JPH098784A - Alarm issuing circuit - Google Patents

Abstract

PURPOSE: To output no secondary alarm when a primary fault is detected and to prevent the congestion of alarms by suppressing the issuing of a secondary alarm signal when a signal output suppressing part inputs a primary fault alarm signal. CONSTITUTION: A primary fault signal 101 to be issued when out-of-synchronism as the primary fault is generated is inputted to a secondary alarm issue suppressing part 12a so that the secondary alarm issue suppressing part 12a can suppress the issuance of a secondary alarm signal 104. Namely, the secondary alarm issue suppressing part 12a suppresses the issuance of the secondary alarm signal 104 by the primary fault signal 101 for detecting the primary fault. Therefore, the issuance of an authentic secondary alarm signal 105a to be issued when the output of a primary alarm signal is delayed is suppressed by a forward protecting means provided at a primary alarm issuing part 9, and the congestion of alarms inside a device alarm part 3 can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alarm output circuit for detecting a failure occurring in, for example, a digital multiplexing device and outputting an alarm, and particularly, it occurs due to a primary failure such as loss of synchronization. The present invention relates to an alarm output circuit that suppresses the output of an alarm corresponding to this secondary failure when a secondary failure such as a parity error is detected.

[0002]

2. Description of the Related Art FIG. 8 is a block diagram showing a configuration of a digital multiplexer disclosed in Japanese Patent Laid-Open No. 103046/1993 to which an alarm output circuit is applied. In the figure, 1 is a network side line accommodating unit, 1a is a primary fault monitoring unit for monitoring a fault occurring in the network side line accommodating unit 1, 2-1 to 2-n are terminal side line accommodating units, 21 to 21. Reference numeral 2n is a built-in terminal-side line accommodating section 2-1 to 2-n, and a secondary failure monitoring section for monitoring a failure that occurs 3 is an apparatus alarm section for performing alarm control of this digital multiplexing apparatus, 4 Is an internal data bus, 5 is an internal alarm bus, 6 is an input signal from the network side, and 71 to 7n are output signals to the corresponding terminal side lines 7-1 to 7-n.

FIG. 9 is a block diagram for explaining the configuration of the primary fault monitoring unit 1a and the secondary fault monitoring unit 21 in FIG. 8. In the figure, 8 is out of synchronization with the input signal 6, for example. When such a primary fault is detected, a primary fault detection unit that outputs a primary fault signal 101 for each frame in which this out-of-synchronization is detected, 9 receives this primary fault signal 101, and forward protection means described later, And, the primary fault signal 101 is verified by using the rear protection means, and if it is recognized that the out-of-synchronization is established, the primary alarm signal 102 is output 1
A secondary alarm output unit, which is a combination of the primary fault detection unit 8 and the primary alarm output unit 9, corresponds to the primary fault monitoring unit 1a in FIG. Further, 10 is a secondary failure signal 103 detected by detecting a secondary failure including a parity error or the like caused by a primary failure such as loss of synchronization with respect to the output signal 71 output from the device data bus 4. Secondary failure detection unit,
Reference numeral 11 indicates the secondary fault signal 103, and when it recognizes that the secondary fault has been established, it outputs a secondary warning signal 104 relating to the primary fault, and 12 indicates the primary warning signal 102. When input, it is a secondary alarm output suppression unit that suppresses the output of the secondary alarm signal 104 and outputs only the genuine secondary alarm signal 105. These secondary failure detection unit 10, secondary alarm output unit 11, and A combination of the secondary alarm output suppression unit 12 corresponds to the secondary failure monitoring unit 21 of FIG.

Next, the above-mentioned front protection means and rear protection means will be briefly described. For example, when performing frame synchronization verification on a signal output by frame synchronization such as the input signal 6, 1. Get in sync as soon as possible. 2. Once synchronization is achieved, do not become out of sync with instantaneous changes in the synchronization pulse due to code errors in the transmission path. 3. Do not judge that synchronization is possible even though it is not synchronized. It must be verified in consideration of the above three conditions.

In order to satisfy the second condition among these,
The forward protection means is a means for determining synchronization loss only after N consecutive frame pulse mismatches, and for example, outputting an alarm to restore synchronization. Also, with this forward protection means, if the value of N is made large, the probability of erroneously establishing frame synchronization is reduced, but if the synchronization is truly lost, the transition to synchronization recovery is delayed, so both values of N are Considering the equilibrium of, about 5 is considered to be appropriate. In addition, in order to satisfy the first and third conditions, if a pattern matching the sync pulse is found,
In order to determine whether or not this is a true synchronization pulse, the means for determining that the synchronization has been achieved for the first time when the synchronization pulses match over the subsequent M frames is called backward protection means. Further, in this rear protection means, if the value of M is increased, the probability of mis-synchronization is reduced, but since the transition to synchronization recovery is delayed, the value of M should be about 2 to 4 in consideration of both balances. Considered to be suitable. Therefore, here, the value of N in the front protection means is set to 5, and the value of M in the rear protection means is set to 2.

Next, the operation of the conventional example will be described with reference to the drawings.
In FIG. 8, the network side line accommodating section 1 receives an input signal 6 in which n channels are time-division multiplexed from the network side line, multiplexes them into n channel data, and outputs them as output signals 71 to 7n. It is output to each of the terminal side line accommodating units 2-1 to 2-n via A. The terminal side line accommodating sections 2-1 to 2-n are separated from each other output signal 71.
To 7n are output to the corresponding terminal side lines 7-1 to 7-n. Further, the primary failure monitoring section 1a of the network side line accommodating section 1 monitors the input signal 6, and when a failure such as loss of synchronization is detected, outputs an alarm to the corresponding monitoring item,
The device alarm unit 3 is notified via the alarm bus 5.

The secondary fault monitoring units 21-2n built in each of the terminal side line accommodating units 2-1-2-n are output data 7-1-7-7 output via the data bus 4. When n is input and monitored and a failure such as a parity error is detected, an alarm is output to the corresponding monitoring item and the device alarm unit 3 is notified via the alarm bus 5. The device alarm unit 3 is
The notified alarm information is edited and an alarm lamp is turned on or an alarm is sent to a host monitoring device (not shown).

Next, the above fault monitoring operation will be described in detail with reference to FIG. For example, if the cable of the network side line is disconnected and the input signal 6 is constantly out of synchronization, the primary failure detection unit 8 outputs the primary failure signal 101.
Is output for each frame. The primary alarm output unit 9 to which the primary fault signal 101 is input verifies the loss of synchronization according to the above-mentioned front protection means, and the loss of synchronization is established when the primary fault signal 101 is input for 5 consecutive frames. Then, the primary alarm signal 102 is output. If the primary failure detection unit 8 detects loss of synchronization, the output signal 7
In No. 1, a secondary failure such as a parity error caused by the above-mentioned loss of synchronization almost always occurs. The secondary failure detection unit 10 detects this secondary failure that has occurred and outputs the secondary failure signal 103. The secondary alarm output unit 11 that has received this secondary failure signal 103 has established this secondary failure. If it is considered that, the secondary alarm signal 104 is output. The timing at which the secondary alarm output unit 11 outputs the secondary alarm signal 104 varies depending on the type of the secondary failure signal 103 to be input. For example, 2
When the next fault signal 103 is a parity error, the parity error has a large influence on each frame, and therefore the fault information should be output for each frame. Obstacle signal 10
A secondary alarm signal 104 corresponding to the secondary fault signal 103 is output for each frame in which 3 is input.

When the secondary alarm signal 104 is caused by, for example, the loss of synchronization of the input signal 6 as described above, all of the secondary failure monitoring units 21 to 2n shown in FIG. The secondary alarm signal is output. In that case, the device alarm unit 3 inputs a plurality of alarms at the same time, and congestion of the alarms occurs, so that it takes time to isolate the failure. Therefore, each of the secondary failure monitoring units 21 to 2n has one
A secondary alarm output suppression unit 12 that suppresses the output of the secondary alarm signal 104 while the secondary alarm signal 102 is being input is provided.
The secondary alarm output suppressing unit 12 suppresses the output of the secondary alarm signal 104 related to the primary failure input when the primary alarm signal 102 is input as described above, and in other cases, for example, 1 When the secondary alarm signal 102 is not input, the input secondary alarm signal 104 is regarded as a secondary fault at the location and a genuine secondary alarm signal 105 is output.

With the above operation, in the conventional alarm output circuit, the loss of synchronism, which is the primary fault in FIG. 8, spreads to the terminal side line accommodating units 2-1 to n, and a secondary fault such as a parity error occurs. The primary failure monitoring section 1a and the secondary failure monitoring section 2 are detected by the secondary failure monitoring sections 21 to 2n.
It is possible to prevent congestion in the device alarm unit 3 caused by simultaneous output of alarms from 1 to 2n, and to easily isolate a failure in the device alarm unit 3.

[0011]

The conventional alarm output circuit operates in the above-described configuration. For example, when the synchronization is lost, the primary alarm output unit 9 receives the input primary fault signal 102. Is verified by using a front protection means for determining that the synchronization pulse is out of synchronization when there is a discrepancy between the synchronization pulses of the frames for five consecutive frames, and the primary alarm signal 102 is output when the failure is considered to be established. There is. Therefore, 1
While the secondary alarm output unit 9 is verifying the primary fault, the secondary alarm output unit 11 outputs the secondary fault signal 1 from the secondary fault detection unit 10.
When 03 is input to output the secondary alarm signal 104 to the secondary alarm output suppression unit 12, the primary alarm signal 102 has not yet been input to the secondary alarm output suppression unit 12. The output of the secondary warning signal 104 is not suppressed, and the authenticity is 2
The next alarm signal 105 is output to the device alarm unit 3. For this reason, there is a problem that the device alarm unit 3 may cause alarm congestion.

The present invention has been made to solve the above problems, and a first object is to output a secondary alarm signal due to a primary failure earlier than an output of the primary alarm signal. However, the present invention provides an alarm output circuit that can suppress the output of the secondary alarm signal. A second object is an alarm output circuit that suppresses the output of the secondary alarm signal even when the primary alarm signal or the primary fault signal is not output due to misidentification of out of synchronization or the like in addition to the first object. Is provided.

[0013]

SUMMARY OF THE INVENTION An alarm output circuit according to the present invention includes a primary failure detection section for outputting a primary failure signal for each of the sync frames in which an input signal formed by a sync frame is out of synchronization. When the primary fault signal is continuously input for a predetermined number of frames, a primary fault output unit that outputs a primary fault signal and a secondary fault signal when a secondary fault caused by the loss of synchronization of the input signal is detected. A secondary failure detection section, which outputs a secondary warning signal when the secondary failure signal is input, and a secondary failure output section which outputs a secondary warning signal, and suppresses the output of the secondary warning signal when the primary failure signal is input. And a signal output suppressing unit for

The alarm output circuit according to the following invention is
When a primary failure detection unit that outputs a primary failure signal for each of the synchronization frames in which an input signal formed by a synchronization frame has lost synchronization and a primary failure signal is continuously input for a predetermined number of frames, 1 A primary alarm output section that outputs a secondary alarm signal, a secondary failure detection section that outputs a secondary failure signal when a secondary failure due to the synchronization of the input signal is detected, and a secondary failure signal when the secondary failure signal is input. A secondary alarm output unit that outputs a secondary alarm signal, and a signal output suppressing unit that suppresses the output of the secondary obstacle signal to the secondary alarm output unit when the primary obstacle signal is input are provided. It is a thing.

The alarm output circuit according to the following invention is
When the signal output suppression unit inputs the primary alarm signal, 1
It performs the same operation as when the next fault signal is input.

An alarm output circuit according to the following invention is
A primary alarm prediction unit that outputs a primary alarm prediction signal that predicts and notifies the occurrence of a primary failure when the ratio of inputting a primary failure signal to the primary alarm output unit exceeds a predetermined value When the signal output suppressing unit inputs the primary warning prediction signal, the same operation as when the primary failure signal or the primary alarm signal is input is performed.

The alarm output circuit according to the following invention is
When a primary failure detection unit that outputs a primary failure signal for each of the synchronization frames in which an input signal formed by a synchronization frame has lost synchronization and a primary failure signal is continuously input for a predetermined number of frames, 1 When a primary alarm output section that outputs a secondary alarm signal and a signal related to the input signal are input and the primary fault signal is input, the input signal is pseudo-normalized and output, A secondary fault that outputs a secondary fault signal when a secondary fault is detected in the signal input from the input signal conversion output unit and an input signal conversion output unit that outputs the input signal as it is when no secondary fault signal is input A detection unit and a secondary alarm output unit that outputs a secondary alarm signal when the secondary fault signal is input are provided.

The alarm output circuit according to the following invention is
When the input signal conversion output unit inputs the primary alarm signal, the same operation as when the primary failure signal is input is performed.

Furthermore, an alarm output circuit according to the following invention is
A primary alarm prediction unit that outputs a primary alarm prediction signal that predicts and notifies the occurrence of a primary failure when the ratio of inputting a primary failure signal to the primary alarm output unit exceeds a predetermined value When the input signal conversion output section inputs the primary warning prediction signal, the same operation as when the primary failure signal or the primary warning signal is input is performed.

[0020]

In the alarm output circuit according to the present invention, the output of the secondary alarm signal is suppressed when the signal output suppressing section inputs the primary fault signal.

The alarm output circuit in the following invention is
When the signal output suppression unit inputs the primary failure signal, it suppresses the output of the secondary failure signal to the secondary alarm output unit.

The alarm output circuit in the following invention is:
When the signal output suppression unit inputs the primary alarm signal, 1
The same operation is performed as when the next fault signal is input.

The alarm output circuit in the following invention is
A primary alarm prediction unit that outputs a primary alarm prediction signal that predicts and notifies the occurrence of a primary failure when the ratio of inputting a primary failure signal to the primary alarm output unit exceeds a predetermined value When the signal output suppressing unit inputs the primary warning prediction signal, the same operation as when the primary failure signal or the primary alarm signal is input is performed.

The alarm output circuit in the following invention is
The input signal conversion output section inputs the signal related to the input signal,
When the primary fault signal is input, the input signal is pseudo-normalized and output, and when the primary fault signal is not input, the input signal is output as it is.

The alarm output circuit in the following invention is
When the input signal conversion output unit inputs the primary alarm signal, the same operation as when the primary failure signal is input is performed.

Further, the alarm output circuit in the following invention is
A primary alarm prediction unit that outputs a primary alarm prediction signal that predicts and notifies the occurrence of a primary failure when the ratio of inputting a primary failure signal to the primary alarm output unit exceeds a predetermined value When the input signal conversion output unit inputs the primary alarm prediction signal, the same operation as when the primary failure signal or the primary alarm signal is input is performed.

[0027]

【Example】

Embodiment 1 FIG. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an alarm output circuit according to the present invention. In the figure, the same reference numerals as those in FIG.
Or, a corresponding portion is shown and the description is omitted. In addition, the difference from FIG. 9 is that the secondary alarm output suppression unit 12a operates in the primary alarm signal 10
The point is that the primary fault signal 101 is input instead of 2. With the configuration shown in FIG. 1, the secondary alarm output suppressing unit 12a outputs the primary alarm signal 101 output when the primary alarm is out of synchronization to the secondary alarm output suppressing unit 12a. The output of the next alarm signal 104 is suppressed.
That is, the secondary alarm output suppression unit 12a suppresses the output of the secondary alarm signal 104 by the primary failure signal 101 for detecting the primary failure, so that the front alarm output unit 9 shown in FIG. By the protection means, the output of the genuine secondary alarm signal 105a output when the output of the primary alarm signal 102 is delayed is suppressed, and the congestion of alarms in the device alarm unit 3 can be prevented. .

Embodiment 2 FIG. FIG. 2 is a block diagram showing the configuration of the alarm output circuit according to the second embodiment. In the figure, the difference from FIG. 1 is that a new primary alarm signal 102 is input to the secondary alarm output suppression unit 12b. In point. That is, the secondary alarm output suppression unit 12b receives the secondary alarm signal 1 when either the primary fault signal 101 or the primary alarm signal 102 is input.
04 output is suppressed, and only if a true secondary failure that is not related to the primary failure occurs
The next alarm signal 105b is output. Further, FIG. 3 shows the second embodiment.
6 is a timing chart showing the timing at which the output of the genuine secondary warning signal 105b is suppressed, where ◯ indicates a normal frame and × indicates an abnormal frame. That is, the abnormal frame shows a case where an error such as a synchronization error occurs in the primary failure and an error such as a parity error resulting from the synchronization failure occurs in the secondary failure.

Next, the operation will be described with reference to the drawings. In FIG. 2, the primary failure signal 101 is sent to the secondary alarm output suppression unit 12b.
And a primary alarm signal 102 are input to input a secondary alarm signal 104
The suppression condition for suppressing the output of is that, for example, when the cable used for the input signal 6 is disengaged and steady disengagement occurs, as in the sixth frame and the eleventh frame shown in FIG. For example, if the synchronization pattern of the synchronization pulse happens to be a normal pattern, the primary failure detection unit 8 cannot verify the synchronization loss of the frame, and the primary failure signal 101 for the frame is not output. However, the secondary warning signal 104 such as a parity error due to the loss of synchronization is output to the secondary warning output suppressing unit 12b. In such a case, in the configuration of FIG. 1, the output of the secondary alarm signal 104 is not suppressed by the secondary alarm output suppressing unit 12a,
The genuine secondary alarm signal 105a is output to the device alarm unit 3.

However, as in the configuration of FIG. 2, in the secondary alarm output suppressing section 12b, when either the primary fault signal 101 or the primary alarm signal 102 is input, the secondary alarm signal 104 is output. By suppressing the output, even if the primary failure detection unit 8 does not output the primary failure signal 101 as in the sixth frame and the eleventh frame shown in FIG. 3, the secondary alarm output suppression unit 12b. This is because it is possible to suppress the output of the genuine secondary warning signal 105b from. That is, if the primary alarm signal 102 is output even if the primary failure is not erroneously detected, the output of the secondary alarm signal 104 relating to the primary failure can be suppressed, and the device alarm unit 3
It is possible to prevent the congestion of the alarm in. If the primary alarm signal 102 is output even when the primary failure is restored, the output of the genuine secondary alarm signal 105b from the secondary alarm output suppression unit 12b can be suppressed, so that the primary alarm is generated. It is possible to prevent the congestion of the alarm in the device alarm unit 3 when the rear protection means for the primary failure is operating in the output unit 9.

Embodiment 3 FIG. FIG. 4 is a block diagram showing the configuration of the alarm output circuit according to the second embodiment. In the figure, the same symbols as those in FIG. 2 indicate the same or corresponding parts, and their explanations are omitted. In FIG. 4, 106 is output from the primary alarm output unit 9,
When the establishment of the primary failure is predicted, the secondary alarm output suppression unit 1
It is a primary warning prediction signal output to 2c. Further, FIG. 5 is a timing chart showing the timing at which the output of the genuine secondary warning signal 105c according to the third embodiment is suppressed. As the primary warning prediction signal 106, for example, the results of 5 frames immediately before the frame that is always input are stored, and if a failure occurs in 4 frames out of the stored 5 frames, It is a signal output by predicting the establishment of a failure.

Next, the operation will be described. The basic operation is the same as that of the second embodiment, and the difference will be described. For example, in the case where the cable used for the input signal 6 comes off and a steady loss of synchronization occurs, the synchronization of the sync pulse happens to occur while the primary alarm signal 102 is not output, as in the fifth frame shown in FIG. When the pattern becomes a normal pattern, the primary failure detection unit 8 cannot detect the out-of-synchronization of the frame and the primary failure signal 1
01 is not output. However, since the secondary alarm signal 104 such as a parity error is output to the secondary alarm output suppressing unit 12c, the secondary alarm output suppressing unit 12b shown in FIG.
The output of the next alarm signal 104 is not suppressed, and the genuine secondary alarm signal 105b is output to the device alarm unit 3. However, in the configuration of FIG. 4, among the 0th to 4th frames, the number of failed frames is 4, so the 5th frame is set to 1 when input.
By outputting the secondary alarm prediction signal 105 to the secondary alarm output suppression unit 12c, the secondary alarm signal 10 in the fifth frame is output.
4 is suppressed and the genuine secondary warning signal 105c is not output. This causes the primary fault signals 101 and 1
Even if the secondary alarm signal 102 is not output, the secondary alarm signal 104 related to the primary failure can be suppressed from being output.

In this embodiment, the primary warning prediction signal 10
6 has been described as being output if there is a failure in 4 out of 5 frames immediately before the input frame, but it goes without saying that the condition may be changed according to the failure occurrence rate of the line used. .

Embodiment 4 FIG. FIG. 6 is a block diagram showing the configuration of the alarm output circuit according to the fourth embodiment. In the figure, the same reference numerals as those in FIG. 4 denote the same or corresponding parts, and the description thereof will be omitted. In FIG. 6, reference numeral 13 suppresses the output of the output signal 71 when any of the primary fault signal 101, the primary warning signal 102, and the primary warning prediction signal 106 is input, and instead, a pseudo normal output. The input signal conversion output unit outputs the signal 71a. With the above-described configuration, the alarm output circuit outputs any one of the primary fault signal 101, the primary alarm signal 102, and the primary alarm prediction signal 106 to the input signal conversion output unit 13.
When the output signal 71a is output to the output terminal 1, the output of the output signal 71 is suppressed, and the pseudo normal output signal 71a is output instead.
The secondary fault related to the secondary fault is not detected, and the secondary alarm signal 104a is surely suppressed.

In the fourth embodiment, the input signal conversion output unit 1
3 for primary failure signal 101, primary alarm signal 102,
In the case where any one of the primary warning prediction signal 106 and the primary warning prediction signal 106 is output, the input signal conversion output unit 13 converts the output signal 71 into the pseudo normal output signal 71a and outputs it. Only the next fault signal 101 is input signal conversion output unit 1
In the same manner, when inputting to No. 3 or when inputting the primary fault signal 102 and the primary alarm signal 102 to the input signal conversion output unit 13, the input signal conversion output unit 13 similarly outputs the output signal 71 in a pseudo normal manner. The output signal 71a may be converted into the output signal 71a and output.

Example 5. FIG. 7 is a block diagram showing the configuration of the alarm output circuit according to the fifth embodiment. In the figure, the same reference numerals as those in FIG. 4 denote the same or corresponding parts, and the description thereof will be omitted. In FIG. 7, 14 is a secondary failure signal output suppressing unit that suppresses the output of the secondary failure signal 103 when any of the primary failure signal 101, the primary warning signal 102, and the primary warning prediction signal 106 is input. Is. Also with the above-described configuration, the output of the secondary fault signal 103b to the secondary alarm output unit 11 can be suppressed, and the alarm congestion in the device alarm unit 3 can be prevented.

In the fifth embodiment, the primary fault signal 101 and the primary warning signal 10 are sent to the secondary fault signal output suppressing section 14.
In the case where any one of the secondary warning prediction signal 106 and the secondary warning prediction signal 106 is output, an example in which the output of the secondary failure signal 103b to the secondary warning output unit 11 is suppressed is shown. Similarly, when only the secondary fault signal output suppressing unit 14 is input, or when the primary fault signal 101 and the primary alarm signal 102 are input to the secondary fault signal output suppressing unit 14, the secondary alarm output is similarly performed. Secondary fault signal 1 for section 11
The output of 03b may be suppressed.

By the way, in the above-mentioned first to fifth embodiments,
Although the alarm output circuit that suppresses the output of the secondary alarm related to the primary failure has been described, in the device to which the alarm output circuit disclosed in the first to fifth embodiments is applied, the secondary alarm signal is output according to the characteristics of the device. It goes without saying that it is acceptable to change the condition for outputting the.

[0039]

According to the present invention, in the alarm output circuit, the output of the secondary alarm signal is suppressed when the signal output suppressing section inputs the primary alarm signal. The next alarm signal is not output, which is effective in preventing the congestion of alarms.

Further, according to the next invention, in the alarm output circuit, when the signal output suppressing unit inputs the primary fault signal, the output of the secondary fault signal is suppressed with respect to the secondary alarm output unit. When the primary failure is detected, the secondary warning signal is not output, and there is an effect that the warning congestion can be prevented.

According to the next invention, the alarm output circuit performs the same operation when the primary output signal is input to the signal output suppressing unit as when the primary failure signal is input. Even if the failure is not erroneously detected, the output of the secondary alarm can be suppressed if the primary alarm is output.

Further, according to the next invention, the alarm output circuit predicts the occurrence of the primary failure when the ratio of inputting the primary failure signal to the primary alarm output section exceeds a predetermined value. If a primary warning prediction unit that outputs a primary warning prediction signal to be notified is provided, and the signal output suppression unit inputs the primary warning prediction signal, if a primary failure signal or primary warning signal is input Since the same operation is performed, even if the primary failure signal and the primary alarm signal are not output, the output of the secondary alarm can be suppressed if the primary alarm prediction signal is output.

Further, according to the following invention, in the alarm output circuit, when the input signal conversion output section inputs a signal relating to the input signal and the primary failure signal is input, the input signal is simulated. When the input signal conversion output unit inputs the primary fault signal, the secondary fault detection unit detects the secondary fault because the input signal is output as it is when the primary fault signal is not input. The effect that the output of the secondary alarm can be surely suppressed by not performing the above.

Further, according to the next invention, the alarm output circuit performs the same operation as when the primary fault signal is input when the input signal conversion output section inputs the primary alarm signal. If the primary alarm is output even if the secondary fault is not detected erroneously, the input signal conversion output section outputs a pseudo-normalized input signal, so the secondary alarm is output reliably. There is an effect that can be suppressed.

Further, according to the present invention, the alarm output circuit predicts the occurrence of the primary failure when the ratio of inputting the primary failure signal to the primary alarm output section exceeds a predetermined value. A primary warning prediction unit that outputs a primary warning prediction signal to be notified is provided, and when the input signal conversion output unit inputs the primary warning prediction signal, the primary failure signal or the primary warning signal is input. Since the same operation as in the case is performed, even if the primary failure signal and the primary alarm signal are not output, if the primary alarm prediction signal is output, the pseudo-normalized input is performed from the input signal conversion output unit. Since the signal is output, there is an effect that the output of the secondary alarm can be surely suppressed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an alarm output circuit according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of an alarm output circuit according to a second embodiment of the present invention.

FIG. 3 is a timing chart for explaining the timing of suppressing the secondary alarm output according to the second embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of an alarm output circuit according to a third embodiment of the present invention.

FIG. 5 is a timing chart for explaining the timing of suppressing the secondary alarm output according to the third embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of an alarm output circuit according to a fourth embodiment of the present invention.

FIG. 7 is a block diagram showing a configuration of an alarm output circuit according to a fifth embodiment of the present invention.

FIG. 8 is a configuration diagram of a digital multiplexing device to which an alarm output circuit is applied.

FIG. 9 is a block diagram showing a configuration of a conventional alarm output circuit.

[Explanation of symbols]

 9a Primary alarm output unit 12a, 12b, 12c Secondary alarm output suppression unit 13 Input signal conversion output unit 14 Secondary failure signal output suppression unit 71a Output signal 101 Primary failure signal 102 Primary alarm signal 103, 103a, 103b 2 Secondary fault signal 104, 104a, 104b Secondary warning signal 105a, 105b, 105c Authentic secondary warning signal 106 Primary warning prediction signal

Claims (7)

[Claims] 1. A primary failure detection unit for outputting a primary failure signal for each of the sync frames in which an input signal formed of a sync frame is out of synchronization, and the primary failure signal continues for a predetermined number of frames. A primary alarm output section that outputs a primary alarm signal, a secondary failure detection section that outputs a secondary failure signal when a secondary failure due to loss of synchronization of the input signal is detected, and the secondary A secondary alarm output section that outputs a secondary alarm signal when a failure signal is input, and a signal output suppressing section that suppresses the output of the secondary alarm signal when the primary failure signal is input are provided. Alarm output circuit. 2. A primary failure detection unit for outputting a primary failure signal for each of the sync frames in which an input signal formed of a sync frame is out of synchronization, and the primary failure signal continues for a predetermined number of frames. A primary alarm output section that outputs a primary alarm signal, a secondary failure detection section that outputs a secondary failure signal when a secondary failure due to loss of synchronization of the input signal is detected, and the secondary A secondary alarm output unit that outputs a secondary alarm signal when a fault signal is input, and a signal output suppression that suppresses the output of the secondary fault signal to the secondary alarm output unit when the primary fault signal is input. And an alarm output circuit. 3. The signal output suppressing unit performs the same operation as when a primary warning signal is input when the primary alarm signal is input, according to any one of claims 1 and 2. The alarm output circuit according to claim 1. 4. A primary alarm prediction signal for predicting and notifying the occurrence of a primary failure is output to the primary alarm output unit when the rate of inputting a primary failure signal exceeds a predetermined value. A primary alarm prediction unit is provided, and when the signal output suppression unit inputs the primary alarm prediction signal, the same operation as when the primary failure signal or the primary alarm signal is input is performed. The alarm output circuit according to item 3. 5. A primary failure detection unit for outputting a primary failure signal for each of the sync frames in which an input signal formed by a sync frame is out of synchronization, and the primary failure signal continues for a predetermined number of frames. When inputting, the primary alarm output section that outputs the primary alarm signal and the signal related to the above input signal are input. When the above primary failure signal is input, the input signal is pseudo-normalized. When a secondary fault is detected in the signal input from the input signal conversion output unit, the secondary fault signal is output when the secondary fault signal is output and the input signal is output as it is when the primary fault signal is not input. An alarm output circuit comprising: a secondary failure detection section for outputting; and a secondary alarm output section for outputting a secondary alarm signal when the secondary failure signal is input. 6. The alarm output circuit according to claim 5, wherein when the input signal conversion output section inputs the primary alarm signal, the same operation as when the primary failure signal is input is performed. . 7. A primary alarm prediction signal for predicting and notifying the occurrence of a primary failure is output to the primary alarm output unit when the rate of inputting a primary failure signal exceeds a predetermined value. A primary alarm prediction unit is provided, and when the input signal conversion output unit inputs the primary alarm prediction signal, the same operation as when the primary failure signal or the primary alarm signal is input is performed. The alarm output circuit according to item 6.