JPH0260340A - Bas type lan - Google Patents

Abstract

PURPOSE:To grasp trouble generation including a generated part with other node when a trouble occurs at the node by providing the detecting means, collecting means and simultaneous multiple address informating means of the action trouble generated at an application part. CONSTITUTION:To a transmission line 10 composed of a coaxial cable, etc., a control station 1 and ordinary station 2-N to constitute the communication node are connected, and the internal part of the station 1 and the stations 2-N is composed of transmitting parts 1a and 2a-Na and application parts 1b and 2b-Nb. The station 1 has a function to collect respective types of control information including the action condition of the application part of respective stations and execute the simultaneous multiple address information by polling for the stations 2-N. By polling periodically in the station 1, the trouble of the application part only generated at the stations 2-N and the trouble of the transmitting part are classified and grasped and further, these pieces of information are simultaneously multiple-address-informed to the stations 2-N. Thus, when the trouble occurs at the node, the trouble generation including up to the generated part can be grasped with other node.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a bus-type LAN, and more specifically to a bus-type LAN using a token passing method in which transmission is controlled based on a logical ring representing the order in which tokens are sequentially delegated. N
Regarding.

(Summary of the Invention) This invention detects a failure occurring in an application unit provided in a node constituting a lotus-type LAN, and the transmission unit detects the failure data, which is collected by a management station, and then Each node station sends a broadcast notification to each station,
This makes it possible to understand the occurrence of failures in other stations, including the location of the failure.

(Prior art and its problems) As a transmission control method for a bus-type LAN, only stations that have access rights to the transmission path, or so-called tokens, transmit data, and each station connected to the transmission path is controlled by the token. There is a circular token passing method.

Generally, the configuration of each node in this system can be divided into a transmission unit that controls transmission by token passing, and a so-called application unit that utilizes this transmission unit.

Conventionally, when a failure occurs in one of these nodes, the response to periodic polling is either an abnormal frame or no response at all. As a result, other notebooks simply recognize that a fault has occurred, and cannot identify whether the fault has occurred in the transmission section or the application section. The problem was that no effective countermeasures could be taken.

(Purpose of the Invention) This invention was made to solve the above problem, and its purpose is to enable other nodes to detect the occurrence of the failure even when a failure occurs in a node. The object of the present invention is to provide a lotus-shaped LAN that can be understood including the following.

(Structure and Effects of the Invention) In order to achieve the object described in item 1, the present invention provides a bus type system in which transmission is controlled by a token passing method based on a logical ring. In A N, a communication node is composed of a management station and a plurality of normal stations, and a means is provided in the transmission section of each node station to detect an operational failure occurring in an application section that uses the communication function, The present invention is characterized by comprising means for collecting failure occurrence data of the application section to a management station, and transmitting means for simultaneously broadcasting the failure station data collected by the management station to each normal station.

In the lotus-type LAN according to the present invention, the transmission section detects a fault that occurs in the application section provided in the node, and after the obtained fault data is once collected in the management station,
By simultaneously broadcasting notification to each normal station, it is possible to obtain effects such as each node station being able to grasp the occurrence of a failure in another station, including the part where the failure occurred.

(Description of Embodiments) FIG. 1 is a diagram showing the overall configuration of a bus-type LAN according to the present invention.

In the figure, a bus-type LAN is constructed by connecting a management station 1 and normal stations 2 to N, which constitute communication nodes, to a transmission path 10 made of a coaxial cable or the like. The insides of the management station 1 and the normal stations 2 to N each include a transmission section a that implements a communication function, and an application section that utilizes the communication function of the transmission section a. The management station 1 is a communication node in the bus-type LAN, and also polls the other normal stations 2 to N to check the application status of other stations.
It has the ability to collect various management information, including the operating status of the control unit, and to simultaneously notify any failures. The normal stations 2 to N have a function of notifying various management information including the operating status of the application section of the local station in response to periodic inquiries from the management station I.

FIG. 2 is a block diagram showing the internal configuration of the node.

As shown in the figure, the node is divided into a transmission section a and an application section. The transmission section a includes the CPU 21, R
It is composed of an OM 22, a RAM 23, a transmission controller 24, and an internal bus 18 that connects these.

Application part: CP LJ 26, ROM2
7, RAM28, 2 I10 interfaces, 1
, and an internal bus 19 that connects them. Furthermore, the transmission section a and the application section share R.
They are configured to be able to exchange data with each other via AM25.

Application part CI) U26 is ROM2
The shared R8M25 executes various application processes according to the programs stored in the R8M25.
A request is made to the transmitter a to send and receive data via the transmitter a.

The CPU 21 of the transmission unit a controls the transmission controller 24 according to a program stored in the ROM 22, and transmits and receives various frames to and from the transmission path 10 connected to the transmission controller 24.

The RAM 23 of the transmission unit a is provided with a network management information table 30 and a local information area 33, which will be described later.

Further, the shared RAM 25 is provided with a monitoring area 40 for monitoring whether or not the application section is operating normally.

FIG. 3 is a diagram showing the contents of the network management information table 30 and the own station information area 33 provided in the RAM 23.

The table 30 stores various management information regarding each node 1 to N of the network L.
The memory area address within 0 corresponds to the node number of each node 1 to N. The configuration of each memory area is
For example, as shown in the memory area 30-2, it consists of a communicable bit 30a, non-response pins 1 to 30b, an application monitoring bit 30C, and another area 30d.

The communicable bit 30a indicates whether communication is possible based on the logical ring participation state of the corresponding node. When this bit 30a is set to ON, it indicates that the corresponding node has joined the logical ring, and tokens are transferred in the order of the addresses of the nodes set to ON.

The non-response bit 30b indicates whether the normal station node responded to polling from the management station or did not respond. If this bit is set on, it indicates that some kind of failure has occurred in the corresponding node. It is possible that the power is on or the power is not turned on.

The application monitoring bit 30c indicates whether an abnormality has occurred in the application section of the corresponding node, and if this bit is on, it means that an abnormality has occurred in the application section.

Other area 30d stores other management information regarding the corresponding node.

Apart from the table 30 regarding the management information of all these nodes, a local station information area 33 is provided in the RAM 23, in which management information about the local station is stored. Own station information area 3
The configuration of table 3 is the same as table 3゜.
a, a non-response bit 33b, an application monitoring bit 33c, and an other area 33d.

FIG. 4 is a flowchart showing the process when the transmission unit a and the application unit access the monitoring area 40 provided on the shared RAM 25 in the node.

As shown in the figure, the monitoring area 40 provided in the shared RAM 25 is accessed by both the CPU 21 of the transmission unit a and the application unit C)) U 26.

The transmission unit a periodically increments the value of the monitoring area 40 (step 401), whereas the application unit a periodically clears the value of the monitoring area 40 (step 401).
Step 411). As a result, some kind of error may occur in the application section, or CP tJ 2
6 goes out of control, the value of the monitoring area 40 reaches a constant value determined by the system (Yes at step 402), the transmission section a
will detect an abnormality in the application section,
The application monitoring bit 33c of the own station information area 33 existing in the work area on the RAM 23 is turned on (step 403).

FIG. 5 is a diagram conceptually showing a logical ring constructed by polling by the management station 1. In this logical ring, there are 8 nodes each assigned in table 30.
Tokens are transferred in the order of the addresses of the relevant memory areas, and when the tokens go around and reach the normal station 5 at the end,
It is shown that the token returns to the first management station 1.

Figure 6 shows the management station 1 in order to understand the operating status of each normal station.
FIG. 2 is a diagram showing a sequence of polling processing performed by.

The management station 1 counts as one round when the 1--kun goes around the logical ring shown in FIG. 5 and returns, and when the counted value reaches a preset value, Start polling the node that is the station. The number of times the polling frame is sent at this time is also set as a system constant.

The figure shows a sequence when the system constant that specifies the number of times a polling frame is sent is set to 1.

First, the management station 1 sends a polling frame to the normal station 2 based on the order of the addresses in the table 30. Then, if the normal station 2 that received the polling frame is functioning normally, it transmits the data stored in its own information area using the polling response frame. Here, if the normal section 2 is not functioning normally, for example, the power is not turned on or some kind of failure has occurred in the transmission section a, there is no response.

From the responses to polling obtained in this way,
The status of the normal unit 2 is grasped, and the information is stored in the memory area of the corresponding address of the table 30 in the management station I.

Next, when the polling frame has been sent a predetermined number of times, the updated network management information of the table 30 is broadcasted to each normal section at once.

Here, again, the token bar shown in FIG.

Shing processing is started. Note that the polling frame transmission 8 for understanding the next normal section operation will be performed for the next normal section 3.

FIG. 7 is a flowchart 1 showing the processing performed by the management station 1 in order to grasp the operating status of the normal section.

In the figure, when the token returns to the management station 1 and it is time to execute the polling process, a polling counter provided in the RAM 23 or the like is cleared (step 701).

Next, the value of this polling number counter is compared with a permissible value of the number of polling times set in advance as a system constant (step 702).

If the value of the polling number counter is less than the allowable number of times (No in step 702), a partner station to send the polling frame is selected (step 703). The normal section selected here is the node station whose address is the address of the node station to which the last polling frame was sent during the previous polling process plus 1.

Next, the management station 1 sends the polling frame 11 to the selected normal section (step 704), and waits for a response from the normal section (step 705).

If a polling response frame is transmitted, each bit in the corresponding memory area of the table 30 is updated according to the received data contents (step 706), then the polling number counter is incremented (step 708), and the process goes to step 702. move on.

If no response is obtained in response to the polling frame transmission, set the no response bit 30b in the corresponding memory area of the table 30 to on in step 707.
), then the polling number counter is incremented (step 708), and the process proceeds to step 702.

Furthermore, if a frame other than the polling response frame is received, corresponding processing is performed.

Thereafter, processing continues until the value of the polling counter reaches the set value, and if the two match (determined in step 702), the updated data in the table 30 is sent to each normal section as network management information. Notify me (
In step 709), the process of determining the operating status of the normal section is ended, and the process proceeds to the token passing process.

In addition, in this polling process, polling is started when the token returns to the management station and the set timing for executing the polling process has come, but the process is started only if there is enough time to circulate the token. It can also be set.

FIG. 8 is a flowchart showing the process when the normal unit notifies the operating status.

In the figure, the normal section receives various frames in an idle state and performs processing such as content identification (step 801).

Next, determine the type of the received frame (step 8
02).

If the received frame 11 is a 1.-kun frame, token reception processing is performed (step 803).

If the received frame is a polling frame, a token response frame containing the contents of the local station information area is transmitted to the management station (step 804).

If the received frame is a network management information frame, the network management information table 3p is updated based on the data of this received frame (step 805).
).

If the received frame is a data frame, data reception processing is performed (step 806).

When each of these frame reception processes is completed, the process returns to step 801 and the next frame reception process is performed.

As is clear from the following two processes, in this invention, by periodically polling performed by the management station, failures occurring only in the application section and failures in the transmission section that occur in the normal station are distinguished from each other and reported to the management station. This network management information is understood and furthermore, the collected network management information is sent to each regular station.
- Simultaneous notification will be sent. As a result, the management station and each normal station can grasp the status of other stations where a failure has occurred, including the location where the failure has occurred.

In this invention, since the location of the failure in the node where the failure has occurred is revealed, the response to the node where the failure has occurred is more accurate than before, and the network can be operated more efficiently. Can be done.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of a bus-type LAN according to the present invention, FIG. 2 is a block diagram showing the internal configuration of a node, FIG. 3 is a configuration diagram of a network management information table, and FIG. 4 is a transmission unit in a node. and a flowchart showing the operation of the application section, FIG. 5 is a diagram conceptually showing the logical ring,
FIG. 6 is a diagram showing the sequence of polling processing in the management station, FIG. 7 is a flowchart showing the operation of the management station,
FIG. 8 is a flowchart showing the operation of the normal station. 1...Management station (node) 1a...Transmission section 1b...Application section 2-N...Normal station (node) '1a-Na... ...Transmission section 2b-Nb...Application section 10...
...Transmission line 18.19...Internal bus 2], 26...CP LJ 22.27...ROM 3 28...RAM 4... ...Transmission controller 5...Shared RAM 9...I10 interface O...
Network management information table Oa... Communication enabled bit ob... No response bit Oc... Application monitoring bit 3...
... Own station information area 0 ... Monitoring area

Claims (1)

[Claims] 1. In a bus-type LAN in which transmission is controlled by a token passing method based on a logical ring, a communication node is composed of a management station and a plurality of normal stations, and a communication node is provided in the transmission section of each node station, A means for detecting an operational failure occurring in an application section that uses communication functions, a means for collecting failure occurrence data of the detected application section at a management station, and a means for transmitting the failure station data collected by the management station to each normal station. A bus-type LAN characterized by comprising: a transmitting means for simultaneously broadcasting a notification to; and a bus-type LAN.