JPH04320128A - Communication system - Google Patents

Abstract

PURPOSE:To attain the transmission/reception even between terminal equipments connected to a different system network via an internal network by making a network controller control a transmission reception circuit capable of controlling the direction of the transmission provided on each system network. CONSTITUTION:In the case of sending transmission information from a terminal equipment 11 to a terminal equipment 21 of a system network (SNet.) 1, 2, the terminal equipment 11 sends each address of an opposite system and the terminal equipment together with information A to the terminal equipment. A network controller 6 always monitors the information A and the opposite system address from the terminal equipment 11 by a transmission reception circuit 8 connected to an internal network 7. After the transmission of the information A, in order to relay and transmit an affirmative reply signal returned by a terminal equipment 21 receiving the information A as being addressed to the terminal equipment 21 itself to the terminal equipment 11, a processor 4 controls the direction of repeaters 61-63. Thus, the transmission and reception is implemented between terminal equipments of different SNet. via the network 7 without use of a large buffer.

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 system networks.

0002

2. Description of the Related Art A conventional communication system for performing transmission between a plurality of system networks is shown in FIG.

In the figure, 1 to 3 are system networks;
11-i, 21-j, 31-k are terminals connected to each system network 1-3, 41-43 are transmitting/receiving circuits to which each system network is connected, 51-53 are respective transmitting/receiving circuits 41-3. 43 is connected to the processor (control device)
4 is 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 that does not exceed the maximum connectable number.

Conventionally, in this type of communication system, a network controller 6 controls each system network 1 to 3.
Among the terminals connected to the system network that received the synchronization signal, the terminals that have a transmission request can transmit after a specific period of time, and if a certain terminal starts transmission. , a method is adopted in which other terminals suspend 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 equal to the number of system networks (three in this prior art), and furthermore, the processor 4 equips the processor 4 with transmission/reception terminals 51 to 53 according to the transmission/reception timing. Switching between each system network.

[0006]

[Problems to be Solved by the Invention] However, in such a method, it is difficult to communicate between terminals connected to the same system network (for example, terminal 11 and terminal 12) or between a terminal (for example, terminal 11) and network controller 6. However, direct transmission and reception between terminals (for example, terminal 11 and terminal 21) connected to different system networks is not possible.

That is, in order to perform this direct transmission and reception, the network controller 6 once receives information transmitted from a terminal (for example, the terminal 11) connected to a certain system network, stores it in the buffer 5, and then First, it is necessary for the network controller 6 to transmit to a terminal (for example, the terminal 21) connected to another system network. Therefore, the network controller 6 has
A large buffer 5 is required.

The present invention has been made in consideration of the above-mentioned problems, and is a relay system in which an internal network is provided inside the network controller 6, and the network controller 6 is a relay that can control the transmission direction provided for each system network. By controlling the devices 61 to 63, it is intended to enable transmission and reception between terminals connected to different system networks via an internal network.

[0009]

[Means for Solving the Problems] The present invention provides a communication system that includes a plurality of grid networks, terminals connected to each grid network, and a network controller that accommodates the grid networks and controls communication between the terminals. In the system, the network controller includes a repeater connected to each system network and capable of controlling the transmission direction, a control device controlling the transmission direction of the repeater, and a transmitting/receiving circuit connected to the control device. , an internal network arranged between each of the repeaters and the transmitting/receiving circuit is provided, and transmits transmission information including a system address and a terminal address transmitted from a terminal connected to a specific system network that transmitted the synchronization signal. A control device controls a repeater provided for each system network to transmit information to the system network of the system address via the transmitting/receiving circuit and the internal network, while transmitting the transmission information to the system network that has received the transmission information. The communication system is characterized in that an acknowledgment signal transmitted from a terminal having an address and a terminal address is transmitted to the specific system network.

0010

[Operation] 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 placing a large burden on the network controller. , the control device controls a repeater provided for each system network, thereby simultaneously transmitting information to the system network of the system address via the transmitting/receiving circuit and the internal network, while transmitting information to the system network from which the transmission information has been received. Since the acknowledgment signal transmitted from the terminal having the address and the terminal address can be transmitted to the specific network, terminals connected to different network networks can simultaneously transmit and receive signals.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a communication system for carrying out transmission between a plurality of system networks according to the present invention. In the same part as Figure 3,
The same reference numerals are used, and the explanation thereof will be omitted.

[0012] 61 to 63 represent each system network 1 to 3.
It is a repeater connected to. The repeaters 61 to 63 are equipped with a transmission circuit and a reception circuit between the grid networks 1 to 3 and the internal network 7, and transmit the received signal from the internal network 7 to the grid network, and conversely, transmit the received signal from the grid network to the internal network. Send to network 7. Such direction control of relay transmission is performed by control signals output from the processor 4 to each of the repeaters 61 to 63. However, only bidirectional relay transmission is possible at the same time, and relay transmission in either direction may not be performed.

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

The feature of the present invention is that, as shown in FIG. 3, repeaters 61 to 63 are installed in place of the transmitting and receiving circuits 41 to 43 corresponding to each system network 1 to 3 in the network controller 6 of the prior art. The repeaters 61 to 63 and the processor 4 are connected by an internal network 7 and one transmission/reception circuit 8 for the internal network 7. In the prior art shown in FIG. 3, the three transmitting/receiving circuits 41 to 43 are connected to the processor 5 via the transmitting/receiving terminals 51 to 53, respectively.
Three repeaters 61 to 63 are connected to the processor 4 via an internal network 7 and a transmitting/receiving circuit 8.

The internal network 7 is located inside the network controller 6, and in this embodiment, the internal network 7 is a wired OR network.
A TTL-level bus network is used.

Furthermore, each terminal has a unique system address for each system network and a unique terminal address for each system, and it is possible to identify the terminal using these.

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

First, the network controller 6 outputs a synchronization signal (2) to the system network 1. At this time, the following control is performed inside the network controller 6.

The processor 4 enables the relay device 61 corresponding to the system network 1 to perform relay transmission from the internal network 7 toward the system network 1, and allows the relay device 61 corresponding to the system network 1 to perform relay transmission in the direction of the system network 1.
, 63 sends a control signal to the repeaters 61 to 63 to prohibit relay transmission. Then, the processor 4 outputs the synchronization signal ■ to the internal network 7 via the transmitter/receiver circuit 8, and outputs this synchronization signal ■ to the system network 1 via the repeater 61.

After outputting the synchronization signal (■), the network controller 6 sends a relay device to relay transmission information A transmitted from a specific terminal connected to the system network 1 to other system networks 2 and 3. 61-63 direction control is performed. That is, the processor 4 enables the relay device 61 corresponding to the system network 1 to perform relay transmission from the system network 1 to the internal network 7, and the other relay devices 62 and 63 enable the relay transmission from the internal network 7 to the system networks 2 and 3. A control signal is sent to the repeaters 61 to 63 to enable relay transmission in the direction of.

[0021] Then, among the terminals 11 to i connected to the system network 1, the terminal (for example, the terminal 11) that makes a transmission request sends the transmission information A after a specific time from the synchronization signal to each terminal in the same system network. When transmission starts, this transmission information A is simultaneously output not only within the system network 1 but also to the other system networks 2 and 3 via the internal network 7 of the network controller 6.

Specifically, for example, when the terminal 11 transmits transmission information A to the terminal 21 connected to the system network 2, the terminal 11 sends the destination system address indicating the system network 2 in the transmission information A. Then, the destination terminal address indicating the terminal 21 is transmitted together with the transmission information A. The network controller 6 constantly monitors the sending information A sent from the terminal 11, especially the destination system address (system network 2), by the transmitting/receiving circuit 8 connected to the internal network 7. Then, in order to relay and transmit the acknowledgment signal (2) returned by the terminal 21 that received the transmission information A addressed to itself to the 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, especially the partner system address (system network 2
) via the transmitting/receiving circuit 8 to which the internal network 7 is connected, and recognizes that this transmitted information A is for the system network 2. And processor 4
When detecting that the transmission information A has ended, the relay device 62 corresponding to the grid network 2 is transferred to the grid network 2.
The other repeaters 61 and 63 send control signals to the repeaters 61 to 63 to enable relay transmission from the internal network 7 to the grid network. Send out. As a result, the terminal 21 that received the transmission information A returns an acknowledgment signal ■
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 synchronization signals (1) and (2) to the system networks 2 and 3, performs similar processing, and repeats this process.

[0024]

[Effects of the Invention] As is clear from the above description, the present invention provides an internal network inside a network controller, and the network controller controls repeaters that are provided for each system network and are capable of controlling the transmission direction. This makes it possible to transmit and receive data even between terminals connected to different system networks via the internal network, so there is no need for a large buffer as in the prior art.

[Brief explanation of drawings]

FIG. 1 shows a communication system for performing transmission between multiple system networks according to the present invention.

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

FIG. 3 shows a conventional communication system that performs transmission between multiple system networks.

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

[Explanation of symbols]

1 to 3 System network 4 Processor 5 Buffer 6 Network controller 7
Internal network 8
Transmitting/receiving circuits 11-i Terminals 21-j Terminals 31-k Terminals 41-43 Transmitting/receiving circuits 51-53 Transmitting/receiving terminals 61-63 Repeater

Claims (1)

[Claims] 1. A communication system comprising a plurality of grid networks, terminals connected to each grid network, and a network controller that accommodates the grid networks and controls communication between the terminals, wherein the network controller includes: , a repeater connected to each system network and capable of controlling the transmission direction, a control device for controlling the transmission direction of the repeater, a transmitting/receiving circuit connected to the controlling device, and each of the repeating devices and the transmitting/receiving circuit. An internal network is provided between the circuits, and the control device transmits 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, for each system network. By controlling a repeater provided at A communication system characterized in that the communication system transmits the received acknowledgment signal to the specific system network.