JP3096486B2 - Communications system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system capable of transmitting data between a plurality of network systems.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional communication system for transmitting data between a plurality of network systems.

[0003] In the figure, 1 to 3 are system networks,
11 to i, 21 to j, 31 to k are terminals connected to the respective system networks 1 to 3, 41 to 43 are transmission / reception circuits connected to the respective system networks, and 51 to 53 are respective transmission / reception circuits 41 to 41. Processor (control device) to which 43 is connected
Reference numeral 4 denotes a transmission / reception terminal, 5 is a buffer connected to the processor 4, and 6 is a network controller. Note that i is any natural number of 11 or more, j is any natural number of 21 or more, and k is any natural number of 31 or more. Further, the number of system networks accommodated in the network controller 6 is arbitrary, and the number of terminals connected to each system network is arbitrary within a range not exceeding the maximum connectable number.

Conventionally, in a communication system of this type, a network controller 6 has a network 1 to 3 each.
A terminal having a transmission request among terminals connected to the system network that has received the synchronization signal can transmit after a specific time, and when a certain terminal starts transmission, The other terminals adopt a method of suspending transmission until the next synchronization signal. As shown in FIG. 4, the synchronization signal is sequentially broadcast to the system networks 1 to 3.

In order to realize this, the network controller 6 equips the processor 4 with transmission / reception terminals 51 to 53 by the number of system networks (three in this prior art). Switching each network.

[0006]

However, in such a method, the terminals connected to the same system network (for example, the terminal 11 and the terminal 12), and the terminal (for example, the terminal 11) and the network controller 6 are connected to each other. Can be transmitted and received, but terminals connected to different system networks (for example, the terminal 11 and the terminal 21) cannot directly transmit and receive.

That is, in order to perform this direct transmission / reception, the network controller 6 temporarily receives information transmitted by a terminal (eg, terminal 11) connected to a certain system network, stores the information in the buffer 5, and In addition, the network controller 6 needs to perform transmission to a terminal (for example, the terminal 21) connected to another system network. Therefore, the network controller 6 requires a large buffer 5.

The present invention has been made in consideration of the above problems, and has an internal network provided inside a network controller 6, wherein the network controller 6 is provided for each system network and is capable of controlling a transmission direction. By controlling the devices 61 to 63, terminals connected to different system networks via the internal network can transmit and receive.

[0009]

According to the present invention, there is provided a communication system comprising a plurality of system networks, terminals connected to the respective system networks, and a network controller which accommodates the system networks and controls communication between the terminals. In the system, the network controller is connected to each system network, a repeater capable of controlling the transmission direction, and a control device that controls the transmission direction of the repeater,
A transmission / reception circuit connected to the control device, and an internal network disposed between each of the repeaters and the transmission / reception circuit are provided, and a system address transmitted from a terminal connected to a specific system network that has transmitted a synchronization signal. And transmission information including the terminal address, the control device, by controlling the repeater provided for each system network, to transmit to the system network of the system address via the transmitting and receiving circuit and the internal network, On the other hand, a communication system characterized by transmitting an acknowledgment signal transmitted from a terminal having the system address and the terminal address having received the transmission information to the specific system network.

[0010]

According to the present invention, transmission information including a system address and a terminal address transmitted from a terminal connected to a specific system network that has transmitted a synchronization signal can be transmitted without imposing a great burden on a network controller. By controlling the repeater provided for each system network, the control device simultaneously transmits to the system network of the system address via the transmission / reception circuit and the internal network, while receiving the transmission information. Since the acknowledgment signal transmitted from the terminal having the address and the terminal address can be transmitted to the specific system network, terminals connected to different system networks can simultaneously transmit and receive.

[0011]

FIG. 1 shows a communication system for transmitting data between a plurality of networks according to the present invention. The same parts as in FIG.
The same reference numerals are given and the description is omitted.

Reference numerals 61 to 63 denote system networks 1 to 3,
It is a repeater connected to. Each of the repeaters 61 to 63 includes a transmission circuit and a reception circuit between the system networks 1 to 3 and the internal network 7, and transmits a reception signal from the internal network 7 to the system network, and conversely, receives a reception signal from the system network. Send to network 7. Such direction control of the relay transmission is performed by a control signal output from the processor 4 to each of the repeaters 61 to 63.
However, only bidirectional relay transmission can be performed at the same time, and relay transmission in either direction can not be performed.

In this embodiment, a bus type network such as RS-485 to which a maximum of 32 terminals can be connected is used as the system networks 1 to 3.

A feature of the present invention is that, as shown in FIG. 3, the transponders 61 to 63 are provided in place of the transmission / reception circuits 41 to 43 corresponding to the respective system networks 1 to 3 in the network controller 6 of the prior art. That is, the repeaters 61 to 63 and the processor 4 are connected by the internal network 7 and the transmission / reception circuit 8 for one internal network 7. In the prior art shown in FIG. 3, the three transmission / reception circuits 41 to 43 are connected to the processor 5 via the transmission / reception terminals 51 to 53, respectively.
Two repeaters 61 to 63 are connected to the processor 4 via the internal network 7 and the transmission / reception circuit 8.

The internal network 7 is inside the network controller 6, and in the present embodiment, a wired OR
A TTL-level bus-type network utilizing the above is used.

Each terminal has a unique system address for each system network and a unique terminal address for each system, which makes it possible to identify the terminal.

In such a configuration, the network controller 6 performs transmission control as shown in FIG.

First, the network controller 6 outputs a synchronization signal to the system network 1. At this time, the following control is performed inside the network controller 6.

The processor 4 enables the repeater 61 corresponding to the system network 1 to perform a relay transmission from the internal network 7 to the direction of the system network 1.
2, 63 are repeaters 61 to 63 so as to prohibit relay transmission.
To send a control signal. Then, the processor 4 outputs a synchronization signal to the internal network 7 via the transmission / reception circuit 8, and outputs the synchronization signal to the system network 1 via the repeater 61.

After outputting the synchronization signal, the network controller 6 relays the transmission information A, which is connected to the system network 1 and is transmitted by a specific terminal, to the other system networks 2 and 3 by relaying. To 63 are performed. That is, the processor 4 enables the repeater 61 corresponding to the system network 1 to perform relay transmission from the system network 1 to the internal network 7, and the other repeaters 62 and 63 connect the internal network 7 to the system networks 2 and 3. The control signal is transmitted to the repeaters 61 to 63 so as to enable the relay transmission in the direction of.

Then, among the terminals 11 to i connected to the system network 1, a terminal (for example, the terminal 11) that has requested transmission is transmitted to each terminal in the same system network after a specific time from the synchronization signal. Is started, the transmission information A is simultaneously output not only in the system network 1 but also to the other system networks 2 and 3 via the internal network 7 of the network controller 6.

More specifically, for example, when the terminal 11 transmits the transmission information A to the terminal 21 connected to the system network 2, the terminal 11 transmits the destination system address indicating the system network 2 in the transmission information A. And the partner terminal address indicating the terminal 21 is transmitted together with the transmission information A. The network controller 6 constantly monitors the transmission information A transmitted from the terminal 11, in particular, the partner system address (system network 2) by the transmission / reception circuit 8 connected to the internal network 7, and the transmission information A is transmitted. Then, in order to relay the acknowledgment signal returned by the terminal 21 that has received the transmission information A to the own station to the transmission source terminal 11 of the transmission information A, the direction control of the repeaters 61 to 63 is performed. That is, the processor 4 transmits the transmission information A transmitted from the terminal 11, in particular, the destination system address (system network 2) to the transmission / reception circuit 8 to which the internal network 7 is connected.
The transmission information A is monitored via the system network 2
Recognize that it is for When the processor 4 detects that the transmission information A has ended, the processor 4 enables the relay 62 corresponding to the system network 2 to perform a relay transmission from the system network 2 to the internal network 7, and the other relays 61, Reference numeral 63 sends a control signal to the repeaters 61 to 63 so as to enable the relay transmission from the internal network 7 toward the system network. As a result, the acknowledgment signal returned by the terminal 21 having received the transmission information A is simultaneously output not only to the network 2 but also to the other system networks 1 and 3 via the internal network 7 of the network controller 6.

The network controller 6 sequentially outputs a synchronizing signal and the same to the system networks 2 and 3 to perform similar processing, and repeats this.

[0024]

As is apparent from the above description, the present invention provides an internal network inside a network controller, and the network controller controls a repeater provided for each system network and capable of controlling a transmission direction. As a result, transmission and reception can be performed between terminals connected to different system networks via the internal network, so that a large buffer as in the related art is not required.

[Brief description of the drawings]

FIG. 1 shows a communication system for performing transmission between a plurality of network systems according to the present invention.

FIG. 2 is a signal flowchart of the present invention.

FIG. 3 shows a conventional communication system for performing transmission between a plurality of network systems.

FIG. 4 is a signal flowchart of the present invention.

[Explanation of symbols]

 1-3 system network 4 processor 5 buffer 6 network controller 7 internal network 8 transmission / reception circuit 11-i terminal 21-j terminal 31-k terminal 41-43 transmission / reception circuit 51-53 transmission / reception terminal 61-63 repeater

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-129548 (JP, A) JP-A-50-88945 (JP, A) JP-A-59-168737 (JP, A) 60240 (JP, A) JP-A-3-6946 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04L 12/28

Claims (1)

(57) [Claims] 1. A communication system comprising a plurality of system networks, a terminal connected to each system network, and a network controller that accommodates the system network and controls communication between the terminals. , Connected to each grid network,
A repeater capable of controlling the transmission direction, a control device for controlling the transmission direction of the repeater, a transmission / reception circuit connected to the control device, and an internal network disposed between each of the repeaters and the transmission / reception circuit The control device controls the repeater provided for each system network by transmitting transmission information including a system address and a terminal address transmitted from a terminal connected to the specific system network that transmitted the synchronization signal. By transmitting the transmission information to the system network of the system address via the transmission / reception circuit and the internal network, the acknowledgment signal transmitted from the terminal having the system address and the terminal address having received the transmission information is identified. A communication system for transmitting to a system network.