JPH02193250A - Computer connection system - Google Patents

Abstract

PURPOSE:To eliminate a need of the increase of the number of transmission lines at the time of increasing the number of computers by not providing each computer with its private transmission line and enabling each computer to transmit a signal to plural transmission lines. CONSTITUTION:Computers 20, 30, 40, 50, and 60 are connected to transmission lines 01 through links 10, and each link 10 consists of a communication interface circuit 11, a transmission selector circuit 13, and a reception selector circuit 12. For the purpose of preventing plural computers from simultaneously using one transmission line 01, each computer detects an idle (unused) transmission line at the time of transmission and sends the signal to only the idle transmission line. Consequently, each computer is not provided with its private transmission line 01 and can transmit the signal to plural transmission lines 01. Thus, it is unnecessary to increase the number of transmission lines at the time of increasing the number of computers.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a complex computer system.

This relates to a method for connecting multiple computers.

[Summary of the invention]

If a dedicated transmission line is provided for each computer, the transmission line must also be added when adding more computers. Therefore, by making it possible for each computer to transmit to multiple transmission lines without providing a dedicated transmission line for each computer, there is no need to add more transmission lines even if more computers are added. A small computer because it does not require any hardware or software.

It is particularly effective for networks of control devices using personal computers and microcomputers.

[Conventional technology]

Nine examples of conventional technology include the Japanese Patent Publication No. 60-51145.
There is a ``computer connection method'' shown in the publication.

The conventional method is to provide a dedicated transmission line for each computer, the details of which will be explained below with reference to the drawings.

FIG. 4 shows computer work according to the conventional method. In the figure, Ll, L2. L3. L4 is.

A link that has buffers and ports for sending and/or receiving, and logic with some decision-making functionality. C.I.

C2, C3 are computers, Ml, M2. , M3 is memory.

Pl, P, 2. P3. ...Pl3 is a peripheral (peripheral device).

Also, links Ll, L2. L3 is computer C+.

The link L4 connects C2 and C3 and connects the peripheral group P7 to P]3. Also ll.

! 2.6 s Z'4 indicates the track.

The inside of the link "1s"2sL3s"4 has a configuration as shown in FIG. 5, for example.

Here, Sl and S2 are buffer memories for transmission and reception, and CE+ and CE2 are input/output ports for a line and a computer, respectively.

The link has the following functions.

Now, when there is a request for transmission from computer C1 to computer C3, link L1 connected to computer C1
The message is stored in the buffer memory S1 along with the address via CF2. When there is a message to be transmitted in the buffer memory S1, a transmission signal including an address is transmitted from the CEI to the line Jl. Link L of addressed computer C3
3 is.

If the receiving buffer memory S2 is full of information, in other words, if the computer is not receiving data, it receives the transmission signal and sends back a signal indicating that it is ready to receive data.

Similarly, control signals between computers.

Exchange data.

[Problem to be solved by the invention]

Therefore, a dedicated transmission line is required for each.

When adding more computers, there are problems in that it is necessary to add more transmission lines and to connect the added transmission lines to all links on the network.

SUMMARY OF THE INVENTION In order to solve the above problems, it is an object of the present invention to eliminate the need to add transmission lines even if computers are added.

[Failure to solve the problem]

In order to achieve the above object, the present invention enables each computer to transmit data to a plurality of transmission lines without providing a dedicated transmission line for each computer.

In this case, in order to prevent multiple computers from using one transmission line redundantly, each computer detects an empty (unused) transmission line before transmitting and sends out only to the empty transmission line. Still at the time of sending out.

It is equipped with means for confirming that a transmission line is not being used redundantly by a plurality of computers, and for recovering when two or more computers are using the transmission line redundantly.

[Effect]

Since this eliminates the need for additional transmission lines when adding computers and connecting them to the network, complicated software control can also be omitted.

〔Example〕

Two embodiments of the present invention will be described in detail below.

FIG. 1 shows an umbrella embodiment of a computer network configured using two computer connection methods according to the present invention. In FIG. 1, computer A20 is connected to transmission line 01 through link 10. In FIG. The link 10 has 8 communication interface circuits 11° transmission selector circuit 13. It is composed of a reception selector circuit 12. The communication interface circuit 11 performs conversion between the data type of the computer A20 and the data type of the transmission line 01. This is because the computer A20 transfers data in a bus format, which is easy to understand, whereas the transmission line 01 transfers data in a serial format. The transmission selector circuit 13 is.

Based on instructions from the computer A20, a transmission line is selected for the transmission data from the communication interface circuit 11, and the transmission data is outputted to the selected transmission line. The reception selector 12 receives data from the transmission line selected by the computer A20.

Output to the communication interface 11. Other computers B to E 30, 40, 50, 60 are also computer A2
0, it is connected to the transmission line 01 through the link 10. Each transmission line 01 is connected to each link 10 in the same way, and the data flowing to each transmission line is of the same data type. When using a transmission line, be sure to periodically output data to the transmission line. conduct.

This operation will be explained below. When the computer A20 transfers data to the computer C40, the computer A20 controls the reception selector circuit 12 to
Select one transmission line 01.

Data flowing to two selected transmission lines 01 is received through the communication interface circuit 11. The received data is 1
If it does not occur even after a fixed period has elapsed, it is assumed that the selected transmission line 01 is being used by another computer, and the combimeter A20 is connected to the communication interface circuit 1.
1. A transmission request signal containing address information to the computer 40 is sent to the transmission line 01 through the transmission selector 13.
The data is repeatedly sent to every 10 regular cycles. If the received data is generated within a fixed period, it is assumed that the transmission line 01 is being used by another computer, and the reception selector 12 is controlled to select another transmission line 01;
Find out if another computer is using it. If the transmission line 01 is in use, the above operation is repeated to search for an unused transmission line 01, and then output the transmission request signal to that transmission line 01.

By controlling the link 10 connected to the computer C40, the computer C40 repeatedly selects all the transmission lines and checks whether there is a transmission request signal to the computer C40. If there is a transmission request signal to yourself, computer C
40 uses the transmission line that received the transmission request signal,
The response signal is sent back to the computer A20, and thereafter the transmission line 01 is transmitted between the computer A20 and the computer C40.
to perform data transfer.

In Figure 1, when adding a new computer,
Just by adding the link 10 to the transmission line 01, there is no need to add the transmission line 01 or change the existing link 10° software.

FIG. 2 is a block diagram showing the link 10 of FIG. 1 and its surroundings in detail. In FIG. 2, the output of the transmission selector circuit 13 is connected to the output gate 14 and the signal detection circuit 11.
Connected to 0. The signal detection circuit 110 constantly monitors the transmission signal from the transmission selector circuit 13, and when detecting the transmission signal, sets the flip-flop 130 and enables the output gate 14 to output the transmission signal to the transmission line 01. . The delay circuit 120 delays the set signal of the flip-flop 130 for a certain period of time, and then
Reset flip-flop 130 and output gate 14
Disable.

This operation will be explained below. computer A20
outputs a fixed length transmission take to the communication ink input circuit 11. Transmission data is transmitted through communication interface 11. At the same time as the signal passes through the transmission selector 13 and is input to the output gate 14, the signal detection circuit 110 sets the 7-lip-flop 130 and outputs it to the transmission line 01.

After the flip-flop 130 is set and fixed-length transmission data is transmitted to the transmission line 01, the flip-flop 130 is reset by the delay circuit 120, and the output gate 14 opens the transmission line 01.

Enables responses from the other party's computer.

The fixed length transmission data can be made variable length by limiting the maximum length. In this example.

Control of the output gate to the transmission line can be easily realized.

FIG. 3 is a block diagram of an embodiment of the present invention in a different manner from the embodiment in FIG. 2.

In the embodiment in FIG. 2, the flip-flop 13
The 0 set signal is delayed by the delay circuit 120,
In the embodiment shown in FIG. 3, the timing generation circuit 300
The flip-flop 130 is reset at regular intervals. In this case, during transmission, the flip-flop 13
Computer A20 needs to send data so that 0 is not reset. Therefore, the timing generation circuit 300 outputs a transmission timing signal to the computer A20. The computer A20 transmits fixed-length transmission data or variable-length transmission data with a limited maximum length based on the transmission timing signal. The data sent by computer A20 is.

Similar to the embodiment shown in FIG. 2, the signal is output to the transmission line. The timing generation circuit 300.

After the time required to transmit the fixed length transmission data or the variable maximum data length, flip-flop 130 is reset and output gate 14 is disabled. According to this embodiment, a timing generation circuit is commonly added to each transmission line in place of the necessary delay circuit corresponding to each transmission line in the embodiment shown in FIG. It can be realized with suitable hardware. Furthermore, when a microcomputer chip with a built-in communication interface circuit is used as a computer, it can be realized with several ICs, including the combiner and the link, which is effective in creating a small and low-cost system.

〔Effect of the invention〕

According to the present invention, a combinator network can be configured without requiring complicated hardware or software, and sequential expansion can be easily performed, so that a network of control devices using small computers, personal computers, and microcomputers can be easily realized. .

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a block diagram showing the links and their surroundings in detail in Fig. 1, and Fig. 3 shows an embodiment different from Fig. 2. Block diagram, Fig. 4 is a block diagram showing the conventional method, Fig. 5 is a block diagram showing the conventional method.
FIG. 2 is a block diagram showing the inside of a conventional link in the figure. 01...Transmission line, 10...Link,
11... Communication interface circuit, 12...
...Reception selector. 13...Transmission selector, 20, 30, 40, 5
0.60...Computers A to E, 14...
River・Ill'-). 110...signal detection circuit, 120...music delay circuit. 130...flip flop, 300・river・
・Timing generation circuit. /U

Claims (1)

[Claims] 1. In the interconnection of a plurality of computers (including peripherals), a plurality of computers each having a link having an input/output port and a sending/receiving buffer, and a plurality of computers having the same number or different links as the computers, a plurality of transmission lines, the plurality of transmission lines are connected to each of the links, and each computer selects an idle transmission line from among the plurality of transmission lines that does not detect a periodic data signal from another computer. Select a line and use it to configure a transmission path for sending a transmission signal including an address signal to another computer, and further enable reception from another computer that receives a transmission desired signal transmitted from the computer. A computer connection method characterized in that a signal is sent backwards using a transmission path configured by the computer, and thereafter data is output periodically while the transmission path is in use. 2. In the scope of claim 1, the signal output to the transmission line has a fixed length, and the gate is opened by detecting the transmission signal from the transmitting computer at the gate output from the link to the transmission line. . A computer connection system comprising: means for outputting the transmission signal to a transmission line; and means for closing the gate after a certain period of time from the start of output to the transmission line. 3. In the claim set forth in item 1 above, the signal to be output to the transmission line has a fixed length, the computer or link is given a timing for outputting to the transmission line at regular intervals, and if there is a transmission signal, the signal is output at that timing. means for outputting the link from the link; means for opening the gate by detecting the transmission signal from the link to a gate outputting the link to the transmission line; and means for outputting the transmission signal to the transmission line by opening the gate; and a fixed time period from the timing. A computer connection system, characterized in that it has means for later closing said gate. 4. A computer connection system according to claims 2 and 3, characterized in that the signal output to the transmission line has a variable length and its maximum length is limited.