JPS61224757A - Switching control system for communication controller - Google Patents

Abstract

PURPOSE:To improve the profitability and reliability of a communication system by providing plural processors, a state latch, a control circuit and a switching display circuit or the like to duplex the controller and to attain automatic changeover. CONSTITUTION:When a processor 1-1 detects that any fault is detected by a communication controller 10-1, the control for a prescribed fault processing is applied and when it is is discriminated that the recovery is disable, a state latch 12-1 is reset and the controller 10-1 becomes a standby controller. When a control circuit 15 detects that the latch 12-1 is changed into a faulty state, a line connector 13 changes over a switch circuit 17 to connect to a communica tion controller 10-2. Thus, a processor 11-2 is operated as an active processor via a changeover display circuit 14-2 of the controller 10-2. The processors 11-1, 11-2 and the state latch 12-1 or the like are provided in this way, then the automatic changeover of the communication controller is made posible in a comparatively small system and the profitability and the reliability of the communication system are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] This is a control method for automatic switching of a communication system having two communication control devices of active/backup configuration and a line connection device for connecting lines. When the communication control device detects a fault in itself, it puts itself into a standby state and notifies the line connection device. The line connection device uses this signal to switch the connection to the previous standby device, and sends a signal to that device to shift it to the active state.

[Industrial application field]

The present invention relates to a failure of a communication control device in an information processing system that has two communication control devices in active/backup configuration and a line connection device for connecting a line to the communication control device in active state. The present invention relates to a control method for automatic switching at times.

When connecting communication lines to an information processing system, connect the required communication lines to a so-called line connection device, which is composed of an interface circuit for each communication line, and connect this line connection device to a communication control device. executes communication control of those communication lines.

Communication control devices were normally connected to computer channels as a type of peripheral device of a central computer, but in recent years, as the communication networks of information processing systems have become larger, the economic structure of communication networks has changed. With this in mind, a communication control device is also installed near a remote terminal device to converge the lines.

Communication control equipment is often configured in a duplex configuration to improve the reliability of the communication system, and is used as a working/backup switch. In the case of installed communication control equipment, it is desirable to automate switching when a failure occurs in order to shorten switching time.

[Prior Art and Problems to be Solved by the Invention] FIG. 3 is a block diagram showing an example of a duplex configuration of a conventional remote subcenter communication control device.

In FIG. 3(a), both the terminal line 1 on the right side of the figure and the center-to-center computer line 2 on the left side are not duplicated, and the communication control device 3-1.3-2 and line connection device 4-1.4 The communication control system 5-1, 5-2 consisting of the communication control systems 5-2 and 5-2 are made redundant, and the connections between them and the lines are switched by a changeover switch 6.

FIG. 3(b) shows a configuration in which the computer lines 7-1 and 7-2 for the center are duplicated in correspondence with the communication control systems 5-1 and 5-2. The center computer side is, for example, a communication control device directly connected to the center computer, and the line? -1,7
-2 is selected as the current one.

Since the main parts of the line connection devices 4-1 and 4-2 consist of individual interface circuits corresponding to each terminal line, there is no problem in this device that would disable communication on all terminal lines. It rarely occurs.

However, in any of the cases shown in Figure 3 (a), mountain), the communication control device and the line connection device are configured as one unit without considering duplication, so when adopting a duplex configuration, , the entire communication control system including both must be duplicated, and as a result, the subcenter tends to become larger and more expensive than necessary.

In addition, switching between the active and backup systems is only performed by manually operating the selector switch 6 or 8 after detecting a communication abnormality on the central computer, for example.
There is a problem in that it takes time to resume normal communication after a failure occurs.

[Means for solving problems]

FIG. 1 is a block diagram showing the principle configuration of the present invention.

The switching circuit 1 accommodates two communication control devices 10-1 and 10-2 and terminal lines, which operate as active devices or standby devices.
7, a line connection device 13 is provided to connect to one of these communication control devices.

Each communication control device 10-1, 10-2 has a switching switch that holds a signal 18-1, 18-2 indicating the occurrence of a failure in the communication control device, and a signal on a connection switching notification line 19 from the line connection device 13. By the signal of the display circuit 14-1.14-2,
Processor 11-1.11-2 that controls its own state etc.
There are also status latches 12-1 and 12-2 for displaying their own failure status and notifying the line connection device 13.

The line connection device 13 includes status latches 12-1, 12-2.
A control circuit 15 that performs switching control by detecting a signal from the switch, and a notification line 19 that notifies switching are provided.

[Effect]

For example, when the power is turned on, the processor 11-1.11-2
Communication control device 1
They each set themselves so that 0-1 operates as the active machine and the communication control device 10-2 operates as a standby machine, and the state launch 12
-1.12-2 displays normal status, line connection device 13
is connected to the communication control device 10-1 of the current machine.

A failure display line 18-1 indicates that a failure of some kind has been detected in the communication control device 10-1.
1 is detected, it executes control for predetermined fault handling. If it is determined that recovery is not possible, the status latch 12-1 is reset to indicate the failure status, and the unit itself becomes a standby machine.

When the control circuit 15 detects that the status latch 12-1 has changed from the normal state to the failure state, the line connection device 13 switches the switching circuit 17 to connect to the communication control device 10-2, and also connects the notification line to the communication control device 10-2. Send a switching signal to 19.

The switching display circuit 14-2 of the communication control device 10-2 is configured so that, in the case of a standby device, the output is reset to turn off, and the output is turned on by the signal 19, and the processor 11-2 , detects its output signal and operates as a working machine.

With the above configuration, the communication control device can be duplicated using a relatively small system, and automatic switching can be performed.

It is a diagram.

Assume that the communication control devices 10-1 and 10-2 are in a normal state as described above, and the communication control device 10-1 is connected to the line connection device 13 as an active device.

In this state, the latch 24 of the switching display circuit 14-1
-1 maintains the initial state and inputs an on signal to the processor 11-1, and the latch 24-2 is reset by the processor 11-2.

Since the status latches 12-1, 12-2 are all displaying normal status, their outputs vA20-1, 20-2 are both on, but the line connection device 13 is connected to the switch of the switching circuit 17. The output line 20-1 on the active side is monitored by switching by the switch 21 of the interlocked control circuit 15.

As mentioned above, when a failure occurs in the communication control device 10-1, the processor 11-1 outputs! The status latch 12-1 is reset to turn off the power supply 20-1, and the latch 24-1 is reset since it becomes a standby machine.

In the line connection device 13, the latch 22 is reset when the output line 20-1 is turned off. latch 22
Due to the reset, the latch 23 is also reset in the next control cycle, but an on signal is sent to the connection switching notification line 19 until the latch 23 is reset.

This signal is transmitted to the status latch 1 in the communication control device 10-1.
2-1 has been reset, the output is blocked, and the communication control device 10-2 inputs the input to the border 24-2 and resets the output to turn on.

The output signal of the latch 24-2 is input to the processor 11-2 through the signal line 25-2, and the program executed by the processor 11-2 detects that the system has been switched to the active machine.

The signal on the connection switching notification line 19 is simultaneously input to the switch holding circuit 26 and generates an output that switches and holds the switching circuit 17 and switch 21 to the opposite side.
The line control device 13 is connected to the newly used communication control device 10-2.

Due to the above switching, the ON signal of the output line 20-2 is input to the latch 22, so the latch 22 and then the latch 23 are
will be reset to its original state.

Therefore, in this state, if a failure occurs in the communication control device 10-2 and the status latch 12-2 is reset by the processor 11-2 in the same manner as described above, the line connection device 13 performs the same switching as described above. If the operation is performed and the communication control device 10-1 is in a normal state, it can start operating as an active device again.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the communication control device can be duplicated using a relatively small system, and automatic switching is possible, thereby improving the economic efficiency and reliability of the communication system. This has a significant industrial effect.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the principle configuration of the present invention, FIG. 2 is a block diagram of an embodiment of the present invention, and FIG. 3 is a block diagram of a conventional duplex configuration. In the figure, l is the terminal line, 2.7-1.7-2 is the center computer line 3-1, 3-
2.10-1.10-2 is a communication control device, 4-1, 4-
2.13 is the line connection device, 6.8 is the changeover switch, 1
1-1.11-2 is a processor, 12-1.12-2 is a status latch, 14-1.14-2 is a switching display circuit, 15 is a control circuit, '17 is a switching circuit, 19 is a connection switching notification line , 22.23 is a latch, and 26 is a switch holding circuit f! -Yu 5 Sun Moon 6 Principles 1 Crest Philosoph Figure 1 Figure 1 F4 also aH Tsuimonomon] Part 1\blots 7th episode! 2 Sono I L, 〒, Mejit Hizo Tsuzuri I゛] Furotsu 2 Ward Kaya 3 Sono

Claims (1)

[Claims] Two communication control devices (operating as active or backup devices)
10-1, 10-2), a line connection device (13) selectively connected to the communication control device (10-1, 10-2) of the current machine is provided, and each communication control device (10-1, 10-2) means (11-1) for setting itself in a failure state and transitioning to a standby operating state when detecting the occurrence of a failure in the communication control device;
, 11-2), means (12-1, 12-2) for notifying the line connection device (13) of the fault condition, and a signal from the line connection device (13) to switch from the backup device to the active device. means (14-1,
14-2), and the line connection device (13) has the notification means (12-1, 1
2-2), the communication control device (10-1,
means (15) for detecting that the communication control device (10-2) is in a failure state and switching the connection from the communication control device to the other communication control device, and to both the communication control devices (10-1, 10-2); , a communication control device switching control system comprising means (19) for notifying the connection switching.