JPS6033760A - Star loop form local network system - Google Patents

Abstract

PURPOSE:To obtain a local network system suitable for general-purpose with expanding performance by connecting plural network controllers in a loop and also connecting plural terminal devices to each network controller in star form. CONSTITUTION:A controller 1 is provided with a CPU5, ROM7, RAM9 and a bus controller 16; a data bus 11, address bus 13, and a controller bus 15 perform signal processing in parallel, and the controller 1 is also provided with a serial/ parallel interface 17 connecting each controller in a loop and a serial/parallel interface 18 connecting plural terminal devices. The network system is constituted by connecting the plural terminal devices 3 to the network controller 1, and CPU5 processes a control signal required for the operation of the controller 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a star-loop local network system that incorporates the respective advantages of star and loop-type local network systems.

BACKGROUND ART Star-type and loop-type local network systems are conventionally known.

The star type connects multiple terminals in a star shape around a central computer, and can be configured as a relatively simple system, but it is difficult to expand the scale of the network. On the other hand, the loop type, for example, connects a plurality of computers in a loop, and can be easily connected, but has the drawback that if an accident such as a disconnection occurs, all communications will stop.

For local network systems within the same room or in small-scale factories, a simple configuration is desired, as well as a system that is versatile and expandable, and conventional network systems were unable to adequately meet these demands. .

The present invention aims to improve the above-mentioned problems, and aims to provide a local network system with a simple configuration that is versatile and expandable.

To achieve the above object, the present invention provides a network controller with a loop connection terminal and a plurality of terminal connection terminals via serial/parallel transfer interfaces, so that a plurality of the network controllers can be connected in a loop. J-R is characterized in that a plurality of terminals are connected to each network controller in a star shape.

Hereinafter, this invention will be described in detail with reference to examples.

FIG. 1 shows an embodiment in which a plurality of terminals 3, 3 are connected to a network controller (hereinafter simply referred to as controller) 1. In FIG.

FIG. 2 shows an embodiment in which a plurality of controllers 1, 1 are connected in a loop shape, and a plurality of terminals 3.3 are connected to each controller in a star shape.

FIG. 3 shows a block diagram of the configuration of the controller 1. As shown in FIG.

The controller 1 has a CPU 5, a ROM 7, a RAM 9, and a bypass capacitor l-roller 1G. Data bus 11, address bus 13, and controller bus 15 perform signal processing in parallel. Serial/parallel transfer interface 17 for connecting each controller in a loop
and multiple serial/parallel interfaces 18 for connecting multiple terminals. '+8 is provided. The serial/parallel transfer interface is, for example, UΔRT (universal asyncl) for asynchronous transfer.
+ronovs receiver /lransmi
tter ) is used.

The controller 1 has a packet assembly and disassembly function,
Terminals that do not have packet assembly and disassembly functions (hereinafter referred to as
(referred to as NPT), the packet assembly or disassembly is performed on behalf of the NPT.

The CPU 5 processes control signals necessary for operating the controller 1. The ROM 7 has software for the CPU 5 to process the controller 1.

The RAM 9 has a status buffer 1 that stores communication status information of each terminal, a delta buffer that temporarily stores transmission and reception transfer data, and a work area that stores required intermediate progress. have

Data for each climbing mountain is transferred via a buffer using a store-and-forward method.

It is possible to connect the desired number of I to I+-ra in a single-knob shape.

The types of terminals connected to each controller include personal computers, floppy disks, printers, plotters, numerical control panels, hard disks, etc. Both terminals having packet assembly and disassembly functions (hereinafter referred to as PTs) and terminals that do not have packet assembly and disassembly functions, that is, NPTs, can be connected. It is preferable that the number of terminals connected is, for example, up to about 10, and the number of terminals can be determined by considering the system scale.

The structure of the packet is shown in FIG. It has a header at the beginning and a stop code at the rear via communication data.

The "status table" shows the communication status of each terminal, allowing you to enter information obtained by multiplying the number of controllers by the number of each terminal, and enter 1 if the terminal is connected and powered on, and O if not. The state buffer of each controller described above has a storage capacity sufficient to store the information of this state daple.

FIG. 5 shows a state in which n controllers 1 are connected in a loop. Each controller 1-1.1-2.1-3,・
...L-n are connected in a loop.

Multiple terminals are connected to each controller. Each controller needs to check the activity status of the connected terminal and inform the other controllers of this status.

For this purpose, for example, the state table is circulated starting from the controller 1-1. The state of each controller can be written in the first round, and the state of each controller can be stored in the second round.

Each controller can override data transfer to terminals connected to other controllers while looking at the stored state table, thus avoiding meaningless transfer procedures from one terminal to another inactive terminal. I can do it.

FIG. 6 shows the transmission control flow p-1-.

The U A RT 18 receives data from the PT or NP-r () and sends an interrupt signal to the CPU 5 (step 102
). In step 105, whether the signal is from P T or N P
If the packet is from NPT, step 106C is sent.

Next, in step 107, it is determined whether it is status information or data information, and if it is status information, the process moves to step 108, where the status information is written in the status buffer 1-S+-.

If you check the data information in step 107, step 11
Move to 0. In step 110, it is determined whether the destination terminals are within the same controller.

If the destination terminal belongs to one of the controllers 1 to 1, the process moves to step 111, where the data information is sent and stored in the 1-word buffer. Transfer is determined in step 112, and step 114
transfers to the next controller.

In step 110, if it is determined that the destination terminal is within the same controller, the process moves to state 116.

In step 116, it is determined whether the destination 9;4: is PT or NPT, and if it is NPT, the packet is disassembled in step 117, and then the process moves to step 118. Step 1
After determining the transmittable state in step 18, transmission is performed in step 120.

As is clear from the description of the above embodiment, an appropriate number of PT or NPT terminals can be connected to one controller, and one controller can be connected to one controller without forming a loop within a narrow area. A plurality of terminals can be connected to the controllers 1 to 1 to form a single star system. Furthermore, since an arbitrary number of controllers can be connected in a loop, it is possible to freely expand the system from a small scale system to a large scale system.

Furthermore, even if a disconnection occurs in the communication circuit between the controllers, communication is possible within each controller 1-0.

The star loop type local network system according to the present invention, which incorporates the respective advantages of star type networks and loop type networks, can provide a versatile and expandable system with a simple configuration.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of a star local network system using one controller, and Figure 2 is a star loop local network system in which multiple controllers are connected in a loop, and each controller is connected to multiple terminals. An explanatory diagram of the system, FIG. 3 is a configuration block diagram of a controller, FIG. 4 is a configuration diagram of a packet, FIG. 5 is an explanatory diagram of a loop-shaped transmission path, and FIG. 6 is a transmission control flowchart. 1... Controller 3... Terminal patent applicant AMADA Co., Ltd. Figure 1 Figure 2 Figure 4 Header Data Stop code Figure 5

Claims (3)

[Claims] (1) The network controller is provided with a loop connection terminal and a plurality of terminal connection terminals via serial/parallel transfer interfaces, so that a plurality of the network controllers can be connected in a loop, and each network controller Star loop type low power cable 1 which is characterized by connecting multiple terminals in a star shape.
to work system. (2) The network controller 1-roller is connected to bucket 1.
-Has an assembly and disassembly function, and when transferring to a terminal that does not have the packet assembly and disassembly function, the packet is disassembled and then transferred, and when transferred from the terminal, the packet is assembled and then transferred. The Star Lube local network 1 to network system according to claim 1, characterized in that data is transferred to another terminal. (3) Each of the network controllers has a communication status storage area, and the unconnected status of the end can be confirmed by a status table that circulates through the loop transmission path at a predetermined time fO. Starlube local network system described in Scope 1.