JP3392314B2 - Data transmission method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transfer method in a protocol converter having a LAN port having a TCP / IP packet communication protocol and a serial port having a character-based data communication protocol, and more particularly to receiving from a LAN port. The present invention relates to a data transmission method having a function of extracting character data encapsulated in a TCP / IP packet and transmitting it to a serial port, and a function of encapsulating character data received by the serial port in a TCP / IP packet and transmitting it to a LAN port.

[0002]

2. Description of the Related Art Generally, a protocol converter having a LAN port having a TCP / IP packet communication protocol and a serial port having a character-based data communication protocol transfers data received from the serial port to an L level.
After receiving character data from a serial terminal at a serial port for transmission to an AN, the received character data is encapsulated in a TCP / IP packet and transmitted to a LAN port.

A conventional method of encapsulating TCP / IP packets in a TCP / IP packet is to encapsulate only the character data received from the serial port as it is and then to the LAN.
To send operation information to the protocol converter and to obtain status information between the host, serial terminal, and protocol converter, use the input device attached to the device or the dedicated control terminal. Was needed. Further, in the case of a system configuration in which a host on the LAN controls and manages a plurality of serial terminals, it is necessary to prepare protocol conversion devices as many as the number of serial terminals.

[0004]

In the data transmission method according to the prior art, a protocol converter is used to perform data communication between a serial terminal connected to a serial port and a host on a LAN connected to a LAN port. In order to set the operating parameters to the protocol converter and to obtain the status information between the host, serial terminal and protocol converter, it is necessary to go close to the protocol converter and use the attached input device. There was a problem saying that there was. Further, in the case of a system configuration in which the host on the LAN performs data communication with a plurality of serial terminals, only the character data is encapsulated in the TCP / IP packet, so that the means for the host to identify the plurality of terminals, for example, I
Since a P address is required for each serial terminal, the number of serial terminals increases and the operation management becomes complicated, and the communication data exchanged between the host on the LAN and the serial terminal is directly encapsulated in TCP / IP packets. to interact, the host can receive packets anyone host if the connected device to the same LAN to send and receive and also to maintain the security due to Turkey <br/> and can analyze communication data device other than the host There was a problem that it was difficult.

An object of the present invention is to eliminate the above-mentioned problems caused by the conventional technique. The host on the LAN can control the protocol converter and the serial terminal, and the host on the LAN can manage the operation of a plurality of serial terminals. It is an object of the present invention to provide a data transmission method which can be easily implemented and which can enhance security of communication data between a host and a serial terminal flowing in a LAN.

[0006]

In order to achieve the above object, the present invention provides a protocol for connection operation between a host of a LAN system having a TCP / IP packet communication protocol and a serial communication terminal having a character-based data communication protocol. In the data transmission method including a conversion device, the protocol conversion device includes a LAN port having a protocol for communicating with TCP / IP packets, a serial port having a protocol for communicating with character-by-character data, and a TCP received at the LAN port. / IP packet for extracting the encapsulated character data, a TCP / IP packet for encapsulating the character data received by the serial port, and a unique format for the TCP / IP packet. F A header adding unit for adding Da, T
A header analysis unit that analyzes the header of the unique format added in the CP / IP packet and the status of the serial communication terminal.
Parameters and serial control signals for controlling
A LAN having a TCP / IP packet communication protocol , which includes an operation parameter section for storing a signal and a status information section.
The system host is responsible for instructing the operating parameters.
TCP / IP packet including its own format addition header
To the protocol converter, and the protocol converter
Header for adding the unique format of the TCP / IP packet
Data is analyzed and set in the operation parameter section and status information section.
The TCP / IP packet communication protocol
Your LAN system host is connected to the serial port.
Is to have control and manage the state of the serial terminal, the character data extraction unit when receiving the TCP / IP packets from the host of the LAN system TCP /
Extracting character data from the IP packet and transfers the serial communication terminal system, the character data <br/> the encapsulating unit is received when receiving the character data from the serial communication terminal system TCP
The first feature is that the data is encapsulated in an IP packet and transferred to the LAN system.

The present invention is also the data transmission method having the above characteristics, wherein the protocol conversion device comprises a plurality of serial
Connect the terminals and enter the identification information for the serial terminals.
Secondly , it is included in the original format additional header .
It is a feature of.

[0008] The present invention is the data transmission method of the first aspect, protocol conversion device, TCP / IP by encrypting character data received from the serial port
It is encapsulated in a packet, and information that indicates the decryption method of the encrypted character data is set in the unique format additional header, and the encrypted format is set in the unique format additional header of the TCP / IP packet received from the LAN port. By recognizing the information indicating the decoding method of the character data, and decoding the character data encapsulated in the TCP / IP packet into the original character data, the security of the communication data between the host and the serial terminal is enhanced. This is the third feature.

Further, according to the present invention, in the data transmission method according to the first feature or later, by allowing the host to include the operation parameter of the protocol converter in the unique format addition header in the TCP / IP packet, the host can easily perform the operation. The fourth characteristic is to control the protocol conversion device.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a protocol conversion device to which a data transmission method according to the present invention is applied, FIG. 2 is an explanatory diagram of a format of a TCP / IP packet used in the data transmission method according to the present invention, and FIG. FIG. 4 is an explanatory diagram of the protocol conversion device according to the present embodiment, and FIG. 4 is a diagram for explaining an operation of controlling a plurality of ports of a protocol with which the protocol conversion device according to the present embodiment communicates in character units.

FIG. 1 is a diagram showing a protocol conversion device 100 to which the data transmission method according to the present embodiment is applied.
In the figure, 200 is an LA that transmits and receives TCP / IP packets.
N port, 201 is a serial port for transmitting and receiving character data, 202 is a LAN, 203 is a control signal line of a serial transmission line, 204 is a data line of a serial transmission line, 3
00 is a character data extraction unit for extracting the encapsulated character data from the TCP / IP packet, 30
1 is an encapsulation unit that encapsulates character data in a TCP / IP packet, 302 is a header analysis unit that analyzes a header of a unique format in a TCP / IP packet, and 303 is a header of a unique format that is added to a TCP / IP packet A bedder adding unit, 304 is a common control unit that controls each function, 305 is an operation parameter unit that stores operation parameters of the apparatus, 306 is a status information unit that stores status information of serial control signals, and 400 is a LAN port 200. An arrow indicating the flow of a received TCP / IP packet, 401 is an arrow indicating the flow of character data to be transmitted to the serial port 201, and 402 is the LAN port 2
00 is an arrow indicating the flow of TCP / IP packets transmitted to 00, and 403 is an arrow indicating the flow of character data received at the serial port.

FIG. 2 is a diagram showing a transfer data format applied to this embodiment. This format includes a TCP / IP packet header 500 and an additional header 501 of a unique format.
Communication character data string 50 between host and serial terminal
2 is a diagram showing a TCP / IP packet 503 composed of 2 and 1. FIG.

FIG. 3 is a diagram showing a system configuration including the protocol conversion device 100 shown in FIG. 1. This system communicates with a host 101 having a protocol for communicating with TCP / IP packets in character unit data. A configuration is shown in which the protocol conversion device 100, which is the target of the present embodiment, is interposed between the serial terminals 102 having a protocol to perform protocol conversion of both.

The flow of data in the present system thus configured will be described below. First, when character data is transmitted from the host 101 side to the serial terminal 102, the character data 502 communicated by the host 101 to the serial terminal 102 is encapsulated as the TCP / IP packet 503 shown in FIG. Send to.

The protocol conversion device 100 receives the TCP / IP packet 503 via the LAN port 200 shown in FIG. 1, extracts the character data 502 in the received data by the character data extraction unit 300, and extracts the data 502. The serial port 20 via the arrow 401
1 and the port 201 transmits character data 502
Is transmitted to the serial terminal 102 via the serial transmission line data line 204. As a result, the serial terminal 102 can receive the character data transmitted from the host 100.

Further, the host 10
When communicating character data to 1, the serial terminal 102 transmits the serial data to the conversion device 100 via the serial data line 204. Protocol converter 1
00, received this from the serial port 201, Cap
TCP / IP for serial data using the cell conversion unit 301
The packet 503 is encapsulated. The encapsulated packet can be transmitted to the host 101 via the arrow 402 and the LAN port 200, whereby the host 101 can receive the character data transmitted from the serial terminal 102.

Next, the processing of the additional header of the unique format added to the TCP / IP packet will be described.

In the system configuration in which the host 101, the protocol converter 100, and the serial terminal 102 are connected as shown in FIG. 3, when the host 101 controls the state of the control signal 203 on the serial transmission line, the host 101:
Predetermined control information is set in the unique format addition header 501 in the TCP / IP packet 503 of FIG. 2 and transmitted to the conversion device 100. The conversion device 100 receives the TC
The header analysis unit 302 analyzes the header 501 of the P / IP packet, and the common control unit 304 controls the state of the control signal 203 on the serial transmission line according to the analysis result. Therefore, the state of the serial transmission line control signal 203 can be arbitrarily changed according to the control information from the host to transfer the serial data.

When the status of the control signal 203 on the serial transmission line is acquired from the host 101, the host 101
Is a TCP including an additional header 501 in which acquisition information is set.
/ IP packet 503 is transmitted to the conversion device 100. In the device 100, the header analysis unit 302 analyzes the additional header 501 in the same manner as described above, and the common control unit 304 acquires the status information unit 306 of the control signal of the serial transmission line according to the analysis result, that is, the status acquisition command, The acquisition information part is added to the additional header 501 by using the header adding part 303.
TCP / IP packet 503 set as
Return to 01. From this, the host 101 can arbitrarily acquire the state of the control signal 203 of the serial transmission line.

As described above, according to the present embodiment, the serial communication between the host 101 having the protocol for communicating with the TCP / IP packet using the protocol conversion device 100 and the serial terminal 102 having the protocol for communicating with the character unit data is performed. The data can be easily transferred, and the host can easily set and acquire the state of the serial transmission path control signal 203.

Next, an embodiment using a protocol conversion device arranged between a plurality of serial terminals and a host will be described with reference to FIG. Putcol conversion device 900 shown in FIG.
Is provided with a plurality of serial ports 201 corresponding to a plurality of serial terminals as compared with the above-mentioned embodiment.

In this system, as shown in FIG. 4, in a system configuration in which a host 101, a protocol conversion device 900, and a plurality of serial terminals 103 to 105 are connected, data in character units received by the conversion device 900 from the serial terminal 103. The columns are capsulated as in the previous embodiment.
The TCP / IP packet 503 is encapsulated using the packetizing unit 301 , the header adding unit 303 adds the identification information indicating the serial terminal 103 to the additional header 501 of this packet, and the packet is transmitted to the host 101. As a result, the host 101 uses the character data 50 based on the identification information included in the additional header 501 of the TCP / IP packet.
2 can be identified as the data transmitted from the terminal 103.

The host 101 is a serial terminal 103.
Character data to the protocol device 900 by encapsulating the character data 502 of the packet in the TCP / IP packet 503, setting the identification information representing the terminal 103 in the additional header 501, and transmitting it to the protocol device 900. It can be transmitted to the terminal 103.

Protocol conversion device 10 according to the present embodiment
When 0 or 900 is applied to the configuration of FIG.
1 and the device 100 or 900 when character data transmitted and received is encrypted and communicated with the device 100 or 900.
Creates a character data string 502 encrypts the data string of character units received from the terminal 102, the header adding unit 3 an additional header 501 that instructs the <br/> decoding method
The TCP / IP packet 503 set in 03 and added with the TCP / IP packet header 500 is transmitted to the host 101.

As a result, the host 101 has an additional header 50.
It is possible to recognize that the character data 502 is encrypted data from the information 1 and restore the original character data.

Further, the protocol conversion device 100 or 9
When the TCP / IP packet 503 shown in FIG. 2 is received from the host 101, the header analysis unit 302 analyzes the packet header 500 and the additional header 501, and a decoding instruction is set in the additional header 501. In this case, the character data 502 is decoded into the original character data, and the character data 502 is transmitted to the terminal 102.

Further, in this system, in the system configuration shown in FIG.
When changing the operation parameter unit 305 of 00 or 900, the host 101 sets information instructing the change of the operation parameter unit in the additional header 501 shown in FIG.
Send to 0 or 900. Upon receiving this, the device 100 or 900 analyzes the additional header 501 by the header analysis unit 302 in the device, and the common control unit 304 changes the operation parameter as the analysis result by the operation parameter unit 30.
The parameters stored in 5 can be changed. That is, this system can set the operating parameters of the protocol converter even if the host is remote.

[0028]

As described above, according to the present invention, a header of a unique format is added to a TCP / IP packet which encapsulates character data and is transmitted and received between a host and a protocol conversion device. A protocol conversion device and a serial terminal can be controlled from a host on a remote LAN, and operation management of a plurality of serial terminals can be easily performed from a host on the LAN. It is possible to enhance security of communication data between terminals.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a protocol conversion device to which a data transmission method according to the present invention is applied.

FIG. 2 is a TCP used in the data transmission method according to the present invention.
Explanatory diagram of the format of the / IP packet.

FIG. 3 is an explanatory diagram of a protocol conversion device according to the present embodiment.

FIG. 4 is a diagram for explaining an operation of controlling a plurality of ports of a protocol with which the protocol conversion device according to the present embodiment communicates in character units.

[Explanation of symbols]

100/900 ... Protocol conversion device, 101 ... Host, 102 ... Serial terminal, 103 ... Serial terminal 1,
104 ... Serial terminal 2, 105 ... Serial terminal n, 2
00 ... LAN port, 201 ... Serial port, 202
... LAN, 203 ... Control signal line of serial transmission line, 20
4 ... Data line of serial transmission line, 300 ... Character data extracting unit, 301 ... TCP / IP for character data
Encapsulation unit for encapsulating packets, 302 ... TC
Header analysis unit that analyzes the header of the unique format in the P / IP packet, 303 ... Header addition unit that adds the header of the unique format in the TCP / IP packet, 3
04 ... Common control unit, 305 ... Operation parameter unit, 306
... Status information part, 400 ... TCP received by LAN port
/ IP packet flow arrow, 401 ... Character data flow arrow to be transmitted to the serial port, 402 ... LAN
Flow arrow of TCP / IP packet sent to port 4
03 ... Flow arrow of character data received by serial port, 500 ... TCP / IP packet header, 501
... Additional header of unique format, 502 ... Communication character data string between host and serial terminal, 503 ... TC
P / IP packet, 600/700 ... Conversion function unit, 80
0 ... Control function unit.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Motonori Sato 1 Horiyamashita, Horiyamashita, Hadano, Kanagawa Prefecture (56) References JP-A-6-85817 (JP, A) JP-A-63- 263945 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04L 29/06 H04L 12/56 G06F 13/00 H04M 11/00

Claims (4)

(57) [Claims] 1. A TCP / IP packet communication protocol
Host of LAN system and data of character unit
Connection operation between serial communication terminals with communication protocol
Data transmission method including protocol conversion device
hand, The protocol converterIs, TCP / IP packet
LAN port with a protocol to communicate with
Port with a protocol to communicate with as much data
And a TCP / IP packet received at the LAN port
Key to retrieve the encapsulated character data from within
Character data extractor and the serial port
The captured character data is encapsulated in the TCP / IP packet.
And the encapsulation unit that creates a TCP / IP packet.
A header addition section for adding a header of its own format, and T
A unique format added in the CP / IP packet
Header analysis part that analyzes the header, Status of serial communication terminal
Parameters and serial control signals for controlling
An operation parameter section and a status information section that store the signal,Equipped
e,LAN system with TCP / IP packet communication protocol
The system host specifies a unique parameter that specifies the operating parameters.
Formats TCP / IP packets that include a format-added header
To the protocol conversion device, and the protocol conversion device
Proprietary format addition header of TCP / IP packet
It can be analyzed and set in the operation parameter section and status information section.
Has a TCP / IP packet communication protocol
LAN system host connected to serial port
Control and manage the status of the serial terminal TCP / IP packet from the host of the LAN system
If you receiveInThe character data extraction unit is TC
Extract character data from P / IP packet
Transfer to the AL communication terminal system and
When character data is received from the communication terminal system
InThe character data received by the encapsulation unit is T
LAN system by encapsulating in CP / IP packet
A data transmission method, characterized in that the data is transferred to. 2. The data transmission according to claim 1, wherein the protocol conversion device connects a plurality of serial terminals and includes identification information corresponding to the plurality of serial terminals in the unique format addition header. Method. 3. The protocol conversion device encrypts character data received from a serial port to perform TCP.
/ IP packet encapsulation, and information that indicates the decoding method of the encrypted character data is set in the unique format additional header, and the encryption set in the unique format additional header of the TCP / IP packet received from the LAN port. Security of communication data between the host and the serial terminal is ensured by recognizing the information indicating the decoding method of the encrypted character data and decoding the character data encapsulated in the TCP / IP packet into the original character data. The data transmission method according to claim 1, wherein the data transmission method is enhanced. Wherein said host, by including the operating parameters of the protocol converter to the proprietary format additional header in TCP / IP packets, claims, characterized in that to control easily protocol converter from the host The data transmission method according to 1 or 2 or 3.