JPH0687575B2 - Network controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to, for example, information processing devices (hereinafter referred to as personal computers) such as personal computers and between information processing devices and domestic subscriber telephone lines or domestic and international telecommunication lines ( The present invention relates to a network control device capable of selectively connecting a plurality of communication lines such as a telex line).

[Prior Art] In recent years, personal computer communication is performed in which a personal computer is connected to a network control device and personal computers exchange information with each other via an existing communication line.

[Problems to be Solved by the Invention] A conventional network control device used for this type of personal computer communication is capable of connecting only one personal computer, and is, for example, a domestic subscriber telephone line or a domestic subscriber telephone line. It is done using communication lines.

However, if you want to use your existing communication line for PC communication, you may want to use not only the domestic telephone line but also the domestic telephone line that has a slower line usage charge even if the line speed is slow, or the like. For that reason, I want to communicate with other countries by personal computer communication using the international subscriber line, and more than one personal computer can be connected,
There is also a demand for exchanging information between multiple PCs connected to the same network control device when no communication line is used. There has been a demand for a network control device capable of efficiently transmitting and receiving the above information.

[Means and Actions for Solving the Problem] The present invention has been made under the above circumstances, and in order to solve the problem, a plurality of personal computers can be connected to the network control device, and a plurality of communication lines, that is, domestic subscriber telephone lines. Also, it is configured to be connectable to a communication line such as a domestic subscriber line or an international subscriber line, and such a network control device includes the following elements and controls.

(A) A main control unit having a first central processing unit and a first selection control unit including a storage unit, and a first communication circuit switching unit.

(B) Telex which has a second central processing unit and a second selection control unit including a storage unit, a reception buffer unit, a reservation buffer unit, and a second communication circuit switching unit, and which is connected to the main control unit via a shared memory. Control unit.

(C) When any personal computer requests connection to any telex line, the first selection control means and the second selection control means work together to request the telex line based on the connection request information. Inquires about whether or not to connect to the computer. If the connection is possible, connect the personal computer to the relevant telex line via the second communication circuit switching means, and if the requested telex line is blocked, respond to the personal computer with this. To do.

(D) When any of the personal computers requests reservation transmission to the telex line, the first selection control means and the second selection control means work together to establish a connection to the reservation buffer section based on the connection request information. Inquiry about availability, if the connection is possible, the personal computer is connected to the reservation buffer unit, and if the reservation buffer unit is blocked, this is responded to the personal computer.

(E) When any of the personal computers requests connection to any of the telephone lines, the first selection control means can inquire whether the requested telephone line can be connected based on the connection request information, and the connection can be established. In this case, the personal computer is connected to the relevant telephone line via the first communication circuit switching means, and if the requested telephone line is blocked, the fact is answered to the personal computer.

(F) When any personal computer requests connection to any other personal computer, the first selection control means inquires based on the connection request information whether or not the connection to the personal computer requested is possible, and the connection is possible. In this case, the personal computer is connected to the personal computer through the first communication circuit switching means, and if the requested personal computer is blocked, the personal computer responds to this fact.

(G) When a connection request is made to any personal computer from any other personal computer or any communication line, the first selection control unit or the second selection control unit and the first selection control unit are connected. Based on the request information, it inquires whether the requested personal computer can be connected, and if the connection is possible, the personal computer is requested via the first communication circuit switching means, the second communication circuit switching means, and the first communication circuit switching means. A personal computer or communication line is connected, and when the corresponding personal computer is blocked, it responds to the personal computer or communication line requesting this.

According to the network control device of the present invention configured as described above,
When any one of a plurality of personal computers connected to the personal computer wants to communicate, the personal computer sends a command for requesting the other party of communication to the network control device. A command is detected, and it is determined whether the communication is through a communication line or between personal computers connected to the same network control device, depending on the type of the command.

Then, the control means connects to the corresponding communication line via the switching circuit when the communication line is not used, or connects to the requested personal computer. In this way, information can be exchanged between other personal computers connected to the same network control device via a communication line.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a standard connection diagram in the case where a personal computer, a telephone line, a telegraph line and the like which are information processing devices are all connected to a network control unit (hereinafter NCU) 1 within a connectable range.

In FIG. 1, the NCU 1 includes a plurality of information processing devices 2 to 2.
5, that is, four personal computers 1 to 4 (PORT1 to PORT4 correspond) and a printer (DTE) that performs data monitor output, etc.
8) is connected, and subscriber telephone lines 1 and 2 are connected via a plurality of intelligent modems (shown as EXT1 and EXT2) 6 and 7 having a data processing function. These personal computers 1 to 4 (PORT1 to 4), printer (DTE) 8, modems (EXT1, EXT2) 6, 7 are RS-232C interface 9a, which is a serial interface whose signal names are shown in Table 1 of FIG. Connected to NCU1 at 9g.

In addition, NCU1 is a telecom line (TL
It is configured to be connected to (X line), and domestic / international T
It can be connected to either one of the LX lines, and switching of these lines can be easily done by switching the short pin inside the NCU1.

FIG. 2 is a block diagram of the NCU 1 in FIG.

In this figure, white arrows indicate the flow of various data and control signal lines including each signal line of the address / data bus of the CPU. The power supply unit 15 supplies the required voltage inside the NCU 1.

The NCU 1 is roughly composed of a main control unit 11 and a telex control unit 12.

The main control unit 11 includes intelligent modems (hereinafter, modems) EXT1 (6) and EXT2 connected to the telephone lines 1 and 2.
(7) Communication control and connection, communication control with personal computers 1 to 4, mutual connection of personal computers 1 to 4 and control from personal computers 1 to 4 to other lines, and output to printer 8. It also controls. The printer 8 serves as an output monitor of transmission and reception when it is connected to the line, and when it is not in operation, it can perform local output from the personal computer by a connection request command from the personal computers 1 to 4.

The telex control unit 12 mainly controls connection to the TLX line and transmission / reception. Main controller 11 and telex controller 12
Between them, there is a dual port RAM 13 which is a "shared memory", by which data for transmission / reception to / from the TLX line is exchanged.

The main control unit 11 is provided with a CPU 21 which is a “first central processing unit”, specifically a general-purpose microprocessor 8085, and a “first selection control unit” including a program ROM 22 and a RAM 23 which are “storage units”. Has been. Then, the CPU 21 reads out the program ROM 22 and executes decoding, and the RAM 23 is used for program control such as temporary storage of data and management of flags. In addition, the input / output port 24 provided in the main control unit 11
Outputs the lighting of the lamp and inputs switch information to the operation unit 14.

The personal computers 1 to 4, the modems 6 and 7, and the printer 8 are connected to the NCU 1 via the connectors 17a to 17g by the RS-232C interface shown in Table 1 of FIG. These controls are done, but it is CPU2
1 is performed by program-controlling controllers 26 to 31 which are controllers of the personal computers 1 to 4, the modem 6 and the printer 8.

The controllers 26 to 31 are all USART (Universal Syn
It is called chronous / Asynchronous Receiver / Transmitter), and is specifically 8251. USART is a serial interface in data communication, which controls the RS-232C interface of this device and converts parallel data into serial data and serial data into parallel data to send and receive data. . The controllers 26 to 31 which are USARTs notify the CPU21 when it receives the data to be sent from the CPU21 or when it receives the data for the CPU21, and the CPU21 always notifies the status of the USART (whether there is data, transfer error or not) as necessary. Etc.) can be read.

PO excluding DTE controller 31 which is USART to printer
Each of the controllers 26 to 30 from the RT1 controller 26 to the EXT1 controller 30 is connected to the port switching circuit 33 which is the "first communication circuit switching means", and the personal computers 1 to 4 and the modems 6 and 7 are connected through the line driver / receiver circuit 34. It is connected to the.

The port switching circuit 33 is a circuit for switching the signal line by RS-232C shown in Table 1 of FIG. 9 by hardware for each connection partner, and connecting the command shown in FIG. When issued, the CPU 21 that detects this issues a command through a signal line, and by switching the connection of the gate circuit inside the port switching circuit 33, the other party to be connected is connected to the personal computer.
Therefore, the port switching circuit 33 is configured by a gate array integrated circuit so as to switch many RS-232C signal lines.

By the way, when data is received from the telephone line 1 via the modem 6, the data is stored in the 512-Kbyte EXT1 reception buffer 25, and the personal computers 1 to 4 can browse and process the data depending on the time. Since the reception from the telephone line 2 via the modem 7 does not have a reception buffer, it is directly communicated with any one of the personal computers 1 to 4 via the port switching circuit 33.

The EXT1 receive buffer 25 is the LINE reservation buffer 44 and LI described later.
It is backed up by the battery 16 together with the NE reception buffer 45, so that it is possible to transmit and receive day and night, and at the same time, it is possible to cope with a power failure.

The line driver / receiver circuit 34 converts the RS-232C interface signal to a ± 12V level signal, so it converts this from a ± 12V level for an input signal to a TTL level signal and reverses it for an output signal. Is to convert from TTL level to ± 12V level signal.

The telex control unit 12 mainly receives the command from the main control unit 11 to connect and control the TLX line, and is a "second central processing unit", which is the CPU 41 (general-purpose microprocessor 8085), A program that is a "storage unit"
A "second selection control means" including a ROM 42 and a RAM 43 is provided. Then, the CPU 41 reads the program ROM 42, which is a "storage unit", and executes the decoding, similarly to the main control unit 11, and the RAM 43 is used for program control such as temporary storage of data and management of flags.

The line control unit 48, which is the "second communication circuit switching means", is a domestic TL.
It has a function that can be selectively connected to either the X line or the international TLX line, and the selection of this connection can be easily set by the internal short pin. The line controller 48 can directly connect to the TLX line from the connector 17h.

The ammeter 49 detects the line current by the line controller 48, and the TLX
Used for setting or monitoring the communication current of the line.

As for CPU21 of the main control unit 11, one of the personal computers 1 to 4 is TLX.
When the command requesting connection with the line is detected, the CPU 41 of the telex control unit 12 is notified of it via the dual port RAM 13. Then, the CPU 41 notifies the CPU 21 if the TLX line is connected, receives the data from the requested personal computer if the line is free, and again USART
It is transferred to the line control unit 48 by the LINE controller 46 which is
Send to TLX line. Further, the CPU 21 and the CPU 41 also accept the call reservation to the TLX line in parallel with the connection request to the TLX line, and like the above TLX line connection request command, the call reservation request command from any other PC In contrast,
If the LINE reservation buffer 44 is empty, the data is stored in the LINE reservation buffer 44 together with the time data from the clock circuit 47, and is transmitted when the predetermined time comes. Furthermore, when data is received from the TLX line, it is also stored in the LINE reception buffer 45 together with the time data from the clock circuit 47,
If there is a request to receive data from any of the PCs,
Send the corresponding received data to the personal computer.

FIG. 3 is a communication mode explanatory diagram for explaining a state in which each mode such as a communication mode executed in the NCU 1 and a data search of transmission / reception is allocated as a port, and the personal computers 1 to 4 are connected to each port.

Abbreviations such as P1, X1, ... PR in the figure are abbreviations of ports to be connected when the port selection command shown in FIG. 4 is issued.

Specifically, X1 is a direct connection port for domestic / international TLX lines, X2 is a reserved port for outgoing calls to TLX lines, and E1 is a modem EXT1.
Connection port to telephone line 1 via EB, telephone line 1
Is a receiving buffer port via the modem EXT1, and E2 is a connection port to the telephone line 2 via the modem EXT2.
The personal computers 1 to 4 can be connected to other personal computers in addition to the connection with these ports.

Further, in this figure, the incoming buffer is specifically the 128 Kbyte LINE receiving buffer 45 of FIG. 2, the outgoing reservation buffer is also the 128 Kbyte LINE reservation buffer 44, and the receiving buffer is the 512 Kbyte EXT1 receiving buffer 25. is there.

In FIG. 4, CP No. 1 ^C _R ▼ of item No. 1 is a command, and is a command for selecting PORT1 which is the personal computer 1. C is P1 in the meaning of the command is the PORT1 a personal computer 1 ▲ ^C _R ▼ shows a CR (carriage return) code. CP of item No. 1
^C _R ▼ can be issued by PCs 2-4. As a result, the personal computer 1 has the item No. 2 other than the item No. 1 CP ▲ 1 ^C _R ▼.
Of CP ▲ 2 ^C _R ▲ CP of item No. 10 ▼ R ^C _R ▼ can issue port selection command, in the third view is connectable to any port other than P1. Same thing for PC 2
It can be said to ~ 4. All of the above control is performed by the CPU 21 of the main control unit 11 in FIG. 2 via the port switching circuit 33 or from the dual port RAM 13 via the CPU 41.

FIG. 6 is a flowchart (hereinafter referred to as a flow) relating to the operating states of the personal computers 1 to 4 shown in FIGS. 1 and 2.
The numbers in the flow indicate steps in the flow.

In Fig. 6, PCs 1 to 4 select the usage pattern (10
1) Do. Depending on the selection, the operation mode shifts to steps 102 to 108. As an example, the personal computer 1 has steps 102 to 1.
It is assumed that 08 is performed. The PC and NCU1 are
A response is also made with a command or response other than the command or response described in the description, but the detailed description of these is omitted. Also, the detailed description of software control on the personal computer side will be omitted.

When it is desired to execute the telex direct communication (102), step 200 is entered. This is a form in which P1 and X1 in FIG. 3 are connected. The personal computer 1 issues a telex direct communication command (201). This is ▼ TLX line port select command CX ▲ 1 ^C _R in Figure 4. On the other hand, NCU1
Responds with a response.

An example of this response is shown in FIG. When the port Abbreviations X1 = x ₁ x ₂ as a personal computer 1 PORT1 issues a CX ▲ 1 ^C _R ▼ command NCU1 are prepared three responses shown in FIG.
That is, port selection is OK Port in use or port selection NG Command error Is. With these three responses, whether or not port selection is possible is answered.

Returning to the flow, another PC is using the TLX line (20
If it is 2), the PC 1 responds while using the NCU1 port. Thus, the process returns to step 100 and the usage pattern is selected (101). Port selection OK When you receive it, the OK display (20
3) appears. Here, the personal computer 1 judges how to use (204)
If it is transmission, the process proceeds to step 205.

Here, although a telegram created in advance from the personal computer 1 may be transferred from a floppy disk or the like, a transmission telegram is created (205), and a predetermined key on the personal computer is depressed to
Transfer to CU1 and enter call origination process (206). This processing is automatically performed inside the NCU 1 by the cooperation processing of the main control unit 11 and the telex control unit 12 shown in FIG. Whether or not to continue this is determined (207), and if it is to continue, the process returns to step 203.

Here, if it is desired to capture the received message (209), the incoming call process (210) is performed. This is to transfer the data in the LINE receiving buffer 45 in FIG. 2 from the dual port RAM 13 to the main control unit 11 and then to the personal computer 1 via the switching circuit 33 by the PORT1 controller 26. After the transfer, the personal computer 1 can perform data filing, screen display on the display, and if a printer different from the printer 8 of FIG. 1 and FIG.

Further, it is assumed that the conversation communication (211) is started after the continuation determination (207). In conversational communication, the personal computer 1 informs the NCU 1 to that effect (212). With this, the NCU 1 only connects with the communication partner, and leaves control to the PC 1 with the connection route of the line established (213), and when it finishes, the PC 1 notifies the end of the conversation communication mode. NCU1 knows this, disconnects the line, and proceeds to the judgment of continuation (207).

Further, it is assumed that other processing (214) is started. in this case,
The personal computer 1 informs the NCU 1 of the information retrieval of the incoming buffer shown in FIG. 3, transfers the information, retrieves the content, and instructs the NCU 1 to erase it if necessary. When it is desired to end the above telex direct communication, the port deselect process (208) is started. That is, when the personal computer 1 turns off the DTR (data terminal ready) signal which is a signal to the NCU1 of the RS-232C interface signal line in Table 1 of FIG.
1 detects the end of this mode by detecting the off state for 1 second or longer, and returns from step 100 to step 101.

The case where the personal computer 1 wants to execute the telex reservation (103) will be described. This is when you receive a response that the TLX line is being used in step 102 mode,
It is used when you want to send on the LX line etc. according to the working hours of the communication partner. This mode is a form in which P1 and X2 are connected in FIG.

PC 1 issues a telex reservation selection command (30
1) Do. This is TLX outgoing reserved port select command CX ▲ 2 ^C _R ▼ of item No. 6 in Figure 4. As described above, the NCU 1 responds with a response indicating whether or not this port can be used, and if possible, enters the steps 303 to 304. If the reservation is a normal reservation (304) that does not require specific settings, the personal computer 1 enters the reservation transmission message creation (305). You may transfer the pre-created message from a floppy disk etc., but enter the calling time, the other party's number, etc. in order to make the format of the specified message.
It is also possible to transfer to U1 and have NCU1 automatically set (306) the reservation.

Next, after determining whether to continue (307), broadcast reservation (3
09). This broadcast reservation sends the same electronic message to any number of places, and can send it to a maximum of 128 places.
Enter the reservation transmission message creation (310) on PC 1,
Create a transmission message together with the transmission time, the number of broadcasts, and the other party's number, and transfer it to NCU1. NCU1 sets broadcast reservation (311)
Then, at a predetermined time, the data is transmitted to each communication partner.

Further, the collective reservation (312) will be described. This is to send multiple messages together in one place. This also creates the reservation transmission message (313) and NCU1
Transfer to. The NCU 1 makes a batch reservation set (312), searches for a reserved telegram for the same partner at a predetermined time, and transmits the relevant telegrams collectively. Other processing (315)
You can search and delete the transmission status of the telegrams reserved in. When the above processing is completed, the port deselect processing (308) is entered, and the process returns to step 100.

If a direct call (104) to the telephone line 1 is desired, step 400 is entered. This mode is P1 and E1 in Fig. 3.
Is connected to the communication partner via the telephone line 1 via the modem 6. The personal computer 1 issues (401) an electric line 1 selection command. This is to issue a ▼ EXT1 line port select command CE ▲ 1 ^C _R of No. 7 in Figure 4. NC as described above
U1 responds with a response indicating whether or not the port can be used, and if possible, the process proceeds from step 402 to step 403. Then, data transmission / reception processing with the communication partner via the telephone line 1 (40
4) Do. This connection is made via the port switching circuit 33 shown in FIG. If these pendencies are judged (405), if it is finished, the port deselect process (406) is entered, and step 1
Return to 00.

When the direct communication (105) of the telephone line 2 is desired to be executed, step 500 is entered. This mode is a mode in which P1 and E2 in FIG. 3 are connected and a connection is established with the communication partner by the telephone line 2 via the modem EXT2. The personal computer 1 issues (501) a line 2 selection command. This is the EXT2 line port select command of item number 8 in Fig. 4.
Issuing a CE ▲ 2 ^C _R ▼. As mentioned above NCU1
Responds with a response indicating whether or not the port can be used, and if possible, enters the steps of steps 502 to 503. Then, data transmission / reception processing with the communication partner via the telephone line 2 (504)
I do. This connection is made via the port switching circuit 33 shown in FIG. The continuation of these is judged (505), and if it is completed, the port deselect process (506) is entered, and the process returns to step 100.

When the response to the reception buffer (106) of the telephone line 1 is to be executed, step 600 is entered. This mode is a mode in which P1 and EB in Fig. 3 are connected, and when you want to retrieve the contents of the receive buffer that stores the data transferred from the telephone line 1 by the modem EXT1 or take in the data. is there. Specifically, the receive buffer is 51 in FIG.
The EXT1 receive buffer 25 has a capacity of 2 Kbytes. The personal computer 1 issues a reception buffer selection command (601). This is EXT1 reception buffer port select command CE ▲ B ^C _R ▼ of item No. 9 in Figure 4. NCU1 responds with a response indicating whether or not the port can be used.
Take steps 2 to 603. Then, the process of fetching the received message is judged (604), and if fetching is desired, a fetch command is issued (605). This acquisition command causes NCU1
The requested message is extracted from the plurality of messages stored in the EXT1 reception buffer 25 shown in FIG. 2 and the personal computer 1 is operated by the EXT1 controller 30 via the port switching circuit 33.
Transfer to. The personal computer 1 performs a message incoming process (606) and performs a process such as filing of a message. It is judged whether or not these are continued (607), and if it is continued, the process returns to step 604, and in the case of other processing (609), the NCU is instructed to take out or delete the received message information. To end the above process, enter the port deselect process (608) and proceed to step 1
Return to 00.

When it is desired to execute printer output, step 700 is entered.
In this mode, the personal computer 1 can locally output to the printer DTE. In FIG. 3, P1 and PR are connected. The personal computer 1 issues a printer selection command (701). This is ▼ DTE port select command CP ▲ R ^C _R of item No. 10 in Figure 4. NCU1 responds with a response indicating whether or not the port can be used.
Take steps 2 to 703. In step 704, the PC 1 of the personal computer 1 issues a predetermined printer print start command (704). As a result, the NCU1 judges the usage status of the printer DTE8, and if the print start is OK, it notifies the PC 1 (705). PC 1 sends data and NCU1
Is transferred to the printer DTE8 and output (706). Thereafter, it is judged whether or not to continue (707), and when it is to be ended, the port deselect process (708) is started, and the process returns to step 100.

If direct communication (108) with another personal computer is desired, step 800 is entered. This mode is a direct communication between the personal computers through the port switching circuit 33 in FIG. 2 without using a communication line. Also, in FIG. 3, P1 and
It is a connection form with any one of P2, P3, and P4. PC 1
Issues (801) a command for selecting a desired communication port, that is, a personal computer desired to be connected. This is item number 2 in Figure 4,
CP which is the port select command of PORT2 to PORT4 of 3 and 4
Either of 2 ^C _R ▼, CP 3 ^C _R ▼ or CP 4 ^C _R ▼. NC
U1 responds with a port availability response, and if possible, enters steps 802 to 803. As described above, the NCU 1 switches the port switching circuit 33 without using the communication line to connect the personal computer 1 to the personal computer 4, for example. After this, communication between PCs is possible with the PCs concerned (80
4), interactive communication of data transmission / reception becomes possible. Less than,
It is judged whether it is continued (805), and when it is ended, the port deselect process (806) is entered and the process returns to step 100.

What has been described for the personal computer 1 in the flow of FIG. 6 is the same for the personal computers 2 to 4.

A case where a plurality of personal computers 1 to 4 operate simultaneously will be described. FIG. 7 is a diagram for explaining an example thereof. In this figure, the personal computer 1 is connected to the TLX line to perform direct communication transmission processing. PC 2 is TL like PC 1
I tried to communicate directly using the X line, but the line is blocked, so I am switching to reservation communication and making reservation transmission processing. In addition, the personal computer 3 and the personal computer 4 are direct communication with each other, and the personal computer 3 desires connection with the personal computer 4. In this figure, the printer 8
Outputs the telex communication monitor under the control of NCU1.

FIG. 8 is the flow in FIG. PC 1 issues a telex direct communication command _{^{CX ▲ 1 C R ▼ (901}} ) as described in the flow of FIG. 6. Select ports that can be connected from NCU1 OK Receives the response of (902) and creates a transmission message (903)
Then, it is transferred to the NCU 1 and enters the outgoing call processing (904). PC 2
Is later than PC 1 and telex direct communication command
If CP ▲ 1 ^C _R ▼ is issued (905), NCU1 cannot connect to port selection NG Receives the response (906). Therefore, PC 2 is switched to telex reservation and telex reservation command CX ▲
Issuing 2 ^C _R ▼ to (907), which receives the response from NCU1 If it is OK (908). After this, a reservation transmission message is created (909) and transferred to NCU1 and the reservation message is set (91).
0). The personal computer 3 issues a personal computer 4 selection command CP (4 ^C _R ) (911) in hope of connection with the personal computer 4. NCU
If the personal computer 4 can be connected, 1 responds with an OK response (912). At this time, the personal computer 4 is notified that it has been connected to the personal computer 3. After that, the communication circuits of the personal computer 3 and the personal computer 4 are connected in the port switching circuit 33 of the block diagram of FIG. (913). This enables direct communication (914) between the personal computer 3 and the personal computer 4. When four personal computers as described above receive data from the telephone line 1 through the modem 6 during the simultaneous operation, the NCU 1 accumulates the received data in the reception buffer of the telephone line 1.

In the embodiment described above, the personal computer is 4
The description has been made assuming that the base and the communication line are domestic / international of the TLX line and the telephone lines 1 and 2, but the number is not limited to this. The number of lines can be increased by using the NCU1. Using the function that allows direct communication between the PC connected to NCU1 and the modem EXT2 via telephone line 2, the same NCU1 is added between NCU1 and modem 7 to make two NCUs. , TLX lines can be distributed domestically and internationally and connected, or additional telephone lines can be added.

[Effect of the Invention] As described above, according to the network control device of the present invention, when it is desired to perform personal computer communication using an existing communication line,
It is possible to connect not only to domestic subscriber telephone lines but also to domestic foreign telephone lines and international subscriber telephone lines, which are cheaper to use even if the communication speed of the line is slow, and to communicate with other countries. Can be connected,
If the communication line is not used, it is possible to send and receive the common law between multiple PCs.

That is, the network control device of the present invention has an effect that it can be connected to a plurality of different communication lines and can efficiently exchange information between personal computers.

[Brief description of drawings]

FIG. 1 is a standard connection diagram when the network control unit (NCU) of the present invention is in operation, FIG. 2 is a block diagram of the network control device of the present invention, and FIG. 3 is a communication mode of the network control unit. FIG. 4 is a diagram showing a communication partner request command, FIG. 5 is a state diagram of one response of the network control device to the communication partner request command, FIG. 6 is a flowchart diagram in operation, and FIG. Is a state diagram showing an example of simultaneous operation of a plurality of personal computers, FIG. 8 is a flow chart diagram of a simultaneous operation of a plurality of personal computers, and FIG. 9 is a table showing signals of the RS-232C interface. 1 ... Network control device 2-5 ... Personal computer 1-4, 6, 7 ... Modem 8 ... Printer 9a-9g ... RS-232C interface, 11 ... Main control unit, 12 ... Telex control unit, 13 …… Dual port RAM (shared memory), 21 …… CPU (first central processing unit) 22 …… Program ROM (storage unit) 23 …… RAM (storage unit) 25 …… EXT1 receive buffer, 26 to 31… ... Controller (USART), 33 ... Port switching circuit, (first communication circuit switching means) 41 ... CPU (second central processing unit), 42 ... Program ROM (storage unit) 43 ... RAM (storage unit) 44 …… LINE reservation buffer, 45 …… LINE reception buffer, 46 …… LINE controller (USART), 48 …… Line control unit (second communication circuit switching means)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shoji Kurohashi 8-1-19 Akasaka, Minato-ku, Tokyo Showa Information Equipment Co., Ltd. (72) Inventor Hitoshi Nagumo 8-1-119 Akasaka, Minato-ku, Tokyo Showa Information Equipment Co., Ltd.

Claims (1)

[Claims] 1. A network control device capable of selectively connecting a plurality of information processing devices and between a plurality of information processing devices and a plurality of different communication lines, including the following elements and controls: Network control device. (A) A main control unit having a first central processing unit and a first selection control unit including a storage unit, and a first communication circuit switching unit. (B) Telex which has a second central processing unit and a second selection control unit including a storage unit, a reception buffer unit, a reservation buffer unit, and a second communication circuit switching unit, and which is connected to the main control unit via a shared memory. Control unit. (C) When any information processing device requests connection to any telex line, the first selection control means and the second selection control means work together to make a request based on the connection request information. Inquires about whether or not to connect to the telex line. If the connection is possible, connect the information processing device to the corresponding telex line via the second communication circuit switching means, and if the requested telex line is blocked, check this. Respond to the information processing device. (D) When any one of the information processing devices requests reservation transmission to the telex line, the first selection control means and the second selection control means work together to send data to the reservation buffer section based on the connection request information. Whether or not the connection is possible is inquired. If the connection is possible, the information processing device is connected to the reservation buffer unit, and if the reservation buffer unit is blocked, this is responded to the information processing device. (E) When any information processing device requests connection to any telephone line, the first selection control means inquires whether or not connection to the requested telephone line is possible based on the connection request information, If the connection is possible, the information processing device is connected to the corresponding telephone line via the first communication circuit switching means, and if the requested telephone line is blocked, this is responded to the information processing device. (F) When any one of the information processing devices requests a connection to any of the other information processing devices, the first selection control means,
Based on the connection request information, an inquiry is made as to whether or not the requested information processing device can be connected. If connection is possible, the information processing device is connected to the information processing device via the first communication circuit switching means, and the requested information processing is performed. When the device is blocked, this is notified to the information processing device. (G) When there is a connection request to any information processing device from any other information processing device or any communication line, the first selection control unit or the second selection control unit and the first selection control The means inquires, based on the connection request information, whether or not the requested information processing device can be connected, and if the connection is possible, through the first communication circuit switching means or the second communication circuit switching means and the first communication circuit switching means. Then, the requested information processing device or communication line is connected to the requested information processing device, and if the requested information processing device is blocked, it responds to the requested information processing device or communication line.