JPH0728293B2 - LAN system - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a LAN (local area network) system using a bus type transmission line using a coaxial cable of, for example, carrier detection multiple access / collision detection (CSMA / CD) system. .

2. Description of the Related Art A conventional system of this type, as shown in FIG. 5, includes a common transmission line 1 using a coaxial cable or an optical cable,
A plurality of transceiver units 2 connected to this transmission line 1,
By the gateway device 3 connected to each transceiver unit 2, the host computer 4 and the plurality of terminals 5 having different communication procedures (protocols) are connected to each other so that data communication can be performed mutually. (See, for example, JP-A-61-289743).

Further, the host computer (hereinafter abbreviated as host) 4 has a multitask processing function for performing data processing with a plurality of terminals 5 such as personal computers, and also monitors the communication status in real time. The communication monitor function 6 to be displayed on the display 7 is configured by software.

With the communication monitor function 6, even if the number or types of the terminals 5 increases and the system becomes complicated, the communication status can be accurately grasped.

However, according to such a configuration, there is a problem that the load of the host suddenly becomes heavy as the system becomes complicated and the throughput of the entire system is significantly reduced.

The above problem occurs for the following reasons.

That is, when the number or types of terminals connected to the host via the transmission line increases and the system becomes complicated, the processing load on the host also increases accordingly. Although it is unavoidable to increase the processing load due to the complexity of the system, the problem here is that the processing load of the communication monitor function increases along with the complexity of the system. For this reason, the host having the communication monitor function must cope with the increase in the processing load of the communication monitor function due to the complexity of the system in addition to the increase in the processing load due to the complexity of the system. As a result, the load on the host is significantly larger than the increase due to the complexity of the system, and the throughput of the entire system is significantly reduced.

The present invention has been made in view of the above problems, and an object thereof is to provide a LAN system capable of displaying a communication status on a monitor without significantly reducing the throughput of the entire system even if the system becomes complicated. And

Means for Solving the Problems In order to achieve the above object, the present invention provides a gateway device provided on a transmission line connecting a host computer and a plurality of communication terminals, and communication data is read from the gateway device and displayed on a monitor. And a communication monitor unit for controlling communication data transmission / reception with the host computer, and a second communication control unit controlling communication data with the plurality of terminals. A communication control unit and a storage unit for storing communication data are provided. The communication monitor unit stores the storage unit when there is no access from the first communication control unit or the second communication control unit to the storage unit. The communication data in is read and displayed. Further, in order to achieve the above object, the present invention provides a gateway device provided on a transmission line connecting a host computer and a plurality of communication terminals, and a communication monitor means for reading communication data from the gateway device and displaying the data on a monitor. The gateway device includes a first communication control unit that controls transmission and reception of communication data with the host computer, and a second communication control unit that controls transmission and reception of communication data with the plurality of terminals, A storage means for storing communication data is provided, and the communication monitor means reads and displays the communication data when new communication data is stored in the storage means.

Advantageous Effects of Invention According to the present invention, since the monitor display of the communication status can be performed without depending on the host by the above configuration, even if the system becomes complicated, the throughput of the entire system is not significantly reduced, and the communication status can be controlled. It is possible to display on the monitor in real time.

Embodiment FIG. 1 shows a schematic configuration of a LAN system according to an embodiment of the present invention.

The LAN system shown in the figure is a bus-type transmission line 1 using the CSMA / CD type coaxial cable described above, a plurality of transceiver units 2 connected to this transmission line 1, and each transceiver unit 2 connected to it. With the gateway device 3, the host computer 4 and the plurality of terminals 5 having different communication procedures (protocols) are connected to each other to perform data communication with each other.

Further, in the LAN system shown in the figure, in addition to the above-mentioned configuration, the communication monitor device 8 is provided in the gateway device 3 interposed between the transmission path 1 and the host computer 4.
Is provided. The communication monitor device 8 is an independent device that is configured separately from the host 4, and is configured to read communication data from the gateway device 3 and display the communication data on the display device 7 in real time.

FIG. 2 shows a schematic configuration of the gateway device 3 provided with the communication monitor device 8.

As shown in the figure, the gateway device 3 includes a transmission line interface control unit 31, a gateway central control unit (CPU) 32, a high-speed RAM (random type) that exchanges communication data with the transmission line 1 side via the transceiver unit 2. ·access·
The shared memory 33 is composed of a memory), a host interface control section 34 for exchanging data with the host 4 side through various interface buses 9, and a multi-bus 35 for connecting the respective sections to each other. Here, the communication monitor device 8 is provided so as to be connected to the multi-bus 35.

The gateway device 3 configured as described above accesses the shared memory 33 from both the transmission line interface control unit 31 and the host interface control unit 34 in a time-divisional manner, so that the transmission lines 1 having different communication means (protocol) from each other. Communication data can be exchanged between the host side and the host 4 side. Therefore, the shared memory 33 temporarily stores communication data exchanged between the transmission path 1 side and the host 4 side. Here, the communication monitor device 8
Aims at the free time when the common memory 33 is not accessed, that is, the opening time of the multi-bus 35, reads the communication data temporarily stored in the shared memory 33, performs the necessary processing, and displays the data. Display on the monitor.

FIG. 3 shows the configuration of the communication monitor device 8 together with the gateway device 3, focusing on the data flow.

As shown in the figure, the communication monitor device 8 is a buffer memory that temporarily stores communication data read from a bus arbiter 81 that monitors an empty state of the multibus 35 in the gateway device 3 and a shared memory 83 in the gateway device 3. 82, an edit processing unit 83 for editing and processing the communication data stored in the buffer memory 83 for monitor display. The monitor data processed by the edit processing unit 83 is sequentially displayed on the display 7.

The operation of the LAN system configured as above will be described below.

FIG. 4 is a flowchart showing an example of the operation of the main part of the LAN system described above.

1 to 4, the communication monitor device 8 is
After waiting the elapse of a predetermined time (Nms) (S1), it is checked whether new communication data has occurred by referring to the pointer area (or directory) of the shared memory 33 in the gateway device 3 or the like. (S2). At this time, the shared memory 33 is referred to by the gateway device 3
In order not to hinder the operation of the above, the emptying of the multi-bus 25 in the gateway device 3 is performed.

Here, as a result of referring to the shared memory 33, if new communication data has not been generated (S3-NO), the same process is repeated after waiting a predetermined time (Nms) again.
1).

On the other hand, if new communication data is generated as a result of referring to the shared memory 33, that is, if some data is exchanged between the host 4 and any terminal 5 (S3-YES), the multi-bus When the vacancy of 35 is estimated, the data stored in the shared memory 33 is read at high speed by DMA (Direct Memory Access) (S4).
The read data is stored as it is in the buffer memory 82 in the communication monitor 8. In this case, shared memory 33
The data read from the memory 33 may be all the data in the memory 33, but in order to minimize the access time of the shared memory 33, that is, the intervening time to the gateway device 3,
It is desirable to use only newly generated communication data.

Thereafter, the data stored in the buffer memory 82 in the communication monitor device 8 is edited into the data for display over a relatively long time (S5). The data processed for display is sequentially displayed on the display (display) (S6).

After that, after a predetermined time (Nms) has elapsed again, the series of operations (S1 to S6) described above is repeated.

As described above, it is checked whether or not new communication data is generated every predetermined time (Nms) and the monitor display is performed. As a result, the host 1 and each terminal 5
The communication status between the two is displayed on the monitor in real time.

What should be noted here is that the above-described monitor operation is performed by the communication monitor device 8 provided in the gateway device 3 without depending on the host 1. As a result, even if the system becomes complicated due to an increase in the number or types of terminals 5,
The load on the host 1 increases only in proportion to the complexity of the system. Therefore, even if the system becomes complicated, it is possible to monitor and display the communication status in real time without significantly reducing the throughput of the entire system.

Although not shown, if necessary, part or all of the data displayed on the monitor may be recorded in a storage medium such as a floppy diskette.

As is clear from the above description, according to the present invention, the communication monitor means connected to the gateway device accesses the storage means from the first communication control means or the second communication control means in the gateway device. By reading and displaying the communication data in the storage means when there is no
Communication data can be displayed without hindering the operation of the gateway device (communication data communication between the host computer and the terminal device), and the communication status can be displayed on the monitor in real time. Also,
Since the communication monitor means reads and displays the communication data when the communication data is newly stored in the storage means in the gateway device, the access time to the storage means, that is, the intervening time to the gateway device is reduced. It can be shortened, and the monitor display can be performed without reducing the throughput of the system.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a LAN system showing an embodiment of the present invention, FIG. 2 is a schematic configuration diagram showing an example of a gateway device forming a part of the system, and FIG. 3 is provided in the system. Fourth Schematic configuration diagram showing an example of a communication monitor device,
FIG. 5 is a flowchart showing an operation example in the main part of the system, and FIG. 5 is a schematic configuration diagram of a conventional LAN system. 1 ... Transmission path, 2 ... Transceiver section, 3 ... Gateway device, 31 ... Transmission path interface control section, 33 ...
… Shared memory, 34 …… Host interface controller, 35 …… Multibus, 4 …… Host computer, 5
...... Terminal amplifier, 7 ...... Monitor display, 8 ...... Communication monitor device, 81 ...... Bus arbiter, 82 ...... Buffer memory, 83 ...... Edit processing section.

Claims (2)

[Claims] 1. A gateway device provided on a transmission path connecting a host computer and a plurality of communication terminals, and communication monitor means for reading communication data from the gateway device and displaying it on a monitor. A first communication control means for controlling transmission / reception of communication data with the host computer, a second communication control unit for controlling transmission / reception of communication data with the plurality of terminals, and a storage means for storing communication data. The communication monitor means reads and displays the communication data in the storage means when there is no access from the first communication control means or the second communication control means to the storage means. Characteristic LAN system. 2. A gateway device provided on a transmission line connecting a host computer and a plurality of communication terminals, and communication monitor means for reading communication data from the gateway device and displaying the monitor data, the gateway device comprising: A first communication control means for controlling transmission / reception of communication data with the host computer, a second communication control unit for controlling transmission / reception of communication data with the plurality of terminals, and a storage means for storing communication data. A LAN system characterized in that the communication monitor means reads and displays the communication data when the communication data is newly stored in the storage means.