JPH01286543A - Network type hierarchy annular communication method - Google Patents

Abstract

PURPOSE:To improve the response and reliability by connecting a subsequent communication line directly, and devising the method such that a detouring circuit is used automatically even if an information exchange module of one location is failed. CONSTITUTION:The system consists of a host communication line 1 and subsequent communication lines 2, 2', the host and subsequent communication lines are connected by an information exchange module 3 and the subsequent communication lines 2, 2' are coupled by an information exchange module 4. Thus, the detouring circuit of information is ensured in the event of faulty exchange modules 3, 4 or traffic congestion and the information is communicated to the information transmission destination in a shortest distance. Thus, the response and reliability are improved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is a network-type ring communication method in which a plurality of peer-to-peer ring communication paths are all connected by an information exchange module, and is particularly applicable to chemical, steel, and power plants. The aim is to apply this method to OA equipment, but it can also be applied to OA equipment.

[Conventional technology]

The basic model of a conventional network consists of a lower-level communication path that connects a plurality of functional modules and an upper-level communication path that connects a group of lower-level communication paths.

For this reason, if an information exchange module connecting one communication path fails or there is a traffic jam, communication with the upper communication path or other lower communication paths becomes impossible, and there is a possibility that the system will go down.

In addition, as related to the present invention, for example, Hitachi Hyoron (1987, VoL69) P, 5-Figure 5rPLANET
There is a basic model for a campus network in

[Problem to be solved by the invention]

The above conventional technology has the following problems.

(1) Communication between one communication path becomes impossible due to failure of the information exchange module between the upper communication path and the lower communication path, or due to traffic congestion.

(2) Although the communication is between lower-level communication channels, data is sent to the higher-level communication channel and then transmitted again to the target lower-level communication channel, resulting in poor responsiveness.

(3) Data on all lower-level communication channels is concentrated on the upper-level communication channel, and the channel occupancy rate of the upper-level channel increases.

An object of the present invention is to solve the above problems at a low cost.

[Means to solve the problem]

The above objective is achieved by installing an information exchange module between the lower communication channels.

Regarding (1) above, information is transmitted from an adjacent lower-level communication path to an upper-level communication path via an information exchange module between lower-level communication paths. The response frame is also transmitted through the same route.

In (2), data is directly transmitted from a lower-level communication path to an adjacent lower-level communication path by an information exchange module between lower-level communication paths without passing through the upper-level communication path.

This improves responsiveness between lower-level communication channels.

(3) Furthermore, information between lower-level communication channels is not transmitted on the upper-level communication path, and the channel occupancy rate of the upper-level channel decreases.

[Effect]

The above method shows a method for improving responsiveness and reliability as a transmission method of the hierarchical communication system, but malfunctions may occur because the detour is determined according to the detour address management table described later. There's nothing to do.

〔Example〕

An embodiment of the present invention will be described below.

The overall configuration of the system will be explained with reference to FIG.

This system consists of an upper communication path 1 and a lower communication path 2.2', and the upper and lower communication paths are connected by an information exchange module 3. Further, the lower communication paths 2 and 2' are connected by an information exchange module 4. The number of each communication path (hereinafter referred to as loop Nα) is
A, the lower communication paths 2 and 2' are denoted by &B and &C, respectively, and each station expresses its own address as a loop Ha and Na.

The structure of a transmission packet will be explained with reference to FIG.

The packet consists of a flag (F), destination address (A) 6, command (C), own station address (SA) 7, and data (D
It consists of an error check (CRC) and an error check (CRC). The local address 7 is indicated by the local loop number 10, and the destination address (A) 6 is a loop address, 10 + station address 11, and a detour address. 11 bit to 18 bit detour second address 9. 19 bit to IF bit detour first address 8. The 18th bit indicates the enable bit of the second detour address, and the IF bit indicates the enable bit of the first detour address 8.

Next, the address set at the time of packet transmission will be explained with reference to FIG.

Assume that a transmission request is generated for station 21 in loop NQB and station 22 in loop &C. In the traditional method,
The packet sent from loop NaB=21=
Received at 11. ni=11 sends to loop &A, and ni=12 in loop &A receives. Furthermore, ni=12 is
It was transmitted to Loop&C and received by 22 stations on Loop&C.

In this method, the address table shown in FIG. 3 is registered in each station. This table is created and registered for each loop rod, but
Stations in the same loop will have the same table. Third
The figure shows the address table of Loop &B.

Since the paget is now sent from loop NaB to loop NaC, the shortest address from the table is 13°oO. In other words, the detour first address 8 is set to 13, and the Enable
e bit sets 1. The second detour address 9 is 00
shall be. In other words, it is transmitted via the 13 stations in the loop NctB to the 22 stations in the loop NaC over the shortest distance. If the information exchange module 4, which has 13 stations, is out of order or in a traffic jam, detour addresses 11 and 12 are set. In other words, the detour first address 8 is set to 11, and the Enable
Set up an e-bit.

Next, set the detour second address 9 to 12 and enable bi
Make a t. This causes the packet to loop &B =
It takes a detour that passes through stations 11 and 12 and reaches station 22 in the loop NaC. At this time, information exchange module 3
When passing through, set the Enable bit to O.

Next, a packet transmission flowchart will be explained with reference to FIG. As assumed in the previous section, the loop Ha B = 21
Assume that the station transmits to 22 stations in the loop NαC.

A transmission request 21 is generated to 21 stations in the loop HaB. Not transmission 22 within the same loop of loop NnB,
Since it is not retransmission 23 or retransmission 24, a new address set 25 is performed and transmission 26 is performed. In the case of repeat transmission 24, CRT
An abnormality is displayed. In the case of retransmission 23, the same data as the first transmission packet is retransmitted 28. The same procedure applies to transmission within the same loop.

In FIG. 5, the routine shown in FIG. 4 is expressed as a subroutine. "Address set 25" is shown. As explained in the section of the address table in FIG. 3, first, the loop Nl1B and the station Arashi 21 are set 31 in the local station address (SA) 7. It is checked (33) whether the information exchange module 3 which is closest to the 0th order and which sets (32) loop NaC and station Na22 to the destination address (A) is normal. If normal, the shortest address is set as the first detour address according to the address table, and enable bet is set 34. If it is abnormal, confirm 35 that the detour information exchange module is normal, and set the detour address to the first. 2nd set enable bit 3
6.

FIG. 6 shows a packet reception flowchart.

Now, the packet transmitted from the 21st station in the loop NaB enters the reception buffer of the information exchange module 4, which is the 13th station 41. Enable the first detour address
Determine whether the bit is set to 1. If 1 is set, it is checked 42 whether the local station address and the first detour address of the packet match. If it matches, enable bi
Erase t43. Set a bit indicating that there is a transmission request for loop C44. Also.

If there is no enable bit in the first detour address,
Determine whether the enable bit is set in the second detour address and check whether the address matches the address of your own station 45
do.

If they match, delete the enable bit 43° If they do not match, set a bit indicating that there is a transmission request for loop & C 44° Next, set the enable bit to the first and second detour addresses If there is no address, determine whether the destination address of the packet matches the local station 47. If they match, reception processing 48 is performed. If they do not match, the packet is determined to be unrelated to the local station.

〔Effect of the invention〕

According to the present invention, there are the following effects.

(1) Lower communication paths are directly connected, resulting in faster responsiveness of communication between lower communication paths and improved controllability.

(2) Conventionally, all communications between lower-level communication paths have passed through upper-level communication paths, and the present invention reduces the communication path load factor of the upper-level communication paths.

(3) Conventionally, the information exchange module that links communication channels has been a bottleneck in terms of reliability.

According to the present invention, even if one information exchange module fails, it is possible to automatically transmit information using a detour, and the man-machine performance and reliability of the system are improved.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of network-type hierarchical circular communication, Figure 2 is a packet configuration diagram, Figure 3 is a diagram showing an address table, and Figure 4 is a diagram showing the address table.
This figure is a transmission flowchart, FIG. 5 is a diagram showing an address set subroutine, and FIG. 6 is a reception flowchart. DESCRIPTION OF SYMBOLS 1... Upper ring communication path, 2, 2'... Lower ring communication path, 3.4... Information exchange module, 5... Function module, 6... Destination address, 7... Own station address. Figure 1 Figure 3 Mouth Figure 6

Claims (1)

[Claims] 1. In multiple peer-to-peer circular communication channels that connect multiple functional modules, all of the circular communication channels are connected by an information exchange module, so failure of the exchange module,
A network-based hierarchical circular communication method that is characterized by making it possible to secure a detour for information during traffic jams and communicating over the shortest distance to an information destination.