JP2533167B2 - Indeterminate system switching circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Overview] An indeterminate system switching circuit that switches a duplicated portion in order to minimize a failure rate. When the indeterminate system switching circuit is divided into two packages, The aim is to provide an indeterminate system switching circuit that operates in a stable manner. When an error occurs in the "0" system signal, an alarm is issued for the "1" system and the system is switched to the "1" system. "0" system switching means for switching to the active system by an alarm from the system and the active system due to an alarm from the "0" system switching means Turns on / off the "1" system switching means that outputs an alarm and switches to the "0" system, the presence or absence of a package that mounts the "0" system and "1" system switching means, and the presence or absence of the active of each system. And the switch-off signal is output as the judgment result. Other system switching control means presence / absence determining means, which adds a presence / absence signal or a switch-off signal of the package of the other system output from the other system switching control means presence / absence determining means, respectively. It is configured so that the switching control condition of the "1" system switching means is set.

[Industrial applications]

The present invention relates to an indeterminate system switching circuit that switches a duplicated portion in order to minimize the failure rate.

For example, there are a localization system and an indetermination system in a switching circuit used for switching the duplication unit of a device that supplies a clock to a digital network.

As shown in FIG. 7, the localization system switching circuit clearly distinguishes an active system (also called an N system) and a standby system (also called an E system) from each other. When the system is restored normally, it is a system that automatically or manually returns to the N system.

On the other hand, the indeterminate system switching circuit has no distinction between the active system and the standby system as shown in FIG. 8. For example, after switching to the 1 system due to the 0 system abnormality, the system switching is performed even if the 0 system abnormality is recovered. Without
It will be used as the active system unless the selected system becomes abnormal.

The package of such an indeterminate switching circuit is normally 0.
The system switching circuit and the 1-system switching circuit are different from each other, and the switching control circuit is mounted in a separate package as a common part.

However, there is a case where the switching control circuit is mounted on the package of the 0-system switching circuit and the 1-system switching circuit at the same time due to the packaging problem, and even in such a case, it is necessary to surely and accurately control the switching. .

[Conventional technology]

FIG. 5 is a diagram for explaining a conventional example, FIG. 6 is a diagram for explaining an output situation of a switching control signal in the conventional example, FIG. 7 is a diagram for explaining a localization system switching control flowchart, and FIG. 8 is a non-localization system. The figure explaining each switching control flowchart is shown, respectively.

FIG. 5A shows a processing circuit 2 for 0-system or N-system signals.
And a selection circuit 3 for selecting the output of the 0-system or N-system processing circuit 2 (these are referred to as 0-system or N-system switching circuit 1)
A 1-system or E-system signal processing circuit 5; a selection circuit 6 for selecting the output of the 1-system or E-system processing circuit 5 (these are referred to as 1-system or E-system switching circuit 4); Alternatively, it comprises an N-system switching circuit 1 and a switching control circuit 7 for controlling switching of the 1-system or E-system switching circuit 4.

Further, the diagram shown in FIG. 5 (B) is a common part shown in FIG. 5 (A), and the control means (circuit C (1/2)) of the switching control circuit 7 (denoted as circuit C, the same hereinafter) is used. 0 system or N system switching circuit 8 having a display), and 1 system or E system switching circuit 9 also having control means of the switching control circuit 7 (displayed by circuit C (2/2)). There is.

The functional blocks 1, 4, and 7 shown in FIG.
Each functional block 1, 4, 7 is mounted in a separate package, and it is possible to switch to the 1-system or E-system switching circuit 4 by an alarm signal even if the 0-system or N-system switching circuit is inserted or removed. .

That is, the switching control circuit 7 outputs a switching signal for switching the selection of the corresponding selection circuits 3 and 6 according to the alarm signal from the 0-system or N-system switching circuit 1 or the 1-system or E-system switching circuit 4. , The output of the switched system and are valid.

In the case of the localization system, the N system is set as the current system as shown in FIG. 7, and even if the N system becomes abnormal, it can be returned to the N system when the abnormality is recovered. In the case of an indeterminate system, the system switched as shown in FIG. 8 continues and operates as the active system.

Next, FIG. 5 (B) comprises a 0-system switching circuit 8 and a 1-system switching circuit 9 which are composed of NAND circuits (hereinafter referred to as NAND circuits) 81, 82 and 91, 92 as shown in FIG. The switching control part is implemented.

Therefore, for example, when an alarm signal is generated from the 0-system switching circuit 8, a control signal for enabling the 1-system switching circuit 9 is output and the 1-system switching circuit 9 is switched.

The "*" mark shown in FIG. 6 has the opposite polarity to that having no "*" mark, and so on. Further, in the case of the localization system switching circuit, it is impossible to divide it as shown in FIG. 5 (B) because the circuit configuration is not symmetrical between the N system and the E system.

On the other hand, in the case of an indeterminate system switching circuit, since there is no distinction between the active system and the standby system, unless there is an abnormality, the system becomes the active system and does not switch even if the system before switching recovers.
The non-localization system switching method is more advantageous than the localization system switching method in that output disturbance due to switching is small.

[Problems to be Solved by the Invention]

However, as shown in FIG. 5 (B) described above, when the 0-system and 1-system are constructed by dividing the package into two packages in the indeterminate system, for example, if the 1-system package is inserted and removed, FIG. Noise is generated in the parts (a) and (b) shown in
There is a problem in that the control signal may malfunction and stable switching cannot be expected when the power supply to one system is cut off or inserted or removed.

An object of the present invention is to provide a non-localization system switching circuit that operates stably even when the non-localization system switching circuit is divided into two packages.

[Means for solving the problem]

 FIG. 1 is a diagram illustrating the principle of the present invention.

In the principle diagram of the present invention shown in FIG. 1, reference numeral 10 indicates an alarm for the "1" system when an abnormality occurs in the "0" system signal and switches to the "1" system. It is the "0" system switching means that switches to the active system by an alarm, and 20 becomes the active system due to the alarm from the "0" system switching means 10, and when an error occurs in the "1" system signal, it becomes Is a "1" system switching means for issuing an alarm and switching to the "0" system, and 30 is a switch for presence / absence of a package for mounting the "0" system and "1" system switching means, and the presence / absence of active use of each system. It is another system switching control means presence / absence determination means that determines whether the package of another system exists or outputs a switch-off signal as a result of the determination by turning on / off of, respectively. Use it as a means.

[Work]

When the redundant system is switched by the non-localizing system switching method, and when the redundant system is divided into two packages and mounted, an alarm signal for switching to another system and other system switching "0" of an indeterminate system by adding a switch-off signal when the presence / absence of each other system package output from the control means presence / absence determining means 30 and the presence / absence of the active state of each system are determined by the switch on / off By configuring the switching control conditions of the system and the "1" system switching means 10 and 20, stable operation is possible even when the duplicated system by the indeterminate system switching system is divided into two packages.

〔Example〕

Hereinafter, the gist of the present invention will be specifically described with reference to the embodiments shown in FIGS.

FIG. 2 is a diagram for explaining an embodiment of the present invention, FIG. 3 is a diagram for explaining a switching processing operation in the embodiment of the present invention, and FIG.
The drawings respectively show diagrams for explaining logic states in the embodiments of the present invention. The same reference numerals denote the same objects throughout the drawings.

The embodiment of the present invention shown in FIG. 2 shows an embodiment of the indeterminate system switching circuit when the indeterminate system switching circuit is divided into two packages as described in FIG. 5 (B).

The two indeterminate system switching circuits 40a and 50a of the present embodiment have the same contents, and when they are powered on at the same time, the switching system 40a corresponding to the "0" system is set as the active system. .

Each switching circuit 40a, 50a includes four inverter circuits 41 (1) to 41 (4), own system alarm ALM (A), and other system alarm ALM.
(B), a logical product circuit (hereinafter referred to as an AND circuit) 42 which takes the logical product of the signal (C) indicating that the other system package PKG is not present and the other system is switched and is functionally off.
(1), other system alarm ALM (B) and own system alarm ALM (A)
AND circuit 42 (2) that takes the logical product with the inverted signal of
And an AND circuit 42 (3) for ANDing the inversion signal of its own alarm ALM (A), the inversion signal of the signal (C), and the switching signal (D) of the external control, and the signal (C) and the external AND circuit 42 (4) that takes the logical product of the control switching signal (D) and the inversion signal, and the alarm ALM (A) of its own system and the alarm ALM (B) of the other system
AND circuit 42 (5) that takes the logical product with the inverted signal of
AND circuit 42 (1) to 42 (4) outputs and a NOR circuit (hereinafter referred to as NOR circuit) 43 that performs a NOR operation of the power-on signal, inverter circuit 41 (4) and AND circuit 42 The output of NOR circuit 44, which takes the NOR of the output of (5) and the output of NOR circuit 43, is set to * S terminal, and the output of NOR circuit 44 is set to *.
An SR type flip-flop circuit (hereinafter abbreviated as SR-FF circuit) 45 connected to the R terminal and controlling the positive output terminal Q according to the output states of the NOR circuit 43 and the NOR circuit 44 is provided.

FIG. 3 is a flow chart of the indeterminate system switching circuits 40a and 50a, which are shown at various points in the flow chart (A) and (* A).
Etc. indicate a logical state. Switch-on (SW-ON) and switch-off (SW-OFF) indicate the result of determining whether the system has been switched manually, etc., and the package (PK
G) Display the state that the PKG of the empty system is removed.

Next, the flow chart shown in FIG. 3 can be described as equation (1) in FIG. 4 (A) and equation (2) in FIG. 4 (B). Equation (1) and equation (2) are equation (3),
It becomes possible to perform the replacement as in the equation (4).

The replacement of the formula (1) with the formula (3) and the replacement of the formula (2) with the formula (4) are examples obtained by the Carnot map, and can be combined into various states. Is.

The present embodiment shown in FIG. 2 is a circuit that realizes the expressions (3) and (4) shown in FIG. 4, and the other system SW-OFF or the other system PKG is used as the system switching condition according to the present embodiment. By adding a condition of nothing and performing a logical operation so as to switch the time system in a state that satisfies this condition, the noise generation condition at the time of inserting / removing the PKG of the other system is removed, and malfunction is prevented.

That is, as shown in Fig. 3, when an alarm (ALM) occurs in the current system that has become the active system due to power-on (PON) or reset (RES), and an alarm (ALM) also occurs in other systems. When the other system is switched off (SW-OFF) (logical state C), it returns to its own system, and when the other system is switched on (SW-ON) (logical state * C), it switches to the other system.

Next, switching to the other system, an alarm (ALM) occurs in the other system, and when the alarm (ALM) does not occur in the own system, it switches to the own system and an alarm (ALM) occurs in the own system. When there is no other system PKG, other system switch on (SW-ON) switches to own system.

The symbols A and * A shown in FIG. 3 indicate the logical states of the symbols shown in FIGS. 2 and 4. As described above, the noise generation condition at the time of inserting / removing the PKG of the other system (inserting / removing the PKG in the power-on state) is removed, and the malfunction due to the noise at the time of inserting / removing the PKG can be prevented.

〔The invention's effect〕

According to the present invention as described above, the switching of the indeterminate system switching circuit divided into two packages can be carried out in a stable state.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the principle of the present invention, FIG. 2 is a diagram for explaining an embodiment of the present invention, FIG. 3 is a diagram for explaining a switching processing operation in the embodiment of the present invention, and FIG. FIG. 5 is a diagram for explaining a logical state in the embodiment of the invention, FIG. 5 is a diagram for explaining a conventional example, FIG. 6 is a diagram for explaining an output situation of a switching control signal in the conventional example, and FIG. 7 is a localization system switching control flowchart. And FIG. 8 are diagrams for explaining the indeterminate system switching control flowchart. In the figure, 1 is a 0 system or N system switching circuit, 2, 5 are processing circuits, 3 and 6 are selection circuits, 4 is a 1 system or E system switching circuit, 7 is a switching control circuit, 8 and 40a are 0 system switching Reference numeral 9, 50a is a 1-system switching circuit, 10 is a 0-system switching means, 20 is a 1-system switching means, 30 is another system switching control means presence / absence determining means, 41 (1) to 41 (4) are inverter circuits, 42 (1) to 42 (5) are AND circuits, 43 and 44 are NOR circuits, 45 is an SR-FF circuit, and 81, 82, 91 and 92 are NAND circuits.

Claims (1)

(57) [Claims] 1. An indeterminate system switching circuit having switching control means for switching to another system when an abnormality occurs in the active system and for making the system the active system unless an abnormality occurs in the switched system. When an error occurs in the "0" system signal (), an alarm () is issued to the "1" system and the system is switched to the "1" system. The alarm () from the "1" system switches to the active system. Due to the 0 "system switching means (10) and the alarm () from the" 0 "system switching means (10), the system becomes the active system, and when an error occurs in the" 1 "system signal (), "1" system switching means (20) that issues an alarm () and switches to "0" system, and whether or not there is a package that mounts the "0" system and "1" system switching means (10, 20), Whether the system is active or not is determined by turning the switch on / off, and the presence / absence of a package of another system or a switch-off signal is output as the determination result. Switching control means presence / absence determining means (30), and the presence / absence signal or switch-off signal of the package of the other system output from the other system switching control means presence / absence determining means (30) is added to the atypical system. An indeterminate system switching circuit, characterized in that the switching control conditions of the "0" system and "1" system switching means (10, 20) are used.