JPH08145728A - Signal waveform recording device - Google Patents

Abstract

PURPOSE: To collect an abnormality monitoring signal waveform from each control equipment at low cost regardless of the increase in the control equipment which is subjected to abnormality monitoring, facilitate the detection of the abnormality signal waveform in which an abnormality generating time is specified, and also facilitate the recording and calling of waveform data. CONSTITUTION: This device has a loop memory 50 for storing the waveform information for signal every time which is outputted from the signal measuring point of a control device over a fixed time band, and renewing the stored waveform information successively from the older waveform information into a newly read waveform information; a signal comparator 70 for comparing the level of the waveform information for signal stored in the loop memory 50 with a preset signal level to determine an abnormality signal waveform, and outputting an abnormality judgment signal when the abnormality signal waveform is judged; and a control part 60A for transferring the waveform information stored in the loop memory 50 to an external recording medium when the abnormality judgment signal is outputted from the signal comparator 70.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal waveform recording apparatus for automatically recording information on an abnormal signal waveform indicating an abnormality of a measurement object and signal waveforms before and after the abnormality.

[0002]

2. Description of the Related Art Conventionally, in order to obtain signal waveform information for performing operation analysis and abnormality analysis of a control device, a sensor for measuring a signal is attached to a sampling point of the abnormality analysis signal of the control device and output from the sensor. A method of sending the received signal to a recorder as a signal waveform recording device and recording the signal waveform on a chart paper has been adopted. FIG. 5 is a block diagram showing a schematic configuration of a recorder as a conventional signal waveform recording device for recording a signal waveform. In the figure, reference numeral 10 is an analog input section for inputting an electrical analog measurement signal such as voltage or current input from a sensor for signal measurement (not shown) through a lead, and 20 is an A / D for digitally converting the analog measurement signal. A conversion unit 30 converts a digitally converted measurement signal into an analog signal and outputs a recording pen (not shown),
It is a recorder drive unit that can be swung left and right on the chart paper flowing in a fixed direction.

Next, the operation of the conventional device will be described.
The analog input unit 10 receives an electric signal, such as a voltage, a current, or a frequency signal, indicating the operation of various devices of the device from an unillustrated control device as an analog signal, and the level of this signal is input to the A / D converter. Convert the level according to. The electric signal whose level has been converted is the A / D conversion unit 2
CPU (not shown) converted to digital signal at 0
Signal analysis processing by.

Further, the electric signal is converted into an analog signal in the recorder driving section 30 to be powered up and inputted as a recording pen driving signal to, for example, a galvanometer for driving the recording pen left and right. As a result, the recording pen sways left and right on the chart paper 40 flowing in a fixed direction according to the amplitude change of the electric signal. Since ink flows out from the portion of the tip of the recording pen that comes into contact with the chart paper 40, the waveform of the electric signal whose amplitude changes with time is continuously drawn on the chart paper 40 to record the signal waveform. To be done.

The waveform recording of the electric signal is continuously performed from the start of the operation of the apparatus to the stop thereof, and after the operation is stopped, the worker observes the change in the waveform of the electric signal recorded on the chart paper 40 to monitor the abnormality. It is determined whether or not an abnormality has occurred. Then, if an abnormality is determined, the waveform of the electric signal before and after the occurrence of the abnormality is checked to perform a waveform analysis for investigating the cause of the abnormality.

[0006]

As described above, the signal waveform sampling by the conventional recorder collects the waveform of the abnormal signal which may occur at an unspecified time, so that the operation is stopped from the start of the operation of the abnormality monitoring target. There is a problem that a large amount of chart paper is consumed and electric power is consumed because the chart paper is kept flowing for a long time, sometimes for one day and night. In addition to that, there was a problem that the chart paper had to be replenished and abnormality monitoring could not be completely unmanned.

Further, when there are a plurality of abnormality monitoring targets, it is necessary to prepare a recorder for each abnormality monitoring target, which is costly. In addition, a signal waveform check is performed from the chart paper flown from each recorder to detect an abnormality signal. There is a problem that it takes a lot of personnel and time to find the waveform, and further, it is difficult to identify the time when the abnormality occurs even if the abnormal signal is found.

The present invention has been made to solve the above problems, and despite the increase in the number of control devices to be monitored for abnormalities, unattended signal waveforms for abnormality monitoring are unattended from each control device at low cost. An object of the present invention is to obtain a signal waveform recording device that can be sampled and collected, and that can easily detect an abnormal signal waveform that specifies an abnormal occurrence time, and that can easily record and call waveform data.

[0009]

According to another aspect of the present invention, there is provided a signal waveform recording apparatus for storing waveform information of a signal output from a measuring point at each time, for a certain period of time, and storing the waveform information. Of the stored waveform information, the oldest waveform information is updated to the newly loaded waveform information in order and stored.
Of the signal waveform stored in the first waveform memory and the signal level preset to determine the abnormal signal waveform, and outputs an abnormality determination signal when determining the abnormal signal waveform. And a second storage means for recording the waveform information stored in the first waveform storage means when the abnormality determination signal is output from the signal comparison means.

A signal waveform recording apparatus according to a second aspect of the present invention is the signal waveform recording apparatus according to the first aspect, wherein an abnormal signal waveform is output when an abnormality determination signal is input from the time measuring means for measuring the measurement time and the signal comparing means. It is provided with a control means for reading each time of the time zone from the time measuring means and recording the respective time and the waveform information for the time zone in the second storage means from the first storage means.

A signal waveform recording apparatus according to a third aspect of the present invention stores the waveform information of the signal output from the measurement point at each time for a certain period of time and stores the stored waveform information. First storage means for updating and storing new waveform information in order from old waveform information, time measuring means for measuring a measurement time, and a trigger for instructing to extract the waveform information from the first waveform storage means. Trigger signal output means for outputting a signal, and when the trigger signal is input from the trigger signal output means, the measurement time is read from the time measuring means, and the read measurement time and the waveform information stored in the first storage means are And a control means for recording in the second storage means.

In the signal waveform recording apparatus according to the invention of claim 4, the waveform information composed of a digital signal having a plurality of bits at each time output from the measurement point is stored for a certain period of time and stored. Of the waveform information, first storage means for updating and storing new waveform information in order from the oldest waveform information, and the bit configuration content of the waveform information stored in this first storage means are preset. And a control means for recording the waveform information stored in the first storage means in the second waveform storage means in the bit configuration.

A signal waveform recording apparatus according to a fifth aspect of the present invention is the signal waveform recording apparatus according to any one of the first to third aspects, in which signals output individually from a plurality of measurement points are sequentially scanned to obtain a first signal waveform recording apparatus. And a signal switching means for outputting to the storage means.

A signal waveform recording apparatus according to a sixth aspect of the present invention is the signal waveform recording apparatus according to any one of the first to third aspects, wherein when the level of the signal output from the measurement point is a certain value or more, Is provided with a signal attenuating means for attenuating at a constant attenuation rate.

A signal waveform recording apparatus according to a seventh aspect of the present invention is the signal waveform recording apparatus according to any one of the first to third aspects, wherein when the level of the signal output from the measurement point is a fixed value or less, Is provided with a signal amplification means for amplifying the signal with a constant amplification factor.

A signal waveform recording apparatus according to an eighth aspect of the present invention is the signal waveform recording apparatus according to any one of the first to seventh aspects, wherein the instantaneous power failure detecting means for detecting an instantaneous power failure and the operation for a certain period of time when the instantaneous power failure is detected. And a control means that operates by this backup power supply and records the waveform information stored in the first storage means in the second storage means during a predetermined time before and after the momentary power failure.

A signal waveform recording apparatus according to a ninth aspect of the present invention is the signal waveform recording apparatus according to any one of the first to eighth aspects, wherein the signal waveform stored in the first storage means is input to a data line. It is provided with a print output means for printing out.

According to a tenth aspect of the present invention, in the signal waveform recording apparatus according to any one of the first to eighth aspects, the control means follows the information reading instruction input from the host computer via the data line. It is characterized in that the waveform information is read from the first storage means.

[0019]

According to the first aspect of the present invention, there is provided the signal waveform recording apparatus, wherein the waveform level among the waveform information stored in the first storage means for updating the stored contents with the passage of time is equal to or higher than the preset signal level. If it is determined by the signal comparison means that the existence is present, the waveform information stored in the first storage means is recorded in the second storage means to record the abnormal signal waveform.

In the signal waveform recording apparatus according to the second aspect of the present invention, among the waveform information stored in the first storage means for updating the stored contents with the passage of time, if the waveform level is equal to or higher than the preset signal level. If it is determined by the signal comparing means that the abnormal signal waveform is stored in the first storage means, the time at which the abnormal signal waveform is determined is recorded in the second storage means to record the abnormal signal waveform information. .

According to another aspect of the signal waveform recording apparatus of the present invention, if a trigger signal for instructing reading of the waveform information stored in the first storage means is input from the trigger signal output means to the control means, The control means reads the current time from the time counting means and the waveform information stored in the first storage means, and records each in the second storage means.

According to another aspect of the signal waveform recording apparatus of the present invention, the control means checks the bit structure of the waveform information composed of a digital signal having a plurality of bits stored in the first storage means, and the abnormal signal is detected from the bit structure. At the time of waveform detection, the waveform information is transferred to the second storage means and recorded.

In the signal waveform recording apparatus according to the invention of claim 5, the signals output from the plurality of measurement points are sequentially scanned by the signal switching device and sent to the first storage means, whereby the first storage means stores the signals. Only one means of sending a signal is required.

In the signal waveform recording apparatus according to the sixth aspect of the present invention, when the level of the signal output from the measurement point is equal to or higher than a certain value, the signal attenuator attenuates the signal at a certain attenuation rate to obtain the first signal. The signal is output to the storage means, and when the value is less than a certain value, the signal is directly output to the first storage means.

According to a seventh aspect of the signal waveform recording apparatus of the present invention, when the level of the signal output from the measuring point is below a certain level, the signal amplifier amplifies this signal with a certain amplification factor.
And outputs a signal directly to the first storage means when the value exceeds a certain value.

In the signal waveform recording apparatus according to the invention of claim 8, when the instantaneous power failure detecting means detects an instantaneous power failure of the apparatus,
The apparatus is operated by a backup power source for a certain period of time, and the waveform information stored in the first storage unit is recorded in the second storage unit between predetermined times before and after the momentary power failure.

In the signal waveform recording apparatus according to the invention of claim 9, when an abnormal signal waveform is detected from the waveform information stored in the first storage device, the waveform information including the abnormal signal waveform is printed out by the output means. To print the signal waveform.

In the signal waveform recording apparatus according to the tenth aspect of the present invention, the waveform information reading can be program-controlled by reading the waveform information from the first storage means in accordance with the information reading instruction from the host computer.

[0029]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. Reference numeral 90A in FIG. 1 is a signal waveform recording apparatus in this embodiment. This signal waveform recording device 90A has a plurality of analog input sections 10 for inputting analog electric signals respectively output from sensors provided for various abnormality monitoring targets in a control device (not shown), and output channels of the analog input section 10 at fixed intervals. , A channel switcher 11, such as a multiplexer, which scans with and outputs electric signals to subsequent A / D converters 20 in sequence for each channel.
A digital input section 12 for inputting a digital electric signal of several bits, a digitized electric signal for each channel sequentially output from the A / D converter 20 and each channel for sequentially output from the digital input section 12. Of the electric signal is recorded as the waveform information of the electric signal at each signal sampling time, and is composed of a loop memory 50 as a first storage means.

Furthermore, the signal waveform recording device 90A updates the electric signal at each time stored in the loop memory 50 to an electric signal at a newer time than an electric signal at an old time, and the level of the stored electric signal is changed. A control unit (control means) 60A for recording a high-level electric signal and an electric signal at a time around the high-level electric signal in an external storage medium (not shown) as a second storage means when the level is equal to or higher than a preset level, and is set by the control device. Abnormal signal level judgment value and loop memory 50
The signal comparator 7 as a signal comparing means for comparing the levels of the electric signals stored in the controller and transmitting the comparison result to the control unit 60A.
0, an external storage medium interface 80 that transfers an electrical signal of an abnormal signal level and an electrical signal of its peripheral time to an external storage medium according to an instruction from the control unit 60A.

Next, the operation of this embodiment will be described.
When an electric signal for abnormality monitoring is input to each input channel of the analog input unit 10 from various devices of the control device,
These electric signals are input to the channel switcher 11.
The channel switcher 11 sequentially scans each channel at a constant cycle and outputs an electric signal to the A / D converter 20 for digital conversion. The digitally converted electric signal is stored in the loop memory 50 for each channel as waveform information of the electric signal.

On the other hand, the level value of each electric signal obtained by computer arithmetic processing (not shown) is input to each input channel of the digital input section 12. The level value is a digital signal having a plurality of bits and is stored in the loop memory 50 for each channel. Loop memory 50
Since the signal of each channel is cyclically and repeatedly stored, after the signal of each channel is stored, from the next storage cycle, old signals are sequentially updated to newly input signals.

The electric signal stored in the loop memory 50 from the A / D converter 20 is constantly compared in the signal comparator 70 with the signal level for abnormal electric signal waveform determination set by the control unit 60A. When it is detected that the level of the stored electric signal exceeds the set signal level, the abnormality determination signal is output to the control unit 60A as a trigger signal.

When the control unit 60A receives the abnormality determination signal, the loop memory 50 obtains the waveform information of the electrical signal of the abnormal level and the electrical signals at the times before and after the input of the electrical signal.
It is recorded in the external storage medium through the external storage medium interface 80.

Further, the control section 60A has a digital input section 1
2 receives the electric signal obtained from the digital signal processing result stored in the loop memory 50, judges the abnormal level of the electric signal from the electric signal bit structure, and inputs the electric signal of the abnormal level and the electric signal. The electric signals before and after the time are recorded in the external storage medium from the loop memory 50 through the external storage medium interface 80. still,
In this embodiment, only the electric signal waveform information indicating the abnormal level is recorded in the external storage medium, but the generation time of the electric signal having the abnormal level may also be recorded.

Example 2. In the first embodiment described above, when the level of the stored electric signal exceeds the preset abnormality determination signal level, the stored electric signal is recorded in the external storage medium. The electric signal may be read from the loop memory and transferred to the external storage medium.

Reference numeral 90B in FIG. 2 shows an electric signal waveform recording apparatus of this embodiment. In the figure, the same reference numerals as those in FIG. 1 indicate the same or corresponding parts. In the figure, 13 is a channel switching device 1.
2, the attenuator as a signal attenuating means for attenuating the signal level at a constant attenuation rate when the level of the electric signal output from the device 2 is a certain value or more, and 61 is a time measuring device as a time measuring device for measuring the actual time with the operation of the device. , 63 is the loop memory 5
An external trigger input unit as a trigger signal output unit that outputs an instruction signal for reading an electric signal from 0 as a trigger signal. The external trigger input unit 63 is at a time set by a timer (not shown) or other control. The trigger signal is output according to the operation of the device.

Although not shown, the attenuator 13 is, for example, a first comparator that outputs an H level signal when the level of the input electric signal is above a certain level, and an H level when the level of the electrical signal is below a certain level. Of the second comparator for outputting the comparator signal and the electric signal of the first comparator which operates when the output signal of the first comparator is at the H level and is attenuated at a constant attenuation rate and output to the A / D converter 20. When the output signals of the attenuator and the second comparator are H level, they are turned on and the input electrical signal is directly A /
It can be configured by an analog switch that outputs to the D converter 20.

Reference numeral 60B denotes a control unit according to the present embodiment. When the control signal is inputted from the external trigger input unit 63, the control unit 60B reads the electric signal sampled at the trigger signal input time from the loop memory 50 and The current time is read from the time counter 61 and transmitted to the host computer through the external storage medium or the communication interface 62.

Reference numeral 91 is a temporary power storage unit as a backup power supply for storing a commercial power supply in a large-capacity capacitor (not shown) while keeping the charge / discharge voltage at a constant level, and 92 is the power stored in the temporary power storage unit 91 for operating the apparatus. A power supply conversion unit for converting the necessary logic circuit power supply and analog circuit power supply, 93 detects a decrease in the charging voltage of the power supply temporary storage unit 91 by a predetermined value or more, detects an instantaneous power failure of the commercial power supply, and outputs a power failure signal 94 to the control unit. It is an instantaneous blackout detection unit that outputs to 60B.

The operation of this embodiment will be described below. The electrical signal sequentially switched and output from the channel switch 11 is input to the A / D converter 20 through the attenuator 13. The attenuator 13 attenuates the signal level to the input level of the A / D converter 20 and outputs it to the A / D converter 20 when the level of the input electric signal is equal to or higher than a certain value. If the level of the electric signal has reached the input level of the A / D converter 20, the A / D converter 20 is not attenuated.
Output to. In this way, the analog electrical signal
By outputting the signal to the A / D converter 20 via 3, it is possible to faithfully record the signal waveform without clipping the peak even for an electric signal having a large input level.

In this manner, while the electric signal input from the analog input section 11 and the electric signal input from the digital input section 12 are being stored in the loop memory 50, the abnormal operation of the equipment of the control device is monitored. When it is time to collect the electrical signal for this purpose, a trigger signal is output from the external trigger input unit 63 to the control unit 60B.

When the trigger signal is input, the controller 60B reads the current time from the time counter 61, reads the electric signal stored in the loop memory 50 in a certain time zone including the current time, and externally stores it through the external storage medium interface 80. Record on media. Alternatively, the read electrical signal may be transferred to the host computer through the communication interface 62 for signal analysis. After the electric signal is recorded in the external storage medium, the electric signal storage in the loop memory 50 is stopped and the electric signal at a predetermined time is stored in the loop memory 50.
You can leave it in. Further, the control unit 60B may receive the start instruction from the host computer through the communication interface 62 and read the contents of the loop memory 50.

If a momentary power failure occurs for some reason during operation of the device, the momentary power failure detection unit 93 detects the state from the power storage status of the temporary power storage unit 91 and sends a power failure signal 9 to the control unit 60B.
4 is output. The temporary power storage unit 91 is, for example, 100
For momentary blackouts of the order of ms, there is no hindrance to the operation of the device because the instantaneous blackout compensation that secures the power supply of the device is performed.

Therefore, when the power failure signal 94 is input, the control unit 60B reads out the instantaneous blackout time from the timekeeping device 61, and also reads out the electrical signals at the time of the instantaneous blackout and at the time before and after the instantaneous blackout from the loop memory 50 so as to read the external storage medium. To record.
Alternatively, the electric signal stored in the loop memory 50 can be saved and saved in an external storage medium.

Example 3. In the second embodiment, the electric signal output from the channel switcher 11 is input to the A / D converter 20 through the attenuator 13, but instead of the attenuator 13, the electric signal is supplied through the amplifier to the A / D converter 20. You may input to. FIG. 3 shows a signal waveform recording device 9 according to this embodiment.
It is a block diagram which shows the structure of 0C. In the figure, the same reference numerals as those in FIG. 2 indicate the same or corresponding parts. In the figure, 14
Is an amplifier as signal amplifying means for amplifying the electric signal output from the channel switch 11 and outputting the amplified electric signal to the A / D converter 20.

The configuration of the amplifier 14 is, though not shown, for example, a first comparator that outputs an H level signal when the level of the input electric signal is below a certain value, and a first comparator when the level of the electrical signal is above a certain value. A second comparator that outputs an H level comparator signal and an electric signal that operates when the output signal of the first comparator is H level are amplified by a constant amplification factor and output to the A / D converter. When the output signals of the amplifier and the second comparator are at the H level, they are turned on and the input electrical signal is directly A /
It can be configured by an analog switch that outputs to the D converter.

When the level of the input electric signal is below a certain value, the signal level is amplified by the amplifier up to the input level of the A / D converter 20 and output to the A / D converter 20. If the level of the electric signal has reached the input level of the A / D converter 20, it is directly output to the A / D converter 20 through an analog switch. As described above, by outputting the analog electric signal to the A / D converter 20 through the amplifier 14, it is possible to record the signal waveform with high resolution even if the electric signal has a small input level. still,
Other operations are the same as those in the first and second embodiments.

Example 4. Although the electric signals stored in the loop memory 50 are transferred to the host computer through the communication interface 62 in the second and third embodiments, even if the stored electric signals are transferred to the print recorder through the communication interface 62. good. FIG. 4 is a block diagram showing the configuration of the signal waveform recording device 90D according to this embodiment. In the figure, the same reference numerals as those in FIG. 3 indicate the same or corresponding portions. In the figure, reference numeral 64 denotes a print recording device as print output means, and this print recording device 64 prints out the waveform of the electric signal transferred from the communication interface 62.

As the operation of this embodiment, when a trigger signal is input from the external trigger input section 63 to the control section 60D,
The control unit 60D reads the electric signal at the time of inputting the trigger signal from the loop memory 50 and outputs it to the communication interface 62. The communication interface 62 converts the input electric signal into data for waveform printing, and prints and records a device 64.
Transfer to Therefore, the monitoring personnel can observe the abnormal electric signal waveform in real time.

Further, the control units 60A, 60B and 60CB may read the contents of the loop memory 50 upon receiving a start command from the host computer through the communication interface 62.

[0052]

According to the first aspect of the invention, the waveform information of the signal output from the measurement point at each time is stored for a certain period of time, and the old waveform of the stored waveform information is stored. First storage means for sequentially updating the information to newly read waveform information and storing it, and preset for determining the level of the signal waveform and the abnormal signal waveform stored in the first waveform storage means. And a signal comparison unit that outputs an abnormality determination signal when an abnormal signal waveform is determined, and the waveform information stored in the first waveform storage unit when the abnormality determination signal is output from this signal comparison unit is recorded. Since the second storage means is provided, the abnormal signal waveform and the signal waveforms before and after the abnormal signal are generated can be recorded only when the abnormal signal is generated, so that there is an effect that the waveform information can be easily collected when the abnormality is generated.

According to the invention of claim 2, in the invention of claim 1, each time of the time zone at the time of outputting the abnormal signal waveform when the abnormality judging signal is inputted from the time measuring means and the signal comparing means is set to the above-mentioned time. The control means for reading each of these times and the waveform information for the time zone from the first storage means to the second storage means is provided.
In addition to the above effect, there is an effect that the time of occurrence of an abnormality can be easily grasped.

According to the third aspect of the invention, the waveform information of the signal output from the measurement point at each time is stored for a certain period of time, and the oldest waveform information is stored in the stored waveform information. First storage means for updating and storing the waveform information newly read in order, time measuring means for measuring the measurement time, and a trigger signal for instructing the extraction of the waveform information from the first waveform storing means. Trigger signal output means, and when the trigger signal is input from the trigger signal output means, the measurement time is read from the time counting means,
Since the read measurement time and the control means for recording the waveform information stored in the first storage means in the second storage means are provided, the waveform information can be read out at any time, so that the signal analysis can be performed. The effect is that information can be easily collected.

According to the fourth aspect of the present invention, the waveform information of the digital signal having a plurality of bits and outputted from the measurement point and processed by the computer at each time is stored for a certain period of time, and the stored waveform information is stored. Of the waveform information stored in the first storage means, the first storage means for storing the waveform information stored in the first storage means while updating the waveform information from the oldest waveform information to the newly read waveform information in order. At this time, since there is provided the control means for recording the waveform information stored in the first storage means in the second waveform storage means, it is possible to easily detect the abnormal signal waveform from the waveform information.

According to the invention of claim 5, in the invention according to any one of claims 1 to 3, the signals individually output from a plurality of measurement points are sequentially scanned and output to the first storage means. Since the signal switching means is provided, the method according to claim 1 to 3
In addition to the above effect, there is an effect that the signals respectively output from a plurality of measurement points can be easily organized and stored.

According to the invention of claim 6, in the invention according to any one of claims 1 to 3, when the level of the signal output from the measurement point is a certain value or more, the signal level is kept at a certain attenuation rate. Since the signal attenuating means for attenuating is provided, in addition to the effects of claims 1 to 3, there is an effect that waveform information can be accurately stored without distorting the waveform of a high level signal.

According to the invention of claim 7, in the invention according to any one of claims 1 to 3, when the level of the signal output from the measurement point is equal to or lower than a constant value, the signal level is maintained at a constant amplification factor. Since the signal amplifying means for amplifying the signal is provided, in addition to the effects of the first to third aspects, there is an effect that the resolution of the signal waveform can be enhanced and the waveform information can be stored even in the case of a low level signal.

According to an eighth aspect of the present invention, in the invention according to any one of the first to seventh aspects, an instantaneous power failure detecting means for detecting an instantaneous power failure, and an ack-up power source that operates for a fixed time when the instantaneous power failure is detected, The control means for operating with the backup power supply and recording the waveform information stored in the first storage means in the second storage means during a predetermined time before and after the momentary power failure is provided. In addition, it is possible to obtain the waveform information of the signal that elucidates the cause of the occurrence of the instantaneous power failure, and it is possible to protect the stored waveform information.

According to a ninth aspect of the invention, in the invention according to any one of the first to eighth aspects, a print output means for printing the signal waveform stored in the first storage means by inputting the data line. In addition to the effects of claims 1 to 8, since the waveform of the abnormal signal can be observed in real time, an abnormal situation can be dealt with immediately.

According to a tenth aspect of the present invention, in the invention according to any one of the first to eighth aspects, the control means is configured to read from the first storage means in accordance with an information reading instruction input from the host computer via the data line. Since the waveform information is read out, in addition to the effects of claims 1 to 8,
Because the readout analysis of waveform information can be controlled programmatically,
There is an effect that it can promote unmanned anomaly monitoring.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a signal waveform recording device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a signal waveform recording device according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a signal waveform recording device according to a third embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a signal waveform recording device according to a fourth embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of a conventional signal waveform recording device.

[Explanation of symbols]

10 analog input section, 11 channel switcher, 12
Digital input section, 13 attenuator, 14 amplifier, 5
0 loop memory, 60A to 60D control unit, 61 time clock, 62 communication interface, 63 external trigger input unit, 64 print recording device, 70 comparator, 80 external recording medium interface, 90A, 90B, 90C,
90D signal waveform recording unit, 91 power temporary storage unit 92
Power converter, 93 Instantaneous power failure detector, 94 Power failure signal.

Claims (10)

[Claims] 1. Waveform information of a signal output from a measurement point at each time is stored for a certain period of time, and among the stored waveform information, a waveform newly read in order from oldest waveform information. The first storage means, which stores the information while updating the information, and the level of the signal waveform stored in the first waveform storage means are compared with a signal level preset for determining the abnormal signal waveform, and the abnormality is detected. A signal comparison unit that outputs an abnormality determination signal when the signal waveform is determined, and a second storage unit that records the waveform information stored in the first waveform storage unit when the abnormality determination signal is output from the signal comparison unit are provided. A signal waveform recording device characterized by the above. 2. Time measuring means for measuring the measurement time, and each time of the time zone when the abnormal signal waveform is output at the time of inputting the abnormality determination signal from the signal comparing means is read out from the time measuring means for these time and the above time zone. The signal waveform recording apparatus according to claim 1, further comprising: a control unit configured to record the waveform information from the first storage unit to the second storage unit. 3. The waveform information of a signal output from a measurement point at each time is stored for a certain period of time, and the stored waveform information is newly read in order from the oldest waveform information. A first storage means for updating and storing the time, a time measuring means for measuring a measurement time, a trigger signal outputting means for outputting a trigger signal for instructing the extraction of the waveform information from the first waveform storing means, When the trigger signal is input from the trigger signal output means, the measurement time is read from the time counting means, and the read measurement time and the waveform information stored in the first storage means are recorded in the second storage means. A signal waveform recording device characterized by being provided. 4. The waveform information consisting of a digital signal having a plurality of bits at each time output from a measurement point is stored for a fixed time period, and the stored waveform information is
When the first storage means stores while updating the old waveform information to the newly read waveform information in order, and when the bit configuration content of the waveform information stored in the first storage means has a preset bit configuration, A signal waveform recording device, comprising: a control means for recording the waveform information stored in the first storage means in the second waveform storage means. 5. A signal switching means for sequentially scanning signals output individually from a plurality of measurement points and outputting the signals to a first storage means. Signal waveform recorder. 6. The signal attenuating means for attenuating the signal level at a constant attenuation rate when the level of the signal output from the measuring point is equal to or higher than a constant value, as set forth in claim 1. The signal waveform recording device according to. 7. The signal amplifying means for amplifying the signal level at a constant amplification rate when the level of the signal output from the measuring point is equal to or lower than a constant value, according to claim 1. The signal waveform recording device according to. 8. An instantaneous power failure detection means for detecting an instantaneous power failure, a backup power supply that operates for a certain period of time when an instantaneous power failure is detected, and a backup power supply that operates in the first storage means between predetermined times before and after the instantaneous power failure. 8. The signal waveform recording apparatus according to claim 1, further comprising a control unit that records the generated waveform information in the second storage unit. 9. The signal waveform according to claim 1, further comprising print output means for inputting the signal waveform stored in the first storage means to the data line and printing it out. Recording device. 10. The signal according to claim 1, wherein the control means reads the waveform information from the first storage means in accordance with an information reading instruction input from the host computer via the data line. Waveform recording device.