JP2010060501A - Waveform measuring instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waveform measuring instrument for effectively using an acquisition data buffer. <P>SOLUTION: The waveform measuring instrument including an AD convertor 2 for converting an analog input signal 20 into a digital signal, a digital memory 3 for storing waveform data from the AD convertor 2, and the acquisition data buffer 10 for storing past waveform data output from the digital memory 3 includes a first determining circuit 16 for storing only the waveform data matched with a prescribed condition from the waveform data stored to the digital memory 3 to the acquisition data buffer 10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a waveform measuring instrument such as a digital oscilloscope, and more particularly to an improvement in acquisition data buffer management.

  FIG. 3 is a circuit configuration diagram of a digital oscilloscope described in FIG. 1 of Japanese Patent No. 2671662 showing an example of a conventional waveform measuring instrument. In FIG. 3, an analog input signal 20 is input to the input amplifier 1. The AD converter 2 receives the output of the input amplifier 1, samples it with a sampling signal output from a sample pulse generator 5 described later, and then performs quantization. The digital memory 3 stores the output data sampled and quantized by the AD converter 2 as waveform data. The digital memory 3 is controlled by a sampling signal output from a sample pulse generator 5 described later.

The acquisition data buffer 10 is connected to the digital memory 3 and has a capacity for storing a plurality of waveform data stored in the digital memory 3 as past waveform data. The first selector 14 is connected to the acquisition buffer 10 and reads desired waveform data from a plurality of stored waveform data. In the first switch 12, the digital memory 3 is connected to one fixed contact a, the first selector 14 is connected to the other fixed contact b, and the movable contact is connected to a signal processing circuit 7 described later.

The signal processing circuit 7 inputs one of the waveform data of the digital memory 3 selected by the first switch 12 or the acquisition buffer 10 selected by the first selector 14 and sets the setting data register 6 described later. Convert to display data based on the data. The display 8 displays the display data converted by the signal processing circuit 7 as a waveform.

The trigger detection circuit 4 receives the output of the input amplifier 1 as an input and outputs a trigger signal. The sampling pulse generator 5 receives the trigger signal output from the trigger detection circuit 4 and outputs a sampling signal according to setting data stored in a setting data register 6 described later.

The setting data register 6 is set with various setting data by an input operation / control circuit 9 described later. The input operation / control circuit 9 performs various settings for input, trigger, data acquisition, processing and the like based on control of the waveform display operation and panel operation. The setting data buffer 11 is connected to the setting data register 6 and has a capacity for always storing a plurality of setting data corresponding to the waveform data stored in the acquisition data buffer 10. The second selector 15 reads setting data corresponding to the waveform data from the setting data buffer 11 in conjunction with the first selector 14. In the second switch 13, the setting data register 6 is connected to one fixed contact a, the second selector 15 is connected to the other fixed contact b, and the movable contact is the sampling pulse generator 5 and the signal processing circuit 7. Connected to.

  The operation of the apparatus of FIG. 3 will now be described. In the normal operation state, the movable contacts of the first switch 12 and the second switch 13 are connected to the fixed contact a. At this time, the input signal 20 is input to the AD converter 2 and the trigger detection circuit 4 via the input amplifier 1. Data sampled and quantized by the AD conversion circuit 2 is stored in the digital memory 3 as waveform data. The acquisition data buffer 10 stores the previous waveform data every time new waveform data is stored in the digital memory 3, and as a result, a plurality of waveform data are always stored.

The waveform data in the digital memory 3 is also input to the signal processing circuit 7, display data is created based on the setting data from the setting data register 6, and the waveform is displayed on the display 8. Here, the setting data in the setting data register 6 is set based on various settings by the input operation / control circuit 9.

The setting data buffer 11 stores setting data in the setting data register 6 every time data in the digital memory 3 is stored in the acquisition buffer 10. With the above operation, in the normal operation state, it is possible to observe by displaying the waveform data on the display 8 for each trigger, and at the same time, the past waveform data is stored in the acquisition data buffer 10 and the setting data at that time is stored in the setting data buffer 11. Can be remembered.

When reading past waveform data from the acquisition data buffer 10, the movable contacts of the first switch 12 and the second switch 13 are connected to the fixed contact b, respectively. Waveform data to be read from the acquisition buffer 10 is selected by the first selector 14, and setting data corresponding to the waveform data to be read by the first selector 14 is selected from the setting data buffer 11 and read by the second selector 15. That is, the waveform data stored in the acquisition data buffer 10 is read out to the signal processing circuit 7 via the first selector 14, and the sample pulse generator 5 and the signal processing circuit 7 correspondingly read out the waveform data. The setting data stored in the setting data buffer 11 is given through the second selector 15. Because of this operation, the user can normally use the same waveform measurement device as before without worrying about waveform data storage, and if he wants to view past waveform data after measurement, the user switches the switch to display the desired waveform data. By designating, past waveform data within the memory size range of the acquisition data buffer 10 can be read and displayed.

  Prior art documents related to the waveform display device include the following.

Japanese Patent No. 2671662

In the prior art, for example, when the measurement target is a memory, the waveform data of the data line of the memory to be measured can be stored in the acquisition data buffer 10 using a write control signal for this memory to be measured (not shown in FIG. 3) as a trigger. However, if only waveform data that exceeds a certain condition, for example, a value with a signal overshoot, is required, the necessary waveform data is selected from the acquisition data buffer 10, and the rest is discarded as unnecessary data. become. That is, the entire storage capacity of the acquisition data buffer 10 is not necessarily used for capturing the necessary waveform data, and therefore the acquisition data buffer 10 cannot be effectively used.

  An object of the present invention is to provide a waveform measuring instrument capable of effectively utilizing an acquisition data buffer.

In order to achieve such a problem, the invention according to claim 1 of the present invention is:
An AD converter for converting an analog input signal into a digital signal;
A digital memory for storing waveform data from the AD converter;
In a waveform measuring instrument comprising an acquisition data buffer for storing past waveform data output from the digital memory,
A first determination circuit is provided that stores only waveform data that meets a predetermined condition from waveform data stored in the digital memory in the acquisition data buffer.

The invention according to claim 2
The waveform measuring instrument according to claim 1, wherein
A first selector for reading out desired waveform data from the waveform data stored in the acquisition data buffer;
A first switch for selectively outputting waveform data read from an acquisition data buffer via the digital memory or the first selector;
A signal processing circuit for displaying the waveform data output from the first switch on a display;
A first setting data register in which first setting data for controlling each part in relation to the storage operation of the digital memory is stored in advance;
A setting data buffer for storing first setting data corresponding to the waveform data stored in the acquisition data buffer;
A second selector that reads the corresponding first setting data from the setting data buffer in conjunction with the first selector;
A second switch that is driven in conjunction with the first switch and that is supplied to each unit, the first setting data read from the setting data buffer via the first setting data register or the second selector;
A second setting data register in which second setting data for setting the predetermined condition in the first determination circuit is stored in advance;
A second determination circuit that reads the first setting data of the first setting data register and stores the first setting data in the setting data buffer only when the determination result of the first determination circuit is input and the condition is met;
It is provided with.

The invention described in claim 3
The waveform measuring instrument according to claim 2,
The second determination circuit is provided in the setting data buffer.

The invention according to claim 4
The waveform measuring instrument according to any one of claims 1 to 3,
The first determination circuit is provided in the acquisition data buffer.

The invention according to claim 5
The waveform measuring instrument according to any one of claims 1 to 4,
An input operation / control circuit for setting setting data in the setting data register is provided.

As is apparent from the above description, according to the present invention, an AD converter that converts an analog input signal into a digital signal, a digital memory that stores waveform data from the AD converter, and an output from the digital memory In the waveform measuring instrument comprising an acquisition data buffer for storing past waveform data to be stored, only waveform data that meets a predetermined condition is stored in the acquisition data buffer from the waveform data stored in the digital memory. By providing this determination circuit, it is possible to provide a waveform measuring instrument that can effectively use the acquisition data buffer.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a circuit configuration diagram showing an example of a waveform measuring instrument according to an embodiment of the present invention. The same parts as those in FIG. 3 are denoted by the same symbols, and redundant description is omitted. A difference from FIG. 3 is that a first determination circuit 16, a second setting data register 17, and a second determination circuit 18 are provided in the circuit configuration of FIG. The first setting data register 6 in FIG. 1 is the same as the setting data register 6 in FIG.

The first determination circuit 16 is connected between the digital memory 3 and the acquisition data buffer 10, reads out the waveform data stored in the digital memory 3, and determines whether or not to store the waveform data in the acquisition data buffer 10. When the determination is made based on the setting of the register 17 and the data is stored, the waveform data read from the digital memory 3 is written into the acquisition data buffer 10. Setting data for determination (second setting data; the same applies hereinafter) is set in the second setting data register 17 by the input operation / control circuit 9. The second determination circuit 18 is connected between the first setting data register 6 and the setting data buffer 11, and the determination result of the first determination circuit 16 is used as an input to make a determination that the first determination circuit 16 stores. Only in this case, the setting data (first setting data; the same applies hereinafter) in the first setting data register 6 is read and written to the setting data buffer 11.

The operation of the apparatus of FIG. 1 will now be described. However, the description which overlaps with FIG. 3 is omitted. Setting data for determination is set in the second setting data register 17 from the input operation / control circuit 9 in advance. During normal operation, only the waveform data determined to be stored by the first determination circuit 16 is stored in the acquisition data buffer 10, and only the setting data determined to be stored by the second determination circuit 18 is stored in the setting data buffer 11. Is done.

That is, only the waveform data determined to be stored by the first determination circuit 16 is stored in the acquisition data buffer 10, and only the setting data corresponding to this waveform data is stored in the setting data buffer 11.

Therefore, it is not necessary to take out the necessary amount from the waveform data for the capacity of the acquisition data buffer 10 and discard the rest as in the conventional example, so that the entire memory size of the acquisition data buffer 10 is used for storing the necessary waveform data. be able to.

Note that the determination conditions as to whether or not the first determination circuit 16 stores the acquisition data buffer 10 based on the setting of the second setting data register 17 include the step response overshoot amount, the rise time, and the entire waveform. Waveform parameter judgments such as average values and RMS values, and zone judgments such as whether the waveform is in the area with the display area / not entered / too much / does not pass are possible, but are not limited to these. Only waveform data that meets complex conditions can be collected.

As is apparent from the above, according to the waveform measuring device having the above-described configuration, all waveform data in the acquisition data buffer becomes useful data, so that waveform measurement can be performed efficiently. Since the acquisition data buffer has a finite memory size, only the useful data in the acquisition data buffer has been discarded in the past, and the others were thrown away. The memory size of the acquisition data buffer could not be used effectively, and the efficiency was poor. .

FIG. 2 is a circuit configuration diagram showing a modification of the waveform measuring device of FIG. The same parts as those in FIG. 1 are denoted by the same reference numerals and redundant description will be omitted. The difference from FIG. 1 is that the acquisition data buffer 10 in the circuit configuration of FIG. 1 includes a first determination circuit 16 and is changed to an acquisition data buffer 19 with a determination function, which will be described later. The register 17 is connected to the acquisition data buffer 19.

  The acquisition data buffer 19 receives the output of the digital memory 3 and, based on the setting data of the second setting data register 17, determines whether or not to store the waveform data and stores the acquisition data with a determination function. It is a buffer.

  The operation of the apparatus of FIG. 2 is substantially the same as that of FIG. 1, but the determination of whether or not to store the waveform data of the digital memory 3 is performed by the first determination circuit 16 in FIG. The difference is that the determination is performed in the acquisition data buffer 19 and that the second determination circuit 18 receives the determination result from the acquisition data buffer 19 instead of the first determination circuit 16.

  According to the waveform measuring instrument of FIG. 2, the configuration can be further simplified, and the wiring between the blocks is reduced, so that cost is saved. Other features are the same as in FIG.

  In FIG. 2, by providing the second determination circuit 18 in the setting data buffer 11, the configuration can be further simplified and cost can be saved.

It is a circuit block diagram which shows one Example of the waveform measuring device which concerns on embodiment of this invention. It is a circuit block diagram which shows the modification of the waveform measuring device of FIG. It is a circuit block diagram which shows an example of the conventional waveform measuring device.

Explanation of symbols

2 AD converter 3 Digital memory 6 First setting data register 7 Signal processing circuit 8 Display 9 Input operation / control circuit 10, 19 Acquisition data buffer 11 Setting data buffer 12 First switch 13 Second switch 14 First Selector 15 second selector 16 first determination circuit 17 second setting data register 18 second determination circuit 20 analog input signal

Claims (5)

An AD converter for converting an analog input signal into a digital signal;
A digital memory for storing waveform data from the AD converter;
In a waveform measuring instrument comprising an acquisition data buffer for storing past waveform data output from the digital memory,
A waveform measuring instrument comprising: a first determination circuit that stores only waveform data that satisfies a predetermined condition from waveform data stored in the digital memory in the acquisition data buffer. A first selector for reading out desired waveform data from the waveform data stored in the acquisition data buffer;
A first switch for selectively outputting waveform data read from an acquisition data buffer via the digital memory or the first selector;
A signal processing circuit for displaying the waveform data output from the first switch on a display;
A first setting data register in which first setting data for controlling each part in relation to the storage operation of the digital memory is stored in advance;
A setting data buffer for storing first setting data corresponding to the waveform data stored in the acquisition data buffer;
A second selector that reads the corresponding first setting data from the setting data buffer in conjunction with the first selector;
A second switch that is driven in conjunction with the first switch and that is supplied to each unit, the first setting data read from the setting data buffer via the first setting data register or the second selector;
A second setting data register in which second setting data for setting the predetermined condition in the first determination circuit is stored in advance;
A second determination circuit that reads the first setting data of the first setting data register and stores the first setting data in the setting data buffer only when the determination result of the first determination circuit is input and the condition is met;
The waveform measuring instrument according to claim 1, further comprising: The waveform measuring instrument according to claim 2, wherein the second determination circuit is provided in the setting data buffer. 4. The waveform measuring instrument according to claim 1, wherein the first determination circuit is provided in the acquisition data buffer. 5. The waveform measuring instrument according to claim 1, further comprising an input operation / control circuit for setting setting data in the setting data register.

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