JPH0669854U - Digital oscilloscope - Google Patents

Abstract

(57) [Abstract] [Purpose] To realize a digital oscilloscope that can easily observe data stored in a digital memory under trigger conditions different from the trigger conditions for data acquisition. According to the present invention, there is provided an A / D converter, a digital memory for storing data output from the A / D converter, and a signal processing indicator for processing the data output from the digital memory. A selector for selecting an output from the A / D converter and an output from a digital memory, a trigger detection circuit, and a signal for controlling writing of data output from the A / D converter based on a trigger signal. A data write control circuit, a data read control circuit for outputting a signal for controlling data output from the digital memory to the signal processing display, an output from the data write control circuit and an output from the data read control circuit And a selector for selecting and outputting to a digital memory.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a digital oscilloscope, and more particularly to improvement of the trigger function of the digital oscilloscope.

[0002]

[Prior art]

 The configuration of a conventional digital oscilloscope is shown in FIG. In the figure, reference numeral 1 denotes an analog / digital converter (hereinafter referred to as an AD converter) that converts an input signal into an analog / digital signal. A trigger detection circuit 2 generates a trigger signal when the output from the AD converter 2 matches the set state. A data write control circuit 3a generates a write signal for the digital memory 4 based on the trigger signal output from the trigger detection circuit 2. The digital memory 4 stores the data from the AD converter 1 based on this write signal. The data stored in the digital memory 4 is input to the signal processing display unit 5, is subjected to data processing, and then is displayed as a waveform to observe the waveform. At this time, when the amount of data stored in the digital memory 4 is enormous, after storing the data in the digital memory 4 under a certain trigger condition and observing the stored data under another trigger condition, There is. In such a case, the data once stored in the digital memory 4 is displayed on the signal processing display unit 5 and the like, and while observing the display, the user visually searches for a portion corresponding to the trigger condition, Need to observe. Some have the function of setting waveform search conditions and searching for waveforms that meet the conditions using a microprocessor or the like, but this is generally expressed by an operation different from the trigger setting.

[0003]

[Problems to be solved by the device]

 For this reason, if the amount of data is enormous, it takes a lot of man-hours when observing by searching for a part that meets another trigger condition and displaying it, that is, the operability in observing is not good. There is a problem. The present invention solves this problem, and even if the data is once stored in the digital memory, a desired waveform can be searched for by the same operation as the trigger setting in the data acquisition, and can be easily observed. The goal is to realize an oscilloscope.

[0004]

[Means for Solving the Problems]

 The present invention has an analog / digital converter for analog / digital converting an input signal, a digital memory for storing the data output from the analog / digital converter, and a signal processing for the data output from the digital memory. A signal processing indicator to be displayed later, a first selector for selecting the output from the analog / digital converter and the output from the digital memory, and an input signal based on the output from the first selector. Is detected as a trigger level and generates a trigger signal, and the data output from the analog / digital converter is written to the digital memory based on the trigger signal output from the trigger detection circuit. And a data write control circuit that performs control for plugging in, and a trigger output from the trigger detection circuit. A data read control circuit that controls output from the digital memory to a signal processing display unit based on a signal, and an output from the data write control circuit and an output from the data read control circuit is selected and output to a digital memory. And a second selector for controlling the digital oscilloscope.

[0005]

[Action]

 By applying the digital trigger again using the data stored in the digital data, it becomes possible to easily observe under the trigger condition different from the trigger condition in the data acquisition.

[0006]

【Example】

 FIG. 1 shows a block diagram of an embodiment of the present invention. In the figure, the same parts as those in FIG. Reference numerals 10 and 11 are selectors. Of the two input terminals in the selector 10, the input terminal a is connected to the output of the AD converter 1, the input terminal b is connected to the output of the digital memory 4, and the output terminal is output to the trigger detection circuit 2 and the trigger circuit. It is selected whether the data input to 2 is output from the AD converter 2 or the digital memory 4. Of the two input terminals of the selector 11, the input terminal a is connected to the output of the data write control circuit 3a, the input terminal b is connected to the output of the data read control circuit 3b, and the output terminal is input to the digital memory 4 via. , Select whether to control reading or writing to the digital memory 4. In normal operation, both the selector 10 and the selector 11 are connected to the a side. Therefore, the same function as the connection of the conventional example in FIG. 2 is performed.

When the operation of re-reading the data stored in the digital memory 4 under the setting of a certain trigger condition is performed, the selectors 10 and 11 are connected to the b side. Therefore, the digital memory 4 is read out under the control of the data read control circuit 3b. Therefore, the data read from the digital memory 4 is input to the trigger detection circuit 2. At this time, if the trigger detection circuit 2 is set to a trigger condition that is different from when the input signal was directly input and acquired, the trigger detection will be performed under other conditions from the already acquired data. .

During this data trigger detection operation, the data output from the digital memory 4 is repeatedly performed from the beginning to the end of the address of the digital memory 4. However, since the data is discontinuous in the vicinity of the data at the start address and the end address of the digital memory 4, it is impossible to obtain a true change of the input signal. Therefore, the generation of the trigger is prohibited in this part.

The data is read and the trigger detection operation is started. When the data read from the digital memory 4 matches the set condition, a trigger signal is output from the trigger detection circuit, and the trigger detection operation ends. Simultaneously with this end, data is transferred from the digital memory 4 to the signal processing display 5 under preset data length and pre / post trigger conditions. The transferred data is subjected to data processing by the signal processing display device 5 and is displayed based on the new trigger condition. Similar to the normal trigger mode, this operation can be set to a mode that ends with one trigger detection and display (so-called one-shot trigger), a mode that continuously executes trigger detection and display, and so on.

[0010]

[Effect of device]

 According to the present invention, a very large amount of data can be acquired in advance, stored in a digital memory, and then the stored data can be used to perform the same trigger setting as in a normal measurement to select a required waveform. Specifically, it is possible to capture data of one rotation of a data storage disk into a digital oscilloscope, and then set a trigger again from the captured data to make an observation that detects bit data. The digital oscilloscope can be realized.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram of an embodiment of the present invention.

FIG. 2 is a configuration diagram of a conventional example.

[Explanation of symbols]

 1 AD converter 2 Trigger detection circuit 3a Data write control circuit 3b Data read control circuit 4 Digital memory 5 Signal processing display 10 Selector 11 Selector

Claims (1)

[Scope of utility model registration request] 1. An analog / digital converter for analog / digital converting an input signal, a digital memory for storing data output from the analog / digital converter, and signal processing of data output from the digital memory. A signal processing indicator to be displayed later, a first selector for selecting an output from the analog / digital converter and an output from the digital memory, and an input signal based on the output from the first selector. A trigger detection circuit for detecting a trigger level and generating a trigger signal, and for writing data output from the analog / digital converter into a digital memory based on the trigger signal output from the trigger detection circuit. And a data write control circuit for controlling the trigger signal output from the trigger detection circuit. A data read control circuit that controls the output from the digital memory to the signal processing display unit based on A digital oscilloscope characterized by having two selectors.