embodiment, the control is such that the data provided by the user is discarded unconditionally, but it is also possible to incorporate control for retransfer and retry.

■Three layers without session layer (Three layers without session layer) ■Three layers with no presentation layer (Three layers without application layer) In this embodiment, the three layers (2) to (4) described above are used in one layer.

Next, with reference to FIGS. 3(a) and (b), L
The transmission route of transmission data in the AN will be explained.

First, R5- of each computer A, B, C, D, E, F
Insert the 25-pin plug-in connector 103 into each 232-C port, and then connect the integrated stereo mini-plug 102 to the stereo mini-jack 103a of the downstream computer via the 25-pin plug-in connector 103 and cable 101. do. Specifically, insert the stereo mini plug 102 of computer A into the stereo mini jack 103a of computer B, and
The stereo mini plug 102 is inserted into the stereo mini jack 103a of the computer C, and the stereo mini plugs 102 are similarly inserted into the stereo mini jack 103a to form a loop-shaped network shown in FIG. Due to the aforementioned pin connections of the 25-pin plug-in connector 103 and the self-loop, each computer is always ready to transmit regardless of the downstream status.

For example, data sent from computer A (transmission data) is transmitted from the second pin of the 25-pin plug-in connector 103 to the cable 101. Stereo mini plug 102. and is input to computer B via the stereo mini jack 103a (belonging to computer B). The data input to computer B is inspected by the three layers, the data link layer, network layer, and transport layer (in this example, the session layer, presentation layer, and application layer are bypassed), and the specified data (destination is data of computer B, BC data, etc.) are imported.

In addition, the data determined to be transferred downstream by the network layer inspection is transferred to the second pin of the 25-pin plug-in connector 103 of computer B, cable 101. It is transferred to computer C via stereo mini plug 102. Similar processing is executed on computer c,
Predetermined data is input into computer C, and other data is transferred to computer D downstream. Thereafter, data is transferred in the same manner as to computers E and F, and finally returns to computer A via a loop-like network.

As is clear from the above description, the cable 101 is used only for transmission to the computer to which it belongs, and the cable 101 of the upstream computer is used for reception. Computers installed in a loop network are
Only one cable 1'01 is required for each computer, in other words, it is sufficient to attach one simple LAN connector device to each computer. Therefore, even when building a network with multiple computers, one R3-2
Only the 32-C port is sufficient.

Furthermore, since the transmission data is one-way from upstream to downstream, data collisions do not occur.

Furthermore, the computer itself takes on the role of a node, creating a nodeless loop, and all data coming from upstream is once imported into the computer and processed by software (3Ns of the data link layer, network layer, and transport layer). (inspection), which can significantly reduce the cost of hardware for building the network.

In the above embodiment, the R3-232-C port,
Although the description has been made by taking a corresponding 25-pin plug-in connector as an example, the present invention is not limited to this.

〔Effect of the invention〕

As explained above, the simple LAN connector device of the present invention has a two-core shield consisting of a first core wire for the login ground, a second core wire for the signal line for transmission data, and a shield for the two-frame ground. wire cable, a stereo mini plug attached to one end of the 2-core shielded wire cable, and connected from its tip to the logic ground and signal line 2 frame ground in that order, and a stereo mini plug attached to the other end of the 2-core shielded wire cable and connected to the external a first stereo mini-jack for inputting data from the outside, and a second stereo mini-jack for bypassing external data to the second core wire; a ti pin (frame ground pin);
Pin 2 (pin for sending data), pin 3 (pin for receiving data), and pin 7 (pin for logic ground)
Since it is equipped with a 25-pin plug-in connector with other pins unused or self-looped, it is possible to create a LAN at low cost and with a simple configuration, and to connect multiple data terminal devices without expanding the R3-232-C port. Mutual communication can be realized.

In addition, the connection method of the simple LAN connector device of the present invention is to use a transmission-only cable that transmits only the signal (transmission data) on pin 2 of the R3-232-C port, and a signal (reception data) on pin 3 of the R3-232-C port. A plurality of data terminal devices equipped with a simple LAN connector device having an input port for receiving the Since the data terminal devices are connected in a loop to transmit data, data collisions can be avoided.

[Brief explanation of the drawing]

FIGS. 1(a) and 1(b) are block diagrams showing an embodiment of a simple LAN connector device of the present invention, FIG. 2(a),
(b) is an explanatory diagram showing how the pins of the 25-pin plug-in connector are used; Figures 3 (a), (b), and (c) are explanatory diagrams showing the connection method of the simple LAN connector device;
Figure 4 (,l), (b), (C) shows the conventional R5--
FIG. 2 is an explanatory diagram showing a connection method using the H.232-C port. Explanation of symbols 101--2-core shielded cable 102----Stereo mini plug

Claims (2)

[Claims] (1) Mutual communication within the premises (local area network: LAN) using input/output ports equipped on data terminal devices such as computers and word processors.
) A simple LAN connector device that realizes the following: a cable including a signal line for transmission data; a plug attached to one end of the cable for connecting the signal line for transmission data; and the other end of the cable. It has a first jack for inputting data from the outside, and a second jack for bypassing the data from the outside to the transmission data signal line of the cable. pin), 2nd pin (
It is characterized by having a 25-pin plug-in connector in which pins other than pin 3 (pin for transmission data), pin 3 (pin for reception data), and pin 7 (pin for logic ground) are unused or self-looped. Simple LAN connector device. (2) Mutual communication within the premises (local area network: LAN) using input/output ports equipped on data terminal devices such as computers and word processors.
) In the connection method of a simple LAN connector device that achieves Simple LAN with input port
multiple data terminal devices equipped with connector devices for
For a simple LAN characterized by connecting a transmission-only cable of one data terminal device to an input port of another data terminal device, and connecting a plurality of data terminal devices in a loop to transmit data. How to connect connector devices.