JPH072976U - Waveform display device - Google Patents

Abstract

(57) [Abstract] [Purpose] To realize a waveform display device capable of automatically changing the display range by following changes in the input waveform during observation. [Structure] CPU, input amplifier, A / D converter for digitally converting the output of this input amplifier, memory, display for displaying the contents of this memory, and maximum value of input signal within a fixed time A maximum / minimum value detection circuit that detects the minimum value,
A trigger cycle detection circuit for detecting a trigger cycle, a man-machine interface for instructing setting conditions, a display range control section for switching the input range in the input amplifier, and an auto setup by an instruction output from the CPU And a display range control unit for inputting a signal from the maximum / minimum value detection circuit and a signal from the trigger period detection circuit and calculating an optimum display range. It is a display device

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a waveform display device having an auto setup function.

[0002]

[Prior art]

 In the conventional waveform display device, once the time axis and voltage axis ranges are set, if the input signal changes after that, the set time axis and voltage axis ranges are manually set again. There was a need.

For example, as shown in FIG. 2, it is assumed that optimum observation is possible with a frequency of 250 KH _Z and an amplitude of 2V. In this state, the input signal is the frequency as shown in FIG. 3 is changed to 500KH _Z, amplitude 1V, it amplitude, etc. is small, also peaks and troughs so that the appear much. In order to improve this display state and make the input signal under the conditions shown in FIG. 3 easier to see as shown in FIG. 4, the observer must set the rotary knob and the like by himself.

[0004]

[Problems to be solved by the device]

 Therefore, after setting the optimum range for the first input signal, the optimum range for observing the input signal after the display setting range has changed due to changes in the amplitude or frequency of the input waveform However, there is a problem that the observer needs to perform a troublesome operation to set the optimum setting. The present invention solves such a problem and realizes a waveform display device that automatically sets the optimum range for observation of the changed input signal even if the signal to be measured changes during observation. To do.

[0005]

[Means for Solving the Problems]

 The present invention has a CPU for controlling the entire apparatus, an analog / digital converter for converting an analog input signal applied via an input amplifier to a digital signal, and a memory for storing the digital output of the analog / digital converter. A display for displaying the contents of this memory; a maximum / minimum value detection circuit for detecting the maximum value and the minimum value of the voltage values of the input signal within a fixed time; and a trigger cycle of the input signal. A trigger cycle detection circuit, a man-machine interface for instructing a display or setting condition from the outside, a display range control unit for switching the input range in the input amplifier, and an auto setup by an instruction output from the CPU Signal from the auto setup controller of the above, the maximum and minimum value detection circuit, and the trigger cycle Output and input signals from the circuit, a waveform display device characterized by providing a display range control unit for calculating the optimal display range.

[0006]

[Action]

 When observing the waveform, it is possible to detect the amplitude and frequency of the input signal and reset the display range based on the result to perform optimum observation of the input signal.

[0007]

【Example】

 FIG. 1 is a diagram showing the configuration of an embodiment of the present invention. In the figure, reference numeral 1 is an input amplifier for inputting a signal from the outside. Reference numeral 2 is an analog / digital converter (hereinafter referred to as ADC), which converts the signal input from the input amplifier 1 into a digital signal. A memory 3 stores the digital data output from the ADC 2. Reference numeral 4 denotes a display, which displays the waveform of the data stored in the memory 3. A maximum / minimum value detection circuit 5 detects the maximum value and the minimum value of the signal input from the input amplifier 1. Specifically, it is realized by using a sample hold circuit or the like. Reference numeral 6 is a trigger period detection circuit, which detects the frequency of the signal input from the input amplifier 1. Specifically, it consists of a circuit that detects when an input signal is in a certain state, generates a trigger signal in that state, and a circuit that measures time such as the trigger signal interval.

A display range control unit 7 controls display settings on the display device 4. That is, control is performed to change the setting of one scale displayed on the display unit 4. A microprocessor (hereinafter referred to as a CPU) 8 outputs a timing clock for writing in the memory 3 or for displaying on the display 4, or a control command for displaying on the display range controller 7. To do. A man-machine interface 9 is used to externally set whether or not the display range follows the input signal. Specifically, it is realized by an operation button or the like. Reference numeral 10 denotes an auto setup control unit, which inputs settings from the man-machine interface 9 and outputs a control signal to the display range comparison unit 11 to control the auto setup operation. Reference numeral 11 denotes the above-mentioned display range comparison unit, which inputs signals from the maximum / minimum value detection circuit 5, the trigger period detection circuit 6, and the display range control unit 7, and outputs the signals to the display range control unit 7 again.

Next, the operation of the present invention will be described. In this case, first, the man-machine interface 9 is set so as to automatically set the waveform display range and the like. As a result, the CPU 8 issues a command to start the setting operation in the display range comparison unit 11. At this time, if there are multiple channels to input signals, it is also necessary to select in advance which channel to set the optimum time axis for observing the input signal. Hereinafter, this selected channel will be referred to as a trigger source.

The input signal of each channel passes through the input amplifier 1 and the maximum / minimum value detection circuit 5 detects the maximum value and the minimum value of the signals input within a certain period. This is detected by using an analog track-hold circuit or by a method of selecting a minimum value and a maximum value from a plurality of values obtained by digitally converting each input signal.

On the other hand, the frequency of the input signal of the trigger source channel is measured by the signal from the channel of the trigger source input to the trigger period detection circuit 6 via the input amplifier 1.

The display range comparison unit 11 receives the output from the maximum / minimum value detection circuit 5 and the output from the display range control unit 7 in each channel, and displays the range of the voltage axis (that , Which is also the range of the normal input amplifier 1) is the optimum one. Whether the time axis range of the display currently set on the display unit 4 is optimal for the input signal is determined by the output from the trigger cycle detection circuit 6 and the output from the display range control unit 7. To judge. If these settings are not optimal, the display range control circuit 7 sets the display range and the like again. With such an operation, when the input signal shown in FIG. 3 is changed to the input signal shown in FIG. 2, the display on the display 4 is changed to the state shown in FIG. The signal can be easily observed.

In order to understand the above operation, description will be made with reference to the flowcharts of FIGS. 5 and 6. Figure 5 shows a flowchart of the operation when the set range is automatically changed when the input signal changes during observation. Also, the operation when the set range is not changed even if the input signal changes during observation is shown in the flowchart of FIG. In FIG. 5, if the amplitude frequency of the input signal is changed in advance, the auto setup control unit 10 is set so as to be optimum for observing the changed input signal. In such a case, the amplitude or frequency of the input signal is compared with the value acquired by the maximum / minimum value detection circuit 5 and the trigger detection circuit 6 and the currently set display range, and this value is acquired. It is judged whether or not it is optimal. If it is not optimum, the control operation is performed by the auto setup control unit 10 so as to automatically reset the display range based on the fetched value. After that, the waveform display is performed by setting the new display range and using the analog-to-digital converted value of the input signal. Also, if the above-mentioned captured value is optimal for the current display, the waveform is displayed as it is.

On the other hand, as shown in FIG. 6, when the auto setup controller 10 is set so that the set range is not changed even when the input signal changes during observation, The input signal is displayed at the currently set display range, and the waveform is displayed using the analog / digital converted value of the input signal.

[0015]

[Effect of device]

 According to the present invention, in the waveform display device, even if the amplitude and frequency of the input waveform change during observation, it is possible to automatically change to the optimum display range for observation. .

[Brief description of drawings]

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

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

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

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

FIG. 5 is a flowchart showing the operation of the present invention.

FIG. 6 is a flowchart showing the operation of the present invention.

[Explanation of symbols]

 1 Input amplifier 2 Analog / digital converter 3 Memory 4 Display 5 Maximum / minimum value detection circuit 6 Trigger cycle detection circuit 7 Display range control circuit 8 CPU 9 Man-machine interface 10 Auto setup control section 11 Display range comparison section

Claims (1)

[Scope of utility model registration request] 1. A CPU for controlling the entire apparatus, an analog / digital converter for digitally converting an analog input signal applied via an input amplifier, and a memory for storing a digital output of the analog / digital converter. A display for displaying the contents of the memory; a maximum / minimum value detection circuit for detecting a maximum value and a minimum value of voltage values of the input signal within a fixed time; and a trigger cycle of the input signal. A trigger cycle detection circuit, a man-machine interface for instructing a display or setting condition from the outside, a display range control unit for switching the input range in the input amplifier, and an auto setup by an instruction output from the CPU Signal from the auto-setup control unit and the maximum / minimum value detection circuit and trigger period Output and input signals from the circuit, the waveform display apparatus is characterized by providing a display range control unit for calculating the optimal display range.