JP3486878B2 - Signal generator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal generator using a direct digital synthesizer (hereinafter referred to as DDS) system, and more particularly to a signal generator having an improved sweep function.

[0002]

2. Description of the Related Art Some conventional signal generators have a sweep function that sequentially changes the output frequency. FIG.
FIG. 1 is a configuration block diagram showing an example of such a conventional signal generator.

In FIG. 13, 1 is a numerical value setting circuit, 2 is a set value memory, 3 is a sweep memory, 4 is a display control circuit,
Reference numeral 5 is a display unit, 6 is a display item memory, and 7 is a display item selection circuit. Reference numeral 50 is a DDS section.

The output of the numerical value setting circuit 1 is connected to the set value memory 2, and the output of the set value memory 2 is connected to the display control circuit 4 and the DDS section 50, respectively. The output of the display item selection circuit 7 is connected to the display item memory 6, and the output of the display item memory 6 is connected to the display control circuit 4. Further, the output of the display control circuit 4 is connected to the display unit 5.

Now, the operation of the conventional example shown in FIG. 13 will be described. The numerical setting circuit 1 sets the sweep start frequency, the sweep end frequency, the sweep time, etc., and the value set by the numerical setting circuit 1 is stored in the set value memory 2. Specifically, the numerical value setting circuit 1 uses, for example, a key and a rotary encoder.

Further, the display item selection circuit 7 selects an item to be displayed on the display section 5, and the selected item is stored in the display item memory 6.

The display control circuit 4 calculates a value to be displayed based on the values stored in the set value memory 2 and the display item memory 6 and outputs it to the display section 5. The display unit 5 is the display control circuit 4
Display based on the output of.

On the other hand, the DDS section 50 makes various settings in the DDS section 50 based on the values stored in the set value memory 2,
The frequency data of the waveform to be swept is stored in the sweep memory 3, and waveform output and sweep are performed.

As a result, various set values such as the sweep start frequency, the sweep end frequency and the sweep time can be set and confirmed through the display section 5.

FIG. 14 is a block diagram showing another example of the conventional signal generator. In FIG. 14, 8 is a numerical value setting circuit, 9 is a sweep operation control circuit, 10 is control means, 11 and 13 are address generators, 12 is a sweep memory, 14 is a waveform memory, and 15 is a D / A converter. Further, 11 to 15 configure the DDS unit 50a.

The outputs of the numerical setting circuit 8 and the sweep operation control circuit 9 are connected to the control means 10, the output of the control means 10 is connected to the address generator 11, and the output of the address generator 11 is connected to the sweep memory 12. To be done.

The output of the sweep memory 12 is connected to the address generator 13, the output of the address generator 13 is connected to the waveform memory 14, and the output of the waveform memory 14 is D.
It is connected to the / A converter 15. Further D / A converter 15
Outputs a waveform.

The operation of the conventional example shown in FIG. 14 will be described. The numerical value setting circuit 8 sets the sweep start frequency, the sweep end frequency, the sweep time, etc., and the DDS unit 50
a performs various settings based on these set values, stores the frequency data of the waveform to be swept in the sweep memory 12 and the output waveform data in the waveform memory 14, and performs waveform output and sweep.

Actually, the frequency data of the waveform to be swept is stored in the sweep memory 12 based on the values of the sweep start frequency and the sweep end frequency, and the address generator 1
1 generates an address with the sweep time as a parameter and reads the stored contents of the sweep memory 12.

The address generator 13 generates an address using the read frequency data as a parameter, reads the contents stored in the waveform memory 14, and the D / A converter 15 converts the read data into an analog value and outputs it. To do.

On the other hand, when the sweep operation control circuit 9 gives an instruction to stop the sweep, the DSS section 50a stops the operation of the address generator 11 and stops the sweep operation.

As a result, it becomes possible to stop the sweep at an arbitrary point. For example, the frequency sweep is performed on an engine or the like whose rotation speed is controlled, and the frequency sweep is stopped at a desired specific point. It becomes possible to obtain various information of the engine.

[0018]

However, in the conventional example shown in FIG. 13, the set values related to the sweep can be confirmed, but the information of the waveform actually output at the present time cannot be obtained. However, there is a problem that the output waveform must be separately measured with a measuring device such as an oscilloscope in order to obtain the information of the waveform.

On the other hand, in the conventional example shown in FIG. 14, although the sweep operation can be stopped, it is not easy to output the waveform immediately before the stop or the waveform immediately after the stop, and more detailed analysis in the vicinity of the desired specific point can be performed. There is a problem that is said to be difficult. In particular, it is very difficult to output the waveform just before the stop. Therefore, an object of the present invention is to realize a signal generator capable of confirming waveform information at the time of sweep and capable of tracing near the sweep operation stop point.

[0020]

In order to achieve such an object, in the first aspect of the present invention, in a direct digital synthesizer type signal generator having a sweep function, a display item is selected to select information. Display item selection means to be held, numerical value setting means to set the numerical value of the item selected by this display item selection means and hold the set value, and sweep to read and hold the sweep value actually output from the sweep memory. It is characterized by comprising a value reading means and a display means for displaying based on respective outputs from the display item selecting means, the numerical value setting means and the sweep value reading means.

According to a second aspect of the present invention, in a signal generator of the direct digital synthesizer system having a sweep function, a numerical value setting circuit for setting a numerical value required for the sweep operation and a sweep operation control for starting or stopping the sweep operation. A circuit, a read width setting means for setting a read point of the sweep memory to be read after the sweep is stopped, a read point selecting means for selecting the read point, and a sweep based on outputs from the read width setting means and the read point selecting means. And a control means for tracing the sweep after the stop.

[0022]

[Operation] By providing a sweep value reading circuit for reading the contents of the sweep memory and a sweep value memory for storing the read data, and by taking in the actually output sweep value, it is possible to confirm the waveform information during the sweep. .

Further, the reading point of the sweep memory is determined by the reading width setting means, and the reading point selecting means reads each reading point to trace near the sweeping operation stop point, in particular, trace immediately before the sweeping operation stop point. Will be easier.

[0024]

The present invention will be described in detail below with reference to the drawings.
FIG. 1 is a block diagram showing the configuration of a first embodiment of a signal generator according to the present invention. Here, 1 to 7 and 50 are shown in FIG.
The same reference numeral as 3 is attached. In FIG. 1, reference numeral 16 is a sweep value reading circuit, and 17 is a sweep value memory.

Further, 1 and 2 are numerical value setting means 51, 6
Reference numerals 7 and 7 constitute display item selecting means 52, 16 and 17 constitute sweep value reading means 53, and 4 and 5 constitute display means 54, respectively.

The connection relationship is almost the same as that of FIG. 13, except that the output of the sweep memory 3 is connected to the sweep value reading circuit 16 and the output of the sweep value reading circuit 16 is connected to the sweep value memory 17. The output of the value memory 17 is connected to the display control circuit 4.

The basic operation of the embodiment shown in FIG. 1 will be described with reference to FIG. FIG. 2 is a plan view showing the display unit 5 and the peripheral operation unit of the embodiment shown in FIG.

In FIG. 2, 18 is a rotary encoder, 19 is a digit shift key, 20 is a numeric keypad, 21 is a numerical display, 22 is a sweep start frequency selection switch, 23 is a sweep end frequency selection switch, 24 is a sweep time selection switch, Reference numeral 25 is a sweep frequency monitor switch.

The switches 22 to 25, which are the display item selection circuit 7, are provided on the display unit 5, respectively.
For example, it is configured by providing a touch switch or the like on the liquid crystal panel.

The values of the sweep start frequency, the sweep end frequency and the sweep time which have already been set are as shown in FIG. 2, respectively.
2. Always displayed immediately after the sweep end frequency selection switch 23 and the sweep time selection switch 24.

The inverted display portion in FIG. 2 is the currently selected display item and changeable set values corresponding to the display item. That is, in FIG. 2, the sweep start frequency selection switch 22 is pushed, and the set sweep start frequency is displayed in the numerical display section 21 in a change waiting state.

In order to change the set value, the cursor shown in "a" in FIG. 2 is moved by the digit movement key 19 and the value of the digit designated by the cursor is changed by the rotary encoder 18, or the ten key 20 is used. Enter the value directly to change the highlighted setting value.

The detailed operation of the embodiment shown in FIG. 1 will be described with reference to FIGS. FIG. 3 is a flow chart showing the operation of the embodiment shown in FIG.
FIG. 4A is a plan view showing the display contents of the display unit 5 when the sweep start frequency is set, when the sweep end frequency is set, when the sweep time is set, and when the sweep frequency is monitored.

First, the sweep operation is started at "a" in FIG. Secondly, when a display item is selected by the display item selection circuit 7 in "b" in FIG. 3, this display item is stored in the display item memory 6 and whether or not the display item is a set value in "c" in FIG. If it is a set value, the corresponding data is read from the set value memory 2 at "d" in FIG.

For example, when the sweep end frequency selection switch 23 is pressed in the state shown in FIG. 4, the selection of the sweep end frequency is stored in the display item memory 6, and is set from the set value memory 2 by the display selection means 4. The sweep end frequency being read is read out and displayed in reverse on the numerical value display section 21 and the sweep end frequency selection switch 23 is displayed in reverse, as shown in FIG.

It is judged whether or not the set value is changed in "e" in FIG. 3, and if there is a change, the changed value in "f" in FIG. 3 is stored in the set value memory 2 and various selection switches 22 to Immediately after 24, the display of the set value which is constantly displayed is updated.

In FIG. 3, it is judged whether or not the display item is changed at "TO", and if there is no change in the display item, "IN" in FIG.
If the display item is changed in the process of "e", the process of "c" in FIG. 3 is performed.

For example, when the sweep time selection switch 24 is pressed in the state shown in FIG. 5, the selection of the sweep time is stored in the display item memory 6 and set by the display selection means 4 from the set value memory 2. The sweep time is read out and displayed in reverse on the numerical value display section 21 and the sweep time selection switch 24 is displayed in reverse.
As shown in.

On the other hand, if the display item in "C" in FIG. 3 is not a set value, the sweep value is read from the sweep value memory 17 in "H" in FIG. 3, and the numerical value display section is displayed in "R" in FIG. 21 is displayed.

Further, it is judged whether or not the display item is changed in "nu" in FIG. 3, and if there is no change in the display item, the process of "h" in FIG. During"
Ha ”processing.

For example, when the sweep frequency monitor switch 25 is pressed in the state shown in FIG. 6, the selection of the sweep frequency monitor is stored in the display item memory 6, and the sweep value reading circuit 16 sequentially reads data from the sweep memory 3. It is read and stored in the sweep value memory 17.

Further, the sweep frequency stored in the sweep value memory 17 is read out by the display control circuit 4 and displayed on the numerical value display section 21, and the sweep frequency monitor switch 25 is highlighted and displayed as shown in FIG. Become. However, since the monitor value of the sweep frequency cannot be changed, the numerical value display section 21 is not reversely displayed.

As a result, the sweep value reading circuit 16 for reading the contents of the sweep memory 3 and the sweep value memory 17 for storing the read data are provided, and the actually output sweep value is taken in, thereby making It is possible to check the waveform information.

FIG. 8 is a block diagram showing the configuration of a second embodiment of the signal generator according to the present invention. Where 1
0 to 15 and 50a are denoted by the same reference numerals as in FIG.
In FIG. 8, 26 is a read width setting circuit, 27 is a read width memory, 28 is a read point selection circuit, and 29 is a read point memory.

Further, 26 and 27 are read width setting means 55.
Reference numerals 28 and 29 respectively constitute read-out point selection means 56.

The connection relationship is almost the same as that of the conventional example shown in FIG. 14 except that the output of the read width setting circuit 26 is connected to the read width memory 27 and the output of the read width memory 27 is connected to the control means 10. On the other hand, the read point selection circuit 2
8 is connected to the reading point memory 29, and the output of the reading point memory 29 is connected to the control means 10. However, the display of the numerical value setting circuit 8 and the sweep operation control circuit 9 in FIG. 14 is omitted.

The operation of the embodiment shown in FIG. 8 will now be described with reference to FIGS.
This will be described with reference to FIG. However, since the basic operation is the same as that of the conventional example shown in FIG. 14, the description of that part is omitted.

FIG. 9 is a plan view showing the display section and peripheral operating section of the embodiment shown in FIG. 8, FIG. 10 is a flow chart showing the operation of the embodiment shown in FIG. 8, and FIG. 11 shows the data in the sweep memory 12. FIG. 12 is a characteristic curve diagram showing the relationship between read points.
Is a table showing the relationship between read points and output frequencies.

In FIG. 9, 30 is a display unit, 31 is a rotary encoder, 32 is a numeric keypad, 33 is a read width display unit, 34 is an output value display unit, 35 is a sweep stop switch, 36 is a read width setting switch, and 37 is a numerical value. It is a confirmation switch.

The switches 35 to 37 are provided on the display unit 30, respectively, and are constituted by providing a touch switch or the like on the liquid crystal panel, for example. Further, the inverted display portion in FIG. 9 indicates that the read width is in a change waiting state.

First, the read width is set at "a" in FIG. 10, and the sweep operation is stopped at "b" in FIG. Further, at "C" in FIG. 10, the rotary encoder 31 which is the read point selection circuit 28 is rotated to input the read point.

At this time, it is judged whether or not the read point is input at "d" in FIG. 10, and when the read point is not input, the state shown in FIG.
Repeat the process of "Ha".

On the other hand, when there is a read-out point input, FIG.
The DDS unit 50a is operated by generating an address based on the read width and read point set in the middle "e" to "e". That is, the content stored in the sweep memory 12 is read at the address, and further, the content stored in the waveform memory 14 is read based on the read value and output to perform tracing.

As a specific operation, the reading width setting switch 36 is pressed to display the reading width currently set on the reading width display portion 33, the reading width is set by the ten keys 32, and the numerical value determination switch 37 is pressed. Press to complete the setting.

Next, the sweep operation is stopped by pressing the sweep stop switch 35, the rotation amount of the rotary switch 31 is detected, and this rotation amount is read out to the reading point memory 29.
To store.

For example, "2.00 kHz" to "4.00"
Consider a case in which sweeping is performed between "kHz" as shown in FIG. 11 and "5.00%" is set as the read width.
"5.00%" indicates that the contents of the sweep memory 12 are divided into 20 and traced.

That is, as shown by the broken line and the alternate long and short dash line in FIG. 11, the address on the horizontal axis is divided into 20, and the broken line and the alternate long and short dash line in FIG. 11 are read points. Further, FIG. 12 shows the characteristic curve diagram shown in FIG. 11 in a table in association with the reading points.

The point at which the sweep is stopped is shown in FIG.
If the points are indicated by “a” and “b” in FIG. 12, the output frequency is “4.0 kHz” at the time of stopping the sweep.

Here, for example, if the reading points are increased by two points, the output frequency changes to "2.67 kHz" as shown by "C" in FIG. If the read points are reduced by 5 points, the output frequency changes to "3.00 kHz" as shown by "d" in FIG.

As a result, by determining the read point of the sweep memory by the read width setting means 54 and selecting the read point to be read by the read point selecting means 55, the trace near the sweep operation stop point, especially immediately before the sweep operation stop point, Makes tracing easier.

In the description of the first embodiment shown in FIG. 1, when the sweep frequency monitor switch 25 is selected, the sweep value reading circuit 16 sequentially reads the data from the sweep memory 3 and stores it in the sweep value memory 17. However, regardless of the selection of the sweep frequency monitor switch 25, the sweep value reading circuit 16 always reads the data from the sweep memory 3 to obtain the sweep value memory 1
It may be stored in 7.

Although the reading width is set to "5.00%" in the description of the second embodiment shown in FIG. 8, the reading width is not limited to this and may be arbitrary. For example, the read width is "1.00%"
Then, the contents of the sweep memory 12 will be divided into 100 and traced, and finer traces will be possible.

[0063]

As is apparent from the above description,
The present invention has the following effects. According to the first aspect of the present invention, the sweep value reading circuit for reading the contents of the sweep memory and the sweep value memory for storing the read data are provided, and the actually output sweep value is fetched to obtain the waveform information at the time of sweep. It is possible to realize a signal generator capable of confirming.

According to the second aspect of the present invention, the read width setting means determines the read point of the contents stored in the sweep memory, and the read point selecting means selects the read point to be read.
A signal generator capable of tracing near the sweep operation stop point can be realized.

[Brief description of drawings]

FIG. 1 is a configuration block diagram showing a first embodiment of a signal generator according to the present invention.

FIG. 2 is a plan view showing a display unit and a peripheral operation unit of the embodiment shown in FIG.

FIG. 3 is a flowchart showing the operation of the embodiment shown in FIG.

FIG. 4 is a plan view showing contents displayed on a display unit when a sweep start frequency is set.

FIG. 5 is a plan view showing the display contents of the display unit when the sweep end frequency is set.

FIG. 6 is a plan view showing the display contents of the display unit when the sweep time is set.

FIG. 7 is a plan view showing the display contents of the display unit during the sweep frequency monitor.

FIG. 8 is a configuration block diagram showing a second embodiment of the signal generator according to the present invention.

9 is a plan view showing a display unit and a peripheral operation unit of the embodiment shown in FIG.

10 is a flowchart showing the operation of the embodiment shown in FIG.

FIG. 11 is a characteristic curve diagram showing a relationship between data in the sweep memory and a read point.

FIG. 12 is a table showing the relationship between read points and output frequencies.

FIG. 13 is a configuration block diagram showing an example of a conventional signal generator.

FIG. 14 is a configuration block diagram showing another example of a conventional signal generator.

[Explanation of symbols]

1,8 Numerical value setting circuit 2 set value memory 3,12 sweep memory 4 Display control circuit 5,30 Display 6 Display item memory 7 Display item selection circuit 9 Sweep operation control circuit 10 Control means 11,13 Address generator 14 Waveform memory 15 D / A converter 16 Sweep value readout circuit 17 Sweep value memory 18,31 Rotary encoder 19 digit move key 20,32 numeric keypad 21 Numerical display 22 Sweep start frequency selection switch 23 Sweep end frequency selection switch 24 Sweep time selection switch 25 sweep frequency monitor switch 26 Read width setting circuit 27 Read width memory 28 Readout point selection circuit 29 Read-out point memory 33 Readout width display 34 Output value display 35 Sweep stop switch 36 Read width setting switch 37 Numerical value confirmation switch 50,50a DDS section 51 Numerical value setting means 52 Display item selection means 53 Sweep value reading means 54 display means 55 Read width setting means 56 Read-out point selection means

Claims (2)

(57) [Claims] 1. A direct digital synthesizer type signal generator having a sweep function, a display item selecting means for selecting a display item and holding selection information, and a numerical value of the item selected by this display item selecting means. Numerical value setting means for setting and holding the set value, sweep value reading means for reading and holding the sweep value actually output from the sweep memory, the display item selecting means, the numerical value setting means and the sweep value reading And a display means for displaying based on each output from the means. 2. A direct digital synthesizer type signal generator having a sweep function, a numerical value setting circuit for setting a numerical value required for a sweep operation, a sweep operation control circuit for starting or stopping a sweep operation, and a sweep stop. A read width setting means for setting a read point of the sweep memory to be read later, a read point selecting means for selecting the read point, and a trace of the sweep after the sweep is stopped based on the outputs of the read width setting means and the read point selecting means. And a control means for performing the above.