JPH0325376A - Signal width measuring instrument - Google Patents

Abstract

PURPOSE:To accurately measure the mean value of the signal width of an incidental pulse signal by single-time measurement by integrating the counted value of one-shot pulses in the presence period of a signal to be measured according to a detection signal for the presence period and finding the mean value of the signal width. CONSTITUTION:When a start signal 107 goes up to H, an FF 13 is turned on and off repeatedly according to rises of one-shot pulses p1 and p2 of a counter 1. Consequently, a clock signal 50 is supplied from an AND gate 10 to a counter 2 only for a period of tx+tw and a counter 5 counts rises of the signal 50. This operation is performed every time the signal to be measured is inputted. When the counted value of the counter 5 reaches a set value and a carry signal 108 goes up to H, the FF 14 turns on the rising of the output signal 104 of a counter 1 and a microcomputer 3 resets a holding means 32 to make a start signal 107 rise and also sends an arithmetic command to a calculating means 35, which calculates the mean value of the signal width.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides a signal having ancillary pulse signals that are present incidentally on each side of the rising edge and falling edge of a main pulse,
For example, an on/off signal of a relay contact or a switch contact that generates a chattering pulse signal is used as the signal to be measured,
Signal IM all that measures the signal width of only the measurement target signal, with one of the incidental pulse signals on each side of the rising and falling sides as the measurement target signal and the other as the non-measurement target signal.
related to fixed equipment.

(Prior Art) Conventionally, a signal under test is input to a retriggerable one-shot circuit having a predetermined operating time width, the one-shot circuit is operated, and the one-shot circuit is activated from the point in time when the signal under test is manually input. There is a signal width measuring device that calculates the signal width of the signal under test by counting the time until the end of the operation and subtracting the operation time width from this time.

According to this device, even if the signal under test occurs intermittently, it is possible to capture the input start point and input end point of the pulse group, making it easy to measure the signal width. Obtainable.

By the way, in addition to such a single measurement value, when obtaining the average value of a large number of measurement values, the above-mentioned device can also be used to obtain the average value by obtaining multiple measurement values and averaging them. However, this naturally requires multiple measurements. In this case, if the signal under test is short
It is fine as long as it occurs frequently during the period, but the smaller the number of occurrences, the more necessary number to calculate the average value.
It takes a long time to complete 1I, and the measurement operator is forced to perform Δ11 constant work until the required number of measured values is obtained.

Therefore, it may be possible to automatically perform this series of operations using a microcomputer, but in this case, the microcomputer would perform processing such as starting measurement, checking the end of measurement, reading data, and adding the data for each measurement. There is a problem in that it requires a lot of effort, which increases the burden.

(Three problems to be solved by the invention) As described above, in the conventional signal width measuring device, when calculating the average value, it is necessary to perform multiple measurements in order to obtain a large number of sample values. This increases the amount of time required to perform the work, and also places a heavy burden on the microcomputer that performs the work.

Therefore, instead of obtaining a plurality of sample values, the inventor of the present invention has considered accumulating data for a plurality of measurements and then taking an average over the number of measurements. However, especially
In the case of a pulse signal attached to both the rising and falling edges of the main pulse, such as chattering pulse No. 1g, it is necessary to distinguish it from the main pulse.
Furthermore, if it is desired to measure only one of the rising and falling signals, it is necessary to distinguish it from the other signal, which is difficult.

The present invention has been made in view of this point, and its purpose is to measure one of the signal signals present on each side of the rising and falling edges of the main pulse. It is an object of the present invention to provide a signal width measuring device that can accurately determine the average value of signal widths without requiring multiple M1 constants even when the other side is excluded from all constants.

[Structure of the invention]

(Means for Solving the Problems) The signal width measuring device of the present invention detects the rising duration and falling duration of the main pulse based on the level of the lmil[lI constant signal at the rising or falling edge of the one-shot 1 pulse. This makes it possible to identify the period of existence of only the signal to be measured, and based on the period of existence detection signal, the count is performed only during the generation of one-shot pulses during the period of existence of the signal to be measured. The value is accumulated, and when the count value reaches the scheduled number of occurrences during the existence period of the signal to be measured, the average value calculation is performed directly on the accumulated count to obtain the average value of the signal width. be.

(Function) According to the present invention, a period in which a non-measurement signal exists in a constant signal and only a measurement target signal exists is detected,
Since the time width of one-shot pulses that occur within that period is counted, by counting, it is possible to obtain cumulative data that does not include the time width of the signal not to be measured, but only the time width of the signal to be measured. , the 3li average value of the signal width can be accurately determined without requiring multiple measurement operations.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a signal width measuring device according to an embodiment of the present invention.

First, in this embodiment, the signal width of a chattering pulse signal generated when a relay is opened and closed is measured, and 21 is a drive transistor, 22 is a relay coil,
23 is a backflow prevention diode, 24 is a relay contact, and 25 is a current limiting resistor.

In the relay circuit consisting of these, an on/off control pulse is input to the base of the drive transistor 21, which turns the transistor 21 on and off, and cuts off current to the relay coil 22 connected to its collector side, causing the contact 24 is opened and closed.

In Fig. 2 (A), the symbol M is the main pulse generated by opening and closing of relay M, and the pulses attached to its leading edge (rising part) and trailing edge (falling part) are is a pulse generated by chattering, and the apparatus of this embodiment is intended to measure the signal widths txi and tX2 of the signals al and a2, respectively, which are made up of a group of pulses.

3 is a microcomputer, which calculates the average value,
It has functions such as setting the number of measurements and generating a start signal, and means 31 to 35 correspond to these functions, respectively.

101 is an input signal from the above relay circuit, and this signal 1
01 is designed to be human-powered at the one-man power end of Exclusive or Gate (hereinafter referred to as EX-OR Gate) 15. A polarity switching signal 111 is supplied to the other input terminal of this EX-OR gate 15. This polarity switching signal 111 has two values, "H" (high level) and "'L" (low level), and the level of the input signal 101 is switched by the level of the polarity switching signal 110 at the EX OR gate 15. It has become.

Here, the subsequent signal processing circuit is basically configured to measure the pulse signal a1 on the rising side of the main pulse M, and therefore, when the pulse signal al in the input signal 101 is measured. , the polarity switching signal 110 is set to "L" so that the input signal 101 is output from the EX OR gate 15 with its polarity unchanged, and when the pulse signal a2 is to be measured, the polarity switching signal 110 is set to "H". ”, the input signal 101 is inverted and E
The signal is outputted from the X-OR gate 15. As an example, in the case of FIG. 2, the pulse signal a2 is the signal to be measured s1, and the pulse signal a1 is the signal not to be measured n. Therefore, in this example, the signal width t of the pulse signal a2 is
x2 is measured as the signal width tX of the measurement object 1; S.

The AND gate 9 allows the input signal 101 to pass only when the gate signal 110 is "H", and 102 is the output signal of the AND gate 9.

A clock oscillator 4 generates a high-precision reference clock signal 50 having a frequency sufficiently higher than the pulse repetition frequency of the burst signal that is the signal under test 102 .

1 is a one-shot counter, 12 is a flip-flop,
7 is the or gate.

The one-shot counter 1 is triggered by the rising edge of the signal 102 (that is, the falling edge of the human input signal 101), and counts the clock pulses of the reference clock signal 50 by a set number.
", and outputs "H" outside the counting operation time.

The count time set by this count 1 value is set longer than one period of the pulse signals at and a2.

Therefore, this one-shot counter 1 is triggered at the rising edge of the first pulse of the signals n and s in the signal 102, and is triggered by the falling edge of the subsequent pulse before the output signal 104 rises, so that the one-shot counter 1 is After being triggered by the rising edge of , the output signal is held at "L" until time tw has elapsed. As a result, the one-shot counter 1 generates a one-shot pulse pl triggered by the signal S to be measured and a one-shot pulse p2 triggered by the signal n not to be measured.

The flip-flop 12 has its data input terminals connected to voltage and T.
I! It is held at "H@" by the voltage VCC, the signal 102 is input to the same clock input terminal, and the signal 104 is inverted input to the reset input terminal.This flip-flop 12 operates when the signal 104 is "H". It is turned on by the rise of the signal 102, its output becomes "L", and is reset by the fall of the signal 104.

Therefore, this flip-flop 12 receives pulse signals al,
When the first pulse of a2 rises, its output becomes “H”
The output becomes "L" when the one-shot pulses pi and p2 fall.

The output signal 112104 of the flip-flop 12 and the one-shot counter 1 is inverted and inputted to the OR gate 7, and the OR gate 7 calculates the logical sum of these signals. Therefore, this OR gate 7 receives the signal 1
12.104 is "L", that is, the period from the first rise of the non-measurement signal n and the measurement object signal S to the rise of the one-shot pulses pi, p2 is "H".
” is output.

Reference numeral 13 denotes a flip-flop serving as means for detecting the period of existence of the signal to be measured; the output signal 102 of the AND gate 9 is inputted to the data input terminal 13 via the inverter 8;
The output signal 104 of the one-shot counter 1 is input to the clock input terminal, and the inverted start signal 107 is input to the reset terminal. This flip-flop 13 is designed to generate the level of the output signal 103 of the inverter 8 at the output terminal at the rising edge of the one-shot pulse pi, p2 when the start signal 107 is "H". As a result, the period between the rise of the one-shot pulse p2 and the rise of the one-shot pulse p1 that occurs immediately after that, that is, the measurement object existence period tS is “H”.
” is output.

Moreover, "H" is output during the period between the rise of the one-shot pulse pl and the rise of the one-shot pulse p2 generated immediately after that, ie, during the non-measurement object existing period tn.

Here, the start signal 107 is transmitted to the measurement mode generating means 32 and the measurement mode holding means 3 of the microcomputer 3.
3.

Here, the start signal 107 is transmitted to the measurement mode generating means 32 and the measurement mode holding means 3 of the microcomputer 3.
3.

The determination mode generating means 32 generates a measurement mode signal when a measurement task name is issued through a console (not shown). The measurement mode holding stage 33 latches this measurement mode signal and raises its output, and the output of the measurement mode holding stage 33 is used as a start signal 107.

10 is an AND gate for gating the reference clock signal 50, and this AND gate 10 allows the reference clock signal 50 to pass when both the output signal 105 of the flip-flop 13 and the output signal of the OR gate 7 are "H". It looks like this. Therefore, from this AND gate 10, the one-shot pulse p during the measurement object existence period ts
The clock signal 50 is output only during the generation period t.

2 is a time width counter. The time sail counter 2 counts the output signal 106 from the AND gate 10, thereby accumulating a count value corresponding to the period tx+tv.

5 is a number counter, which counts the number of times the measurement object existence period ts appears by counting the rising edge of the output of the flip-flop 13, and the count value corresponds to the number of counting operations of the time counter 2;
When the count value reaches the set value, carry signal 108
Set to “H”.

This number setting to the number counter 5 is performed by the number setting means 33 of the microcomputer 3.

14 is a flip-flop for control at the end of measurement, and its data input terminal receives the carry signal 1 of the number counter 5.
08 is manually input, the output signal 104 of the one-shot counter 1 is input to the clock input terminal, and the start signal 107 is input to the reset terminal. This flip-flop 14 turns on at the first rise of the signal 104 (output of the one-shot counter 1) after the carry signal 108 from the number counter 14 becomes 'H'.
The output signal 109 is set to “H”, and the output signal 110 is set to “H”.
The output signal 110 is given as a gate signal to an AND gate 91, and the output signal 109 is
-1 This is given to the microcomputer 3 as a notification of the end of a regular operation.

The end confirmation means 34 of the microcomputer 3 resets the measurement mode holding means 33 in response to the rise of the output signal 109 of the flip-flop 14, and also issues an operation command to the calculation means 35.

The calculation means 35 reads the count value of the time width counter 2 in response to the calculation command from the completion confirmation means 34, and calculates the average value of the signal width tx of the signal S to be measured.

Here, the average value of the signal width tx is Ay(tx), the cumulative ripple of the signal width tx corresponding to the count value from the time width counter 2 is Σ(tx), and the set value from the number setting 1,000 steps 31 is n. At this time, the calculation means 35 performs the calculation expressed by the following equation.

That is, Av(tx)-(Σ(tx)/n)-tv.

The calculation means 35 supplies the value obtained by this calculation to an output device such as a monitor or a printer to display the value,
Alternatively, the average value obtained is supplied to a means for determining whether or not it is a desired value, and is caused to make the determination.

Next, the operation of the apparatus of this embodiment configured as described above will be explained.

First, in the initial state, star} (J number 107 is "L"
At this time, the flip-flop 14 is reset, and its output signal 110 is at "H".

Therefore, AND gate 9 is open and input signal 10
1 passes through the AND gate 9 and is supplied to the flip-flop 12 and the one-sit counter 1. Therefore, Fig. 2 (A). (B). As shown in (C), a flip-flop 12 and a one-shot counter 1
responds to the non-measurement signal n and the measurement object signal S, and the OR gate 7 generates an OR output of their inverted signals.

Therefore, the rise of the output signal 104 of the one-digit counter 1 also acts on the flip-flop 13, but since the start signal 107 is "L" and turn-on is prohibited, its output remains "L". It becomes. Therefore, AND gate 10 is closed and time counter 2
Since the clock signal 50 is not supplied to the time counter 2, the time counter 2 does not perform a counting operation.

Then, when the start signal 107 becomes "H", the time counter 2 and the number counter 5 are initialized, and the reset of the flip-flop 13 is released, and after this release, as shown in FIGS. It repeats on and off in response to the rise of the one-shot pulses pi and p2.

As a result, as shown in Figure 2 (G), (tx ten tv)
The clock signal 50 is supplied from the AND gate 10 to the time counter 2 for a period of , and the rise of the signal 105 is counted by the number counter 5. The operations of the time counter 2 and the number counter 5 are performed every time the signal S to be measured is input, and the time counter 2 accumulates (tx + tv) by the number of inputs, and the number counter 5 accumulates (tx + tv) for the number of inputs. The number of times will be counted.

When the count value in the number of times counter 5 reaches the set value and the carry signal 10g becomes "H", it waits for the output signal 104 of the one-shot counter 1 to rise, that is, the end of the counting operation of the time counter 2 for that time. After a while, the flip-flop 14 is turned on. Then, the end confirmation means 34 of the microcomputer 3 learns of the end of the measurement, resets the measurement mode holding means 32, lowers the start signal 107, and issues an operation command to the calculation means 35. The average IAv(tx) will be calculated as follows.

As described above, when the microcomputer 3 raises the start signal 107 once, the data for calculating the average value is automatically collected by the external circuit, and the microcomputer 3 issues the completion notification signal 109 at the end of the process. All you have to do is perform a predetermined calculation in response to and find the average value.
There is no need for the microcomputer 3 to perform processing such as raising a start signal, confirming the end of measurement, reading data, and accumulating data every time a measurement value for one measurement target signal S is obtained. The burden is greatly reduced, and the idle time from the start of the star 1 signal 107 to the end of the measurement operation can be used effectively.

Here, in this embodiment, the measurement object existence period ts is detected, and the one-shot pulse pt generated within that period is
Since we count the time width of
It is possible to obtain cumulative data that does not include the time width txt of the non-measurement target signal n, but includes only the time width of the measurement target signal, and therefore the required number is accurate.

Furthermore, although the above explanation describes the case of calculating the average value, in the device of this embodiment, if the number set in the number setting means 33 is set to "1", the calculation means 35 performs the above calculation. However, it is also possible to obtain a signal width measurement value of a single signal S to be measured instead of an average value.

In the above device, the polarity switching signal 111 is
If you set it to L#, in the signal processing system after AND gate 9,
This pulse signal al becomes the measurement target signal S, the other pulse signal a2 is set as the non-measurement target signal n, and the average value of the time width tX1 of the pulse signal al is determined.

〔Effect of the invention〕

As explained above, according to the present invention, a period in which only a signal to be measured exists without any non-measured signal in the signal under test is detected, and the time width of one-shot pulses generated within that period is counted. Therefore, by counting, it is possible to obtain cumulative data that does not include the time width of the signal not to be measured, but only the special width of the signal to be measured. Even when one of the incidental pulse signals is to be measured and the other is not to be measured, the average value of the signal width can be accurately determined without requiring multiple measurements.

DESCRIPTION OF SYMBOLS 1... One shot counter, 2... Time counter, 3... Microcomputer, 31... Measurement mode generation means, 32... Measurement mode holding means, 33...
- Number of times setting means, 34... Measurement completion confirmation means, 35.
... Average value calculation means, 4 ... Reference clock oscillator, 5
. . . Number of times counter, 10 . . . AND gate for reference clock gate, 13 . Exclusive or gate for M...main pulse %al, a2.
...Additional pulse signal, S...Measurement target signal, n...
Δ-1 constant non-target signal, pl. p2: one-shot pulse, ts: measurement target existence period, tn: non-measurement target existence period.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a signal width measuring device according to an embodiment of the present invention, and FIG. 2 is an operation timing chart thereof.

Claims (1)

[Scope of Claims] In a signal under test that has ancillary pulse signals that are present on each side of the rising and falling sides of the main pulse, one of the incidental pulse signals on each of the rising and falling sides is used as the signal to be measured. A signal width measuring device that measures the signal width of only the signal to be measured, with the other being a signal not to be measured, the operating time width being determined by the counting operation time when counting a set number of reference clock signals. , a retriggerable one-shot pulse generating means that generates a one-shot pulse by being triggered by a pulse of the auxiliary pulse signal, and a retriggerable one-shot pulse generating means that captures the level of the signal under test at the rising or falling edge of the one-shot pulse. By determining the period of existence of the rising edge and the period of existence of the falling edge of the main pulse, the period of existence of the measurement object in which only the signal to be measured exists without the non-measurement signal is detected, and its presence is detected. Existence period detection means for outputting a period detection signal; Time counting means for performing a counting operation only during the generation of the one-shot pulse in the measurement object existence period based on the existence period detection signal and accumulating the count value; Completion notifying means for generating a measurement end signal when the count value of the counting means reaches a scheduled number of appearances in the measurement object existing period; and in response to the measurement end signal, the count value of the time counting means is A signal width measuring device comprising: average value calculation means for calculating the average value of the signal width by performing an average value calculation on the read signal.