JPH07183832A - Switchover controller - Google Patents

Abstract

PURPOSE:To prevent the switchover of a system when a package is extracted by latching a switchover signal only when a trigger signal having a pulse width equal to or more than a prescribed pulse width is inputted. CONSTITUTION:A latch pulse generation circuit 11 transmitting a latch pulse 12 of a fixed pulse width is provided on a control package 6. A pulse width monitoring circuit 13 monitoring the pulse width of a latch pulse 12 and outputting a latch pulse 130 only when the pulse width is a prescribed width or more is provided on a reception package 5. Therefore, even if noise is generated and is inputted to a reception package 5 as a latch pulse 12 when a control package 6 is extracted, a latch pulse 130 is not outputted because the width is smaller than a prescribed width and the contents of the output of a switch circuit 15 is not switched. Therefore, when the control package 6 is extracted, a protective state is not required, and even if the package is erroneously extracted, the contents of the output is not switched.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching control device, and more particularly to a switching control device having a package for selectively transmitting a plurality of signals.

[0002]

2. Description of the Related Art In general, a system is often adopted in which a device has a 0-system and a 1-system redundant configuration, and when a failure occurs in one system, the system is switched to the other system to continue the operation to improve the reliability of the device. To be done. That is, one of the 0-system and the 1-system is in use and the other is in standby, and operation is continued while performing switching control of these.

For example, a 0-system package and a 1-system package are prepared, and when a failure occurs on the working side, the spare side is newly made to work, and the failed package is repaired or replaced.

Now, the configuration of a conventional switching control device for a package having a 0-system and a 1-system redundant configuration will be described with reference to the drawings.

FIG. 3 is a block diagram showing the configuration of a conventional switching control device. In the figure, the conventional switching control device is
The receiving package 5 that receives the signal 3 from the 0-system package 1 and the signal 4 from the 1-system package 2 and switches between these outputs, and the failure of the 0-system and 1-system packages is detected and the receiving package is detected according to the detection result. And a control package 6 for performing control of No. 5 in FIG.

The control package 6 receives the alarm information signals 10 and 20 from the 0-system and 1-system packages as inputs and determines the presence / absence of a fault in both packages, and the determination circuit 7 determines that there is a fault. A switching signal generation circuit 8 that sends a switching signal 9 at this time and a latch pulse generation circuit 16 that sends a latch pulse 17 when the determination circuit 7 determines that there is a failure are included.

The receiving package 5 includes a latch pulse control circuit 18 which outputs a latch pulse 180 in response to the input of the latch pulse 17, and a latch circuit which latches the switching signal 9 in response to the input of the latch pulse 180. 10
And a switching circuit 15 which selectively outputs the signals 3 and 4 as an output 150 according to the system selection signal 14 which is the output. That is, the latch pulse 180
The content of the output 150 is switched by the switching signal 9 being latched by the latch circuit 10 by using as a trigger signal.

The control package 6 can be electrically connected to and disconnected from the receiving package 5.

Here, when the protect information signal 19 is in the non-protected state, the latch pulse control circuit 18 is
The latch pulse 17 is sent as it is as the latch pulse 180. On the other hand, when the protect information signal 19 is in the protected state, the latch pulse 180 is not transmitted.

In such a structure, when the control package 6 is inspected and maintained, the control package 6 is pulled out from a connector (not shown) and electrically separated from the receiving package 5. When removing it, noise (so-called beard)
Is generated and is input to the receiving package 5 as the latch pulse 17 to be latched and the system selection signal 14 is transmitted, so that the content of the output 150 of the switching circuit 15 may be switched.

Therefore, by setting the protect information signal 19 to the protect state, the output 150 of the switching circuit 15 is set.
It is possible to remove the control package 6 without switching the contents of.

[0012]

However, the above-mentioned conventional switching control device has a drawback in that it must be protected when the control package is removed. In addition, if the control package is accidentally removed in the non-protected state, the output content of the switching circuit may be switched.

Here, a technique for reducing the influence of noise by using a flip-flop is disclosed in Japanese Patent Publication No. 2-60098, but even when such technique is used, there are the same drawbacks as described above.

The present invention has been made to solve the above-mentioned conventional drawbacks, and an object thereof is a switching control device in which the system is not switched when the control package is removed even without the protection state. Is to provide.

[0015]

A switching control device according to the present invention comprises a latch means for latching a switching signal for switching a signal to be transmitted in response to an input of a trigger signal, and a first latching means according to the latch output. And a first package having switching means for selectively sending the second signal, and a signal sending means for sending the switching signal and the trigger signal, and electrically connected to the first package, A switching control device having a second package which can be detached freely, the trigger control means for inputting the trigger signal to the latch means only when the pulse width of the trigger signal is a predetermined width or more; It is provided in the package of.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of an embodiment of a switching control device according to the present invention, and the same portions as those in FIG. 3 are designated by the same reference numerals. In the figure, the switching control device according to one embodiment of the present invention is different from the conventional one, in that a latch pulse generation circuit 11 for sending a latch pulse 12 having a constant pulse width is provided in the control package 6, and This is that the receiving package 5 is provided with a pulse width monitoring circuit 13 that monitors the pulse width and outputs the latch pulse 130 only when the width is equal to or larger than a predetermined width.

According to this structure, even when noise (so-called beard) is generated when the control package 6 is removed and is input to the receiving package 5 as the latch pulse 12, its width is smaller than the predetermined width. Therefore, the latch pulse 130 is not output, and therefore the output 15 of the switching circuit 15 is
The contents of 0 are never switched.

That is, the content of the output 150 is switched by latching the switching signal 9 in the latch circuit 10 using the latch pulse 130 as a trigger signal. However, since the pulse width of the latch pulse 12 is small, the latch pulse 1
30 is not output and the content of the output 150 is retained as it is. Therefore, it is not necessary to put the control package 6 into the protected state when the control package 6 is removed, and the contents of the output 150 are not switched even if the control package 6 is removed by mistake.

Here, an example of the internal configuration of the pulse width monitoring circuit 13 will be described with reference to FIG. The same figure (a)
In the pulse width monitoring circuit 13, a monostable multivibrator (monostable multivibrator) 131 that outputs a pulse 133 having a constant pulse width in response to the input of the latch pulse 12 and the latch pulse 12 and the pulse 13
The comparison circuit 132 compares the three pulse widths and outputs the latch pulse 130 having a pulse width corresponding to the difference.

A monostable multivibrator (hereinafter abbreviated as multivibrator) 131 has a well-known RC time constant circuit, and a pulse 13 having a pulse width corresponding to the time constant.
3 is output. What is important here is that the pulse width of the pulse 133 is sufficiently longer than the noise waveform and the latch pulse 1
The time constant is adjusted in advance so that it becomes shorter than 2.

The comparison circuit 132 can be constructed using a well-known AND circuit, for example.

The pulse width monitoring circuit 13 having such a configuration
The operation will be described with reference to FIGS.

First, referring to FIG. 1B, when a normal latch pulse 12 is input, a pulse 133 having a pulse width t responds to the rising of the latch pulse 12 and the multivibrator 1 receives the pulse 133.
It is output from 31. In this case, since the latch pulse 12 has a larger pulse width than the pulse 133, the comparison circuit 132 outputs the latch pulse 130 having a pulse width corresponding to the difference. Therefore, the latch pulse 130 is input to the latch circuit and the switching circuit is switched.

On the other hand, when noise is generated when the control package is removed and is input as the latch pulse 12, the result is as shown in FIG. That is, referring to the figure, in response to the rise of the latch pulse 12, the pulse width t
Pulse 133 is output from the multivibrator 131. In this case, since the latch pulse 12 is due to noise and has a pulse width much smaller than the pulse 133, the latch pulse 130 is not output from the comparison circuit 132. Therefore, the latch pulse is not input to the latch circuit, and the switching circuit is not switched.

Therefore, the system does not switch even if the package is removed, regardless of whether it is in the protected state or not.
The protect function is unnecessary. Even if noise is generated when the package is connected not only when the package is removed, but the pulse width is small, the switching circuit is not switched as in the above case.

As described above, since the control package can be freely inserted and removed, the inspection and maintenance of the control package can be easily performed. The present invention, in which this package can be freely inserted and removed,
Obviously, it can be widely applied to communication devices, information processing devices, and the like.

[0028]

As described above, according to the present invention, the pulse width is monitored and the switching signal is latched only when the trigger signal having the pulse width larger than the predetermined pulse width is input. The effect is that the system does not switch.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a switching control device according to an embodiment of the present invention.

2A is a block diagram showing an internal configuration example of a pulse width monitoring circuit in FIG. 1, and FIGS. 2B and 2C are time charts showing the operation thereof.

FIG. 3 is a block diagram showing a configuration of a conventional switching control device.

[Explanation of symbols]

 7 Judgment Circuit 8 Switching Signal Generation Circuit 10 Latch Circuit 15 Switching Circuit 11 Latch Pulse Generation Circuit 13 Latch Pulse Monitoring Circuit 131 Monostable Multivibrator 132 Comparison Circuit

Claims (2)

[Claims] 1. Latch means for latching a switching signal for switching a signal to be transmitted in response to an input of a trigger signal, and first and second signals are selectively transmitted according to the latch output. A first package having switching means, and a second package having signal sending means for sending the switching signal and the trigger signal and electrically connectable to and disconnectable from the first package. A switching control device, wherein trigger control means for inputting the trigger signal to the latch means only when the pulse width of the trigger signal is equal to or larger than a predetermined width is provided in the first package. apparatus. 2. The trigger control means includes a monostable multivibrator which outputs a signal having a constant pulse width in response to the generation of the trigger signal, and the pulse width of the trigger signal is more than the pulse width of the output signal. 2. The switching control device according to claim 1, wherein the trigger signal is input to the latch means when the value becomes larger.