JP2003273895A - Network switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a network switch which can transfer a large capacity of communication data between two or more network systems of a non- connected state and can surely maintain security of each network system. <P>SOLUTION: When the time for execution designated to a schedule file arrives, a channel is connected to only one LAN designated to the file by making it correspond to the time via a network converter. A relay computer decides a processing code designated by dealing with the connecting time to the file, receives communication data from a server, if the code is 'get', while it transmits the data to the server, if the code is 'put'. When the transmission and the reception of the data are completed, the LAN connected to the computer is disconnected by the converter, and each LAN is returned to the network system which is independent and is in a non-connected state to other LANs. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network switch interposed between two or more network systems for transferring communication data between the two or more network systems which are not connected to each other in a normal state. .

[0002]

2. Description of the Related Art In recent years, a company uses a network system in which a plurality of computers are connected to each other via a local area network (LAN) in order to process the business. A network system includes a plurality of client computers (hereinafter simply referred to as "clients") which are terminal computers used by users of the network system, and a specific server computer (hereinafter simply referred to as "server") that provides various services to the clients. , ") Are connected to each other via a LAN. Such a network system
Data (information) can be transferred between servers and clients belonging to the network system, and various data are shared.

In particular, a large-scale enterprise has a wide variety of businesses, and generally, a plurality of business network systems specialized for each business are constructed. In each business network system, the degree of importance and confidentiality of data differs depending on the business processed by the business network system. For business network systems that process data with high importance or confidentiality, access from other business network systems should be restricted, and data with high importance or confidentiality should be transferred to other business network systems. It becomes necessary to prevent the leakage and ensure its security.

Various methods have heretofore been proposed as measures for ensuring the security of the business network system. One method is to disconnect each business network system. In such a case, the business network system that processes data of high importance or the like is reliably separated from other business network systems, so that it can be accessed from another business network system via the LAN network. It is prevented and high security is secured.

[0005]

However, when a plurality of business network systems existing in the same company are not connected to each other as described above, data may be shared between different business network systems. Requires copying data from one business network system to a recording medium such as a flexible disk and moving the data to another business network system via the recording medium. However, the storage capacity of a recording medium such as a flexible disk is much smaller than the data capacity that can be transferred via a LAN network. Therefore, when moving a large amount of data from one business use network system to another business use network system, the data needs to be divided and recorded in a plurality of recording media, which makes the work extremely complicated. There was a problem.

The present invention has been made to solve the above-mentioned problems, and can transfer a large amount of communication data between two or more network systems which are in a non-connection state in a normal state, and each network can be transferred. It is an object of the present invention to provide a network switch capable of reliably maintaining system security.

[0007]

In order to achieve this object, the network switch according to claim 1 relays communication data by interposing between two or more network systems that are not connected to each other. Corresponding to the disconnection holding means for holding the line to each of the two or more network systems in the disconnected state, and the connection time which is the time to change the line disconnected by the disconnection holding means to the connected state, the two or more Means for designating any one of the network systems and communication mode of reception or transmission of communication data, and connection when the connection time designated to the specification means arrives. Connection means for connecting a line to the network system designated by the designation means in association with time, and connection by the connection means A communication form judging means for judging the communication form specified by the specifying means in association with the time;
When the communication form determining means determines that the communication form is reception, the receiving means for receiving communication data from the network system to which the line is connected by the connecting means, and the reception of the communication data by the receiving means are completed. In this case, there is provided disconnection return means for returning the line between the network system connected by the connection means to the disconnected state by the disconnection holding means.

According to the network switch of the present invention, when the connection time designated by the designating means arrives, one network system is designated by the connecting means in correspondence with the connection time to the designating means. The line is connected with the chisel. Here, when the communication form determination means determines that the communication form designated by the designation means in association with the connection time is reception, the communication data is
The receiving means receives from one network system to which the line is connected by the connecting means. When the reception of the communication data is completed, the disconnection recovery means restores the line to the one network system to the disconnected state by the disconnection holding means.

A network switch according to a second aspect is
2. The network switch according to claim 1, wherein the relay data storage unit capable of storing the communication data received by the receiving unit and the communication data stored in the relay data storage unit are designated by the communication form determination unit. Transmission means for transmitting to the network system to which the line is connected by the connection means when it is determined that the communication mode stored in the means is transmission, and the disconnection recovery means includes the transmission means. When the transmission of the communication data by the above is completed, the line with the network system connected by the connecting means is returned to the disconnected state by the disconnection holding means.

According to the network switch of the second aspect, the network switch operates in the same manner as the network switch of the first aspect, and when the designated connection time arrives at the designation means, the connection means responds to the connection time. The line is connected to only one network system designated by the designation means. Here, when the communication form determination means determines that the communication form designated in association with the connection time to the designation means is transmission, the communication data stored in the relay data storage means is transmitted by the transmission means. ,
It is transmitted to the one network system to which the line is connected by the connecting means. When the transmission of the communication data is completed, the disconnection recovery means restores the line to the one network system to the disconnected state by the disconnection holding means.

The network switch according to claim 3 is
2. The network switch according to claim 1, wherein the network system to which the line is connected by the connecting means is capable of storing communication data in association with transmission permission data for permitting transmission of communication data. And a first detecting means for detecting whether or not the transmission permission data is stored in the transfer source data storage means, and the receiving means is provided with the transmission permission data by the first detection means. Is detected,
The communication data stored in the transfer source data storage means in association with the transmission permission data is received.

According to the network switch of the third aspect, the network switch operates in the same manner as the network switch of the first aspect, and when the line is connected to one network system by the connection means, the first detection means It is detected whether or not the transmission permission data is stored in the transfer source data storage means of the network system. As a result of the detection, if the transmission permission data is stored in the transfer source data storage means, the reception means receives the communication data stored in the transfer source data storage means in association with the transmission permission data.

A network switch according to claim 4 is
4. The network switch according to claim 3, wherein the communication data is composed of a file that can be managed by a basic operation system of a computer, and the transmission permission data is associated with the transmission permission data, and the transfer source data storage means is provided. In the case where it is composed of a file of empty data with the same file name as the file name of the communication data stored in, the first detecting means, based on the file name of the transmission permission data, The transmission permission data is detected from the transfer source data storage unit, and the reception unit is the transmission permission detected by the first detection unit from the communication data stored in the transfer source data storage unit. The communication data having the same file name as the data file name is received.

According to the network switch of the fourth aspect, the network switch operates in the same manner as the network switch of the third aspect, and when the connection means connects the line to the one network system, the communication permission data is The 1 detection means detects whether or not the data is stored in the transfer source data storage means based on the file name. As a result of the detection, among the communication data stored in the transfer source data storage means, the communication data having the same file name as the file name of the transmission permission data detected by the first detection means is received by the reception means. Be received.

A network switch according to a fifth aspect is
3. The network switch according to claim 2, wherein the network system to which a line is connected by the connecting means is associated with communication data stored in the relay data storage means and rejects reception of the communication data. In the case where the transfer destination data storage means capable of storing the reception refusal data is provided, the transfer destination data storage means is provided with second detection means for detecting whether or not the reception refusal data is stored. The means, when the reception refusal data is detected by the second detection means, prohibits the transmission of the communication data stored in the relay data storage means in association with the reception refusal data.

According to the network switch of the fifth aspect, the network switch operates in the same manner as the network switch of the second aspect, and when the line is connected to one network system by the connecting means, the second detecting means It is detected whether or not the reception refusal data is stored in the transfer destination data storage means of the network system. As a result of the detection, if the reception refusal data is stored in the transfer source data storage means, the transmission means prohibits the transmission of the communication data stored in the relay data storage means in association with the reception refusal data.

A network switch according to claim 6 is
The network switch according to claim 5, wherein when the reception refusal data is composed of an empty data file that can be managed by a basic operation system of a computer, communication data stored in the relay data storage means. Is a file having the same file name as the file name of the reception refusal data stored in the transfer destination data storage means in association with the communication data, and the second detection means is Receiving refusal data is detected from the refusing data storage means based on the file name of the receiving refusal data, and the transmitting means detects the second detection among the communication data stored in the relay data storing means. It is prohibited to send the communication data with the same file name as the file name of the reception refusal data detected by the method. It is intended to.

According to the network switch of the sixth aspect, the network switch operates in the same manner as the network switch of the fifth aspect, and when the line is connected to one network system by the connecting means, the reception refusal data is The 2 detection means detects whether or not the data is stored in the transfer destination data storage means based on the file name. As a result of the detection, of the communication data stored in the relay data storage means, the communication data with the same file name as the file name of the reception refusal data detected by the second detection means is transmitted by the transmission means. Transmission is prohibited.

The network switch according to claim 7 is
The network switch according to any one of claims 1 to 6, further comprising a relay storage device provided with the relay data storage means, wherein the disconnection holding means has one end connected to the relay storage device and the other end connected to the relay storage device. Two or more contact switches provided with two or more network systems individually connected, and all of the two or more contact switches are held in an open state.
Only one of the two or more contact switches is closed, and the disconnection return means opens one contact switch closed by the connecting means from the closed state. It is to return to the state.

[0020]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a circuit diagram showing an electrical configuration of a network switch 1 which constitutes a part of a network switch 40 which is an embodiment of the present invention. The network switch 1 is a device for switching the connection destination of the relay computer 50 to any one of the plurality of LANs 101 to 103, and includes a DC power supply circuit 2, an auxiliary power supply circuit 3, and a first interface circuit 4.
A second interface circuit 5, a network switching gate circuit 6, a reset gate circuit 7, a reset signal generating circuit 8, a reset relay drive circuit 9, a reset relay 10, and a first network relay drive circuit 11. And a second network relay drive circuit 12 and a third
Network relay drive circuit 13, first network relay 14, second network relay 15, third network relay 16, and LAN connector unit 17
It has and.

DC power supply circuit 2 of network switch 1
Is a stable +12 from a 100 V (volt) AC power supply.
It is a circuit that generates and outputs a V voltage. DC power supply circuit 2
The + 12V voltage generated by the auxiliary power circuit 3 and the first
Through, it is supplied as a drive voltage to each circuit such as the third network relay drive circuits 11 to 13. The auxiliary power supply circuit 3 is a circuit for generating a + 9V DC constant voltage from the + 12V DC voltage output from the DC power supply circuit 2, and has a three-terminal constant voltage having an input end, an output end, and a ground end. The regulator 3a is provided.

The + 12V DC voltage supplied from the DC power supply circuit 2 is input to the input terminal of the three-terminal constant-voltage regulator 3a, and a 0.1 μF capacitor C7 having one end grounded to the circuit and one end grounded to the circuit. And a 470 μF capacitor C9. On the other hand, the output terminal of the three-terminal constant-voltage regulator 3a has one end connected to the circuit ground.
1 μF capacitor C6 and 10 with one end grounded
A μF capacitor C8 is connected. These capacitors C6 to C9 are for removing high frequency noise from the input / output voltage to / from the auxiliary power supply circuit 3. 3
The ground end of the terminal constant voltage regulator 3a is grounded to the circuit.

The first interface circuit 4 is a communication serial interface (CO
M1) 56 converts the first control signal input from the M1) 56 into a voltage signal corresponding to the input logic level of the network switching gate circuit 6, and is mainly used for the communication connector CN1.
And a photo coupler TLP1. The communication connector CN1 has two connection pins, that is, a pin 1 and a pin 2, and the pin 1 is a first for controlling the network switch 1 from the communication serial interface 56 of the relay computer 50. A control signal is input, and its 2nd pin is grounded.

The second interface circuit 5 is a communication serial interface (CO
M2) The second control signal input from 57 is converted into a voltage signal corresponding to the input logic level of the network switching gate circuit 6, and mainly the communication connector CN2.
And a photo coupler TLP2. Similarly to the communication connector CN1, the communication connector CN2 also has two connection pins, that is, a pin 1 and a pin 2, and the pin 1 is connected from the communication serial interface 57 of the relay computer 50 to the network switch 1. The second control signal for controlling the signal is input, and the second pin is grounded.

The voltage levels of the first control signal input to the first interface circuit 4 and the second control signal input to the second interface circuit 5 are normally 0V (in the off state). Therefore, the voltage is + 5V when the signal is generated (in the ON state).

First and second interface circuits 4, 5
The photo couplers TLP1 and TLP2 of the communication connector C
It is for insulating the N1 and CN2 sides, that is, the relay computer 50 side and the network switching gate circuit 6 side. One ends of 10 kΩ resistors R1 and R2 are connected to the anodes of the LEDs of the photocouplers TLP1 and TLP2, respectively, and the other ends of the resistors R1 and R2 are connected to the first pins of the communication connectors CN1 and CN2, respectively.
The resistors R1 and R2 are for limiting the current flowing to the LEDs of the photocouplers TLP1 and TLP2.

The cathodes of the LEDs of the photocouplers TLP1 and TLP2 are two of the communication connectors CN1 and CN2.
The circuit is grounded by being connected to the No. pin respectively. On the other hand, the phototransistors of the photocouplers TLP1 and TLP2 have collectors of +9 of the auxiliary power supply circuit 3.
The other ends of 10 kΩ resistors R3 and R4, which are respectively connected to the output of V and whose circuit is grounded, are connected to the emitters thereof. Further, the other ends of these resistors R3 and R4 are respectively connected to the input ends of the NOR gate NOR1 which is the input end of the network switching gate circuit 6.

According to the first interface circuit 4 configured as described above, when the first control signal input to the 1st pin of the communication connector CN1 is turned on, that is, the first control signal changes from 0V to + 5V. When it comes to, photo coupler TLP
The phototransistor 1 turns on and the photocoupler TL
The output voltage of P1 changes from low level to high level,
The logic level input to the input terminal of the network switching gate circuit 6 is changed from "0" to "1".

Similarly, also in the second interface circuit 5, when the second control signal input to the 1st pin of the communication connector CN2 is turned on, that is, when the second control signal changes from 0V to + 5V, The phototransistor of the photocoupler TLP2 is turned on, and the photocoupler TLP2 is turned on.
The output voltage of is changed from the low level to the high level, and the logic level input to the input end of the network switching gate circuit 6 is changed from "0" to "1".

The network switching gate circuit 6 has a first
And the output voltage (output logic level) to the first to third network relay drive circuits 11 to 13 according to the input logic level input from the second interface circuits 4 and 5.
Is for changing. The network switching gate circuit 6 includes five NOR gates NOR1 to NOR5.
And three AND gates AND1 to AND3 and four NAND gates NAND1 to NAND4.

In the network switching gate circuit 6, first, the input end of the NOR gate NOR1 and the output ends of the first and second interface circuits 4 and 5 and the NOR gate NOR2.
Is connected to the output end of the NOR gate NOR1, the input end of the AND gate AND1 is connected to the output ends of the first and second interface circuits 4 and 5, and the input end of the NOR gate NOR3 is connected to the output end of the AND gate AND1. ing. The input end of the NOR gate NOR4 is NOR gate N.
It is connected to the output end of OR3, and its output end is connected to the input end of the third network relay drive circuit 13. The input end of the NOR gate NOR5 is connected to the resistor R25 of the third network relay drive circuit 13.

The input end of the AND gate AND2 is connected to the output end of the first interface circuit 4, the output end of the NOR gate NOR2 and the output end of the NOR gate NOR3,
The input end of the AND gate AND3 is connected to the output end of the second interface circuit 5, the output end of the NOR gate NOR2 and the output end of the NOR gate NOR3, and the input end of the NAND gate NAND1 outputs the output end of the AND gate AND2 and the output of the NOR gate NOR5. The input end of the NAND gate NAND2 is connected to the output end of the AND gate AND3 and the output end of the NOR gate NOR5. Further, the input end of the NAND gate NAND3 is connected to the output end of the NAND gate NAND1, and the input end of the NAND gate NAND4 is connected to the output end of the NAND gate NAND2. The output terminal of the NAND gate NAND3 is the first
Connected to the input end of the network relay drive circuit 11,
The output terminal of the NAND gate NAND4 is connected to the input terminal of the second network relay drive circuit 12.

According to the network switching gate circuit 6, when the input logic levels from the first and second interface circuits 4 and 5 are both "0", the first to third network relay drive circuits 11 to 11 are provided. "0" (low voltage) is output to 13 as the output logic level. Further, the network switching gate circuit 6 outputs the output logic level to the first and second network relay drive circuits 11 and 12 when both the input logic levels from the first and second interface circuits 4 and 5 are “1”. "0" (low voltage) is output as, while "1" (high voltage) is output as an output logic level to the third network relay drive circuit 13. Further, the network switching gate circuit 6 is
When the input logic level from the first interface circuit 4 is "1" and the input logic level from the second interface circuit 5 is "0", the output logic level to the first network relay drive circuit 11 is "1". "(High voltage) is output, while" 0 "(low voltage) is output as the output logic level to the second and third network relay drive circuits 12 and 13. Further, the network switching gate circuit 6 receives the second network relay when the input logic level from the first interface circuit 4 is “0” and the input logic level from the second interface circuit 5 is “1”. "1" (high voltage) as the output logic level to the drive circuit 12
On the other hand, “0” (low voltage) is output as an output logic level to the first and third network relay drive circuits 11 and 13.

The reset gate circuit 7 receives the three logic levels output from the network switching gate circuit 6 and changes the output voltage (output logic level) to the reset signal generating circuit 8. It is composed of three NOR gates NOR6 to NOR8. The input end of the NOR gate NOR6 of the reset gate circuit 7 is
NAND gate NAN of the network switching gate circuit 6
It is connected to the output end of D3 and the output end of NOR gate NOR4. Further, the input end of the NOR gate NOR7 is connected to the output end of the NOR gate NOR6, and the NOR gate NOR6 is connected.
The input end of 8 is the output end of the NOR gate NOR7 and the NAND gate NAND4 of the network switching gate circuit 6.
The output end of the NOR gate NOR8 is connected to the input end of the reset signal generating circuit 8.

According to the reset gate circuit 7 described above, when the logic levels output from the network switching gate 6 are all "0", the output logic level to the reset signal generating circuit 8 is "1" (high voltage). ) Is output, but when the output logic level from the network switching gate 6 is other, "0" (low voltage) is output to the reset signal generation circuit 8 as the output logic level. That is, the reset gate circuit 7 outputs "1" (as an output logic level to the reset signal generating circuit 8 only when both the input logic levels from the first and second interface circuits 4 and 5 are "0". It outputs a high voltage).

The reset signal generation circuit 8 generates a reset signal based on the output logic level of the reset gate circuit 7 and outputs it to the reset relay drive circuit 9. The reset signal generating circuit 8 is a timer circuit TM.
(NE555) is a one-shot multivibrator, and the ground terminal 1 of the timer circuit TM thereof.
Is circuit grounded. Trigger end 2 of timer circuit TM
Is connected to the output end of the NOR gate NOR8 of the reset gate circuit 7 via a 0.1 μF capacitor C10, and further connected to the DC power supply circuit 2 via a resistor R24 of 1 kΩ.
It is connected to the + 12V output.

The output terminal 3 of the timer circuit TM is connected to the input terminal of the reset relay drive circuit 9, and the control voltage terminal 5 is connected to a 0.01 μF capacitor C1 having one end grounded to prevent malfunction due to noise. Has been done. Further, the reset terminal 4 of the timer circuit TM is connected to the power source voltage terminal 8, and the power source voltage terminal 8 is +12 of the DC power source circuit 2.
It is connected to the output of V and is also connected to one end of a resistor R5 of 100 kΩ. A threshold end 6 and a discharge end 7 are connected to the other end of the resistor R5, and further, the threshold end 6 and the discharge end 7 are connected.
Is connected to a 50 μF capacitor C2 whose one end is circuit grounded.

According to the reset signal generating circuit 8, when the logic level output from the reset gate circuit 7 is "1", the output voltage from the output terminal 3 of the timer circuit TM is 0 volt, and When the logic level output from the gate circuit 7 changes from "1" (high voltage) to "0" (low voltage), the capacitor C10 and the resistor 24
The voltage applied to the trigger end 2 falls momentarily by the C / R differentiating circuit composed of. By the fall of the voltage applied to the trigger terminal 2, the output terminal 3 of the timer circuit TM is
Is output as a reset signal.

Simultaneously with the output of the reset signal, the capacitor C2 is charged through the resistor R5, and the capacitor C2
When the voltage at the threshold end 6 rises to about 8V due to the charging of, the voltage at the output end 3 of the timer circuit TM becomes about 0V and the output of the reset signal is stopped. The output holding time of the reset signal is almost equal to a value obtained by multiplying the product of the resistance value of the resistor R5 and the electric capacity of the capacitor C2 by 1.1,
It is set to about 5.5 seconds (= 1.1 × 100 kΩ × 50 μF).

The reset relay drive circuit 9 is for operating the reset relay 10 based on the reset signal, and the anode is connected to the output end of the reset signal generation circuit 8 (that is, the output end 3 of the timer circuit TM). The diode D2 is provided. The diode D2 is for preventing the reverse flow of the current to the output terminal 3 of the timer circuit TM, and the cathode thereof has a resistance R of 10 kΩ.
One end of 6 is connected. The other end of the resistor R6 is connected to a resistor R7 of 10 kΩ whose one end is circuit-grounded and the base of the transistor Q1. The emitter of the transistor Q1 is circuit grounded, and its collector is connected to one end of the coil L of the reset relay 10 and the anode of the diode D1.

The reset relay 10 is of a B contact (break contact, normally closed (NC, Normally Close) contact) type, and has an electrical contact SW when the coil L is demagnetized.
Is closed (ON state), and when the coil L is excited, the electric contact SW is opened (OFF state). The other end of the coil L of the reset relay 10 is connected to the + 12V output of the DC power supply circuit 2 and the cathode of the diode D1. The diode D1 is for returning a current caused by the counter electromotive force generated in the coil L of the reset relay 10. The electrical contact SW is turned on or off by demagnetizing or exciting the coil L, one end thereof is connected to the + 12V output of the DC power supply circuit 2, and the other end thereof is connected to the first to third network relay drive circuits 11 to 11. Thyristors THY1 to THY in 13
It is connected to each of the three anodes.

According to the reset relay drive circuit 9 and the reset relay 10, when the reset signal output from the reset signal generation circuit 8 is turned on, a voltage of +12 V is applied to the input terminal of the reset relay drive circuit 9 to cause resistance. R6
A base current flows to the base of the transistor Q1 via the transistor Q1, and the transistor Q1 is turned on. Then, a current flows between the collector and the emitter of the transistor Q1, the coil L of the reset relay 10 is excited, and the electrical contact SW is turned off. After the generation of the reset signal, when the output holding time (about 5.5 seconds) of the reset signal has elapsed, the reset signal is turned off and the coil L of the reset relay 10 is turned on.
Is demagnetized, and the electrical contact SW is turned on.

The first to third network relay drive circuits 11 to 13 include the first to third network relays 14 to.
It is a circuit for turning on or off 16. The first network relay drive circuit 11 includes a diode D3 having an anode connected to the output terminal of the NAND gate NAND3 of the network switching gate circuit 6, and the second network relay drive circuit 12 includes a NAND gate NAND4 of the network switching gate circuit 6. The third network relay drive circuit 13 includes a diode D4 having an anode connected to the output end thereof and a diode D4 having an anode connected to the output end of the NOR gate NOR4 of the network switching gate circuit 6.
5 are provided respectively. These diodes D3 ~
D5 prevents backflow of current to the network switching gate circuit 6, and the cathodes of the diodes D3 to D5 are connected to one ends of resistors R8 to R10 of 10 kΩ.

To the other ends of the resistors R8 to R10 are connected 1 kΩ resistors R11 to R13 each having one end grounded to the circuit, and 0.01 μF capacitors C3 to C5 each having one end grounded to the circuit, respectively. , Thyristor TH
The gates of Y1 to THY3 are connected to each other. The cathodes of the thyristors THY1 to THY3 are connected to the resistors R14 to R16 of 1 kΩ whose circuit grounds are connected at one end, and to the resistors R17 to R19 of 10 kΩ connected to the bases of the transistors Q2 to Q4 at their one ends. Has been done. The emitters of the transistors Q2 to Q4 are circuit-grounded, and the collector of the transistor Q2 is at one drive voltage end of the first network relay 14 and the collector of the transistor Q3 is at one drive voltage end of the second network relay 15. , The collector of the transistor Q4 is connected to one drive voltage terminal of the third network relay 16, respectively.

Also, the third network relay drive circuit 1
3 has one end of a resistor R25 of 10 kΩ connected between the cathode of the thyristor THY3 and the resistor R19.
The other end of 25 is connected to the input end of the NOR gate NOR5 of the network switching gate circuit 6. Here, the NOR gate NOR5 and the resistor R25 form a malfunction prevention circuit for preventing malfunction of the first to third network relay drive circuits 11 to 13. When both the first and second control signals are turned on to close each contact set of the third network relay 16 and then the first and second control signals are turned off, both signals are turned off at the same time. May not be possible, and there may be a time difference between the turning off of both signals.

In such a case, one of the first and second control signals is pseudo matched with the turned-on state, and therefore one of the first network relay drive circuit 11 and the second network relay drive circuit 12 is in the third state. There is a risk that either the first network relay 14 or the second network relay 15 will be turned on at the same time as the third network relay 16 by operating simultaneously with the network relay drive circuit 13. The malfunction prevention circuit is a circuit for preventing malfunctions in which the network relay drive circuits 11 to 13 operate at the same time.

For example, when the first and second control signals are turned on (21d and 22d in FIG. 2) and the transistor Q4 is turned on (32b in FIG. 2), the base current of the transistor Q4 passes through the resistor R25, It flows into the input end of the NOR gate NOR5, the input logic level of "1" is input to the input end of the NOR gate NOR5, and the output logic level of "0" is output from the output end of the NOR gate NOR5. Since the output logic level of the NOR gate NOR5 becomes "0" in this way, the output logic level of the AND gates AND2 and AND3 is "1" regardless of the ON or OFF state of the first and second control signals, and the NAND gate NAND3. , NAN
The output logic level of D4 becomes "0". Nand Gate N
If the output logic level of AND3, NAND4 is "0", the first and second network relay drive circuits 11, 1
Since the second transistors Q2 and Q3 are turned off, only the transistor Q4 of the third network relay drive circuit 13 is turned on.

Thereafter, for example, after the first control signal is turned off (change from 21d to 21e in FIG. 2), the second control signal is turned off (change from 22d to 22e in FIG. 2) with a slight delay.
If so, since the transistor Q4 is turned on,
The base current of the transistor Q4 continues to flow to the input terminal of the NOR gate NOR5 via the resistor R25. result,
Since the input logic level of "1" is input to the input end of the NOR gate NOR5, the output logic level of the NOR gate NOR5 becomes "0". Therefore, the AND gate AND2, regardless of the ON or OFF state of the first and second control signals.
The output logic level of AND3 becomes "1", and the output logic level of NAND gates NAND3 and NAND4 becomes "0". If the output logic level of the NAND gates NAND3 and NAND4 is "0", the transistors Q2 and Q3 of the first and second network relay drive circuits 11 and 12 are kept off, and therefore the third network relay drive circuit 13 Therefore, the on state of only the transistor Q4 is maintained. As a result, it is possible to prevent a malfunction in which the third network relay 16 and the first network relay 14 are simultaneously turned on when both the first and second control signals are switched from the on state to the off state.

The second control signal is turned off (22d in FIG. 2).
(Change from 21d to 22e) and then the first control signal is turned off (change from 21d to 21e in FIG. 2) with a slight delay, similarly to the case described above, the third network relay drive circuit 13 Only the transistor Q4 can be kept on. As a result, it is possible to prevent a malfunction in which the third network relay 16 and the second network relay 15 are simultaneously turned on when both the first and second control signals are switched from the on state to the off state.

First to third network relays 14-1
6 is an A contact (make contact, normally open (NO, Normally O
pen) contact) type, coil (not shown)
When the coil is demagnetized, all the electrical contact groups are in the open state (OFF state), and when the coil is excited, all the electrical contact group are in the closed state (ON state). Further, each of the network relays 14 to 16 has a pair of drive voltage terminals for applying a voltage to the coil in order to operate each of the contact sets, and each of the network relays 14 to 16 is provided.
The other drive voltage end of is connected to the + 12V output voltage of the DC power supply circuit 2. A diode D6 having a cathode connected to the output side of the DC power supply circuit 2 is provided between the pair of drive voltage terminals of the network relays 14 to 16.
~ D8 are inserted respectively. This diode D6
~ D8 is for causing a current to flow back due to the counter electromotive force generated in the coils of the network relays 14-16.

The LAN connector unit 17 includes a repeater connector CN3 connectable to the LAN interface 58 of the relay computer 50, a first LAN connector CN4 connectable to the first LAN 101, and a second LAN connector CN5 connectable to the second LAN 102. Third LAN1
03 is connectable to the third LAN connector CN6. Each of these connectors CN3 to CN6 has the same number (for example, four) of connection pins, and in particular,
Each connection pin of the relay connector CN3 is connected to the first LAN connector C via each contact group of the first network relay 14.
N4 and the second LAN connector CN5 via the contact groups of the second network relay 15, and the third LAN connector CN6 via the contact groups of the third network relay 16.
, And each can be connected.

The operation of the network switch 1 configured as described above will be described with reference to FIG. Figure 2
[Fig. 3] is an operation explanatory view of the network switch 1. In addition,
Below, the repeater connector CN3 of the network switch 1
Will be described as an example in which the first LAN connector CN4 is connected to the third LAN connector CN6 in order, but the connection order of the connectors CN3 to CN6 is not limited to this.

As shown in FIG. 2, in the initial state, both the first and second control signals output from the relay computer 50 are in the off state (21a, 22a).
And the output voltages of the second interface circuits 4 and 5 both become low voltages (23a and 24a), and the three output logic levels of the network switching gate circuit 6 are "00".
0 ”(25a, 26a, 27a). This allows
The transistors Q2 to Q4 of the first to third network relay drive circuits 11 to 13 are turned off (30a, 31
As a result, the first to third network relays 14 to 16 are turned off.

The relay computer 50 is connected to the first LAN 101.
When connecting to, ie, repeater connector CN3 and first L
The case of connecting to the AN connector CN4 will be described. In such a case, first, only the first control signal is changed from the off state to the on state (21b, 22a), and only the output voltage of the first interface circuit 4 is changed from the low voltage to the high voltage (23b, 24a), This high voltage state is maintained until the first control signal is turned off. As a result, only the output logic level of the NAND gate NAND3 becomes "1" (high voltage) (25b, 26a, 27a), and the output of the network switching gate circuit 6 becomes "100".

In response to the output of the network switching gate circuit 6, the output logic level of the reset gate circuit 6 is changed from "1" to "0", and the reset signal generating circuit 8 which receives the output changes the reset signal. Is turned on (28b). When the reset signal is turned on, the transistor Q1 of the reset relay drive circuit 9 is turned on, whereby the coil L of the reset relay 10 is excited and the electrical contact SW is changed from the on state to the off state (29b).
By turning off the electric contact SW, the thyristors THY1 to THY of all the network relay drive circuits 11 to 13 are turned on.
3 is turned off, and as a result, the transistors Q2 to Q4 are held in the off state (30a, 31a, 32).
a).

About 5.5 seconds after the reset signal is turned on (28b), the reset signal is turned off (2
8c), whereby the transistor Q1 of the reset relay drive circuit 9 is turned off, and the coil L of the reset relay 10 is turned on.
Is demagnetized and the electrical contact SW is changed from the off state to the on state (29c). When the electrical contact SW is turned on, the thyristors T of all the network relay drive circuits 11 to 13 are turned on.
+12 of the DC power supply circuit 2 to the anode of HY1 to THY3
The V output is applied. Nand Gate NAN at this point
Since the output logic level of D3 is kept at "1", the gate voltage is applied to the gate of the thyristor THY1 of the first network relay drive circuit 11 by this. As a result, of the thyristors THY1 to THY3, only the thyristor THY1 becomes conductive, and only the transistor Q2 is turned on (30b, 31a, 32a), and the first
Each contact group of the network relay 14 is closed (ON), and the relay connector CN3 and the first LAN connector CN4 are connected.

By the way, the first control signal is maintained in the on state for about 10 seconds (21b) and then returned to the off state again (21c). As a result, the first interface circuit 4
Since the output voltage of the device returns from the high voltage to the low voltage (2
3c, 24a), the output logic level of the NAND gate NAND3 becomes "0" (low voltage) (25c, 26a,
27a), the output of the network switching gate circuit 6 becomes "000". Although the application of the gate voltage to the thyristor THY1 is stopped in response to the output of the network switching gate circuit 6, the electrical contact SW of the reset relay 10 is in the open state (off state) in the thyristor THY1 which has once become conductive. ), The conductive state can be maintained. Therefore, the transistor Q2 is in the on state (30b, 31) until the next reset signal is generated.
a, 32a), that is, the closed state (on state) of each contact set of the first network relay 14 is held, and the connection state between the relay connector CN3 and the first LAN connector CN4 is held.

Next, the relay computer 50 is connected to the second LAN.
A case of connecting to 102, that is, a case of connecting the repeater connector CN3 and the second LAN connector CN5 will be described. In such a case, first, only the second control signal is turned from the off state to the on state (21c, 22b), and only the output voltage of the second interface circuit 4 is changed from the low voltage to the high voltage (23c, 24b), and the high voltage is output. The voltage state is maintained until the second control signal is turned off. As a result, only the output logic level of the NAND gate NAND4 becomes "1".
(High voltage) (25c, 26b, 27a), and the output of the network switching gate circuit 6 becomes "010". In response to the output of the network switching gate circuit 6, the output logic level of the reset gate circuit 6 is "1".
Is changed from “0” to “0”, and the reset signal is turned on by the reset signal generation circuit 8 which receives the change (28
d). When the reset signal is turned on, the transistor Q1 of the reset relay drive circuit 9 is turned on, whereby the coil L of the reset relay 10 is excited and the electrical contact SW is changed from the on state to the off state (29d). When the electrical contact SW is turned off, the thyristor THY1 of the first network relay drive circuit 11 is turned off, and the transistor Q2 is initialized (reset) to the off state (30).
c). As a result, the contact sets of the first network relay 14 are opened (OFF state), and the relay connector CN3.
Then, the first LAN connector CN4 is disconnected.

About 5.5 seconds after the reset signal is turned on (28d), the reset signal is turned off (2
8e), whereby the transistor Q1 of the reset relay drive circuit 9 is turned off, and the coil L of the reset relay 10 is turned on.
Is demagnetized and the electrical contact SW is changed from the off state to the on state (29e). When the electrical contact SW is turned on, the thyristors T of all the network relay drive circuits 11 to 13 are turned on.
+12 of the DC power supply circuit 2 to the anode of HY1 to THY3
The V output is applied. Nand Gate NAN at this point
Since the output logic level of D4 is maintained as "1", the gate voltage is applied to the gate of the thyristor THY2 of the second network relay drive circuit 12 by this. As a result, of the thyristors THY1 to THY3, only the thyristor THY2 becomes conductive, and only the transistor Q3 is turned on (30c, 31b, 32a), and the second
Each contact group of the network relay 15 is closed (ON), and the relay connector CN3 and the second LAN connector CN5 are connected.

On the other hand, after the second control signal is kept in the on state for about 10 seconds (22b), it returns to the off state again (2
2c), which causes the output voltage of the second interface circuit 5 to return from the high voltage to the low voltage (23c,
24c), the output logic level of the NAND gate NAND4 becomes "0" (low voltage) (25c, 26c, 27).
a), the output of the network switching gate circuit 6 is "00".
It becomes "0". Upon receiving the output of "000", the application of the gate voltage to the thyristor THY2 is stopped. The conduction state is maintained. Therefore, the transistor Q3 is in the ON state (30c, 3 until the next reset signal is generated.
1b, 32a), that is, the closing (ON) of each contact group of the second network relay 15 is held, and the connection state between the second LAN connector CN5 and the relay connector CN3 is held.

Next, the relay computer 50 is connected to the third LAN.
A case of connecting to 103, that is, a case of connecting the relay connector CN3 and the third LAN connector CN6 will be described. In such a case, first, both the first and second control signals are turned from the off state to the on state, and the on state is held for about 10 seconds (21d, 22d). In this case, the output voltages of the first and second interface circuits 4 and 5 both change from low voltage to high voltage (23d, 2
4d), the high voltage state is maintained until the first and second control signals are turned off. As a result, NOR gate NOR4
Only the output logic level of (1) becomes a high voltage (25c, 26c, 27b), and the output of the network switching gate circuit 6 becomes "001".

Receiving the output of "001", the output logic level of the reset gate circuit 6 is changed from "1" to "0", and the reset signal generating circuit 8 receiving this output turns on the reset signal. (28f). When the reset signal is turned on, the electrical contact SW of the reset relay 10 is turned off from the on state via the reset relay drive circuit 9 (29f), the thyristor THY2 of the second network relay drive circuit 12 is turned off, and the transistor THY2 is turned off. Q3 is initialized (reset) to the off state (31
c). As a result, each contact set of the second network relay 15 is opened (OFF state), and the relay connector CN3.
Then, the second LAN connector CN5 is disconnected.

About 5.5 seconds after the reset signal is turned on (28f), the reset signal is turned off (2
8g), whereby the electrical contact SW is turned on from the off state via the reset relay drive circuit 9 (29
g). As a result, the + 12V output of the DC power supply circuit 2 is applied to the anodes of the thyristors THY1 to THY3 of all the network relay drive circuits 11 to 13. At this time, the output logic level of the NOR gate NOR4 is kept at "1", so that the gate voltage is applied to the gate of the thyristor THY3 of the third network relay drive circuit 13. As a result, the thyristor THY1
~ Of THY3, only thyristor THY3 becomes conductive and only transistor Q4 is turned on (30c, 31).
c, 32b), each contact group of the third network relay 16 is closed (on), and the relay connector CN3
And the third LAN connector CN6 are connected.

On the other hand, the first and second control signals are maintained in the on state for about 10 seconds (21d, 22d) and then returned to the off state (21e, 22e), whereby the first and second interface circuits are reset. Since the output voltages of 4,5 return from the high voltage to the low voltage (23e, 24e), the output logic level of the NOR gate NOR4 is "0" (low voltage).
(25c, 26c, 27c), the output of the network switching gate circuit 6 becomes "000". This "0
The application of the gate voltage to the thyristor THY3 is stopped in response to the output of "00".
Indicates that the electrical contact SW of the reset relay 10 is open (OFF)
Until that time, the conductive state is maintained. Therefore, the ON state (30c, 31c, 32b) of the transistor Q4, that is, the closed state (ON state) of each contact group of the third network relay 16 is maintained until the next reset signal is generated, and the third LAN connector is held. CN6 and relay connector CN
The connection state with 3 is maintained.

In addition, when the relay computer 50 and all of the first to third LANs 101 to 103 are returned to the disconnected state, that is, the relay connector CN3 and the first to third LANs.
A case will be described where all of the LAN connectors CN4 to CN6 are connected to return to the disconnected state. In such a case, first, both the first and second control signals are turned from the off state to the on state, and the on state is held for less than the output holding time of the reset signal (for example, 3 seconds) (2
1f, 22f). As a result, both the output voltages of the first and second interface circuits 4 and 5 change from low voltage to high voltage (23f, 24f), and the high voltage state is held until the first and second control signals are turned off. As a result, only the output logic level of the NOR gate NOR4 is "1".
(High voltage) (25c, 26c, 27d), and the output of the network switching gate circuit 6 becomes "001".

In response to the output of "001", the output logic level of the reset gate circuit 6 is changed from "1" to "0", and the reset signal generating circuit 8 which receives the output turns on the reset signal. (28h). When the reset signal is turned on, the electrical contact SW of the reset relay 10 is turned from the on state to the off state via the reset relay drive circuit 9 (29h), the thyristor THY3 of the second network relay drive circuit 12 is turned off, and the transistor THY3 is turned off. Q4 is initialized (reset) to the off state (32
c). As a result, each contact group of the third network relay 16 is opened (OFF state), and the repeater connector CN3
Then, the third LAN connector CN6 is disconnected.

Thereafter, when the reset signal remains on (28h) and the first and second control signals are turned off (21
g, 22g), which causes the output voltage of the first and second interface circuits 4 and 5 to return from a high voltage to a low voltage (23g, 24g), so that the output logic level of the NOR gate NOR4 is "0" (low voltage). (25c,
26c, 27e), the output of the network switching gate circuit 6 becomes "000". Upon receiving the output of "000", the application of the gate voltage to the thyristor THY3 is stopped. About 5. after the reset signal is turned on (28h).
After 5 seconds, the reset signal is turned off (28
i), whereby the electrical contact SW is turned on from the off state via the reset relay drive circuit 9 (29i).
As a result, all the network relay drive circuits 11 to 11
The + 12V output of the DC power supply circuit 2 is applied to the anodes of thirteen thyristors THY1 to THY3.

Since the output logic level of the NOR gate NOR4 is "0" at this point, the gate voltage to the gate of the thyristor THY3 of the third network relay drive circuit 13 is turned off. As a result, the thyristors THY1 to THY
3 becomes non-conductive and transistors Q2 to Q4
Is held in the off state (30c, 31c, 32c), each contact group of all the network relays 14 to 16 is opened (off state), and the repeater connector CN3 and all the LAN connectors CN4 to CN6 are not connected. Will be initialized.

As described above, according to the network switcher 1, the relay connector CN3 is connected to three LAs according to the combination of the two first and second control signals.
It is possible to switch to any one of the N connectors CN4 to CN6, and it is also possible to put all of the connectors CN3 to CN6 into a non-connected state in which they are not connected to any other. Therefore, the relay computer 50 operates as the servers 70, 8
When neither of the transfer files 0 and 90 is transmitted or received, the LANs 101 to 103 can be maintained in a non-connected state, and the security of each LAN 101 to 103 can be ensured.

Next, the network switch 40 in which the above-mentioned network switch 1 is used will be described with reference to FIGS. 3 to 12. The network switch 40 of the present embodiment includes the network switch 1 described above and the relay computer 5 connected to the network switch 1.
It is composed of 0 and 0. The relay computer 50 is a computer used for controlling the network switch 1 and relaying file data transferred between different networks.

FIG. 3 is a block diagram of the network switch 40. As shown in FIG. 3, the communication cable 6 is connected to the communication connectors CN1 and CN2 of the network switch 1.
LAN cables 63 are connected to the relay connector CN3, respectively, and the network switch 1 is connected to the relay computer 50 via these cables 61 to 63. The LAN cable 63 is a transmission medium of a wired communication system for LAN,
A twisted pair cable (twisted pair cable), a coaxial cable, an optical fiber cable, or the like is used.

On the other hand, the first LAN 10 is connected to the first to third LAN connectors CN4 to CN6 of the network switch 1.
1 to 103 are respectively connected, and the network switch 1
Are connected to server computers (hereinafter referred to as "servers") 70, 80, 90 via the respective LANs 101 to 103. Here, each contact group in each of the network relays 14 to 16 of the network switch 1 is initially (normal).
It is opened and electrically disconnected. Therefore, in the normal state, each of the LANs 101 to 103 constitutes an independent network system in which all of them are not connected to each other, and the relay computer 50 is also connected to the LAN1.
All of 01 to 103 are not connected. As a result, the security of each LAN 101 to 103 in the normal state can be ensured.

The server 70 is the above-mentioned first LAN.
Two client computers 11 via 101
1, 112, and the server 80 is the second L described above.
Two clients 121, 122 via the AN 102
The server 90 is connected to the two clients 131 and 132 via the LAN 103 described above. It should be noted that each server does not necessarily need to be connected to two clients, and may be connected to one or more clients.

FIG. 4 shows a block diagram of the server 70 (80, 90). In addition, as shown in FIG.
Since both 80 and 90 have the same configuration, only each configuration of the server 70 will be described below. However,
Then, after the reference numerals of the respective components of the server 70, the reference numerals of the respective components of the servers 80 and 90 corresponding thereto are shown in parentheses.

As shown in FIG. 4, the server 70 has an MP
A U71, a ROM 72, a RAM 73, and a LAN interface 74 are provided, and these are connected to each other via a bus line composed of an address bus, a data bus and a control signal line. This bus line is an input / output port 75
The input / output port 75 is also connected to a hard disk device (HD) 76. The LAN 101 is connected to the LAN interface 74. In addition, MPU, ROM, RAM, LAN
For the interfail, refer to the description of each component of the relay computer.

The HD 76 is a rewritable large-capacity storage medium that stores an operating system (OS), various application programs, and the like.
The daemon 76a and the transfer file memory 76b are provided.

The FTP daemon 76a uses the FTP (File T
It is a program for controlling the FTP server (server 70) according to a protocol called ransfer protocol. More specifically, the FTP daemon 76a decodes the command transmitted from the relay computer 50,
If the command is a command for requesting the transfer of the file stored in the transfer file memory 76b described later (hereinafter referred to as “GET command”), the file stored in the transfer file memory 76b is transferred to the relay computer 50. Send to.

On the other hand, the command transmitted from the relay computer 50 requests the writing of the file to the transfer file memory 76b (hereinafter referred to as "PUT command").
In this case, the file stored in the transfer relay memory 60c of the relay computer 50 is written in the transfer file memory 76b.

The transfer file memory 76b is a memory for storing a file transmitted to the relay computer 50 or a file received from the relay computer 50 via the network switch 1. The transfer file memory 76b roughly stores two types of files: a transfer file and a lock file. Here, the transfer file refers to the first to third LANs 101 to 1
The data that is to be transferred mutually between the 03 is a file in which the data is actually recorded. On the other hand, the lock file is a file that functions as a flag for permitting or prohibiting the transmission / reception of the transfer file associated with the lock file. is there.

The transfer file is a file in which text data composed of ASCII character code is actually recorded, and the lock file has the same file name as that of the transfer file and is substantially It is a file in which various data is not recorded. For example,
The file name and extension of the transfer file is “tenso.
In the case of “txt”, the file name and extension of the lock file corresponding to the transfer file are “tenso.loc”.
k ”. In this specification, the file name means a part excluding the extension. Further, the extension of the transfer file is ".txt" indicating that it is file data in the text format, and the extension of the lock file is ".lock" indicating that it is a lock file.
Are used respectively.

When the server 70 functions as the transfer source server, the transfer file stored in the transfer file memory 76b is stored only when the corresponding lock file is stored in the transfer file memory 76b.
Transmission to the relay computer 50 is permitted. On the other hand, when the server 70 functions as the transfer destination server, when the transfer file stored in the transfer relay memory 60c of the relay computer 50 described later does not have the corresponding lock file stored in the transfer file memory 76b. As long as the transfer to the server 70 is permitted.

Returning to FIG. 3, the relay computer will be described. The relay computer 50 controls the network switcher 1 and connects itself to any one of the first to third LANs 101 to 103 by the network switcher 1 to communicate with any of the servers 70, 80, 90. A computer for sending and receiving (transferring) files. Since each of the LANs 101 to 103 constitutes an independent network in a normal state, a file transfer process can be realized by transmitting and receiving files to and from the relay computer 50 and relaying the relay computer 50. Of.

The relay computer 50 includes an MPU 51,
ROM 52, EEPROM 53, RAM 54, clock circuit 55, communication serial interfaces 56, 57, L
AN interface 58, input / output port 59, HD6
0 is provided. Of these, MPU51 and ROM5
2. The EEPROM 53, the RAM 54, the clock circuit 55, the communication serial interfaces 56 and 57, the LAN interface 58, and the input / output port 59 are mutually connected by a bus line composed of an address bus, a data bus, and a control signal line. There is. I / O port 59
Is also connected to HD60, and MPU51 and H
It functions as an interface with the D60.

The MPU 51 is an arithmetic unit that operates based on the programs stored in the ROM 52, the operating system and various application programs stored in the HD 60, and performs various types of information processing. The clock circuit 55 is for measuring the time, and the time measured by the clock circuit 55 is the MPU.
It is read by 51 and used for each process. ROM
52 is a basic program for operating the CPU 51,
It is a non-rewritable memory that stores various data.

The EEPROM 53 is a rewritable non-volatile memory, and the data stored in the EEPROM 53 is retained even after the relay computer 50 is powered off. This EEPROM 53 is a timer counter 5 for storing the execution interval of the schedule check process of FIG.
3a. The relay computer 50 executes the schedule check process of FIG. 7 at every time interval of the value stored in the timer counter 53a, for example, every one minute in this embodiment.

The RAM 54 is a rewritable memory for storing various data and has an end flag 54a and a lock file designation flag 54b. The end flag 54a is a flag indicating whether or not the file transfer program 60i described later has ended. When the end flag 54a is turned on, the relay computer 50 outputs the first and second control signals 21f and 22f (see FIG. 2) to the network switch 1 so that the reset signal 28h in the on state (see FIG. 2)) to initialize the connection state of the network switching device 1 and the relay computer 50 and the first to third LANs 101 to 103.
And are disconnected.

The lock file designation flag 54b is
12 is a flag showing whether or not lock file names 607g and 607i are specified in the schedule file 600 described later, and the transfer file receiving process of FIG.
It is used in the transfer file transmission process. The relay computer 50 executes processing for transmitting or receiving a lock file with the FTP server when the lock file designation flag 54b is turned on, and when the flag 54b is turned off, the FTP server Does not send or receive lock files to and from. The lock file designation flag 54b is set to off in the initial state.

The communication serial interface 56 is
It is a communication channel that employs a serial transmission method that continuously transmits digital data bit by bit using a single signal line, and is a communication port called a COM1 port. Via the communication cable 61 connected to the communication serial interface 56, the relay computer 50 uses the communication connector CN1 of the network switcher 1.
And outputs a first control signal to the first interface circuit 4 of the network switch 1.

The communication serial interface 57 is
Similar to the communication serial interface 56, it is a communication channel using a serial transmission system, and is a so-called CO
It is a communication port called M2 port. A communication cable 62 is connected to the communication serial interface 57, and the relay computer 50 is connected to the communication connector CN2 of the network switch 1 via the cable 62, and the second computer of the network switch 1 is connected. The second control signal is output to the interface circuit 5.

A LAN cable 63 is connected to the LAN interface 58, and the relay computer 50
Is connected to the repeater connector CN3 of the network switch 1 via the LAN cable 63, and as a result, the first
It is possible to connect to or disconnect from the third LANs 101 to 103.

The HD 60 is mainly composed of a user program memory 60a, an FTP client program 60b, a transfer relay memory 60c and a schedule file memory 60.
d, a transaction memory 60e, a network switching daemon 60f, a transaction processing program 60g, a switching control program 60h, a file transfer program 60i, and an error message program 60j.

The user program memory 60a is a memory for storing various user programs. The user program stored in the user program memory 60a is stored in advance in the user program memory 60a by a person who uses the network switch 40, for example, the administrator of the first to third LANs 101 to 103, and is relayed, for example. 1 F by computer 50
Transfer files received from the TP server to other FTP
This is a program for processing the data in the transfer file before sending it to the server.

The FTP client program 60b is
The FTP server (server 70,
80, 90) for operating the commands such as the GET command and the PUT command described above to the servers 70, 80, 90.

The transfer relay memory 60c is composed of the servers 70, 8
This is a memory for temporarily storing a transfer file transmitted from 0, 90 and a lock file corresponding thereto. For example, when the servers 70, 80, 90 are transfer source servers, their transfer file memories 76b, 86b,
The transfer file stored in 96b and the lock file corresponding thereto are temporarily written and stored in the transfer relay memory 60c. On the other hand, the servers 70, 80, 9
When 0 is the transfer destination server, the transfer file stored in the transfer relay memory 60c and the lock file corresponding thereto are written in any of the transfer file memories 76b, 86b, 96b in the transfer destination server.

The schedule file memory 60d is a memory for storing the schedule file 600 in which the execution schedule of the file transfer transaction processing (see FIG. 8) by the relay computer 50 is recorded. The schedule file 600 is, for example, a text format file, and its data part is a variable length record. In FIG. 5, the schedule file 60d
The conceptual diagram of the data part of is shown.

As shown in FIG. 5, the schedule file 600 is provided with a plurality of data lines as the data part in order from the first line to the bottom, and each data line has a start time 601 and an end time. 602 and execution interval 603
Execution day code 604, connection destination code 605,
The processing code 606 and the designated parameter 607 are recorded.

The start time 601 specifies the time at which the file transfer transaction process (see FIG. 8; the same applies hereinafter) is first executed for the data row to which the start time 601 belongs. The end time 602 specifies the time at which the file transfer transaction process is finally executed for the data row to which the end time 602 belongs. Here, the end time 602 is treated as valid data only when the execution interval 603 is specified, and is ignored when the execution interval 603 is not specified. The execution interval 603 designates a time interval, in minutes, at which the file transfer transaction process relating to the data row to which the execution interval 603 belongs is executed. Then, the file transfer transaction process is executed.

The execution day code 604 specifies the day of the week on which the file transfer transaction process for the data row to which it belongs is executed, and specifies Sunday to Saturday by the numerical value "0" to "6". . This execution day code 604 can add "0" to "6" when designating a plurality of days. For example, when executing the file transfer transaction processing every day from Monday to Friday, "12345" is set. Is specified. When executing the file transfer transaction processing every day regardless of the day of the week, "0" to "6" are changed to "01".
However, in such a case, a specific code (for example, “*”) may be designated as the execution day code 604.

The connection destination code 605 is a file transfer transaction process relating to the data row to which the connection destination code 605 belongs.
It is for designating which one of 3 is connected.
Specifically, when the connection destination code 605 is “NET1”, the relay computer 50 is transferred to the first LAN 101 and “NE” is set.
In the case of "T2", the relay computer 50 is set to the second LAN 10
2, the control signal is output from the relay computer 50 to the network switch 1 so as to connect the relay computer 50 to the third LAN 103 in the case of "NET3".

The processing code 606 is a file transfer transaction processing relating to the data row to which it belongs, and the relay computer 50 makes the relay computer 50 (ie, the server 70,
80, 90), or data for designating whether to send or receive a transfer file. Specifically, the FTP client program 60b sends either a GET command or a PUT command. Is specified. That is, when the processing code 606 specifies “get”, the relay computer 50 GETs.
While the command is transmitted to the FTP server, the PUT command is transmitted to the FTP server when "put" is specified.

When a user program name is designated in the processing code 606, the user program corresponding to the user program name is set to the relay computer 50.
Can be read from the user program memory 60a and executed. In such a case, a parameter required for executing the user program can be designated in the designated parameter 607 described below.

The designated parameter 607 designates various parameters necessary for executing the file transfer transaction process for the data row to which it belongs, and includes the host name 607a, user ID 607b, and
Password 607c, remote directory name 607
d, local side directory name 607e, first transfer file name 607f, first lock file name 607g, second
Transfer file name 607h, second lock file name 607
i.

Note that, in one data line of the schedule file 600, the set of the transfer file name and the lock file name recorded in the designated parameter 607 is not necessarily the first transfer file name 607f and the lock file name as shown in FIG. It is not limited to two sets of 607g, the second transfer file name 607h, and the lock file name 607i. That is, since the schedule file 600 is a variable-length record, one set or three or more sets of transfer file names and lock file names may be recorded.

The host name 607a is the relay computer 5
F that performs file transfer transaction processing with 0
This data is used to specify the server name or IP address of the TP server (any of the servers 70, 80, 90), and this host name 607a specifies the FTP server to which the relay computer 50 should log in. The user ID 607b is an ID code for logging in to the FTP server specified by the host name 607a, and the password 607c is a password for logging in to the FTP server specified by the host name 607a. This user name 607b and password 607c are
The FTP client program 60b sends it to the FTP server specified by the host name 607a, and
The server determines whether to authenticate the login of the relay computer 50 based on the user name 607b and the password 607c.

The remote-side directory name 607d is the FTP server (servers 70, 8) that is the storage destination or storage source of the transfer file and the lock file in the file transfer transaction processing by the relay computer 50.
0 or 90) directory name. The local-side directory 607e represents the directory name of the relay computer 50 that is the storage source or storage destination of the transfer file and the lock file in the file transfer transaction processing by the relay computer 50.

These directory names 607d and 607
e is combined with the following file names 607f to 607i so that transfer files and lock files can be stored in the memories 60e and 76 in the HDs 60, 76, 86, and 96.
Addresses stored in b, 86b and 96b are shown. The address here is HD6.
It does not indicate a specific sector and track number on 0, 76, 86, 96. H by a well-known basic OS
Which files are stored in the respective storage units on the D60, 76, 86, 96 are all managed. Therefore, if at least the directory name and the file name are referred to from each program, the data corresponding to the directory name and the file name will be HD60, 76, 8
It is possible to confirm in which storage unit on 6, 96 the data is stored. That is, in that sense, the directory name and the file name indicate the addresses on the HD 60, 76, 86, 96.

The relay computer 50 uses the processing code 60.
When "get" is specified in 6, the transfer file or lock file stored in the directory specified by the remote directory name 607d is received from the FTP server, and the local file name 607e is received.
Write to the own directory specified in. On the other hand, when “put” is specified in the processing code 606,
The transfer file or the lock file stored in the own directory designated by the local directory name 607e is transmitted to the FTP server and written in the directory of the FTP server designated by the remote directory name 607d.

The first transfer file name 607f (or the second transfer file name 607h) represents the file name of the transfer file transmitted / received between the relay computer 50 and the FTP server by the file transfer transaction processing by the relay computer 50. The first lock file name 607g (or the second lock file name 607)
i) represents the file name of the lock file corresponding to the transfer file specified by the first transfer file name 607f (or the second transfer file name 607h).

Returning to FIG. 3, description will be made. The transaction memory 60d stores the transaction processed by the file transfer transaction processing as a file,
It is a memory that functions as a buffer for storing the file. The transaction is generated by the schedule check process of FIG. 7 based on the designated parameter 607 from the connection destination code 605 of the schedule file 600 when the execution time of the file transfer transaction process of FIG. 8 arrives. The file transfer transaction processing of FIG. 8 is controlled based on the transaction.

In this embodiment, the connection destination code 605, the processing code 606 and the designated parameter 607 (host name 607) recorded in the schedule file 600 are recorded.
a, user ID 607b, password 607c, remote side directory name 607d, local side directory name 607e, first transfer file name 607f, first lock file name 607g, second transfer file name 607h and second lock file name 607i), It shall be reflected as is in the transaction.

Network switching daemon 60f
Checks the contents of the schedule file 600,
It is a program for creating a transaction corresponding to the content and writing it in the transaction memory 60d, and for activating the transaction processing program 60g. Also, the transaction processing program 6
0g is a program for connecting the relay computer 50 to any one of the first to third LANs 101 to 103 according to the content of the transaction stored in the transaction memory 60d, and executing the transmission / reception processing of the transfer file. Is.

By executing the transaction processing program 60g, the switching control program 60h
It is a subroutine program called during the processing of the program 60g, and is used to output the first and second control signals according to the contents of the transaction to the network switch 1. The file transfer program 60i is a subroutine program that is called during the processing of the transaction processing program 60g by the execution of the transaction processing program 60g. Used to

The programs for the main process of FIG. 6 and the schedule check process of FIG. 7 are stored in the network switching daemon 60f, and the program of the file transfer transaction process of FIG. 8 is stored in the transaction processing program 60g. The switching control processing program of FIG.
The programs for the transfer file receiving process in FIG. 11 and the transfer file transmitting process in FIG. 12 are included in the file transfer program 60i.

The error message program 60j sends various messages to the SMTP server (not shown) connected to the first to third LANs, and sends the various messages to the FTP server by e-mail by the SMTP server. , A program for contacting the user of the FTP server. Here, the message transmitted to the SMTP server by the error message program 60j is an error message indicating that transmission / reception of a transfer file is prohibited in the FTP server, and the user ID 607b specified in the schedule file 600.
Error message indicating that the FTP server cannot be logged in due to an error in the password or password 607c, or a normal message when the error indicated by the above error message has not occurred within a certain time (for example, 1 hour),
and so on.

When the error message program 60j is executed by the relay computer 50 and the SMTP server receives the message resulting from the execution, the SMTP server sends the content of the error message received from the relay computer 50 to the FTP server by electronic mail. To do. On the other hand, when a normal message is received from the relay computer 50, the e-mail is sent from the SMTP server to the FT.
Not sent to the P server. In addition, within a certain period, SMTP
If the server does not receive the message from the relay computer 50, the SMTP server
It is determined that an abnormality has occurred in the above, and a message indicating that is transmitted to the FTP server to notify the LAN administrator. The SMTP server includes a relay computer 5
The FTP is associated with the host name or IP address of the FTP server that transmits / receives the transfer file to / from the FTP.
The mail address of the server is stored, and an electronic mail is transmitted to a predetermined FTP server based on this mail address.

By the way, the relay computer 50 uses the FT
When transmitting / receiving a transfer file to / from the P server (any of the servers 70, 80, 90), the schedule file 600 is stored in the transfer file memory of the FTP server according to whether the lock file is stored. There is a case where the file transfer transaction processing based on it cannot be performed with the FTP server. In such a case, the relay computer 50 uses the F as the transfer source or transfer destination of the transfer file.
An error message is sent by e-mail to the TP server via the SMTP server to warn the user of the FTP server. Note that the error message in such a case indicates, for example, the file name of the lock file corresponding to the transfer file whose transmission and reception are prohibited by the FTP server, and the transmission and reception of the corresponding transfer file by the lock file. Etc. are included.

Next, the operation of the network switch 40 will be described with reference to FIGS. 6 to 12. Figure 6
6 is a flowchart showing a main process performed by the relay computer 50. This process is performed by executing the network switching daemon 60f. First, the schedule file 600 stored in the schedule file memory 60c is read out to the RAM 54 (S
1) After that, time counting for the value stored in the timer counter 53a is started (S2). After starting this timing, MP
U51 monitors the clock circuit 55 and executes schedule check processing (S3).

After execution of the schedule check process which is the process of S3, it is judged whether or not the time count for the value stored in the timer counter 53a has ended (S4), and if the time count has ended (S4). : Yes), the process proceeds to S2, and time counting for the value stored in the timer counter 53a is started again (S2). As a result, the execution of the schedule check process (S3) is instructed for each value minutes stored in the timer counter 53a (that is, every minute). On the other hand, if the time counting started in the process of S2 is not finished by the determination of S4 (S4: No), another process is executed (S5), and the process waits until the time is finished.

FIG. 7 is a flowchart showing the schedule check process. This schedule check process is executed in the process of S3 of FIG. 6 described above, and is a process for checking every schedule recorded in the schedule file 600 every minute.
In the schedule check process, first, the MPU 51 performs R
Schedule file 6 read on AM54
The first data row of 00 is read (S11), and the execution time (execution time of the file transfer transaction process) is calculated from the start time 601, end time 602, and execution interval 603 of the read data row (S12). After the execution time is calculated, the current time is read from the clock circuit 55 in minutes (S13), and the read current time is compared with the execution time calculated in S12.

As a result of the comparison, if there is an execution time that matches the current time (S14: Yes), the execution day code 604 is read from the data line to which the start time 601 used in S12 belongs (S15). , Clock circuit 5
The current day of the week (data) is extracted from 5 (S16). If there is an execution day code 604 that matches the current day of the clock circuit 55 (S17: Yes), the execution day code 604.
From the data line of the schedule file 600 to which is belongs, based on the connection destination code 605, the processing code 605 and the designated parameter 607,
It is written in the transaction memory 60d of the HD 60 (S18).

After writing the transaction, MPU5
1 determines whether or not the transaction processing program 60g is being activated (S19), and if it is not being activated (S19).
19: No), transaction processing program 60g
Is activated (S20), and the file transfer transaction process of FIG. 8 is executed. On the other hand, if the transaction processing program 60g is currently being activated (S19: Y
es), to check the next data line in the schedule file 600, S20 is skipped and the process proceeds to S21.

If there is no execution time that matches the current time of the clock circuit 55 in the above-described processing of S14 (S
14: No), since the execution time of the file transfer transaction processing has not arrived for the data row used in the calculation in S12, the processing is performed to check the next data row recorded in the schedule file 600. The process proceeds to S21. Further, when there is no execution day code 604 that matches the current day of the clock circuit 55 in the above-described processing of S17 (S17: No), regarding the data row from which the execution day code 604 is extracted in the processing of S15,
Since the execution day of the file transfer transaction process has not arrived, the process is performed in S2 in order to check the next data line recorded in the schedule file 600.
Move to 1.

In the case of the No branch of S14, the No branch of S17, and the Yes branch of S19, it is judged whether or not all the data lines recorded in the schedule file 600 have been checked (S21), and all the data lines are checked. If the check has not been completed (S21: No), the next data line is read from the schedule file 600 (S21).
22), and the processing from S12 onward is repeated. By repeating this, the transactions which have reached the execution time of the file transfer transaction processing are accumulated in the transaction memory 60d one after another. On the other hand, if the check is completed for all the data rows of the schedule file 600 (S21: Yes), this schedule check process is ended.

FIG. 8 is a flow chart showing the file transfer transaction processing. This file transfer transaction process is performed by the transaction memory 60d.
The switching control process of FIG. 9 and the file transfer process of FIG. 10 are controlled for each transaction stored in the. In this file transfer transaction processing, first, one transaction stored in the transaction memory 60d is read onto the RAM 54 (S31), and the switching control processing of FIG. 9 is executed (S32). By this execution, the network switch 1
The relay computer 50 is connected to any one of the first LAN 101, the second LAN 102, and the third LAN 103 via the.

After the switching control processing is executed, the processing code is checked (S33), and the processing code is "ge".
If it is “t” or “put” (S33: Yes), FIG.
A file transfer process of 0 is executed (S34). By this execution, the relay computer 50 transmits / receives the transfer file and the lock file to / from any one of the first to third LANs 101 to 103 via the network switch 1. On the other hand, the processing code is "ge
If it is not "t" or "put" (S33: No), the user program process is executed (S35). In the process of S35, the user program is read from the user program memory 60a based on the transaction,
Execute the user program.

After the processing of S34 and S35, the end flag 53a is turned on (S36), the switching control processing of FIG. 9 is executed (S37), and by this execution, the relay computer 50 via the network switch 1. Is the first
Through, the connection state with any one of the third LANs 101 to 103 is disconnected. As a result, the first to third LANs 10
The security of the LANs 101 to 103 is ensured because each of the LANs 1 to 103 returns to an independent network system. After disconnecting the connection state, the end flag 53a is turned off again (S38), and it is determined whether or not there is the next transaction in the transaction memory 60d (S39). If the next transaction is stored in the transaction memory 60d (S39: Y
es), the process proceeds to S31, and the processes from S31 to S38 are repeated until the processing of all the transactions stored in the transaction memory 60d is completed, and when the processes of all the transactions are completed (S).
39: No), the file transfer transaction processing ends.

FIG. 9 shows a flow chart of the switching control process. This switching control process is a process for changing the first and second control signals output to the network switch 1 based on the connection destination code and the end flag 54a. In this switching control process,
First, it is determined whether the end flag 54a is on (S4
1) If the end flag 54a is off (S41: N)
o), the relay computer 50 is connected to the first to third LANs 10.
In order to connect to any one of 1 to 103, the connection destination code in the transaction read onto the RAM 54 in S31 of the file transfer transaction process of FIG. 8 is checked (S42).

If the result of checking the connection destination code is "NET1" (S43: Yes), only the first control signal is turned on (S49) and the on state is held for about 10 seconds (S50: No), after about 10 seconds have passed (S
50: Yes), the first control signal is turned off (S51).
As a result, the relay connector CN3 and the first LAN connector CN4 of the network switch 1 are connected, and the relay computer 50 and the first LAN 101 are connected.
If the connection code is "NET2" (S43: N
o, S44: Yes), only the second control signal is turned on (S52), and the on state is maintained for about 10 seconds (S5).
3: No), after about 10 seconds have passed (S53: Ye
s), the second control signal is turned off (S54). As a result, the relay connector CN3 of the network switch 1 and the second LAN connector CN5 are connected, and the relay computer 50 and the second LAN 102 are connected. Furthermore, if the connection code is "NET3" (S43: No, S4
4: No, S45: Yes), both the first and second control signals are turned on (S55), the on state is held for about 10 seconds (S56: No), and after about 10 seconds have passed (S5).
6: Yes), both the first and second control signals are turned off (S57). As a result, the relay connector CN3 and the third LAN connector CN6 of the network switch 1 are connected, and the relay computer 50 and the third LAN 103 are connected.

If the connection destination code is none of the above (S43: No, S44: No, S45: N
o) Since the connection destination code is invalid, this switching control process is forcibly terminated.

On the other hand, in the judgment of S41, the end flag 54a
Is on (S41: Yes), the connection state between the relay computer 50 and any one of the first to third LANs 101 to 103 is cut off, so that both the first and second control signals are turned on. (S46), the ON state is about 3
Hold for 2 seconds (S47: No), and after about 3 seconds (S
47: Yes), both the first and second control signals are turned off (S48). As a result, the repeater connector CN3 and the first to third LAN connectors C of the network switch 1 are connected.
The connection state between N4 to CN6 is cut off, and the connection state between the relay computer 50 and the first to third LANs 101 to 103 is cut off.

FIG. 10 is a flowchart of the file transfer process. This file transfer process is a process executed in S34 of the file transfer transaction process of FIG.
This is a process for realizing file transmission / reception between 0, 80, and 90. In the file transfer process, first, the FTP client program 60d is activated (S61), and the server 70, based on the host name in the transaction,
Connection is made to any one of the 80 and 90 FTP servers (S62). Upon receiving this connection, the FTP server transmits a command requesting transmission of the user ID and password to the relay computer 50.

Of course, the relay computer 50 executes the switching control process of FIG. 9 prior to the execution of the file transfer process, and the FTP server designated by the host name in the transaction is connected. In addition, it is connected to any one of the first to third LANs 101 to 103.

On the other hand, the relay computer 50 waits until it receives the user ID and password transmission request command transmitted from the FTP server (S63: N).
o), when the command is received (S63: Yes),
The user ID and password specified in the transaction are sent to the currently connected FTP server (S6).
4). When the FTP server receives this user ID and password, the FTP server receives them as its own FTP.
Decryption is performed by the daemons 76a, 86a and 96a. As a result of the decryption, if the user ID and password received from the relay computer 50 are valid, the FTP server
A command for authenticating the login is transmitted to the relay computer 50.

The relay computer 50 waits until it receives a command to authenticate the login from the FTP server (S65: No), and when it receives the command (S6).
5: Yes), the type of the processing code designated in the transaction is determined (S66). The processing code is "g
If "et" (S66: Yes), the transfer file receiving process of FIG. 11 is executed (S67), and the process code is "pu".
If “t” (S66: No), the transfer file transmission process of FIG. 12 is executed, and the file transfer process ends.

FIG. 11 is a flowchart of the transfer file receiving process. This transfer file receiving process is performed by FTP.
Any one of the servers 70, 80, 90 to be the server
Is a process of receiving the transfer file from the transfer relay memory 60e and storing the received transfer file in the transfer relay memory 60e. Relay computer 5 via network switch 1
Since the transfer file receiving process of FIG. 11 can be executed for all the servers 70, 80, 90 connected to 0, only the case where the server 70 functions as the FTP server will be described below, and the other servers 80 , 90 will be omitted.

As shown in FIG. 11, first, in S31 of FIG.
In step S7, the first transfer file name specified in the transaction read is checked (S7
1) Furthermore, it is confirmed whether the lock file name corresponding to the transfer file name is designated in the transaction (S72). If the lock file name corresponding to the transfer file name is specified in the transaction (S7
2: Yes), the lock file designation flag 54b is turned on (S73), and the transfer file memory 7 in the server 70 is based on the lock file name and the remote directory name designated in the transaction.
The address of 6b is checked (S74).

If the lock file name corresponding to the transfer file name is not specified in the transaction in the process of S72 (S72: No), the server 70 is in an environment in which a lock file cannot be created, or Checking the lock file stored in the transfer file memory 76b of the server 70, judging that the 70 side wants to periodically send the transfer file at regular intervals regardless of the presence or absence of the lock file. If not, the process proceeds to S76.

If there is a lock file corresponding to the address checked in S74 (S75: Yes), the relay computer 50 determines that the transfer of the transfer file corresponding to the lock file is permitted by the server 70, First, based on the transfer file name used in the confirmation in S72 and the address indicated by the remote directory name specified in the transaction, a command requesting transmission of the transfer file stored in the transfer file memory 76b of the server 70 is issued. , To the server 70 (S76). This transfer file transmission request command is
It is received by the server 70 and decrypted by the FTP daemon 76a of the server 70. As a result of decryption, the server 70
Reads the transfer file, which has been requested to be transmitted from the relay computer 50, from the transfer file memory 76b and transmits it to the relay computer 50.

On the other hand, the relay computer 50 waits until the reception of the transfer file transmitted from the server 70 is completed (S77: No), and when the reception of the transfer file is completed (S77: Yes), the transfer file is transferred. Is written in the transfer relay memory 60e (S78). At this time, the transfer relay memory 60e in which the transfer file is written
The address inside is the address indicated by the file name of the transfer file received in S77 and the local directory name specified in the transaction. After writing the transfer file in the transfer relay memory 60e in S78, the relay computer 50 sends to the server 70 a command to delete the original data of the transfer file received in S77 from the transfer file memory 76b (S79). This delete command is received by the server 70 and decrypted by the FTP daemon 76a of the server 70. As a result of decryption,
The server 70 deletes the transfer file, which has received the deletion request from the relay computer 50, from the transfer file memory 76b.

After the processing of S79, it is determined whether or not the lock file designation flag 54b is on (S8).
0). If the lock file designation flag 54b is on (S80: Yes), a command requesting transmission of the lock file stored in the address checked in S74 is transmitted to the server 70 (S81). The lock file transmission request command is received by the server 70 and decrypted by the FTP daemon 76a of the server 70. As a result of the decryption, the server 70 reads the lock file, which has been requested to be transmitted from the relay computer 50, from the transfer file memory 76b, and then the relay computer 50
Send to.

On the other hand, the relay computer 50 waits until the reception of the lock file transmitted from the server 70 is completed (S82: No), and when the reception of the lock file is completed (S82: Yes), the lock file is received. Is written in the transfer relay memory 60e (S83). At this time, the address in the transfer relay memory 60e where the lock file is written becomes the address indicated by the file name of the lock file received in S82 and the local directory name specified in the transaction. S
After writing the lock file received from the server 70 in 82 to the transfer relay memory 60e, the relay computer 50
Transmits a command to delete the original data of the lock file received in S82 from the transfer file memory 76b to the server 70 (S84). The delete command is received by the server 70, and the FTP daemon 7 of the server 70 receives the delete command.
Decoded by 6a. As a result of the decoding, the server 70 deletes the lock file, which has received the deletion request from the relay computer 50, from the transfer file memory 76b.

As described above, by the processing of S76 to S79, one transfer file is transferred (transmitted) from the transfer file memory 76b of the server 70 to the relay computer 50 and written in the transfer relay memory 60e, and at the same time, the server 70 is deleted from the transfer file memory 76b. Further, by the processing of S81 to S84, the lock file corresponding to the transfer file is transferred (transmitted) from the transfer file memory 76b of the server 70 to the relay computer 50 and written in the transfer relay memory 60e, and at the same time, transferred by the server 70. It is deleted from the file memory 76b. In this way, by deleting the lock file corresponding to one transfer file from the transfer file memory 76b of the server 70, the server 70
It can be determined that the relay computer 50 has completed the reception of the transfer file.

By the processing up to S84, a set of transfer file and lock file is transferred (received) from the server 70.
After that, the lock file designation flag 54b is turned off and initialized (S85). After the flag 54b is turned off (S85), or the lock file designation flag 5
If 4b is off (S80: No), it is determined whether or not all transfer file names specified in the transaction have been checked (S86), and if all transfer file names have not been checked. (S86: No),
The next transfer file name specified in the transaction is checked (S87), the process proceeds to S72, and S
The processing after 72 is repeated. After that, if all transfer file names specified in the transaction have been checked (S86: Yes), this transfer file receiving process is ended.

On the other hand, if there is no lock file corresponding to the address checked in the process of S75 (that is, the transfer of the lock file and the transfer file corresponding thereto is prohibited from the server 70) (S75: N
o), start the error message program 60j,
An error message indicating that the transfer of the transfer file is prohibited is sent to the SMTP server (not shown) connected to the first LAN 101, addressed to the server 70 (S8).
8). As a result, the user of the server 70 that is the transmission source of the transfer file can be prompted to create the lock file corresponding to the transfer file in the transfer file memory 76b. After the error message is transmitted by the process of S88, the process proceeds to S85 and S7 is performed.
The lock file designation flag 54b turned on in 3 is turned off and initialized.

FIG. 12 is a flowchart of the transfer file transmission process. This transfer file transmission process is performed by FTP.
Any one of the servers 70, 80, 90 to be the server
Is a process for transmitting and storing the transfer file to the destination. For all the servers 70, 80, 90 connected to the relay computer 50 via the network switcher 1, FIG.
Since the transfer file transmission process of 2 can be executed,
Only the case where the server 80 functions as the FTP server will be described, and the description of the other servers 70 and 90 will be omitted.

As shown in FIG. 12, first, in S31 of FIG.
Check the first transfer file name specified in the transaction read in the process (S9
1) Further, it is confirmed whether the lock file name corresponding to the transfer file name is designated in the transaction (S92). If the lock file name corresponding to the transfer file name is specified in the transaction (S9
2: Yes), the lock file designation flag 54b is turned on (S93), and the transfer file memory 8 in the server 80 is based on the lock file name and the remote side directory name designated in the transaction.
The address of 6b is checked (S94).

If the lock file name corresponding to the transfer file name is not specified in the transaction in the process of S92 (S92: No), the server 80 is in an environment in which a lock file cannot be created, or Checking the lock file stored in the transfer file memory 86b of the server 80, judging that the 80 side wants to receive the transfer file at regular intervals regardless of the presence or absence of the lock file. No, the process proceeds to S96.

If there is no lock file corresponding to the address checked in S94 (S95: No), the relay computer 50 determines that the transfer of the lock file and the corresponding transfer file is permitted by the server 80. First, based on the transfer file name used in the confirmation in S92 and the local directory name specified in the transaction, the transfer relay memory 60e.
Read the transfer file from
It transmits to the server 80 (S96). At this time, the relay computer 50 also requests the server 80 to write a command to write the transfer file transmitted by itself to the address in the transfer file memory 86b indicated by the remote directory name and the transfer file name specified in the transaction. Send at the same time.

The transfer file and the command thus transmitted from the relay computer 50 are received by the server 80, and the command is decrypted by the FTP daemon 86a of the server 80. As a result of the decryption, the server 80
The transfer file received from the relay computer 50 is written in the transfer file memory 86b designated by the command. On the other hand, the relay computer 50 waits until the transmission of the transfer file to the server 80 is completed (S97: N
o), when the transmission is completed (S97: Yes), S9
The original data of the transfer file that has been transmitted in step 7 is deleted from the transfer relay memory 60e (S98).

After the processing of S98, it is determined whether or not the lock file designation flag 54b is ON (S9).
9). If the lock file designation flag 54b is ON (S99: Yes), the transfer relay memory 60e is based on the lock file name confirmed in S94 and the local directory name specified in the transaction.
The lock file is read from and the lock file is transmitted to the server 80 (S100). At this time, the relay computer 50 also sends to the server 80 a command requesting to write the lock file transmitted by itself to the address in the transfer file memory 86b indicated by the remote side directory name and the lock file name specified in the transaction. Send at the same time.

The lock file and command transmitted from the relay computer 50 in this way are stored in the server 80.
The command is decoded by the FTP daemon 86a of the server 80. As a result of decryption, the server 80
Writes the lock file received from the relay computer 50 to the transfer file memory 86b designated by the command. On the other hand, in the relay computer 50, the server 8
Wait until the transmission of the lock file to 0 is completed (S
101: No), when the transmission is completed (S101: Y)
es), the original data of the lock file transmitted in S101 is deleted from the transfer relay memory 60e (S10).
2).

As described above, by the processing of S96 to S98, one transfer file is transferred from the transfer relay memory 60e of the relay computer 50 to the server 80 and written in the transfer file memory 86b, and at the same time, in the relay computer 50. It is deleted from the transfer relay memory 60e. Further, by the processing of S100 to S102, the lock file corresponding to the transfer file is transferred from the transfer relay memory 60e of the relay computer 50 to the server 80 and written in the transfer file memory 86b, and at the same time, the transfer relay memory of the relay computer 50. It is deleted from 60e. In this way, by writing the transfer file of 1 and the corresponding lock file to the transfer file memory 86b of the server 80, the server 80 can determine that the transfer file transmission by the relay computer 50 has been completed.

By the processing up to S102, a set of transfer file and lock file is transferred (transmitted) to the server 80.
After that, the lock file designation flag 54b is turned off and initialized (S103). After the flag 54b is turned off (S103), or when the lock file designation flag 54b is turned off (S99: No), it is determined whether or not all the transfer file names designated in the transaction have been checked. (S104), if all transfer file names have not been checked (S104:
No), the next transfer file name specified in the transaction is checked (S105), the process proceeds to S92, and the processes after S92 are repeated. After that, when the check of all transfer file names specified in the transaction is completed (S104: Yes), this transfer file transmission process is ended.

On the other hand, if there is a lock file corresponding to the address checked in the process of S94 (that is, the transfer of the lock file and the transfer file corresponding thereto is prohibited from the server 80) (S95: Y).
es), activates the error message program 60j, and sends an error message indicating that transfer of the transfer file is prohibited to the server 80 to an SMTP server (not shown) connected to the second LAN 102 (not shown). S106). This can prompt the user of the server 80, which is the destination of the transfer file, to delete the lock file corresponding to the transfer file from the transfer file memory 86b. Note that S106
After sending the error message by the process
In step S03, the lock file designation flag 54b turned on in step S93 is turned off and initialized.

In the present embodiment, the connection time is designated by the designating means according to the first aspect, the execution time calculated based on the start time 601, the end time 602 and the execution interval 603 of the schedule file 600 is Applicable As the connecting means according to claims 1 and 7, FIG.
S32 processing (specifically, S43 and S49 in FIG. 9)
To S51, S44 and S52 to S54, or S45 and S55 to S57). The process of S66 of FIG. 10 corresponds to the communication form determining unit according to claim 1, and the processes of S76 and S77 of FIG. 11 correspond to the receiving unit. Further, the disconnection recovery means according to claims 1 and 7 corresponds to the processing of S37 of FIG. 8 (specifically, the Yes branch of S41 of FIG. 9 and the processing of S46 to S48). The transmitting means according to claim 2 is S96 in FIG.
And the processing of S97. The process of S74 of FIG. 11 corresponds to the first detecting means of claims 3 and 4, and the branch of Yes of S75 and the processes of S76 and S77 correspond to the receiving means. The process of S94 of FIG. 12 corresponds to the second detection means of claims 5 and 6, and the Yes branch of S95 corresponds to the transmission means. Further, a transfer file corresponds to the communication data to be transferred in the present invention, and a lock file corresponds to the transmission permission data and the reception refusal data.

The present invention has been described above based on the embodiments, but the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. Is easily guessed.

For example, in the present embodiment, the original data of the transfer file is forcibly deleted from the transfer file memory of the FTP server in the processing of S79 and S84 of FIG. 11, but the transfer file receiving processing of FIG. Is not necessarily limited to this. For example, in the schedule file 600, transfer file deletion designation data indicating whether or not to delete the transfer file original data from the transfer file memory of the transfer source server, and whether or not to delete the lock file original data corresponding to the transfer file And a lock file deletion designation data indicating that. In such a case, a process of checking transfer file deletion designation data in a transaction created based on the schedule file is provided between the processes of S78 and S79 in FIG. 11, and as a result of the check, the transfer file deletion designation data is designated in the transaction. The processing of S79 may be executed only when the above has been done. Similarly, between the processes of S83 and S84 of FIG. 11, a process of checking the lock file deletion designation data of the transaction created based on the schedule file is provided, and as a result of the check, the lock file deletion designation data is designated for the transaction. The process of S84 may be executed only when data is designated. As a result, if the deletion designation data is not recorded in the schedule file of the relay computer 50 in advance, the transfer file and the lock file are transferred from the transfer file memory of the transfer source server to the relay computer 5.
It is possible to prohibit the deletion by 0.

[0158]

According to the network switch of the first or second aspect, the line for transmitting and receiving the communication data is connected only to any one of the two or more network systems by the connecting means. Further, the disconnection holding means holds the disconnection state of the line to the other network system. Therefore, since the line is not simultaneously connected to two or more network systems, the non-connection state between the network systems can always be maintained, and the security of each network system can be ensured. .

Moreover, even for the line connected to the network system for transferring the communication data, when the transmission / reception of the communication data is completed, the disconnection recovery means restores the disconnected state by the disconnection holding means. Since the lines to all network systems can be held in a disconnected state during non-transmission / reception of, there is an effect that the security can be further improved.

Further, the line connection to the network system is automatically performed when the connection time designated by the connection unit to the designation unit arrives, and the communication data is transmitted / received with this line connection as a trigger. Therefore, unlike the prior art, it is not necessary to manually exchange data between two or more networks that are not connected to each other via a recording medium such as a flexible disk, and the storage capacity of such recording medium is further increased. It is possible to share a large amount of data exceeding the above range between two or more networks that are not connected to each other.

According to the network switch of the third or fourth aspect, in addition to the effect of the network switch of the first aspect, the communication permission data is stored in the transfer source data storage means of the network system which is the communication source. The communication data corresponding to the communication permission data can be received by the receiving means only when the communication data is present. Therefore, for example, when a plurality of communication data are stored in the transfer source data storage means in the network system, only the communication data requested to be transferred is transmitted from the plurality of communication data via the transmission permission data. Therefore, there is an effect that the communication data can be surely specified and erroneous transfer of communication data can be prevented.

According to the network switch of the fifth or sixth aspect, in addition to the effect of the network switch of the second aspect, the reception refusal data is stored in the transfer destination data storage means of the network system as the communication destination. If so, the transmission means can prohibit the transmission of the communication data stored in the relay data storage means in association with the reception refusal data. Therefore, for example, when a plurality of communication data is stored in the relay data storage means,
Only the communication data that is required to be transferred to the network system from among the plurality of communication data can be reliably identified through the reception refusal data, and it is possible to prevent erroneous transfer of the communication data. .

According to the network switch of the seventh aspect, in addition to the effect of the network switch according to any of the first to sixth aspects, a relay storage device provided with relay data storage means and two or more network systems. Since two or more contact switches are provided between the relay storage device and the contact storage device, the relay storage device and the two or more network systems can be electrically and reliably separated by opening the two or more contact switches. Therefore, there is an effect that information leakage from each network system can be reliably prevented when communication data is not transmitted / received.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an electrical configuration of a network switch that constitutes a part of a network switch that is an embodiment of the present invention.

FIG. 2 is an operation explanatory diagram of a network switching device.

FIG. 3 is a block diagram of a network switch.

FIG. 4 is a block diagram of a server computer connected to a LAN.

FIG. 5 is a conceptual diagram of a data part of a schedule file.

FIG. 6 is a flowchart showing main processing executed by a relay computer.

FIG. 7 is a flowchart showing a schedule check process.

FIG. 8 is a flowchart showing a file transfer transaction process.

FIG. 9 is a flowchart of a switching control process.

FIG. 10 is a flowchart of a file transfer process.

FIG. 11 is a flowchart of a transfer file receiving process.

FIG. 12 is a flowchart of a transfer file transmission process.

[Explanation of symbols]

1 Network switching device (disconnection holding means) 14-16 Network relay (contact switch) 40 Network switch 60 Hard disk device (HD)
(Relay storage device) 60e Relay transfer memory (relay data storage means) 70, 80, 90 Server computer (part of two or more network systems) 76b, 86b, 96b Transfer file memory (transfer source data storage means, transfer destination data) Storage means 101-102 LAN (part of two or more network systems) 111,112 Client computer (part of two or more network systems) 121,122 Client computer (part of two or more network systems) 131,132 Client computer (part of two or more network systems) 600 Schedule file (designating means) 606 Processing code (designation of communication form) 605 Connection destination code (designation of any one of two or more network systems)

Claims (7)

[Claims] 1. A network switch for relaying communication data between two or more network systems which are not connected to each other, and disconnection holding means for holding a line to each of the two or more network systems in a disconnected state. Corresponding to the connection time, which is the time at which the line disconnected by the disconnection holding means is changed to the connection state, one of the two or more network systems and the reception or transmission of communication data When the designation means for designating any one of the communication modes and the connection time designated for the designation means arrive, the line is connected to the network system designated by the designation means in association with the connection time. The connection means and the communication mode specified by the specifying means are determined in association with the connection time of the connection means. And a receiving unit that receives communication data from the network system to which the line is connected by the connecting unit when the communication form determining unit determines that the communication form is reception. When reception of communication data is completed,
A network switch comprising: a disconnection recovery unit that recovers a line between the network system that is in the connection state by the connection unit to the disconnection state by the disconnection holding unit. 2. Relay data storage means capable of storing communication data received by the reception means, and communication data stored in the relay data storage means are stored in the designation means by the communication form determination means. If it is determined that the communication form being sent is transmission,
And a disconnection recovering means, when the transmission of the communication data by the transmitting means is completed, the disconnecting and returning means is set to the connected state by the connecting means. 2. The network switch according to claim 1, wherein the line to the existing network system is returned to the disconnection state by the disconnection holding means. 3. The network system to which a line is connected by the connecting means includes a transfer source data storage means capable of storing communication data in association with transmission permission data for permitting transmission of communication data. In this case, the transfer source data storage means is provided with a first detection means for detecting whether or not the transmission permission data is stored, and the reception means is provided when the transmission permission data is detected by the first detection means. 2. The network switch according to claim 1, wherein the communication data stored in the transfer source data storage means is received only in association with the transmission permission data. 4. The communication data is composed of a file that can be managed by a basic operation system of a computer, and the transmission permission data is stored in the transfer source data storage means in association with the transmission permission data. In the case of being composed of an empty data file having the same file name as the communication data file name, the first detecting means is based on the file name of the transmission permission data, and is based on the transfer source data storage means. From the communication data stored in the transfer source data storage unit, the reception unit having the same file name as the transmission permission data detected by the first detection unit. 4. The network switch according to claim 3, wherein the communication data with the file name of 5. The reception refusal data for refusing the reception of the communication data, associated with the communication data stored in the relay data storage means, by the network system to which the line is connected by the connecting means. When the transfer destination data storage means capable of storing is provided, the transfer destination data storage means includes second detection means for detecting whether or not the reception refusal data is stored, and the transmission means includes the second detection means. 3. The network switch according to claim 2, wherein, when the reception refusal data is detected by the detection unit, the transmission of the communication data stored in the relay data storage unit in association with the reception refusal data is prohibited. 6. When the reception refusal data is composed of an empty data file that can be managed by a basic operation system of a computer, the communication data stored in the relay data storage means is converted into the communication data. The file name of the reception refusal data is associated with the file name of the reception refusal data stored in the transfer destination data storage means, and the second detection means is a file name of the reception refusal data. Receiving refusal data is detected from the refusal data storage means based on the above, and the transmission means receives the reception data detected by the second detection means among the communication data stored in the relay data storage means. Characterized by prohibiting the transmission of communication data with the same file name as the file name of the rejection data The network switch according to claim 5, further comprising: 7. A relay storage device provided with the relay data storage means, wherein the disconnection holding means has one end thereof connected to the relay storage device and the other end thereof connected to the two or more network systems, respectively. And two or more contact switches, which hold all of the two or more contact switches in an open state, wherein the connecting means is one of the two or more contact switches. Only one of them is in a closed state, and the disconnection return means is closed by the connecting means.
7. The network switch according to claim 1, wherein one of the contact switches is returned from a closed state to an open state.