JP2993289B2 - Electric signal measuring instrument - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a method of operating a waveform storage device in an electric signal measuring instrument such as a digital oscilloscope.

[0002]

2. Description of the Related Art In a conventional electric signal measuring instrument equipped with a waveform storage means, when a waveform stored in a waveform storage device is selected and read, the contents of a directory display include a file name, date, Only text such as comments was displayed. Originally, the directory display is a function for searching for a file to be read. However, in the case of a waveform, it is difficult to identify a characteristic of the waveform only by a file name and identify the waveform.

[0003]

For this reason, it cannot be confirmed whether or not the waveform stored in the file is a necessary waveform unless the file is loaded. Therefore, there is a problem that the capacity of the waveform data has been increased recently or the access time of an external medium such as a floppy disk takes a long time, and the operability is poor. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve such a problem and to realize an electric signal measuring instrument capable of easily reading a required electric signal waveform in a directory display.

[0004]

SUMMARY OF THE INVENTION The present invention provides an analog / digital converter for digitizing an input analog signal, a waveform memory for storing digital data from the analog / digital converter as it is, and a waveform memory for storing the digital data. A compression operation means for compressing data for displaying a plurality of stored data on a single raster, a CPU for controlling the whole, and storing data from the waveform memory and data from the compression operation means, respectively. An external storage device for storing waveform data irrespective of a power supply state of the main body;
A display memory for storing data from the compression operation means or data from an external storage device as display data,
A display for displaying data stored in the display memory, wherein the trace waveform of the selected file is also displayed in the directory display when reading the external storage device. is there.

[0005]

When the waveform data is stored in the external storage device, trace data as simple waveform data is also stored at the same time, and when a file is selected in the directory display, the trace data of the selected file is also displayed. The required waveform data can be read out.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings.
FIG. 1 is a basic configuration diagram of the present invention. In the figure, 10
Digitizes an analog signal input by an analog / digital converter (hereinafter, referred to as an ADC). A waveform memory 20 stores digital data from the ADC 10 as it is. Numeral 30 denotes a compression operation means for compressing the data stored in the waveform memory 20 for each of a plurality of data to be displayed on one raster. A display memory 40 stores data from the compression operation means 30 or data from an external storage device as display data. Reference numeral 50 denotes an external storage device which stores data from the waveform memory and data from the compression operation means, and stores the data irrespective of the state of the power supply of the main body. In the external storage device 50, areas of a header 51, a waveform data memory 52, and a trace memory 53 are provided for each waveform data to be stored.
The header 51 has the measurement information of the waveform data, the waveform data memory 52 has the actual analog / digital converted waveform data, and the trace memory 53 has the trace data for simple display in directory display. Is stored. Numeral 60 denotes a CPU for controlling the whole. A display 70 displays data from the display memory.

The operation in such a configuration will be described.
First, the input signal is converted into a digital signal by the ADC 10 and stored in the waveform memory 20. Usually, this data is about 100K [kilo] words (200K [kilo] bytes) per waveform. Here, one waveform refers to a continuous signal change captured in one sampling (a plurality of samplings in the case of random sampling or the like). However, the display 7
The resolution at 0 will be determined by the number of CRT rasters used (FIG. 2). Therefore, the waveform data is compressed by the compression / calculation means 30 so that it can be displayed on the raster, stored in the display memory 40, and displayed on the display 70. On the other hand, the above-described 100K [kilo] word waveform data is stored in the waveform data memory 5 of the external storage device 50.
2 is stored.

Here, the data stored in the trace memory 53 will be described. The number of rasters of the display 70 (CRT) is 500. Therefore, when the waveform data is 100
Since there are K points, the horizontal resolution of the waveform display is 500 points (500 rasters) and the 100K points are compressed to 1/200 for display. For example, as shown in FIG. 3, the compression operation means 30 performs maximum value / minimum value compression. In this case, the maximum value and the minimum value of each block (200-point data) are obtained and are set as raster data.
Therefore, as a result, the trace data for display (50
Raster data for 0 points) is 1000 points (Fig. 2),
Stored in the display memory. The trace data is stored in the trace memory 53 at the same time when the waveform data is stored in the waveform data memory 52. Therefore, when a directory is displayed as shown in FIG. 4, the selected waveform ([EEE. *] In FIG. 4) is displayed as trace data read from the trace memory 53. That is,
The waveform in the directory display can be traced (waveform display) for one waveform by drawing a straight line using the MAX-MIN value of the selected waveform in the trace memory 53.

[0009]

As is apparent from the above description,
According to the present invention, it is possible to realize an electric signal measuring instrument capable of reading out a required electric signal waveform.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of the present invention.

FIG. 2 is an explanatory diagram of the operation of the present invention.

FIG. 3 is an explanatory diagram of an operation of the present invention.

FIG. 4 is an explanatory diagram of the operation of the present invention.

[Explanation of symbols]

 Reference Signs List 10 analog / digital converter 20 waveform memory 30 compression operation means 40 display memory 50 external storage device 51 header 52 waveform memory 53 trace memory 60 CPU 70 display

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI G09G 5/36 G09G 5/36

Claims (1)

(57) [Claims] 1. An analog / digital converter for digitizing an input analog signal, a waveform memory for storing digital data from the analog / digital converter as it is, and a plurality of data stored in the waveform memory. And 1
Compression operation means for compressing data to be displayed on one raster; CPU for controlling the whole; data from the waveform memory and data from the compression operation means, which are stored independently of the power state of the main body. An external storage device for storing waveform data; a display memory for storing data from the compression operation means or data from the external storage device as display data; and a display for displaying the data stored in the display memory. An electric signal measuring instrument, wherein a trace waveform of a selected file is also displayed in a directory display when reading an external storage device.