JPH0541094A - Analog signal sampling device - Google Patents

Abstract

PURPOSE:To fetch a signal at a half period of a maximum sampling period by storing alternately a measured value obtained with a prescribed sampling and changing no structure of a signal fetching device. CONSTITUTION:The analog signal 1 from a measured device is sampled from a firs sampling start point 2 at the interval of a sampling period 4. The first measured values 6 (a, b, C,...) are stored to the odd number of an arrangement 8 succeedingly. Next, the same analog signal as the first is outputted once more from the measured device, is sampled from a second sampling start point 3 delayed by time 5 of a half of the sampling period from the first sampling start point 2. The second measured values 7 (f, g, h,...) are stored to the even number of the arrangement 8 succeedingly. Thus, the data column equivalent to a case sampling by the half period of the sampling period 4 is stored to the arrangement 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an analog signal sampling device, and more particularly to a measuring device for sampling an analog signal at a constant cycle.

[0002]

2. Description of the Related Art Generally, an analog signal sampling device is a device for periodically sampling a part of a continuous signal to read a value and representing the value as a data string.

FIG. 3 (a) is a waveform diagram showing the operation of a conventional analog signal sampling device, and FIG. 3 (b) is an array representing a stored data string.

As shown in FIG. 3A, the analog signal 1
A value is read from the signal acquisition start point 9 at every sampling cycle 4 designated by the signal reading device, and the measured value 10 at that time is sequentially stored in the array 8 as shown in FIG. 3 (b). Thus, the original analog signal component is expressed in the data string.

The data stored in the array 8 is analyzed by signal processing such as Fourier transform.

At 5 MHz, 512 data samples, generally about 100 μs for acquisition and about 100 m for signal processing.
s time is required.

[0007]

In the conventional analog signal sampling device, since the sampling interval of the signal is determined by the sampling period of the signal capturing device, the analog signal is captured at a shorter interval than the maximum sampling period of the signal capturing device. There is a problem in that it cannot be applied to an indispensable measurement.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and to provide an analog signal sampling apparatus which can take in a signal at a half cycle of the maximum sampling cycle without changing the structure of the signal taking apparatus. .

[0009]

The structure of the present invention comprises means for sampling an analog signal output from a device under test at a constant cycle, and means for arranging and storing the measured values obtained by said means. In the provided analog signal sampling device, the measured value obtained by sampling the analog output signal of the device under test at a constant cycle is stored in an odd number of the array, and then the same analog signal is newly generated from the device under test. It is characterized in that a means for storing the measured value obtained by sampling the middle of the previous measuring points in an even number of the array is provided.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1A is a waveform diagram showing the operation of the first embodiment of the present invention, and FIG. 1B is a diagram showing an array for storing the measurement results of FIG. 1A. .

In FIG. 1, in this embodiment, the analog signal 1 from the device under test is sampled at a sampling period 4 from the sampling start point 2 of the first sampling.
The first measured value 6 [a, b, c, ...] Is stored in the array 8 in the odd-numbered order.

Next, the same analog signal as the first time is output from the device under test one more time, and it is delayed from the first sampling start point 2 by a time 5 which is half the sampling period.
Sampling is performed at intervals of a sampling cycle 4 from the sampling start point 3 of the second time. The second measured value 7 [f, g, h, ...] Is stored in the even number of the array 8 in order.

Therefore, the array 8 stores a data string equivalent to the case where sampling is performed at a half cycle of the sampling cycle 4.

FIG. 2A is a waveform diagram showing the operation of the second embodiment of the present invention, and FIG. 2B is a diagram showing an array for storing the measurement results of FIG. 2A. In FIG. 2, in this embodiment, the analog signal 1 is sampled from the sampling start point 9 at intervals of the sampling cycle 4. The first measured values [a, b, c, ...] Are stored in the array 8 in odd-numbered order.

Next, the same analog signal for the first time is generated from the device under test at a point 5 times earlier than half the sampling cycle, and sampling is performed at the sampling cycle 4 from the same sampling start point 9 as the first time. The second measured values [f, g, h, ...] Are stored in the array 8 in even-numbered order.

Therefore, the array 8 stores a data string equivalent to the case where sampling is performed at a half cycle of the sampling cycle 4, as in the first embodiment.

In both the first and second embodiments, the data stored in the array 8 is analyzed by signal processing such as Fourier transform. In addition, in the first and second embodiments, the data acquisition is required twice, but since the data acquisition requires only about 1/1000 of the signal processing, it hardly affects the entire measurement time. .

[0018]

As described above, according to the present invention,
Without changing the structure of the signal capture device, it is possible to capture signals at half the maximum sampling period,
Further, it has an effect that a signal acquisition device having a double maximum sampling period can be applied to the measurement with the same accuracy.

[Brief description of drawings]

1A and 1B are a waveform diagram showing the movement of an analog signal sampling apparatus of a first embodiment of the present invention and an array diagram showing storage of measurement results.

2 (a) and 2 (b) are respectively a waveform diagram showing the movement of the second embodiment of the present invention and an array diagram showing storage of measurement results.

FIG. 3 is a waveform diagram showing the movement of a conventional analog signal sampling device and an array diagram showing the storage of measurement results.

[Explanation of symbols]

 1 Analog signal 2 1st sampling start point 3 2nd sampling start point 4 Sampling period 5 Half time of sampling period 6 1st measurement value 7 2nd measurement value 8 Array 9 Sampling start point 10 measurement value

Claims (1)

[Claims] 1. An analog signal sampling device comprising: means for sampling an analog signal output from a device under test at constant intervals; and means for arranging and storing the measured values obtained by said device. The measured value obtained by sampling the analog output signal of the measuring device at a constant cycle is stored in the odd-numbered array, and then the same analog signal is newly generated from the device under test to sample the middle of the previous measuring point. An analog signal sampling apparatus comprising means for storing the obtained measured values in even-numbered arrays.