JPH0213024A - Switching circuit - Google Patents

Abstract

PURPOSE:To prevent a phenomenon that an operation system is successively moved alternately between both panels by providing the output part of a lock signal to stop a switching to a switching circuit to automatically switch the panel of a standby system to the operation system when a trouble is generated to the panel to compose the operation system. CONSTITUTION:When an ALM is not generated to a circuit 2 and the ALM is generated to a circuit 1, the circuit 1 and circuit 2 are switched to the standby system and operation system, respectively. When the circuit 1 is the standby and the ALM is generated and when the circuit 2 is the operation system and the ALM is generated, the phenomenon that the operation system is alternately moved between the circuit 1 and circuit 2 is generated, and when a lock is applied, namely, at the time of a lock signal l7=0, an l5 (l6) is not influenced. Consequently, even when the ALMs are generated to both systems, by applying the lock signal from an external part, the phenomenon that the operation system is alternately moved between the circuit 1 and circuit 2 can be prevented.

Description

[Detailed description of the invention] [Industrial application fields] The present invention relates to a switching circuit.

In particular, if the equipment panel is in active and backup configurations,
The present invention relates to a switching circuit that enables switching between these panels.

[Prior Art] In a conventional switching circuit, when a failure occurs in the active panel among the two panels that constitute the active system and the standby system, if the failure does not occur in the standby system panel, The standby panel was automatically switched to the active panel without any conditions.

[Problems to be Solved] In the conventional switching circuit described above, if no failure occurs in the standby panel but a failure occurs in the active panel, switching to the standby system is performed, and the standby system becomes the active system. The active system becomes the standby system.

However, since a panel that becomes a standby system is reset, it is determined that there is no failure for a certain period of time.

If a failure occurs again on the operational system during this period,
Since the conventional switching circuit performs the switching operation automatically, there is a problem in that the active system moves alternately and continuously between the two panels.

The present invention was made in view of the above problems, and even if a failure occurs in the active panel and the standby panel, it is possible to prevent the active panel from moving alternately and continuously between the two panels. The purpose is to provide a switching circuit that can be locked from the outside.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes two identical panels constituting an active system and a standby system, and when a failure occurs in the panel constituting the active system among these panels, automatic The switching circuit for switching from a standby panel to an active panel is configured to include an output section for outputting a lock signal to stop the switching.

[Example] An example of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an embodiment.

In the figure, the control device has a current and a standby configuration, and has an 1 or N system circuit and a 2 or E thread circuit. These circuits 1 and 2 are one and the same panel. Therefore, it does not matter which one is in use and which one is in reserve.

3 and 4 are NAND circuits. These NAND circuits 3 and 4 will cause a panel failure (hereinafter referred to as ALM) if the panel is not locked (described later).
, recovery is transmitted, but if there is a talk/link, the high output (rl
J) to communicate.

5 and 6 are NAND circuits into which the outputs of the NAND circuits 3 and 4 are input. These NAND circuits 5 and 6, as will be described later, receive and receive active and standby state signals from the other panel, and output signals that indicate whether the panel is in active or standby mode depending on the presence or absence of ALM in its own panel.

1 is the ALM signal of the N-system circuit 1. This signal statement is rlJ (h
(high) and is “0” if there is no ALM.

12 is an ALM signal of the E thread circuit 2. This signal intersection 2 is rlJ (high) when there is an ALM generated in the E thread circuit 2, and is "0" when there is no ALM, similar to the above-mentioned signal 2.

lx is the input signal for ACT of the N yarn circuit l, and the NA
It is output from the ND circuit 3.

DA is the input signal for ACT of the E yarn circuit 2, and the NA
It is output from the ND circuit 4.

is is the ACT signal of the N thread circuit 1 outputted from the NAND circuit 5, and is the ACT signal of the E thread circuit 2 outputted from the NAND circuit 6. When these ACT signals (sentences or sentences) are "0", one circuit (N thread circuit 1 or E thread circuit 2) becomes the active system, and when it is "1", it becomes the standby system. These ACT signals 13. fL6 is connected to the NAND circuits 6 and 5 of the other circuits, and serves as a signal for determining switching and at the same time as a signal indicating the operation or standby state of the own panel.

Statement 2 is a lock signal for stopping switching between the active system and the standby system, and is output from an output section (not shown). Switching is possible when this lock signal is "1", and switching is stopped when it is "0". Further, when this lock signal statement is rlJ and the ALM signal (standing or statement 2) is O/1, the ACT input signal (1
ff or! 14) or 110.

The overall operation will be sequentially explained below.

First, the case where the lock is not applied, that is, the case where the lock signal 1y=1 will be explained.

In circuit 1, if there is no ALM, then = 0 and 7 = 1, so AC = 1, and !
2. When 6=1, standing s=o.

Therefore, the circuit 1 becomes the active system, and the circuit 2 becomes the standby system.

Here, there is no ALM in 1 circuit 2 (J12=O makes it stand a
= 1), and if ALM occurs in circuit 1, then
i, y=1. And the sentence becomes =1, see.

=0. And since 1s=1, the sentence.

becomes "1". Therefore, in circuit 2, the statement,
Since =1 makes the sentence =1, the sentence =0. As a result, circuit 1 is switched to the standby system, and circuit 2 is switched to the active system.

Next, a case where the active system changes alternately between circuit 1 and circuit 2 will be explained.

Assume that ALM occurs when circuit 1 is on standby (statement, = 1), and there is no ALM when circuit 2 is active. At this time, the circuit engineer will reset the circuit when ALM occurs, so there will be no ALM for a fixed period of time B, =
o).

Here, if ALM occurs on the circuit 2 side as well, Circuit 2 is dan 2-1, standing, = 1, so it is a sentence.

Since n = 0 and statement = 1, n a = 1, and circuit 2 changes to a standby system.

Conversely, in circuit 1, since sentence, 20, u, = 1, alternating = 1,
And since l s = 1, the sentence = 0,
Circuit 1 changes to the operational system.

However, when circuit 1 detects ALM again, circuit 2 is reset due to the occurrence of ALM and there is no ALM for a certain period of time, so in the same way as above, circuit 1 is switched to the standby system and circuit 1 is switched to the operating system. It will change into a system.

When ALM occurs in circuit 1 and circuit 2 in this way, a phenomenon occurs in which the active system moves alternately between circuit 1 and circuit 2.

Next, when a lock is applied, that is, a lock signal statement,
The case where =0 will be explained.

For example, if there is no circuit 1 or ALM, the statement = 0), and the operation system (
Sentence, = Q), circuit 2 or standby system (stand.

= 1), then tate, 20, sentence, = o, so tate 3 = 1, and u, = l
Therefore, the sentence is 20.

Here, if ALM occurs in circuit 1, then cross = 1
Since the sentence = 0, 13 = 1 remains and has no effect on Is C1s ).

Even if ALM occurs in both systems,
By applying a lock signal from the outside, it is possible to prevent the active system from moving alternately between circuit 1 and circuit 2.

[Effects of the Invention] As explained above, the present invention provides a lock signal that locks the status of both systems even if a failure occurs in the active panel and the standby panel. It is possible to prevent the phenomenon of continuous alternating movement between panels.

[Brief explanation of the drawing]

Figure 1 shows FIG. 2 is a diagram of one embodiment of the present invention. Ru. :panel Sentence: lock signal

Claims (1)

[Claims] In a switching circuit that includes two identical panels forming an active system and a standby system, and automatically switches the standby panel to the active system when a failure occurs in the panel forming the active system among these panels, the switching circuit A switching circuit characterized by comprising an output section for a lock signal that stops the switching circuit.