JP5303440B2 - Waveform observation apparatus and waveform observation method - Google Patents

Description

  The present invention relates to a technique for observing the waveform of a repetitive signal such as a data signal or a clock signal.

  As an apparatus for observing the waveform of a high-speed data signal, an apparatus that employs an equivalent time sampling method is conventionally known.

  In the equivalent sampling method, a cycle Ts (= N · K + ΔT or N · K) that is different from an integer N times the clock cycle Tc of a signal input to the sampling unit by a predetermined resolution time ΔT that is sufficiently smaller than the clock cycle. -ΔT) sampling signal, information on the waveform of the input signal is acquired with a time resolution of ΔT, and the waveform is reproduced, and the waveform of the signal is observed much faster than the speed of the sampling unit. Can do.

  A waveform observation apparatus employing such an equivalent time sampling method is disclosed in, for example, the following Patent Document 1.

JP 2002-71724 A

  In the waveform observation apparatus using the above equivalent time sampling method, waveform information cannot be acquired correctly unless the timing for acquiring a series of waveform information is set to a timing synchronized with the input signal.

As the method, a configuration shown in FIG. 5 can be considered.
That is, the observation target signal Sx input from the signal input terminal 10a to the sampling unit 11 is input to the trigger signal generation unit 12, the clock component Cx is reproduced, and synchronized with the rising or falling edge of the reproduced clock component Cx. The triggered signal TRG is given to the sampling signal generator 13.

  A sampling signal Cs having a period that is a predetermined resolution time ΔT at a period that is an integral multiple of the waveform repetition period of the observation target signal Sx is sent from the sampling signal generator 13 to the rising or falling timing of the trigger signal TRG. To the sampling unit 11 to obtain data necessary for reproducing a series of waveforms.

  After that, sampling is started from the timing synchronized with the trigger signal TRG, and a series of waveform data acquisition processing is repeated, and the obtained waveform data is averaged, and the waveform of the observation target signal is obtained. To display.

  However, in recent years, in the waveform observation apparatus of the equivalent time sampling method as described above, there is a demand for simultaneously observing the waveforms of a plurality of signals with the same measurement system. This can be handled by incorporating a plurality of sets.

  However, in this case, among the signals input from the signal input terminals, it is necessary to input the signal to be synchronized to the signal input terminal connected to the trigger signal generating unit 12, and the synchronization is performed with another signal. If this is desired, the signal cable must be replaced with the signal input terminal, which is extremely inconvenient.

  Furthermore, if a trigger signal generator is provided for each signal input terminal, the circuit scale increases, the device becomes larger, and the cost increases.

  The present invention solves these problems and can apply trigger synchronization to any of the signals to be observed input to a plurality of input terminals without performing cable replacement work on the signal input terminals. An object of the present invention is to provide a waveform observation apparatus and a waveform observation method that can be configured compactly at low cost.

In order to achieve the above object, a waveform observation apparatus according to claim 1 of the present invention includes:
A plurality of signal input terminals (21A, 21B);
A signal selector (23) for selecting one of the observation target signals input from the plurality of signal input terminals;
A trigger signal generation unit (30) for extracting a clock component from the observation target signal selected by the signal selection unit and generating a trigger signal synchronized with the clock component;
A sampling signal generator (35) for generating a sampling signal having a period different from the integer multiple of the waveform repetition period of the observation target signal by a predetermined resolution time from the timing at which the trigger signal is received;
A plurality of sampling units (22A) that sample the observation target signals input from the plurality of signal input terminals each time they receive the sampling signal output from the sampling signal generation unit, convert the signals into digital signal sequences, and output the signals. 22B)
An indicator (45) for waveform display;
Based on the digital signal sequence output from said plurality of sampling unit, and a display processing unit (40) for displaying waveforms of the plurality of signals input to the input terminal the observation target signal to the display waveform An observation device,
A frequency measurement unit (50) for measuring the frequency of the observation target signal input from the plurality of signal input terminals;
The signal selection unit receives the measurement result of the frequency measurement unit and preferentially selects a signal having a low frequency of the observation target signal input from the plurality of signal input terminals .

The waveform observation apparatus according to claim 2 of the present invention is
A plurality of signal input terminals (21A, 21B);
A signal selector (23) for selecting one of the observation target signals input from the plurality of signal input terminals;
A trigger signal generation unit (30) for extracting a clock component from the observation target signal selected by the signal selection unit and generating a trigger signal synchronized with the clock component;
A sampling signal generator (35) for generating a sampling signal having a period different from the integer multiple of the waveform repetition period of the observation target signal by a predetermined resolution time from the timing at which the trigger signal is received;
A plurality of sampling units (22A) that sample the observation target signals input from the plurality of signal input terminals each time they receive the sampling signal output from the sampling signal generation unit, convert the signals into digital signal sequences, and output the signals. 22B)
An indicator (45) for waveform display;
A waveform including a display processing unit (40) for displaying waveforms of observation target signals input to the plurality of signal input terminals on the display unit based on digital signal sequences output from the plurality of sampling units. An observation device,
An error rate measuring unit (60) for measuring an error rate of an observation target signal input from the plurality of signal input terminals;
The signal selection unit receives the measurement result of the error rate measurement unit and preferentially selects a signal having a low error rate of the observation target signals input from the plurality of signal input terminals.

The waveform observation apparatus according to claim 3 of the present invention is
A plurality of signal input terminals (21A, 21B);
A signal selector (23) for selecting one of the observation target signals input from the plurality of signal input terminals;
A trigger signal generation unit (30) for extracting a clock component from the observation target signal selected by the signal selection unit and generating a trigger signal synchronized with the clock component;
A sampling signal generator (35) for generating a sampling signal having a period different from the integer multiple of the waveform repetition period of the observation target signal by a predetermined resolution time from the timing at which the trigger signal is received;
A plurality of sampling units (22A) that sample the observation target signals input from the plurality of signal input terminals each time they receive the sampling signal output from the sampling signal generation unit, convert the signals into digital signal sequences, and output the signals. 22B)
An indicator (45) for waveform display;
A waveform including a display processing unit (40) for displaying waveforms of observation target signals input to the plurality of signal input terminals on the display unit based on digital signal sequences output from the plurality of sampling units. An observation device,
A frequency measuring unit (50) for measuring the frequency of the observation target signal input from the plurality of signal input terminals ;
An error rate measuring unit (60) for measuring an error rate of the observation target signal input from the plurality of signal input terminals ,
The signal selection unit, the frequency measurement unit and receives the measurement result of the error rate measuring unit, the frequency is low rather and error rate of the inputted observed target signal from said plurality of signal input terminals preferentially a low casting It is characterized by selecting.

The waveform observation apparatus according to claim 4 of the present invention, in the waveform observation apparatus according to any one of claims 1 to 3,
Having an operation part (24),
The signal selection unit may perform any operation by operating the operation unit in addition to the preferential selection by the frequency or the preferential selection by the error rate with respect to the observation target signal input from the plurality of signal input terminals. It can be selected .

The waveform observation method according to claim 5 of the present invention is:
Selecting any one of observation target signals input from a plurality of signal input terminals (21A, 21B);
Extracting the clock component from the selected observation target signal and generating a trigger signal synchronized with the clock component;
Generating a sampling signal having a period that is different from the integer multiple of the waveform repetition period of the observation target signal by a predetermined resolution time from the timing of receiving the trigger signal;
Sampling the signals to be observed input from the plurality of signal input terminals each time the sampling signal is received, converting each of the signals into a digital signal sequence, and outputting the digital signal sequence;
On the basis of the signal sequence of sampled digital, and the step of displaying a waveform to be observed signal inputted to the plurality of signal input terminals A including waveform observation method,
Measuring a frequency of an observation target signal input from the plurality of signal input terminals,
Among the observation target signals input from the plurality of signal input terminals, a signal having a low frequency is preferentially selected as an observation target signal used for generating the trigger signal.

The waveform observation method according to claim 6 of the present invention is:
Selecting any one of observation target signals input from a plurality of signal input terminals (21A, 21B);
Extracting the clock component from the selected observation target signal and generating a trigger signal synchronized with the clock component;
Generating a sampling signal having a period that is different from the integer multiple of the waveform repetition period of the observation target signal by a predetermined resolution time from the timing of receiving the trigger signal;
Sampling the signals to be observed input from the plurality of signal input terminals each time the sampling signal is received, converting each of the signals into a digital signal sequence, and outputting the digital signal sequence;
Displaying a waveform of an observation target signal input to the plurality of signal input terminals based on the sampled digital signal sequence, and a waveform observation method comprising:
Measuring an error rate of an observation target signal input from the plurality of signal input terminals,
A signal having a low error rate among observation target signals input from the plurality of signal input terminals is preferentially selected as an observation target signal used for generating the trigger signal .

The waveform observation method according to claim 7 of the present invention is:
Selecting any one of observation target signals input from a plurality of signal input terminals (21A, 21B);
Extracting the clock component from the selected observation target signal and generating a trigger signal synchronized with the clock component;
Generating a sampling signal having a period that is different from the integer multiple of the waveform repetition period of the observation target signal by a predetermined resolution time from the timing of receiving the trigger signal;
Sampling the signals to be observed input from the plurality of signal input terminals each time the sampling signal is received, converting each of the signals into a digital signal sequence, and outputting the digital signal sequence;
Displaying a waveform of an observation target signal input to the plurality of signal input terminals based on the sampled digital signal sequence, and a waveform observation method comprising:
Measuring a frequency and an error rate of an observation target signal input from the plurality of signal input terminals,
Wherein the frequency is low rather and error rates of the plurality of signals inputted from the input terminal the observation target signal is characterized by preferentially selected as an observation target signal using a low casting for said trigger signal occurs.

Moreover, the waveform observation method of Claim 8 of this invention is the waveform observation method in any one of Claims 5-7 ,
In addition to the preferential selection by the frequency or the preferential selection by the error rate with respect to the observation target signal input from the plurality of signal input terminals, it is input from the plurality of signal input terminals by an operation on the operation unit . Any one of the observation target signals can be selected as the observation target signal used for generating the trigger signal.

  As described above, the waveform observation apparatus and method of the present invention adopts an equivalent time sampling method, and arbitrarily selects any one of the observation target signals input to the plurality of signal input terminals, and sets the observation target signal as the observation target signal. Since the trigger signal is generated based on this and sampling for each observation target signal is started at the timing synchronized with the trigger signal, any of the observation target signals input to the plurality of input terminals is Trigger synchronization can be applied without replacing the signal cable, making signal observation easy. In addition, since it is not necessary to provide a trigger signal generator for each signal input terminal, it can be configured at low cost and in a small size.

  In addition, when an arbitrary signal to be observed input to a plurality of signal input terminals can be selected by an operation on the operation unit, the observer can perform trigger synchronization on a desired signal.

  In addition, in the case where a signal having a low frequency of an observation target signal input from a plurality of signal input terminals is preferentially selected, for example, when a clock signal and a data signal synchronized with the clock signal are input, Since a data signal with a low frequency is selected with priority, all waveforms including the signal with the low frequency can be displayed reliably.

  In addition, a signal with a low error rate that is input from a plurality of signal input terminals is preferentially selected, so that a stable trigger signal can be generated from a high-quality signal, and an accurate signal can be generated. Waveform observation can be performed.

Configuration diagram of an embodiment of the present invention Timing chart for explaining the operation of the embodiment Diagram showing an example of the displayed waveform Configuration diagram of another embodiment of the present invention Configuration diagram of waveform observation device with trigger function

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a configuration of a waveform observation apparatus 20 to which the present invention is applied.

  The waveform observation apparatus 20 has a plurality of signal input terminals 21A and 21B (two in this example, but three or more) for inputting the observation target signals Sxa and Sxb.

  Here, the observation target signals Sxa and Sxb are electric signals, for example, a data signal inverted in a differential format, an output signal of a multiplexer, an input signal to the test circuit and its output signal, a data signal and a clock from the data output device Signals etc., both of which are synchronized with each other.

  The observation target signals Sxa and Sxb input to the signal input terminals 21A and 21B are input to the sampling units 22A and 22B, respectively, and input to the signal selection unit 23, and one of them is selected.

  The sampling units 22A and 22B can be configured by A / D converters when the observation target signals Sxa and Sxb are electric signals. Further, when the observation target signals Sxa and Sxb are optical signals, the optical signals can be received by a photoelectric converter (light receiver) and converted into an electrical signal, which can be sampled by an A / D converter.

  In addition, when the observation target signals Sxa and Sxb are optical signals, as described in Patent Document 1, the optical signal is incident on the optical modulator light, and optical sampling is performed. A configuration may be employed in which light is received by a photoelectric converter and converted into an electrical signal, and this is converted into a digital signal sequence by an A / D converter.

  Here, the signal selection unit 23 is arbitrarily selected by the user by operating the operation unit 24 including a number of keys and switches. The observation target signal selected by the signal selection unit 23 is input to the trigger signal generation unit 30.

  The trigger signal generator 30 reproduces the clock component from the input observation target signal, and generates a trigger signal TRG synchronized with the rising or falling of the clock component.

  Here, the trigger signal TRG determines the sampling start timing when a series of waveform data is acquired by equivalent time sampling, and the cycle Ttrg is used to acquire a desired number of waveform data in the sampling cycle Ts. It is set longer than the necessary time and equal to an integral multiple of the waveform repetition period.

  For example, if the repetition period Ta of the waveform of the signal to be observed is 1 nS (1 GHz in terms of frequency) and the sampling period Ts is 1 μS (= 1000 · Ta) +1 pS (= ΔT), the sampling period is 1 nS in 1000 samplings. A series of waveform data can be obtained with a resolution of 1 pS, and the trigger period Ttrg may be set so as to be longer than the required time 1 mS + 1 nS and equal to an integer multiple of 1 nS. However, since there is actually a phase fluctuation of the clock component to be recovered, the timing at which the clock component level transitions at the timing closest to an integer multiple of the repeated waveform after the elapse of the time required for the predetermined number of samplings And

  The trigger signal TRG is input to the sampling signal generator 35. The sampling signal generator 35 generates a sampling signal Cs having a period Ts that is different by a predetermined resolution time ΔT with respect to an integer N times the waveform repetition period Ta of the observation target signal from the timing at which the trigger signal TRG is received. The sampling period and the trigger period can be set by operating the operation unit 24.

  Further, here, the signal cycle is described as a reference. However, in an actual circuit, a PLL circuit or a DDS circuit is used, and the frequency is used as a reference, and an integer N / N of the waveform repetition frequency Fa of the observation target signal. In contrast, a sampling signal Cs having a frequency difference corresponding to a predetermined resolution time ΔT is generated.

  The sampling signal Cs is input to the plurality of sampling units 22A and 22B. The sampling units 22A and 22B sample the observation target signals input from the signal input terminals 21A and 21B every time they receive the sampling signal Cs, convert them into digital signal sequences Da and Db, and output them to the display processing unit 40. To do.

  The display processing unit 40 stores the digital signal sequences Da and Db output from the sampling units 22A and 22B in a memory (not shown) in the order of sampling, and displays the waveform of the observation target signal on the display 45 based on the stored data. Display.

Next, the operation of the waveform observation apparatus 20 having the above configuration will be described.
It is assumed that inverted data signals such as (a) and (b) of FIG. 2 are input to the two signal input terminals 21A and 21B as observation target signals Sxa and Sxb, for example.

  Here, for ease of explanation, it is assumed that one of the observation target signals Sxa and Sxb is inputted by repetition of a 5-bit signal “10110” and the other is “01001”.

  The bit rates of the observation target signals Sxa and Sxb are known to the observer, and the sampling signal Cs having a period Ts corresponding to the bit rate and the time resolution is set to be output from the sampling signal generator 35. . Further, the above-described trigger cycle Ttrg is also set within the above-described conditions.

  Here, when the observer selects the signal Sxa input to the signal input terminal 21A side by operating the operation unit 24, for example, the signal Sxa is input to the trigger signal generation unit 30, and the signal Sxa in FIG. Thus, the clock component Cx synchronized with the signal Sxa is reproduced, and the trigger signal TRG synchronized with the rising edge of the clock component Cx, for example, is output as shown in FIG.

  The sampling signal generator 35 that has received the trigger signal TRG outputs a sampling signal Cs having a period Ts to the sampling units 22A and 22B from the rising timing of the trigger signal TRG as shown in FIG. Sampling of the input signals Sxa and Sxb is performed by the signal Cs, and the data signal sequences Da and Db obtained by the sampling are output to the display processing unit 40 as shown in (f) and (g) of FIG.

  When this sampling is obtained by dividing the data signal repetition period Ta by the time resolution ΔT, data of a 5-bit-long repetitive waveform of the input signal is obtained. By plotting the signal input terminals 21A and 21B on the time axis, the waveforms of the input signals Sxa and Sxb can be displayed.

  As an actual waveform display method in the display processing unit 40, a process of starting data acquisition from the timing synchronized with the trigger signal TRG and obtaining waveform data for 5 bits is performed by a previously specified averaging number. The waveform is averaged and the waveform is averaged to obtain a waveform in which random noise is suppressed, and the display waveform is sequentially updated.

  When observing the waveform displayed in this way, if the input signal from which the trigger signal is obtained contains a large amount of noise or the amplitude is significantly reduced due to, for example, an abnormality in the device under test The effect may cause a timing shift of the trigger signal, and an expected waveform may not be observed.

  In this case, the observer switches the signal to be input to the trigger signal generation unit 30 by operating the operation unit 24. Here, if there is no abnormality in the newly input signal, it is possible to generate a trigger signal with a stable timing, so that the waveforms of both input signals can be displayed correctly, and the large noise described above is included. Waveform and waveforms with greatly reduced amplitude can be observed, and abnormalities in the device under test can be recognized.

  As described above, in the waveform observation apparatus 20 according to the embodiment, an arbitrary input signal can be input to the trigger signal generation unit 30 by the operation of the operation unit 24, and even when there are a plurality of signal input terminals. The trigger input signal can be easily changed without changing the cable for the signal input terminal.

  Although the above embodiment relates to the waveform observation apparatus of the present invention, the following waveform observation method for performing signal processing equivalent to the above embodiment is also disclosed.

  That is, the waveform observation apparatus of the above embodiment selects one of the observation target signals Sxa and Sxb input from the plurality of signal input terminals 21A and 21B, and extracts the clock component from the selected observation target signal. Then, the trigger signal TRG is generated by receiving the trigger signal TRG at a stage where the trigger signal TRG synchronized with the clock component is generated and at a period different from the integer multiple of the waveform repetition period of the observation target signal by a predetermined resolution time. And a step of sampling the observation target signals Sxa and Sxb input from the plurality of signal input terminals 21A and 21B each time the sampling signal Cs is received, converting each of the signals to a digital signal sequence, and outputting the digital signal sequence And observation targets input to multiple signal input terminals based on the sampled digital signal sequence We have implemented waveform observation method comprising the steps of displaying the issue of the waveform.

  Furthermore, in the above embodiment, the selection process is performed according to the operation of the operation unit 24 as an example of the process of selecting either the observation target signal Sxa or Sxb.

(Second Embodiment)
In the above embodiment, an example in which the observer selects a signal to be input to the trigger signal generation unit 30 by operating the operation unit 24 has been described. Alternatively, selection processing according to the error rate can be automatically performed.

  FIG. 4 is a block diagram of an embodiment having a manual selection mode, a frequency selection mode, and an error rate selection mode.

  In this embodiment, in addition to the configuration of the above-described embodiment, a frequency measurement unit 50 and an error rate measurement unit 60 are provided, and the signal selection unit 23 performs the above-described manual operation according to the mode specified by the operation unit 24. One of selection, selection by frequency, and selection by error rate is performed.

  The frequency measuring unit 50 measures the frequencies fa and fb of the observation target signals Sxa and Sxb input to the signal input terminals 21A and 21B, and outputs the results to the signal selection unit 23.

  The error rate measurement unit 60 measures the error rates Ea and Eb of the observation target signals Sxa and Sxb input to the signal input terminals 21A and 21B, and outputs the results to the signal selection unit 23.

  When the manual selection mode is designated, the signal selection unit 23 performs signal selection processing according to the operation of the operation unit 24 as described above.

  When the frequency selection mode is designated, the frequencies fa and fb from the frequency measuring unit 50 are compared, and the observation target signal with the lower frequency is preferentially selected. The reason why the lower frequency is selected here is to display the repetitive waveform of the data signal with the lowest frequency, and also when observing the waveform of the data signal and its clock signal, etc. This is to eliminate the inconvenience that a repetitive waveform of a data signal cannot be displayed due to a trigger applied to a clock.

  When the error rate selection mode is designated, the error rates Ea and Eb from the error rate measurement unit 60 are compared, and the observation target signal with the lower error rate is preferentially selected. This is a function for enabling stable waveform observation by using a trigger signal generated by a signal having higher quality. Although not shown, the measured error rates Ea and Eb are displayed on the display 45 by the display processing unit 40.

  When the input signal to be supplied to the trigger signal generating unit 30 is automatically selected on the apparatus side as described above, for example, it is displayed on the screen of the display unit 45 so that the selected signal input terminal can be identified. I do.

  In this way, in the case where the apparatus selects the one that is advantageous for observation by comparing the frequency and error rate of the input signal and inputs it to the trigger signal generator 30, the signal that is always determined to be appropriate for trigger generation is obtained. Since it is selected, even if the quality of the input signal changes during measurement, a stable waveform display can be performed following the change, so that the observer can observe the waveform without confusion.

  Although the case where the frequency selection mode and the error rate selection mode are exclusively used has been described here, they can be used together. That is, when there are a plurality of input signals having the same low frequency (bit rate), the error rate is compared to select the one with the lower error rate.

  The second embodiment includes the step of measuring the frequencies of the observation target signals Sxa and Sxb input from the plurality of signal input terminals 21A and 21B in the waveform observation method of the present invention described above. Sxb having a low frequency is preferentially selected, and includes a step of measuring an error rate of observation target signals Sxa and Sxb input from a plurality of signal input terminals, and the observation target signal Sxa , A waveform observing method characterized by preferentially selecting a low error rate among Sxb.

  Further, as described above, the above embodiment has been described with two signal input terminals, but the present invention can also be applied to a waveform observation apparatus having more signal input terminals and sampling units.

  20 …… Waveform observation device, 21A, 21B …… Signal input terminal, 22A, 22B …… Sampling unit, 23 …… Signal selection unit, 24 …… Operation unit, 30 …… Trigger signal generation unit, 35 …… Sampling signal Generating unit, 40 ... Display processing unit, 45 ... Display unit, 50 ... Frequency measuring unit, 60 ... Error rate measuring unit

Claims (8)

A plurality of signal input terminals (21A, 21B);
A signal selector (23) for selecting one of the observation target signals input from the plurality of signal input terminals;
A trigger signal generation unit (30) for extracting a clock component from the observation target signal selected by the signal selection unit and generating a trigger signal synchronized with the clock component;
A sampling signal generator (35) for generating a sampling signal having a period different from the integer multiple of the waveform repetition period of the observation target signal by a predetermined resolution time from the timing at which the trigger signal is received;
A plurality of sampling units (22A) that sample the observation target signals input from the plurality of signal input terminals each time they receive the sampling signal output from the sampling signal generation unit, convert the signals into digital signal sequences, and output the signals. 22B)
An indicator (45) for waveform display;
Based on the digital signal sequence output from said plurality of sampling unit, and a display processing unit (40) for displaying waveforms of the plurality of signals input to the input terminal the observation target signal to the display waveform An observation device,
A frequency measurement unit (50) for measuring the frequency of the observation target signal input from the plurality of signal input terminals;
The waveform selection apparatus, wherein the signal selection unit receives a measurement result of the frequency measurement unit and preferentially selects a signal having a low frequency of an observation target signal input from the plurality of signal input terminals . A plurality of signal input terminals (21A, 21B);
A signal selector (23) for selecting one of the observation target signals input from the plurality of signal input terminals;
A trigger signal generation unit (30) for extracting a clock component from the observation target signal selected by the signal selection unit and generating a trigger signal synchronized with the clock component;
A sampling signal generator (35) for generating a sampling signal having a period different from the integer multiple of the waveform repetition period of the observation target signal by a predetermined resolution time from the timing at which the trigger signal is received;
A plurality of sampling units (22A) that sample the observation target signals input from the plurality of signal input terminals each time they receive the sampling signal output from the sampling signal generation unit, convert the signals into digital signal sequences, and output the signals. 22B)
An indicator (45) for waveform display;
A waveform including a display processing unit (40) for displaying waveforms of observation target signals input to the plurality of signal input terminals on the display unit based on digital signal sequences output from the plurality of sampling units. An observation device,
An error rate measuring unit (60) for measuring an error rate of an observation target signal input from the plurality of signal input terminals;
The signal selection unit receives the measurement result of the error rate measuring unit, the plurality of signal waveforms you characterized in that error rates are selected low preferentially to be observed signal inputted from the input terminal Observation device. A plurality of signal input terminals (21A, 21B);
A signal selector (23) for selecting one of the observation target signals input from the plurality of signal input terminals;
A trigger signal generation unit (30) for extracting a clock component from the observation target signal selected by the signal selection unit and generating a trigger signal synchronized with the clock component;
A sampling signal generator (35) for generating a sampling signal having a period different from the integer multiple of the waveform repetition period of the observation target signal by a predetermined resolution time from the timing at which the trigger signal is received;
A plurality of sampling units (22A) that sample the observation target signals input from the plurality of signal input terminals each time they receive the sampling signal output from the sampling signal generation unit, convert the signals into digital signal sequences, and output the signals. 22B)
An indicator (45) for waveform display;
A waveform including a display processing unit (40) for displaying waveforms of observation target signals input to the plurality of signal input terminals on the display unit based on digital signal sequences output from the plurality of sampling units. An observation device,
A frequency measuring unit (50) for measuring the frequency of the observation target signal input from the plurality of signal input terminals ;
An error rate measuring unit (60) for measuring an error rate of the observation target signal input from the plurality of signal input terminals ,
The signal selection unit, the frequency measurement unit and receives the measurement result of the error rate measuring unit, the frequency is low rather and error rate of the inputted observed target signal from said plurality of signal input terminals preferentially a low casting waveform observing apparatus you and selects the. Having an operation part (24),
The signal selection unit may perform any operation by operating the operation unit in addition to the preferential selection by the frequency or the preferential selection by the error rate with respect to the observation target signal input from the plurality of signal input terminals. waveform observing apparatus according to any one of claims 1-3, characterized in that can be selected. Selecting any one of observation target signals input from a plurality of signal input terminals (21A, 21B);
Extracting the clock component from the selected observation target signal and generating a trigger signal synchronized with the clock component;
Generating a sampling signal having a period that is different from the integer multiple of the waveform repetition period of the observation target signal by a predetermined resolution time from the timing of receiving the trigger signal;
Sampling the signals to be observed input from the plurality of signal input terminals each time the sampling signal is received, converting each of the signals into a digital signal sequence, and outputting the digital signal sequence;
Displaying a waveform of an observation target signal input to the plurality of signal input terminals based on the sampled digital signal sequence, and a waveform observation method comprising :
Measuring a frequency of an observation target signal input from the plurality of signal input terminals,
A waveform observation method , wherein a signal having a low frequency among observation target signals input from the plurality of signal input terminals is preferentially selected as an observation target signal used for generating the trigger signal . Selecting any one of observation target signals input from a plurality of signal input terminals (21A, 21B);
Extracting the clock component from the selected observation target signal and generating a trigger signal synchronized with the clock component;
Generating a sampling signal having a period that is different from the integer multiple of the waveform repetition period of the observation target signal by a predetermined resolution time from the timing of receiving the trigger signal;
Sampling the signals to be observed input from the plurality of signal input terminals each time the sampling signal is received, converting each of the signals into a digital signal sequence, and outputting the digital signal sequence;
Displaying a waveform of an observation target signal input to the plurality of signal input terminals based on the sampled digital signal sequence, and a waveform observation method comprising:
Measuring an error rate of an observation target signal input from the plurality of signal input terminals,
A waveform observation method that preferentially selects an observation target signal having a low error rate among the observation target signals input from the plurality of signal input terminals as an observation target signal used for generating the trigger signal . Selecting any one of observation target signals input from a plurality of signal input terminals (21A, 21B);
Extracting the clock component from the selected observation target signal and generating a trigger signal synchronized with the clock component;
Generating a sampling signal having a period that is different from the integer multiple of the waveform repetition period of the observation target signal by a predetermined resolution time from the timing of receiving the trigger signal;
Sampling the signals to be observed input from the plurality of signal input terminals each time the sampling signal is received, converting each of the signals into a digital signal sequence, and outputting the digital signal sequence;
Displaying a waveform of an observation target signal input to the plurality of signal input terminals based on the sampled digital signal sequence, and a waveform observation method comprising:
Measuring a frequency and an error rate of an observation target signal input from the plurality of signal input terminals,
It characterized in that the frequency is low rather and error rate of the observation target signal inputted from said plurality of signal input terminals is preferentially selected as an observation target signal using a low casting for said trigger signal generating waveform observation method. In addition to the preferential selection by the frequency or the preferential selection by the error rate with respect to the observation target signal input from the plurality of signal input terminals, it is input from the plurality of signal input terminals by an operation on the operation unit . waveform observation method according to any one of claims 5-7, characterized in that any of a can be selected as an observation target signal used for the trigger signal generation to be observed signal.

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