JPS60182823A - Automatic switching system - Google Patents

Abstract

PURPOSE:To attain sure switching by allowing a control unit to transmit a pulse to plural units in succession with a selection signal and allowing each unit to judge the pulse signal as an effective switching signal. CONSTITUTION:If a fault takes place in duplicated units 101, 102, fault information is transmitted to the control unit 103 via lines 105, 106. The control unit 103 returns a unit selection signal to the units 101, 102, the units 101, 102 receive the signal at D FFs 210, 211, then a unit selection signal reading pulse outputted from the control unit 103 is used as a trigger, fetches in each unit and unit selection signals 212, 213 are used as the information whether the unit is used actually as an active device or a spare device. Thus, the possibility of malfunction is less even if level fluctuation or noise exists on the control lines 107, 108 attanded with generation of a fault, and the state just before is held succeedingly even if a controller is disconnected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to an automatic switching system for devices such as information processing devices or communication devices configured in a multiplexed manner to improve reliability. In particular, the present invention relates to an improvement in a system for automatically switching multiplexed units 1- to active or standby.

[Description of prior art]

Conventionally, automatic switching of redundant configuration equipment concentrates fault information from the redundant units in the control unit.
Based on this information, a unit selection signal indicating whether each unit is in use or as a reserve is output to each unit at a binary level, and each unit is selected as being in use or as a reserve depending on the level of the unit selection signal from the control unit. This is the method.

FIG. 1 is a block diagram of a conventional automatic switching device. In FIG. 1, a duplicated unit 101.1
Information as to whether 02 is normal or a fault has occurred is sent to control unit 03 via fault information lines 105 and 106. Then, the control unit 103 determines which unit is to be used as a working unit or a standby unit based on these receiving devices, and sends the unit/node selection signal to the duplicated unit via a control line 107.10B. 101.1
Send to 02 at binary level. In this case, if both units are in a normal or failed state, one will be in active use and the other will be in reserve (essentially, either will do). Furthermore, if one of the units is in a faulty state, the control unit 103 determines that the faulty unit becomes the spare and the other unit becomes the active unit. Duplicated unit 0
At 1.102, the level of the uni-node selection signal sent through the control lines 107 and 108 is detected, and a state corresponding to that level is established. In this way, automatic switching between duplicated uni-nodes is performed,
In this method, the control lines 107.10B are susceptible to noise and level fluctuations from other sources. In this case, control uni-no) 103, albeit for a short time.
Unit 10i, 1 which is duplicated with the level output by
There is a risk that the input level of 02 will be the opposite or will be in an incorrect state. Also, the control unit 10
If 3 is pulled out, control line 107
．． 108 are both temporarily in an open state, and as duplex units 101 and 102, both receive inputs indicating the same state, and both may become active or standby.

Therefore, in this conventional method, each unit l-101,1
There is a risk of making a mistake in determining whether 02 is in active use or as a standby. Furthermore, if control unit 103 is removed, not only will automatic switching not be possible, but control unit 103 will not be able to switch automatically.
There were drawbacks such as the inability to maintain the normal state immediately before being removed.

[Purpose of the invention]

The present invention eliminates the above-mentioned drawbacks, eliminates the error in determining whether the unit is in use or a spare due to level fluctuations in the unit selection signal from the control unit, and even when the control unit is removed, the normal operation is maintained until just before the control unit is removed. The purpose is to provide an automatic switching method that maintains the state.

[Features of the invention]

The present invention is the same as the conventional system up to the point where a control unit selection signal is output to each unit, but this alone does not determine whether each unit is in active use or in reserve. The control unit outputs a unit selection signal read pulse after the unit selection signal to each multiplexed UNISO 1-, and each unit first outputs the unit selection signal read pulse sent from the control unit to the unit selection signal read pulse. It is configured to use a trigger to determine whether the unit is in use or standby, and then maintain the state where it is first determined (27) until the unit 1 is input again and the selection signal read pulse, and whether it is in use or standby by the unit selection signal There is no error in judgment, and even if the control unit is removed, it maintains the normal state it was in just before it was removed.

That is, the present invention includes a plurality of units, each of the plurality of units is provided with a means for transmitting failure information, and receives this failure information and sends a selection signal to one of the plurality of units, UNISO 1-. In an automatic switching system equipped with a control unit that controls one unit to operate as a working unit and the other unit to stand by as a standby unit, a pulse signal is sent to the control unit after the selection signal is sent out. have the means,
Each of the plurality of units is characterized in that it is provided with means for reading the received selection signal as valid by the pulse signal.

[Explanation based on examples]

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

FIG. 2 is a block diagram of an automatic switching system according to an embodiment of the present invention. In FIG. 2, the same parts as in FIG. 1 are designated by the same reference numerals. Fault information from the duplicated units 101 and 102 is connected to the control unit 103 via fault information lines 105 and 106. Unit selection signals are output from the control unit 103 to control lines 107 and 108, respectively.

Here, the feature of the present invention is the flip-flop portion surrounded by a dashed line. That is, the flip-flops 210 and 211 are D-type flip-flops, to which the D-type control lines 107 and 108 are connected, respectively. In addition, a unit selection signal read pulse is sent from the control unit 103 to the flip-flops 210 and 210 via the unit selection signal read pulse line 209.
Connected to the T input of 1. flip flop 210.2
The Q output from 11 is sent out when the T input arrives;
It is used as information on whether the unit is currently in use or on standby in the duplicated units 101 and 102.

The operation of the automatic switching method of the duplex configuration device having such a configuration will be explained. In Fig. 2, the fault information is sent from the duplicated units 101 and 102 to the control line 103, and the unit selection signal is returned from the control unit 103 to the duplicated units 101 and 102, as shown in Fig. 1. Same as example. The duplicated units 101 and 102 receive the unit selection signal at Frisopflo 7'' 210 and 211,
Thereafter, a unit selection signal read pulse outputted from the control unit 103 is taken into each UNISO 1- as a trigger, and the unit selection signals 212 and 213 are used as information as to whether the unit will be used in actual use or as a backup. By doing this, even if there is level fluctuation or noise in the control lines 107 and 108 for a short time due to the occurrence of a fault, the unit selection signal read pulse is input as a trigger after the fluctuation has passed and the unit selection signal has stabilized. be done. Therefore, the possibility of making a mistake in determining the level is sufficiently reduced. Further, when the control unit 103 is removed, the flip-flops 210 and 211 are not triggered, so that the state immediately before the control unit 103 is removed can be maintained and the best state can be maintained.

Although the case where there are two duplexed units has been described above, the automatic switching method of the present invention can also be used when there are a plurality of duplexed units.

〔Effect of the invention〕

In the present invention, each multiplexed UNI/NOD does not immediately use the UNI/2 selection signal, but when the unit selection signal read pulse is taken in as a trigger, the unit selection signal is used to determine whether it is currently in use or in reserve. By using this information as information, it is possible to obtain a multiplexing device switching system that is not affected by level fluctuations in the unit selection signal and that can maintain the best state even when the control unit is removed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a conventional automatic switching system. FIG. 2 is a block diagram of an automatic switching system according to an embodiment of the present invention. 101, 102...duplicated unit, 103
...Control unit, 105.106...Fault information line, 107.10B...Control line, 209...Unit selection signal reading pulse line, 210.211...Flip-flop, 212.2
13... Uni, y-to selection signal. Patent ratio: 11 people Naotaka Ide, patent attorney representing NEC Corporation

Claims (1)

[Claims] (1) A plurality of units are provided, and each of the plurality of units is provided with a means for transmitting fault information, and upon receiving the fault information, a selection signal is sent to one of the plurality of units, and the selection signal is sent to one of the plurality of units. In an automatic switching system comprising a control unit that controls one unit to operate as a working unit and another unit to standby as a standby unit, the control unit is provided with means for transmitting a pulse signal after transmitting a selection signal, The automatic switching system is characterized in that each of the plurality of units is provided with a means for reading the received selection signal as a valid one using the pulse signal.