JP4328299B2 - Phase alarm circuit and alarm generation method - Google Patents

Description

  The present invention relates to a phase alarm circuit and an alarm generation method for a wireless transmitter having a redundant configuration.

  In some microwave radio communication systems that require high reliability, the transmitter / receiver is switched without interruption by using a redundant redundant configuration. As the transmission signal speeds up, it is important that the phase of the transmission wave matches in addition to the transmission frequency and transmission power level when switching the transmitter without interruption. Conventionally, a phase difference is detected by detecting beats that occur when there is a difference between the transmission waves of the two transmitters in the phase difference between the active and standby transmitters (for example, Patent Documents). 1).

FIG. 5 is a block diagram showing a functional configuration of a conventional phase alarm circuit that detects a phase difference between transmission waves to detect an abnormality of the transmitter and generates an alarm (hereinafter referred to as an alarm).
In FIG. 5, the conventional phase alarm circuit takes out the output to measure the phase of each transmitter 1a, transmitter 1b, and each transmitter, for example, couplers 2a and 2b which are directional couplers, and coupler 2a. 2b is input and outputs a beat signal from both transmitters, a switch 4 is input to which the transmission waves of the two transmitters are input and outputs one of them to the antenna, and an input beat signal Is compared with an internal reference signal and outputs a phase error signal to the phase adjustment unit 11 of the transmitter 2b, and an alarm unit 60 that monitors the beat signal and outputs an alarm when a certain level is exceeded. It has.

  With the above configuration, for example, the phase adjustment unit 11 of the other standby transmitter 1b adjusts the phase difference between the two transmitters in a required range in accordance with one of the active transmitters 1a. Can fit.

  The alarm unit 60 generates an abnormal signal by comparing a buffer 610 to which a beat signal is input, an amplifier 620 for adjusting a signal such as a level of the beat signal, a predetermined alarm level and a beat signal input from the amplifier 620. In order to prevent malfunction due to noise or the like, the comparator 630 to be output is provided with an alarm mask unit 640 that does not output an alarm signal unless the abnormal level continues for a predetermined time (here, 1 second).

The two transmitters 1a and 1b generate transmission waves based on a reference oscillator (not shown), and fluctuations in frequency and phase difference are not abrupt. Therefore, the conventional phase alarm circuit and alarm unit 60 may malfunction due to noise. I was able to prevent it. However, if either transmitter 1a or 1b malfunctions and phase out-of-synchronization occurs between the two transmitters, resynchronization or automatic operation can be performed by a predetermined procedure instead of normal phase difference adjustment. It is necessary to perform processing such as switching. However, in such a case, the alarm unit 60 is within the mask time of the alarm mask unit 640 even though a short pulse alarm signal of 1 second or less is repeatedly output from the comparator 630. Had a problem that no alarm was output.
JP-A-5-227233 (Page 6, FIG. 1)

  When out-of-synchronization occurs between two transmitters that are switched in a redundant configuration, the conventional phase alarm circuit outputs an alarm signal in spite of repeated high-speed pulse alarm signals. There was a problem that was not output.

  The present invention has been made in order to solve the above-described problem, and a phase alarm for notifying a malfunction of a phase difference that occurs at high speed between transmission waves of two transmitters of a redundant configuration that can be switched between each other while preventing malfunction due to noise. An object is to provide a circuit and an alarm generation method thereof.

  In order to achieve the above object, a phase alarm circuit according to the present invention is a phase alarm circuit that detects a phase difference between two transmission waves of a redundant configuration that can be switched to each other from a beat signal of the transmission wave. A comparator that generates and outputs an active alarm signal when the beat signal exceeds a predetermined alarm level, and is triggered by a rising edge of the alarm signal input from the comparator. A retriggerable mono-multi circuit that generates and outputs a second alarm signal that keeps the time output state active, and an output of the alarm signal of the comparator is input to one input terminal, The output of the second alarm signal from the circuit is input to the other input terminal, and the logical sum of the two alarm signals input is the third An OR circuit that outputs as an alarm signal, and the third alarm signal is input, and the third alarm signal in an active state after a second predetermined time longer than the first predetermined time has elapsed is used as an alarm. And an alarm mask circuit for outputting.

  The alarm generation method for the phase alarm circuit according to the present invention is an alarm generation method for a phase alarm circuit that detects a phase difference between two transmission waves of two transmitters in a redundant configuration that can be switched to each other from a beat signal of the transmission wave. The phase alarm circuit includes a comparator, a retriggerable mono-multi circuit, an OR circuit, and an alarm mask circuit, and the comparator exceeds the input beat signal in comparison with a predetermined alarm level. The alarm signal is generated and output, and the retriggerable mono-multi circuit to which the alarm signal is input is triggered by a rising edge of the alarm signal input from the comparator, and has a first predetermined time. A second alarm signal that keeps the output state active is generated and output to the OR circuit, and the OR circuit The alarm signal output from the comparator is input to one input terminal, the second alarm signal output from the retriggerable mono-multi circuit is input to the other input terminal, and the both alarm signals input Is output as a third alarm signal, and the alarm mask circuit to which the output of the OR circuit is input is in an active state after a second predetermined time longer than the first predetermined time has elapsed. The logical sum warning signal is output as an alarm.

  According to the present invention, it is possible to provide a phase alarm circuit and an alarm method thereof capable of preventing malfunction caused by noise and detecting an abnormality occurring at high speed.

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

FIG. 1 is a block diagram showing a functional configuration of a phase alarm circuit 8 of a redundant transmission system according to an embodiment of the present invention.
In FIG. 1, the redundant transmission system takes out its output in order to measure the phase of each of the transmitter 1 a, the transmitter 1 b, and each transmitter. For example, the outputs of couplers 2 a and 2 b and couplers 2 a and 2 b by directional coupler Is input to the mixer 3 that outputs the beat signals of both transmitters, the transmission waves of the two transmitters are input, the switch 4 that outputs one of them to the antenna, and the input beat signal to the internal reference signal And a phase difference detection unit 5 that outputs a phase error signal to the phase adjustment unit 11 of the transmitter 2b, and a phase alarm circuit 8 that outputs an alarm when the beat signal is monitored and exceeds a certain level. .

  The phase alarm circuit 8 includes a low speed alarm unit 6 and a high speed alarm unit 7. The low-speed alarm unit 6 is the same except that the alarm mask unit 64 is omitted from the configuration of the alarm unit 60 of FIG. 5 described above, and the output of the comparator 63 is input to the OR circuit 76 of the high-speed alarm unit described later. The amplifier 62 and the comparator 63 of the low-speed alarm unit 6 have a higher frequency-to-gain characteristic compared to a comparator 73 described later in order to avoid malfunction due to noise.

  The high-speed alarm unit 7 includes a buffer 71 to which a beat signal is input, an amplifier 72 for adjusting a frequency characteristic and a level for amplifying the beat signal, a predetermined alarm level and a beat signal input from the amplifier 72, and an alarm signal. In order to prevent malfunction caused by noise or the like, the alarm mask unit 74 that outputs an alarm after the alarm signal has passed for a predetermined time (here, 1 second) and the output of the comparator 73 are An input one-shot multi (hereinafter referred to as mono-multi) 75, and an OR circuit 76 that inputs the output of the mono-multi 75 and the comparator 63 of the low-speed alarm unit 6 and outputs a logical sum output to the alarm mask unit 74. I have.

  As will be described later, the amplifier 72 and the comparator 73 have a gain-frequency characteristic in the amplifier 62 and the comparator 63 of the low-frequency alarm unit 6 so as to detect a beat signal that changes in an early cycle when an out-of-synchronization occurs. Compared to the high frequency range, in other words, it has high-speed response.

FIG. 2 is a principle diagram of an operation in which an alarm signal is generated from a beat signal that is an output of the mixer 3, and FIG. 3 is a principle diagram of an operation in which an alarm signal is generated from a beat signal when a loss of synchronization occurs. .
The operation of each component of the phase alarm circuit 8 of the present invention will be described below with reference to FIGS.
In FIG. 2 (a), the beat signal from the mixer 3 is input to the low speed alarm unit 6.

  In a transmission system that performs switching without interruption by a redundant configuration, the two transmitters 1a and 1b generate the transmission radio wave so as to be synchronized from a common reference oscillator (not shown). Differences in frequency and phase are kept small. Therefore, the input from the mixer 3 to the comparator 63 of the low-speed alarm unit 6 is a gently curved beat signal B. When the predetermined alarm level th is exceeded, the comparator output C of the comparator 63 (hereinafter referred to as an alarm signal). Is an alarm signal that activates the “H” level, and the alarm signals of the abnormal periods c 1 and c 2 are output to one input terminal of the OR circuit 76 of the high-speed alarm unit 7. The OR circuit 76 outputs the input warning signal to the alarm mask 74. Note that the alarm signal may be one that activates the “L” level, but hereinafter, the processing operation of the phase alarm circuit 8 will be described with the “H” level active.

  The alarm mask unit 74 is provided with an alarm monitoring time of a1 in order to prevent malfunction due to instantaneous noise. For example, only the alarm signal of the portion after the 1-second “H” level (abnormal period c2) continues is used as an alarm signal. Output. As a result, the alarm signal of 1 second or less in FIG. 2B (abnormal period c1) is not output as an alarm as shown in FIG. 2C, and the alarm signal of the abnormal period exceeding 1 second is displayed in the alarm mask unit. 74 is output as an alarm.

  In FIG. 2, the alarm level th shows the case of positive polarity, but the operation of outputting an alarm signal in the case of a negative polarity alarm level not shown is the same as described above. As the comparator, a comparator circuit that determines a negative alarm level (not shown) is used, or a comparator circuit that determines a bipolar alarm level is used.

  In the transmitter 1b, feedback control is performed in which the phase adjusting unit 11 suppresses the beat signal level by an error signal from the phase difference detecting unit 5 to which the same beat signal is input, and one of the transmitters 1a and 1b is selected. Even if a transmission frequency or phase difference occurs, it is stored with a predetermined phase difference. However, when a major failure or abnormality occurs in the operation of either one of the transmitters 1a and 1b, the transmission frequency and phase difference between the two transmitters are not synchronized, and the two transmitters 1a and 1b are not synchronized with each other. Independent operation will be performed.

  FIG. 3A shows the waveform of the beat signal B input to the comparators 63 and 73 in the out-of-synchronization state. In such a case, unlike the beat signal in the case of being synchronized, the beat signal changes frequently in one second or less. Then, as shown in FIG. 3B, the comparators 63 and 73 output a warning signal when the alarm level th is exceeded. However, when only the comparator 63 of the low-speed alarm unit 6 is provided as in the conventional phase alarm circuit, even if alarm signals are repeatedly output, the alarm mask unit 74 is a short time of 1 second or less. Does not output an alarm as shown in FIG.

  On the other hand, the content of the beat signal input to the high speed alarm unit 7 processed by the comparator 73 is basically the same as that processed by the comparator 63 of the low speed alarm unit 6, but the output of the comparator 73 is Furthermore, it is input to the mono multi 75 with high speed response. The mono multi 75 detects a rising edge of the alarm signal output from the comparator 73, and obtains a predetermined alarm monitoring time period a (here, an alarm signal) so that a time longer than the alarm signal output from the comparator 73 is obtained. An active “H” signal is output (see FIG. 3D). The output is input to the other terminal of the OR circuit 76. .

  The mono multi 75 is a retriggerable one-shot multi and is triggered by an input alarm signal. If the next alarm signal is input again during the output of “H”, in other words, the “H” state within 0.7 seconds, the “H” state is again “H” for 0.7 seconds from the input time point. "" Is continued further, so that the "H" state can be held for one second or longer.

  That is, since the output of the mono multi 75 is input to the other input terminal of the OR circuit 74, a beat signal frequently exceeding the alarm level as shown in FIG. In addition, an “H” level signal of 1 second or more is output to the OR circuit 76. The OR circuit 76 further outputs a warning signal that is continuous for 1 second or more to the alarm mask unit 74. Therefore, when a short-time pulse warning signal is generated continuously, the alarm mask unit 74 The alarm is output as shown in FIG.

  A self-diagnosis unit (not shown) to which the output alarm signal is input further observes the alarm signal state, and executes a procedure such as automatic switching of the transmitter according to a predetermined procedure.

  Thus, when the comparator 73 of the high-speed alarm unit 7 outputs “H” due to instantaneous (single or not frequently generated) noise, the alarm output from the mono multi 75 is at the “H” level. Since the time is less than 1 second, an alarm is not output from the alarm mask 76 so that malfunction due to noise can be prevented and an alarm signal is continuously generated at a high speed such as out of synchronization. An alarm can be output.

  Even if it is instantaneous, if several short pulse noises are input consecutively, there is a risk of malfunction that outputs the same alarm signal as in the case of loss of synchronization. Don't be. For that purpose, the mono multi 75 is retriggered by noise within the time of holding “H”, and it is necessary to adjust so that it does not exceed 1 second. Actually, according to the operating characteristics of the transmitters 1a and 1b and the noise characteristics depending on the installation conditions such as the cable route, the time for holding “H” for 0.7 seconds as exemplified above or in place thereof is adjusted. By obtaining the logical sum of the multi 75 output and the alarm signal from the low speed alarm unit 6 by the OR circuit 75, the phase alarm circuit is set so that the detection sensitivity and stability are optimized.

FIG. 4 is a block diagram showing a functional configuration of the phase alarm circuit 8 of the redundant transmission system according to the embodiment of the present invention.
In the second embodiment, the low-speed alarm unit 6 is omitted, and the circuit scale is kept small. In the first embodiment, the amplifiers 62 and 72 are able to cope with a difference in signal characteristics between the case where the beat signal input from the low speed alarm unit 6 and the high speed alarm unit 7 is out of synchronization and the case where the beat signal is normal. In addition, the comparators 63 and 73 have different frequency characteristics, and the output time length of mono-multi is adjusted to prevent malfunction of alarm generation due to noise. However, in the second embodiment, the amplifier 72 and the comparator 73 have a neutral frequency characteristic so that only one comparator is required, and the low-speed alarm unit 6 is omitted. The details of the operation can be easily inferred from the above description, and will be omitted. However, even if a loss of synchronization occurs, a plurality of continuous short pulsed comparator outputs are maintained so that the mono-multi 75 keeps the "H" state long. By converting and outputting, an alarm signal can be generated and output.

  As described above, the phase alarm circuit according to the present invention can provide a phase alarm circuit and an alarm method for notifying malfunctions caused by noise and notifying abnormalities occurring at high speed.

1 is a block diagram showing a functional configuration of a phase alarm circuit according to Embodiment 1 of the present invention. The principle of operation in which an alarm signal is generated from a beat signal. The operation | movement principle figure with which an alarm signal is produced | generated from the beat signal when a loss of synchronization arises. The block diagram which shows the function structure of the phase alarm circuit concerning Example 2 of this invention. The block diagram which shows the function structure of the conventional phase alarm circuit.

Explanation of symbols

1a, 1b Transmitter 11 Phase adjustment unit 2a, 2b Coupler 3 Mixer 4 Switch 5 Phase difference detection unit 6 Low speed alarm unit 61, 71 Buffer 62, 72 Amplifier 63, 73 Comparator 7 High speed alarm unit 74 Alarm mask unit 75 Monomulti 76 OR circuit 8 Phase alarm circuit

Claims (6)

In the phase alarm circuit for detecting the phase difference between the transmission waves of the redundantly configured transmitters that are mutually switched from the beat signal of the transmission waves,
A comparator that generates and outputs an active alarm signal when the beat signal input exceeds a predetermined alarm level; and
A retriggerable mono-multi circuit that is triggered by a rising edge of the alarm signal input from the comparator and generates and outputs a second alarm signal that keeps the output state active for a first predetermined time;
The output of the alarm signal of the comparator is input to one input terminal, the output of the second alarm signal from the retriggerable mono-multi circuit is input to the other input terminal, and both of the input alarm signals are input. An OR circuit that outputs a logical sum of the above as a third alarm signal;
An alarm mask circuit for outputting the third warning signal in an active state after the second predetermined time longer than the first predetermined time as an alarm is input as the third warning signal; A phase alarm circuit characterized by that. In the phase alarm circuit for detecting the phase difference between the transmission waves of the redundantly configured transmitters that are mutually switched from the beat signal of the transmission waves,
First and second comparators that generate and output an active alarm signal when each beat signal is compared to a predetermined alarm level,
A retriggerable mono-multi circuit that generates and outputs a second alarm signal that is triggered by a rising edge of an alarm signal input from the first comparator and that keeps the output state active for a first predetermined time;
The second alarm signal is input to one input terminal, the output of the alarm signal from the second comparator is input to the other input terminal, and the logical sum of the two alarm signals input is a third An OR circuit that outputs an alarm signal;
An alarm mask circuit for outputting the third warning signal in an active state as an alarm after the second predetermined time longer than the first predetermined time elapses when the third warning signal is input; Phase alarm circuit characterized by.   The phase alarm circuit according to claim 2, wherein the first comparator responds faster than the second comparator. In an alarm generation method of a phase alarm circuit for detecting a phase difference between transmission waves of a transmitter having a redundant configuration that can be switched to each other from a beat signal of the transmission wave,
The phase alarm circuit includes a comparator, a retriggerable mono-multi circuit, an OR circuit, and an alarm mask circuit.
The comparator is
When the input beat signal exceeds a predetermined alarm level, an active alarm signal is generated and output,
The retriggerable mono-multi circuit to which the alarm signal is input,
Triggered by a rising edge of the alarm signal input from the comparator, generates a second alarm signal that keeps the output state active for a first predetermined time, and outputs the second alarm signal to the OR circuit;
In the OR circuit, the alarm signal output from the comparator is input to one input terminal, the second alarm signal output from the retriggerable mono-multi circuit is input to the other input terminal, The logical sum of both alarm signals that are input is output as a third alarm signal,
The alarm mask circuit to which the output of the OR circuit is input,
An alarm generation method for a phase alarm circuit, wherein the alarm signal of the logical sum in an active state after a second predetermined time longer than the first predetermined time has elapsed is output as an alarm. In an alarm generation method of a phase alarm circuit for detecting a phase difference between transmission waves of a transmitter having a redundant configuration that can be switched to each other from a beat signal of the transmission wave,
In the alarm generation method of the phase alarm circuit for detecting the phase difference between the transmission waves of the two transmitters of the redundant configuration that can be switched to each other from the beat signal of the transmission wave,
The phase alarm circuit includes first and second comparators, a retriggerable mono-multi circuit, an OR circuit, and an alarm mask circuit,
The first and second comparators are:
When each beat signal that is input exceeds the predetermined alarm level, an active alarm signal is generated and output,
The retriggerable mono-multi circuit to which the alarm signal is input from the first comparator,
A second alarm signal that is triggered by the rising edge of the input alarm signal to keep the output state active for a first predetermined time is generated and output to the OR circuit;
In the OR circuit, the second alarm signal output from the retriggerable mono-multi circuit is input to one input terminal, and the alarm signal output from the second comparator is input to the other input terminal. A logical sum of the two alarm signals input as a third alarm signal,
The alarm mask circuit to which the third alarm is input from the OR circuit outputs the third alarm signal in an active state after an elapse of a second predetermined time longer than the first predetermined time as an alarm. An alarm generation method for a phase alarm circuit.   6. The alarm generation method according to claim 5, wherein the first comparator responds faster than the second comparator.

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