JPH0520015B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a communication network management system, and more particularly to a management system for a bus structure network in which communication devices accommodating terminal devices are interconnected via communication lines.

Prior Art In a conventional bus structure network, the status of its own communication device is broadcasted to all other communication devices at regular intervals, and each receiving communication device broadcasts the status of the source communication device every time it receives the status of the source communication device. It is now updated and maintained. Then, each receiving side communication device monitors the status of these sending source communication devices, and if a simultaneous broadcast notification cannot be received from a specific communication device for a long time, it determines that the specific communication device is down. It's getting old.

In such conventional methods, if a situation occurs in which a communication device on the receiving side cannot receive simultaneous broadcast notifications, it is determined that the specific communication device is down even though it is active within the network. There are drawbacks.

OBJECTS OF THE INVENTION An object of the present invention is to provide a communication network management method that makes it possible to disconnect a specific communication device from the system only when the specific communication device is definitely down.

Composition of the Invention According to the present invention, there is provided a management method for a communication network in which a plurality of communication devices each including a terminal device are interconnected through a communication line, and in which the status of the own communication device is checked at predetermined time intervals. Each receiving side communication device updates and retains the status of the source communication device each time it receives the information, and while monitoring this retained content, it sends a broadcast notification to all communication devices from a specific communication device for a certain period of time. If a simultaneous broadcast notification is not received, a return confirmation signal is transmitted to this specific communication device, and the state of the specific communication device is determined based on the response state to this confirmation signal. A communication network management method is obtained.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention.
A plurality of communication devices 1a to 1n each accommodating terminal devices 2a to 2n are interconnected through a communication line 3. As shown in the figure, the communication device 1a activates the interface section 11, the simultaneous broadcast communication section 12, and the simultaneous broadcast communication section 12 every 30 seconds.
Second timer 13, receiving unit 14, and other communication device 1
It has a memory device 15 that stores the received contents of the simultaneous broadcast notifications from the terminals b to 1n, respectively. Further, the communication device 1a outputs an echo signal to a monitoring counter device 16 that monitors each content of the memory device 15, and to other communication devices, and transmits an echo response signal in response to an echo signal from another communication device. It has a transmitting section 17 and a controller 18 that controls each of these sections.

The memory device 15 is connected to all other communication devices 1b~
It has memory areas 15b to 15n corresponding to each other to store information received by broadcast notification from 1n. Further, the monitoring counter device 16 similarly has corresponding counters 16b to 16n for monitoring the memory contents of the respective memory areas 15b to 15n. It is assumed that the remaining communication devices 1b to 1n have exactly the same configuration.

Figure 2 is a flow diagram for simultaneous broadcast notification.
The status of the own communication device is broadcasted to all other communication devices by the broadcast communication section 12 (step 20). In this case, the 30 second timer 13 issues a broadcast notification every 30 seconds (step 21). This simultaneous broadcast notification is sent from the communication device 1a to the other devices 1b to 1n, and at the same time, it is also sent from the communication device 1b to the other devices 1a and 1c to 1n, and also for each device 1c to 1n. It's exactly the same.

FIG. 3 is a flowchart showing the reception of simultaneous broadcast notifications performed in the flowchart of FIG. 2. For example, to explain the operation at the time of reception in the communication device 1a, each simultaneous broadcast notification (referred to as reception management information) from all the other communication devices 1b to 1n is sent to the memory device 1a.
5 to the corresponding memory areas 15b to 15n, respectively (step 31). After 30 seconds have elapsed, each reception management information that is newly notified at once will be
The previous information will be replaced in the corresponding memory areas 15b to 15n (step
32), new reception management information is always written in each memory area.

It is assumed that exactly the same operation is performed for the remaining communication devices 1b to 1n.

FIG. 4 is a flowchart when checking reception management information received in this way.
A is for checking the contents of the memory area 15b in the memory device 15 (reception management information based on broadcast notification from the communication device 1b). As a result of checking the contents of the corresponding memory 15b (step 41), if reception management information exists, it is determined that the memory contents are good; however, if it is determined that no reception management information has been received (that is, reception management information has not been received), then ( step
42), corresponding counter 16b of monitoring counter 16
The value of is set to -1 (step 43). It is assumed that the initial set value of the counter is 9, for example. If the value of this counter 16b is not 1 (step 44), the system waits for the next broadcast notification to check reception management information (step 45,
41).

If the result of checking the contents of the memory 15b is good (step 42), the corresponding counter 16b is initialized to a value of 9 (step 48).
On the other hand, if the value of the counter 16b becomes 1 (step 44), it means that the management information from the communication device 1b has not been received eight times in a row, so the transmitter 17 is activated for the first time and the echo signal is transmitted. Device 1
b (step 46).

In the communication device 1b that has received this echo signal, if the communication device 1b is operating normally, the transmitter 17 is activated and sends back the echo response signal to the communication device 1a.
If the communication device 1a is not operating normally and is in a down state, this echo response signal will not be returned, so a reception determination of this echo response signal is performed on the communication device 1a side (step 47). As a result, if the echo response signal is not received, it is determined that the communication device 1b is down (step 49), and if the echo response signal is received, the counter 15b is initialized (step 48).

The operation shown in FIG. 4 is sequentially performed for each of the memories 15b to 15n within 30 seconds. It is assumed that all of the above operations are performed by a program within the controller 18.

In this way, a communication device that has not been able to receive reception management information from a specific communication device 8 times in a row (this number is not limited and can be multiple times) Since the echo signal is sent out independently for each communication device, if a specific communication device is out of order, all communication devices will be unable to receive reception management information eight times in a row, and all communication devices will receive the specific communication information almost simultaneously. By sending echo signals to each communication device independently, all communication devices can accurately determine that a specific communication device is down only when no response signal is received in response to the echo signal. It will become.

Effects of the Invention As described above, according to the present invention, in addition to continuous non-reception of reception management information, reconfirmation is performed using an echo signal, so there is an effect that reliable management of communication devices is possible.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIGS. 2 to 4 are flowcharts explaining the operation of the blocks in FIG. 1. Explanation of symbols of main parts, 1a to 1n...communication device, 12...broadcast communication unit, 13...timer,
15...Memory device, 16...Timer device, 17
...Transmission section.

Claims (1)

[Claims] 1 A management method for a communication network in which multiple communication devices each containing a terminal device are interconnected via a communication line, in which the status of its own communication device is simultaneously transmitted to all other communication devices at predetermined intervals. Each receiving communication device updates and retains the status of the source communication device each time it receives it, and monitors this retained content if the simultaneous broadcast notification is not received from a specific communication device for a certain period of time. 1. A communication network management system characterized in that a return confirmation signal is sent to this specific communication device, and the state of the specific communication device is determined based on the response state to this confirmation signal.