JPH05336141A - Loop network - Google Patents

Abstract

PURPOSE:To attain the efficient communication with high reliability by classifying synchronization data and asynchronization data in the loop network, communicating them through separate transmission lines so as to detect fault and to re-configure the loop network on the occurrence of the fault, thereby preventing the system-down of the network. CONSTITUTION:Communication processing units 121-124 are connected in a loop by using duplicate transmission lines. The communication processing units 121-124 classify the synchronization data and asynchronization data and send them through loop networks 111, 112 and a fault detection section 21 to detect a fault is provided and data requiring much time actually such as voice signal and moving picture and data not requiring much time actually such as a text and a still picture are sent simultaneously. Moreover, a fault is detected to re-configure the network. Thus, the efficient communication with high reliability is realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a loop network having a plurality of communication processing devices for transmitting / receiving synchronous data and asynchronous data in communication between a plurality of computers.

[0002]

2. Description of the Related Art In recent years, many computer systems have increased opportunities to handle various data at the same time. In addition to text (data that has a small capacity and does not need to maintain real time) and voice (data that has a small capacity that needs to maintain real time), data (data needs to have a large capacity and keep real time) is included as data. Data) and still images (data that has a large capacity and does not need to be kept in real time) have come to be handled by computers. In order to efficiently transmit the data having such a property, how to efficiently transmit the text or the still image while maintaining the real time property of the voice or the moving image becomes a problem.

In a conventional loop network, real-time data such as voice and moving images are communicated using synchronous data transfer, and text and still images are communicated using asynchronous data transfer.

Further, in the conventional bus network, real-time data such as voice and moving images are communicated using the contention system, texts and still images are communicated using the time division system, and two communication systems are used. Japanese Patent Laid-Open No. 3-270432 discloses an integrated system.

FIG. 6 is a block diagram of a conventional loop network, in which 25 is a double loop network in opposite directions,
261 to 264 are composed of a plurality of communication processing devices that transmit and receive data.

Synchronous data transfer is performed by each communication processing device 261.
When ~ 264 receives a transmission right called a token, it can transmit the synchronization data synchronized with the reception of the token at any time. On the other hand, in asynchronous data transfer, each of the communication processing devices 261 to 264 is used only when the token is circulating sufficiently quickly.
Is designed to be able to send asynchronous data that is not synchronized with token reception. This will be described below with reference to FIGS. 7A and 7B, showing an example of the transmission of the synchronous data and the asynchronous data and the token transmission timing.

In order to determine the target circulation time of the token circulating in the loop network, a target token circulation time (hereinafter referred to as TTRT) value is determined. This determination of the TTRT value requires the communication processing devices 261 to 264 to be fast enough to support the request of the synchronous traffic, and the TTRT value is set to the shortest value among them (hereinafter referred to as TOPR). Is set as. In addition, each communication processing device 2
The rate counters 61 to 264 are arranged when the TOPR value set in TRT expires, that is, TOPR.
The value value is down-counted, and when that time has elapsed, it increases to 1 and is cleared each time a token is received, and each communication processing device 261 to 264 has previously received the token. From TOP set to TRT
If the token is received again before the R value expires,
That is, if the rate counter is 0, the token is considered to have arrived within the target time, and otherwise the token is considered to be delayed.

When the token arrives at each of the communication processing devices 261 to 264 within the target time, that is, when the token circulates sufficiently quickly, the current value in TRT is set in the token holding timer (hereinafter referred to as THT), TR
The TOPR value is reconstructed in T and TRT is restarted. At that time, after the synchronous data is transmitted by receiving the token, the asynchronous data can be transmitted for a time corresponding to the current value set in THT. When the current value set in THT has expired, and when there is no asynchronous data to be transmitted, the token is the next communication processing device 261-264.
Passed to. When the token arrives at the communication processing device later than the target time, the rate counter is reset but the TRT is not reset. In this case, only the synchronous data is allowed to be transmitted, and after the synchronous data is transmitted, the token is passed to the next communication processing device. In this way, the loop network has two functions, synchronous data transfer for transmitting synchronous data and asynchronous data transfer for transmitting asynchronous data.
It is a type of data transfer.

FIG. 8 is a block diagram of a conventional bus network of the configuration 2. 35 is a bus according to the contention system, 36 is a bus according to the time division system, 371 to 374 are communication processing devices, 3
Reference numeral 8 is a bus control device.

The bus control unit 38 is a time division type bus 36.
Is a device for controlling the use of a slot generator. The contention system bus 35 and the time division system bus 36 can be configured by a coaxial cable or a twisted pair. The communication processing devices 371 to 374 and the bus control device 38 are connected to both the contention system bus 35 and the time division system bus 36.

Transmission using the contention system bus 35
For example, when communication is performed from the communication processing device 371 to the communication processing device 373, data to which the address of the communication processing device 373 of the transmission destination is added is transmitted to the line contention system bus 35. The data is transmitted to the communication processing devices 371 and 373 other than the destination, but is received only by the communication processing device 373 having the above address. In order to perform the above-mentioned transmission, first, the contention system bus 35 must be reserved for itself. Because a plurality of communication processing devices 371 to 37
If the signals from 4 are simultaneously transmitted to the contention system bus 35, the data collide and communication cannot be performed.

Securing the bus 35 for the contention system is done as soon as possible in the bus network for the contention system. That is, in order to secure the line, each communication processing device 371
~ 374 will be contested. It is possible to communicate only after securing a line.

In the time division method, time is divided into fixed short times called time slots, which are periodically assigned to the communication processing devices 371 to 374 that have issued transmission requests. The communication processing devices 371 to 374 can communicate only during the time slot assigned to itself. The bus control device 38 controls which time slot is assigned to which communication processing device 371-374. The bus control unit 38 generates one bus control signal for permitting communication to a designated communication processing unit for one time slot. All of the communication processing devices 371 to 374 receive this bus control signal, but only the designated communication processing device is permitted to communicate within the time slot time. For example, when the communication processing device 371 wants to communicate using the time division system bus 36 as described above, the transmission request is acquired by the line contention system bus 35 by the line contention system, and the bus control device 3
Send to 8. Bus controller 38 that received the transmission request
Transmits a bus control signal that permits communication to the communication processing device 371 that requested transmission. As a result, the communication processing device 371 that issued the transmission request can communicate. Therefore, since data is transmitted from each of the communication processing devices 371 to 374 in a short cycle, the communication can be made to have a real time property, and the voice and the moving image that need the real time property can be communicated. ..

In this way, by having both the contention system bus 35 and the time division system bus 36, real-time data such as voice and video is communicated using the contention system, and text and Still images are communicated using a time division method, and the two communication methods can be integrated for communication.

[0015]

However, in the above-mentioned conventional configuration 1, only the synchronous data transfer is permitted when each communication processing device has a large amount of synchronous data, and after the completion of transmission of the synchronous data, the token is the next communication processing device. Passed to.
As a result, asynchronous data transfer cannot be performed. Further, in the above configuration 2, when a failure occurs in the transmission path, the transmission path cannot be transmitted, and when a failure occurs in the communication processing device, the network is cut off. Moreover, when a failure occurs in the control device that performs control, the entire network stops.

The present invention solves the above-mentioned conventional problems by dividing the transmission paths of synchronous data and asynchronous data without impairing the reliability, self-healing property and expandability of the double loop network. It is to reliably transmit a large amount of data that does not require real time while maintaining real time.

[0017]

In order to achieve this object, the loop network of the present invention comprises a plurality of communication processing devices having a processing function of synchronous data transfer and asynchronous data transfer, which are looped by a dual transmission path. Connect and transmit data. Each communication processing device has two data transmission / reception control units for controlling data transmission / reception, a central processing unit unit for controlling data transmission, two transceiver units for transmitting / receiving data to / from each transmission line, and transmission data centrally. A switch unit for allocating to each transceiver unit according to transmission information from the processing device, two transmission timer units for giving timings of data transmission cycles to each data transmission / reception control unit, and two storage units for storing data to be transmitted to the two transceiver units. A transmission buffer unit, a reception memory buffer unit that temporarily stores data received from each transceiver unit, an address table unit that stores address information of transmitted and received data,
A central processing unit is provided with a fault detecting unit that detects a faulty portion of a transmission path and gives it to a central processing unit. The dual transmission path is divided into a transmission path for synchronous data transfer and a transmission path for asynchronous data transfer to perform transmission, and a failure detection unit detects a network failure and notifies each communication processing device. It is characterized by notifying and connecting the dual transmission lines in the communication processing devices at both ends of the fault location, reconfiguring a single loop network, and transmitting synchronous data transfer and asynchronous data transfer in an integrated manner. is there.

[0018]

According to the present invention, with the above configuration, the dual transmission line in the loop network is divided into the synchronous data transfer transmission line and the asynchronous data transfer transmission line for communication. Therefore, in each communication processing device, communication that requires real-time processing, such as voice and moving images, is performed using the synchronous data transfer transmission path. For communication that does not require real-time processing, such as text and still images, it is possible to use different transmission paths depending on the type of communication data, such as how to perform communication on the asynchronous data transmission path. Further, when a failure occurs in the loop network, the transmission line is reconfigured and the synchronous data and the asynchronous data are integrated to enable communication.

As a result, in the loop network of the present invention, real-time performance can be realized by dividing the transmission paths of synchronous data and asynchronous data without impairing the reliability, self-healing property, and expandability of the double loop network. It is possible to reliably transmit a large amount of data that does not require real-time performance while maintaining the same.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1A is a configuration diagram of a loop network according to an embodiment of the present invention. 111 and 112 are double loop networks in opposite directions, 111 is a loop network for transmitting synchronous data, and 112 is asynchronous data. A loop network for transfer, 121 to 124 are composed of a plurality of communication processing devices for transmitting and receiving data.

FIG. 1B is a schematic diagram of the communication processing devices 121 to 124 according to an embodiment of the present invention.

Reference numeral 131 is a synchronous data transmission / reception control unit for controlling transmission / reception of synchronous data, 132 is an asynchronous data transmission / reception control unit for controlling transmission / reception of asynchronous data, 14 is a central processing unit unit for controlling data transmission, and 151 is , A transceiver unit for transmitting / receiving synchronous data to / from the loop network 111, a reference numeral 152, a transceiver unit for transmitting / receiving asynchronous data to / from the loop network 112, a reference numeral 161, a synchronous transmission timer for giving a timing of a transmission cycle of the synchronous data to the synchronous data transmission / reception control unit 131 Numeral 162, a numeral 162, an asynchronous transmission timer unit that gives the timing of the transmission cycle of asynchronous data to the asynchronous data transmission / reception control unit 132, 171 a synchronous transmission buffer unit that stores the synchronous data to be transmitted to the transceiver unit 151, and 172 a transceiver unit. Async data to send to 152 Asynchronous transmission buffer unit for storing,
Reference numeral 18 is a common reception buffer unit that temporarily stores data received from each transceiver, 19 is a switch unit that distributes transmission data to each transmission buffer unit 171, 172 according to transmission information from the central processing unit 14, and 20 is An address table section 21 for storing address information of data to be transmitted and received, and a failure detection section 21 for detecting a failure point on the transmission path and giving it to the central processing unit 14.

The synchronous data transfer is divided into a fixed short time called a time slot, and is periodically assigned to each of the communication processing devices 121 to 124. When each of the communication processing devices 121 to 124 receives the transmission right called the synchronization token, it can communicate the synchronization data synchronized with the reception of the synchronization token only during the time slot assigned to itself. The time slot is the synchronous transmission timer unit 16 of each of the communication processing devices 121 to 124.
Controlled by 1. All communication processing devices 121 to 124
Is allowed to communicate only within his time slot time. For example, when the communication processing device 121 wants to communicate using the synchronous data transfer as described above, the transceiver unit 15
The synchronization transmission timer unit 16 receives the synchronization token from 1
By 1, the timing of the synchronous data transmission cycle is given to the synchronous data transmission / reception control unit 131. The synchronous data transmission / reception control unit 131 transmits the synchronous transmission data stored in the synchronous transmission buffer unit 171 by the switch unit 19 from the transceiver unit 151 to the loop network 111 only within the time of the time slot allocated in synchronization with this. ..

Therefore, each of the communication processing devices 121 to 12
From No. 4, data is transmitted in a short cycle, so that it is possible to give communication with real time property, and it is possible to communicate voice and moving images that require real time property.

In the asynchronous data transfer, for example, when the communication processing device 121 communicates with the communication processing device 123, the communication processing device 121 receives the asynchronous token from the transceiver unit 152, and the transmission timer unit 162 causes the asynchronous data transmission / reception control unit 132. Is given the timing of the asynchronous data transmission cycle. Asynchronous data transmission / reception control unit 132
Is switched by the switch unit 19 to the asynchronous transmission buffer unit 172.
The asynchronous transmission data stored in is added to the address of the communication processing device 123 of the transmission destination, and the transceiver unit 15
2 to the loop network 112. The asynchronous transmission data is also transmitted to the communication processing devices 121 and 123 other than the transmission destination, but is received only by the communication processing device 123 having the above address by the address table unit 20 and stored in the reception memory buffer unit 19.

In this way, by having both synchronous data transfer and asynchronous data transfer, real-time data such as voice and moving images are communicated using synchronous data transfer, and text and still images are asynchronous. Communication is performed using data transfer, and the two communication methods can be integrated for communication.

Next, a case where a failure occurs in the loop network will be described. The configuration of the loop network shown in FIG. 2 is the same as that described with reference to FIG. 1, so detailed description thereof will be omitted.

When the fault is the transmission line, the fault point 2 of the transmission line
In the communication processing unit 122 next to 2, the token does not arrive even if the token circulation time is exceeded. Communication processing device 122
The central processing unit 14 of this causes the fault check signal to be transmitted to its loop network 111. If this signal does not return to itself within the token circulation time, the loop network 111 transmits a failure detection signal to each of the communication processing devices 121, 123, and 124. With this signal, the fault detection unit 21 of each of the communication processing devices 121, 123, and 124 notifies the central processing unit 14 that a fault has occurred in the network, and the fact that the fault has been recognized is notified by the loop network 112 as the source of the fault detection signal. The fault recognition signal is transmitted to the communication processing device 122. The communication processing device 122, which is the communication source, recognizes that a failure has occurred at the location of the transmission path 22 by receiving this failure recognition signal, and notifies the respective communication processing apparatuses 121, 123, and 124 to the location of the transmission path 22. The loop network 111 transmits again the fault detection signal added with the information that the fault has occurred. The fault detection unit 21 of each communication processing device notifies the central processing unit 14 by this signal, and transmits a fault recognition signal to the communication processing device 122 that is the transmission source of the fault detection signal by the loop network 112 that the fault location is recognized. To do. The communication processing device 12 that is the communication source of this failure recognition signal
2, the communication processing device 121 receives the failure by receiving the error.
~ 124 has recognized. After that, failure point 2
By connecting and returning the loop networks 111 and 112 by the communication processing devices 121 and 122 at both ends of 2, the single loop network 23 is reconfigured as shown in FIG. 3, and the token circulating by the communication processing device 122 is removed. Discard and issue a token to communicate by integrating synchronous and asynchronous. Then, each of the communication processing devices 121 to 12
The central processing unit 14 of No. 4 integrates synchronous data and asynchronous data for communication as described in the conventional loop network technology. If this signal returns to you within the token lap time, recognize that the token has disappeared for some reason, reissue the token, and before this signal returns to you within the token lap time. If the token arrives late, this signal is erased by itself and communication is continued.

Since the configuration of the loop network of FIG. 4 is the same as that described with reference to FIG. 1, its detailed description will be omitted.

When the failure is the communication processing apparatus, in the communication processing apparatus 124 next to the communication processing apparatus 123 at the failure point,
Similar to the above, tokens do not arrive even if the token patrol time is exceeded. The central processing unit 14 of the communication processing unit 124 is
The fault inspection signal is transmitted to the loop network 111. If this signal does not return to itself within the token circulation time, the loop network 111 transmits a failure detection signal to each of the communication processing devices 121, 122, 123. With this signal, the failure detection unit 21 of each communication processing device notifies the central processing unit 14 that a failure has occurred in the network, and the fact that the failure has been recognized is notified by the loop network 112 to the communication processing apparatus that is the transmission source of the failure detection signal. The fault recognition signal is transmitted to 124. The communication processing device 124, which is the communication source, recognizes that a failure has occurred in the communication processing device 123 by receiving this failure recognition signal, and notifies the communication processing device 12 to each of the communication processing devices 121 and 122.
The loop network 111 transmits again the fault detection signal added with the information that the fault has occurred in No. 3. The fault detection unit 21 of each communication processing device notifies the central processing unit 14 by this signal, and transmits a fault recognition signal to the communication processing device 124 that is the transmission source of the fault detection signal by the loop network 112 that the fault location is recognized. To do. The communication processing device 124, which is the communication source, receives the failure recognition signal to detect the failure as a result of the communication processing devices 121 and 122.
It means that 124 has recognized. After that, the communication processing devices 122 and 124 at both ends of the communication processing device 123 at the failure point connect and return the respective transmission lines to reconfigure the single loop network 24 as shown in FIG. Discard the existing token and issue the token for communicating by integrating synchronous and asynchronous.
Then, the central processing unit 14 of each of the communication processing devices 121, 122, and 124 performs communication by integrating the synchronous data and the asynchronous data as described in the conventional loop network technology. If this signal returns to you within the token lap time, recognize that the token has disappeared for some reason, reissue the token, and before this signal returns to you within the token lap time. If the token arrives late, this signal is erased by itself and communication is continued.

As described above, according to the present embodiment, real-time synchronous data such as voice or video and asynchronous data such as text or still image that does not require real-time are simultaneously provided in the loop network. When communicating, the synchronous data and asynchronous data are classified by the communication processing device, and by communicating through separate transmission paths, the real time property of voice and video is maintained, while the text and still images that do not require real time property are maintained. Images can be transmitted efficiently.

Further, when a failure occurs in the loop network, the failure is detected by the communication processing device to reconfigure a single loop network, and synchronous data transmission and asynchronous data transmission are integrated to perform communication.
It is possible to prevent the loop network from being stopped.

[0034]

As described above, according to the present invention, in a communication processing device, synchronous data and asynchronous data are classified into a loop network composed of a plurality of communication processing devices having dual transmission paths. By communicating through separate transmission paths, there is an effect that text and still images can be efficiently transmitted while maintaining the real-time property of voice and moving images.

Moreover, when a failure occurs in the loop network, a single loop network is reconfigured and synchronous data transmission and asynchronous data transmission are integrated for communication, thereby preventing the loop network from being stopped and improving reliability. It has the effect of improving.

[Brief description of drawings]

FIG. 1A is a configuration diagram of a loop network according to an embodiment of the present invention, and FIG. 1B is a schematic diagram of a communication processing apparatus according to the embodiment.

FIG. 2 is a configuration diagram of a loop network having the same configuration as in FIG. 1 when a transmission line failure occurs

FIG. 3 is a diagram showing a reconfigured single loop network.

FIG. 4 is a configuration diagram of a loop network having the same configuration as when a communication processing device failure occurs.

FIG. 5 is a diagram showing a reconfigured single loop network.

FIG. 6 is a configuration diagram of a conventional loop network having a configuration 1.

FIG. 7A is a diagram showing an example of token transmission timing. FIG. 7B is a diagram showing an example of token transmission timing.

FIG. 8 is a configuration diagram of a conventional bus network having a configuration 2.

[Explanation of symbols]

 111 Loop Network for Synchronous Data Transfer 112 Loop Network for Asynchronous Data Transfer 121-124 Communication Processing Device 131 Synchronous Data Transmission / Reception Control Unit 132 Asynchronous Data Transmission / Reception Control Unit 14 Central Processing Unit Unit 151 Transceiver Unit 152 Transceiver Unit 161 Transmission Timer Unit 162 Transmission timer unit 171 Synchronous transmission buffer unit 172 Asynchronous transmission buffer unit 18 Common reception buffer unit 19 Switch unit 20 Address table unit 21 Failure detection unit

Claims (2)

[Claims] 1. In a loop network for transmitting data by connecting a plurality of communication processing devices having a processing function of synchronous data transfer and asynchronous data transfer in a loop by a dual transmission path, each communication processing device comprises: Two data transmission / reception control units for controlling data transmission / reception, a central processing unit unit for controlling data transmission, two transceiver units for transmitting / receiving data to / from each of the transmission lines, and transmission data from the central processing unit. A switch unit for allocating to each transceiver unit according to transmission information, a transmission timer unit for giving a timing of a data transmission cycle to each data transmission / reception control unit, and storing data to be transmitted to each transceiver unit 2
One transmission buffer unit, a reception memory buffer unit for temporarily storing the data received from each transceiver,
An address table unit that stores address information of data to be transmitted and received, and a fault detection unit that detects a faulty portion of a transmission path and gives it to the central processing unit are transmitted and received between communication terminals connected to the communication processing unit. Data is divided into two types, synchronous data and asynchronous data, in the central processing unit according to real-time property, and the dual transmission path is divided into a synchronous data transfer transmission path and an asynchronous data transfer transmission path for transmission. A characteristic loop network. 2. A fault detection unit detects a fault in the network, notifies each of the communication processing units, and connects the double transmission lines in the communication processing units at both ends of the fault location to form a single loop network. The loop network according to claim 1, wherein the loop network is reconfigured, and the synchronous data transfer and the asynchronous data transfer are integrated and transmitted.