JPH02224545A - Local area network - Google Patents

Abstract

PURPOSE:To attain early recovery by providing a transmission section sending a token count stored in a token count section through the reception from a token count acquisition command transmission section to a local area network connection device. CONSTITUTION:A token count section (f) of a local area network connector LIU#i clears a token count by an initializing command from a common control section (e). Then the token count section increments the token count by one every time the detection of a token is informed from a token detection transmission section (d). The token count is inputted to a token count response transmission section (g) and sent as a token count response by a transmission command from the control section (e) to a transmission section (g). A token count acquisition command transmission section (h) of a loop monitor SVU sends a token count acquisition command to the transmission line with the command transmission command from a common control section e'. Each acquired token count is compared to specify the transmission line period with less token count.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is used for controlling a token passing loop type network. The present invention relates to detection of intermittent failures in token passing occurring on a loop.

〔overview〕

The present invention monitors the token passing state and transmits a new token to the network when token passing is interrupted for a predetermined time.In a local area network, the token count value of each connected device connected in a loop is sent to a loop monitoring device. By importing and comparing the respective token count values, it is possible to identify transmission line sections or connection devices where token loss is likely to occur, identify the location where intermittent failures occur, and repair them at an early stage.

[Conventional technology]

Conventionally, in this type of token-passing loop type network, if the loop monitoring device that monitors the operating status of the entire network does not return the previously sent token to the loop monitoring device even after a certain period of time determined by the network has passed. In this case, the token was assumed to have disappeared on the loop network, and a new token was sent to the loop network to prevent network operation from stopping due to the interruption of token passing.

[Problem that the invention seeks to solve]

With conventional control methods, it is possible to prevent the entire network from going down due to intermittent token loss, but it is necessary to identify which connected devices or transmission line sections on a loop network are likely to experience token loss. However, it is difficult to quickly identify and eliminate defective areas where intermittent failures occur.

The present invention is intended to eliminate such drawbacks, and aims to provide a network that can identify connection devices or transmission line sections where token loss is likely to occur, and identify faulty locations at an early stage.

[Means for solving problems]

In the present invention, one loop monitoring device and a plurality of local area network connection devices are connected in a loop through a transmission path, and the loop monitoring device monitors a token passing state, and when token passing is interrupted for a predetermined period of time. In the local area network, the local area network is provided with a means for transmitting a new token to the network, and the local area network connecting device includes a token counting unit that counts the number of tokens received from the network and relayed to the network, and the loop monitoring device To,
a token count acquisition command sending unit for instructing to transmit the token count value stored in the token counting unit of the local area network connection device specified in the command; The present invention is characterized by comprising a token count response sending unit that sends the token count value stored in the token counting unit to the network upon receiving a command from the count acquisition command sending unit.

[Effect]

The token counting unit of the local area network connection device counts and stores the number of tokens received from the network and relayed to the network.

The token count acquisition command sending unit of the loop monitoring device instructs the local area network connection device specified in the command to send the token count value stored in the counting means, and receives the token of the local area network connection device that receives this instruction. The count response sending unit sends the token count value stored in the token counting unit to the network.

In this way, the local area network connection device specified in the command responds to the token count acquisition command newly added to the loop monitoring device and sent, and transmits the token count stream stored in the token counting means to the network. This makes it possible to identify transmission line sections and connection devices with low token counts due to intermittent failures, etc., and to enable early repair.

〔Example〕

Next, embodiments of the present invention will be described based on the drawings.

FIG. 2 is a block diagram showing the overall configuration of a token passing loop type network according to an embodiment of the present invention. In its overall configuration, a loop monitoring device SVU and local area network connection devices LIU#0 to LIU#n are connected in a loop through transmission lines .about.L, . . . , L.

Figure 1 shows the second [! FIG. 1 is a block diagram showing the internal configuration of the local area network connection device LIU#i and the loop monitoring device SVU shown in FIG. Here, only the i-th device LIU#i of the local area network connection devices is shown. Local area network connection device LIU#i
and the loop monitoring device SVU have almost the same functions, and the common control unit e, e' determines whether or not to incorporate the local area network connection device LIU#i and the loop monitoring device SVU into a loop network. Relay control unit aS switched by control of e and e'
a' and a transmission path via relay control units a and a',
A reception control unit that receives information manually input from Ls, b
' and local area network connection device LIU#
When i and the loop monitoring device SVU each hold a token and have the transmission right, the transmission path is transmitted via the relay control unit aSa' according to an instruction from the common control unit eSe'. SLt++
Detects token information from the transmission path information received via the transmission control units c and c' and the relay control unit a1a' and notifies the common control unit eSe' of the token detection. , e' includes a token detection and transmission unit dSd' that sends the held token to the transmission path upon notification of completion of token holding from e'. 1 is equipped with a token counter f that counts the number of tokens received from the network and relayed to the network, and the loop monitoring device SVU is equipped with a local area network connection device L specified in the command.
The IU#1 is provided with a token count acquisition command sending unit that gives an instruction to send the token count value stored in the token counting unit f, and the local area network connection device LIU#i is provided with a token count acquisition command sending unit. The token counting response sending unit g is provided to send the token count value stored in the token counting unit f to the network upon receiving a command from the token counting unit f.

Next, the operation of the embodiment of the present invention configured as described above will be explained.

When the token detection and transmission unit d of the local area network connection device LIU#i detects a token on the transmission path LL, it notifies the common control unit e of the token detection and also notifies the token counting unit f of the token detection. The token detection and transmission unit d' of the loop monitoring device SVU is configured to be able to send a token to the transmission line even in response to a token regeneration instruction from the common control unit e' due to the token not being detected on the transmission line for a certain period of time.

After the token counting unit f of the local area network connection device LIU #1 clears the token count value to 0 according to an initialization instruction from the common control unit e, it outputs a token every time it is notified of token detection from the token detection sending unit d. Add 1 to the count value.

The token count value is input to the token count response sending unit g, and is sent to the transmission line as a token count response by a sending instruction from the common control unit e to the token count response sending unit g. The token count acquisition command sending unit of the loop monitoring device SVU sends a token count acquisition command to the transmission line in response to a command sending instruction from the common control unit e'.

Figure 3 shows the token count acquisition command sent by the loop monitoring device SVU and the local area network connection device L.
An example of the format of the token count response that the IU responds to is shown below. When the token count acquisition command shown in FIG. and
S, SVU is the loop monitoring device SV that generated this command.
This is the address of U on the network, and COM stores the token count acquisition command value.

Also, the token counting response glue shown in FIG.

SVU is a copy of the value stored in the S, SVU field of the token count acquisition command and indicates the loop monitoring device SVU from which the token count response should be received, and S, LIU is the copy of the value stored in the S, SVU field of the token count acquisition command.
It is a copy of the value stored in the field and indicates the local area network connection unit LIU that sent the token count response, and T, CUNT indicates the number of tokens received before counting the token and sending the response.

After the local area network connection device LIU is initialized, the token counting unit f increases the token count value by 1 every time it is notified of token detection on the transmission path from the token detection sending unit d.
are doing. When the token count acquisition command sending unit of the loop monitoring device SVU sends a token count acquisition command to the transmission path according to the instruction from the common control unit e', this command is sent to the local area network connection device LIU#i specified in the LIU field. This command is immediately received by the reception control unit of the common control unit e, and the common control unit e recognizes the reception of the token count acquisition command to the reception control unit.

Thereafter, the token detection and transmission unit d notifies the reception of the token, and this local area network connection device LI
When U#i has the transmission right, the common control He transfers the LIU, S, and SVU information stored in the token count acquisition command to the token count response sending unit g, and issues a token count response sending instruction.

The token counting response sending unit g receives the information transferred from the common control unit e and takes the LIU, S, and SVU information of the token counting response S, LIU, respectively, and stores them in the SVU field. Token count response T, CU
After storing it in the NT field, it is sent to the token count response transmission path.

The token count response sent to the transmission path is received by the reception control unit a' of the loop monitoring device SV'U in the same way as normal data. Local area network connection device L
After sending the token count response, IU#i sends the reserved token to the transmission path in the same way as after normal data transmission.

〔Effect of the invention〕

As described above, according to the present invention, the loop monitoring device obtains the token count value of each connected device connected to the loop network, and compares the obtained token count values. It is possible to identify a transmission line section and a connecting device with a small number of tokens by considering the order of the connected connecting devices, which has the effect of allowing early repair.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a local area network connection device and a loop monitoring device according to an embodiment of the present invention. FIG. 2 is a block diagram showing the configuration of a token passing loop type network according to an embodiment of the present invention. FIG. 3 is a diagram showing a format example of a token count acquisition command and a token count response according to an embodiment of the present invention. SVU...Loop monitoring device, LIU#0 to LIU#n
...Local area network connection device, L. ~L, , Ls... Local area network transmission line, a, a'... Relay control unit, bSb'... Reception control unit, c, c'... Transmission control unit, d, d' ...
Token detection sending unit, e, e'... common control unit, f.
... Token counting section, g... Token counting response sending section, h... Token counting acquisition command sending section.

Claims (1)

[Scope of Claims] 1. One loop monitoring device and a plurality of local area network connection devices are connected in a loop through a transmission path, and the loop monitoring device monitors a token passing state, In a local area network equipped with means for transmitting a new token to the network when time is interrupted, the local area network connecting device includes a token counting unit that counts the number of tokens received from the network and relayed to the network, a token count acquisition command sending unit for instructing the loop monitoring device to transmit a token count value stored in the token counting unit of the local area network connection device specified in the command; A local area network characterized in that the connecting device includes a token count response sending unit that sends a token count value stored in the token counting unit to the network upon receiving a command from the token count acquisition command sending unit.