JPH01241919A - Counter system - Google Patents

Abstract

PURPOSE:To attain measurement with high accuracy and simple means by using plural counters so as to count an asynchronous error at the start and end point of the count between a count period pulse and a pulse to be counted. CONSTITUTION:A time between a pulse P to be counted just before the arrival of a count period pulse (n) and the count period pulse (n) itself is converted into a clock pulse by a T counter 2 and a time between the count period pulse (n) and the pulse P to be counted coming just after the pulse (n) is converted into the clock pulse by a S counter 3 respectively, and the pulse to be counted arrived during the period of the count period pulse is counted by an N counter 1 and the count is calculated based on the value. Thus, the count value of the pulse subject to asynchronous error is converted by means of a simple means employing simply plural counters 1-3 and measurement with high accuracy is applied inexpensively and lightly.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a pulse signal counting method.

Conventional technology In the counting method in which the pulses to be counted are counted by a counter during the period of the counting period pulse, the occurrence of non-periodic errors at the counting start and end points of the counting period pulse and the opening of the counting period pulse is unavoidable. When the counter count value is small, this error becomes large enough to not be ignored.

For this reason, the problem that the invention attempts to solve is to make the period of the counting period pulse sufficiently large, or to count after multiplying the pulse to be counted. For measurement purposes, it may not be acceptable to do so, and to multiply the pulses to be counted, a multiplier circuit is required, and that circuit requires a counter with a large number of digits, making it complicated and expensive. is unavoidable.

The present invention provides a counting method that solves the above problem by a simple means using a plurality of counters.

Method for Solving Problems The present invention converts the time between the counted pulse immediately before the arrival of the counting period pulse and the counting period pulse, and the time between the counting period pulse and the counted pulse immediately thereafter into the number of clock pulses using a counter. At the same time as the conversion, the pulses to be counted that arrive during the period of the counting period pulse are counted by a separate counter, and the counted value NBj is calculated based on the following equation.

However, NL≧1 (1) where Ti-1: (counter count value Tj, which is the time between the th counting period pulse and the immediately preceding counted pulse converted into the number of clock pulses) + 1st counting period pulse and its Counter count value SL, which is the time between the immediately preceding counted pulses converted into the number of clock pulses: Counter count value SL, which is the time between the first counting cycle pulse and the immediately following counted pulse, which is converted into the number of clock pulses SL+1'', L Counter count value NL obtained by converting the time between the ``th counting period pulse and the pulse to be counted immediately after it into the number of clock pulses: Counter count value of the pulse to be counted included in the period of the counting period pulse or more is the counting period pulse Number of pulses to be counted N included in
When L is 1 or more, but when N is converted into the number of clock pulses by a counter, and the counting cycle pulses that arrive during the period of the pulse to be counted are counted by another counter, and the counted value N~ is calculated based on the following equation.

However, J≧1 (2) Here, Tj-1: Counter count value T obtained by converting the time between the /th pulse to be counted and the immediately preceding counting cycle pulse into the number of clock pulses, i: The 1,000th pulse to be counted Counter count value SL, which is the time between a pulse and the counting period pulse immediately before it, converted into the number of clock pulses: Counter count value S, which is the time between the first counted pulse and the immediately following counting period pulse, which is converted into the number of clock pulses. ! +l: Counter count value (N) obtained by converting the time between the 1+1st pulse to be counted and the counting period pulse immediately after it into the number of clock pulses (N): Counter count value of the counting period pulses included in the period of the pulse to be counted First, to explain the case where N is 1 or more, the counter calculates the number of pulses before and after the fifth arrival of the counting period pulse corresponding to the non-periodic portion of the pulse to be counted before and after it. ,: The count value SL I TL-1 is calculated, and based on the count value < Sc, / (SL+Tj
-l), a count value corresponding to the time lag between the count period pulse and the pulse to be counted immediately after it is obtained. At the same time, after the arrival of this th counting period pulse, j+1+1
Only the number of pulses to be counted, N, sent out during the arrival of the pulse with the number of pulses to be counted is counted by another counter, and by subtracting 1 from it, the number of pulses to be counted, N, which is sent out during the arrival of the pulse with the number of pulses to be counted, corresponds to the number of periods of the pulse to be counted, which is included in the pulse to be counted. Count values are obtained.

Also, before and after the arrival of the +1st counting period pulse, the counter calculates the count value 3L + l as in the 5th case.
, 7L is calculated, and based on the counted value (TL / (
TL+SL+1), a count value corresponding to the time lag between the L+lth counting period pulse and the immediately preceding counted pulse is obtained.

By calculating the sum of these, a count value corrected for the non-periodic portion of the count period pulse B, the +1st pulse, and the pulse to be measured can be obtained.

In addition, the count value T, S obtained before and after this j+1+1th number period pulse is the next ++1+1th εt
Calculation of the count value corresponding to the non-periodic portion at the starting point when calculating the count value between the first count cycle pulses, that is, Si+I/
(Sj +I + Tε), and thereafter, in the same manner as described above, a count value is calculated by continuously correcting the non-periodic error for each period of the counting period pulse.

Next, when NL is less than 1, the pulse to be counted is replaced with a counting period pulse, and the counting period pulse is replaced with a pulse to be counted, so that J and i+1 of the pulse to be counted are replaced.
Obtain the non-periodic portion of the counting period pulse for the th period in the same manner as above, and finally calculate the reciprocal value of the obtained result to calculate the number of pulses to be counted included in the period of the counting period pulse. It is a thing,
Its operation is similar to that described above except for the permutation and reciprocal operations described above.

Embodiment In FIG. 1 showing an embodiment configured with three counters and FIG. 2 showing its waveform explanatory diagram, 1.2.3 represents each count value NLITL-+ 1SL IN t described above.
+l HT LI SL1. . . . They are an N counter, a T counter, and an S counter, respectively. The pulses to be counted γ are introduced into the N counter 1, and the counting period pulse Y is applied as a control signal, so that the number N of pulses to be counted per period of the counting period pulse is determined.

The NiH, . A clock pulse C having a sufficiently higher frequency than the pulse to be counted 1 is introduced into the next T counter 2 and S counter 3, and the aforementioned pulse to be counted r1 and the counting period pulse R are introduced as a control signal. The clock pulse C is reset to zero each time a pulse to be counted arrives, and counting of the clock pulse C is started, and the counted value is stored in the storage section of the computing unit 4 when a counting period pulse arrives, thereby obtaining the counted value T.
ε-1+TL+... is calculated, and the S counter is set to zero when the counting period pulse arrives, starts counting clock pulses, and stores the counted value in the storage section of the computing unit 4 when the next pulse to be counted arrives. By doing so, the above count value S
L+Sc+1. ... is being calculated. Then, in the calculator 4, the calculation according to equation (1) is executed based on these counted values.

The above is for the case where the number of pulses to be counted included in the period of the counting period pulse is 1 or more, but as shown in Figure 3, when the number of pulses to be counted included in the period of the counting period pulse is less than 1. can be obtained by replacing the input terminals of the pulses to be counted and the counting period pulses in the one shown in FIG.

In addition, although the above example uses three counters,
The T counter and the S counter are shared, for example, Tj-1
After counting, it is sent to the arithmetic unit 4, and the open count value (Ti-+ 1S ()) until the arrival of the next pulse to be counted is calculated.
may be counted by the same counter, and the counted value may be sent to the calculator 4, and S( may be calculated from the difference between the values of both companies).

The effects of the invention are as described above, and the present invention converts pulse counts with non-periodic errors compensated for by simply using a plurality of counters, and enables high-precision measurement at low cost and easily. can be done.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIGS. 2 and 3 are waveform explanatory diagrams thereof. 1.2.3: Counter 4: Arithmetic unit

Claims (1)

[Scope of Claims] 1. Converting the time between the counted pulse immediately before the arrival of the counting period pulse and the counting period pulse and the time between the counting period pulse and the counting period pulse immediately after that into the number of clock pulses by a counter, A counting method N_R_i=(Si)/(Si+Ti_-_1)+Ni in which the pulses to be counted that arrive during the period of the counting period pulse are counted by a separate counter and the counted value N_R_i is calculated based on the following formula.
-1+(Ti)/(Ti+Si_+_1) where N_i
≧1 Here, Ti_-_1: Counter count value obtained by converting the time between the i-th counting period pulse and the immediately preceding counted pulse into the number of clock pulses Ti: Between the i-th counting period pulse and the immediately preceding counted pulse Counter count value Si, which is the time converted into the number of clock pulses: Counter count value Si, which is the time between the i-th counting period pulse and the immediately following counted pulse converted into the number of clock pulses._+_1: The i+1th counting period pulse and its Counter count value Ni obtained by converting the time between the pulses to be counted immediately after to the number of clock pulses: Counter count value 2 of the pulses to be counted included in the period of the pulse to be counted, the count period pulse immediately before the arrival of the pulse to be counted, and the number of clock pulses. A counter converts the time between the counted pulses and the time between the pulse to be counted and the immediately following counting period pulse into the number of clock pulses, and counts the counting period pulses that arrive during the period of the pulse to be counted by another counter, Counting method N_R_j=([S_j]/[S_i+T_j_-_1
]+N_j-1+[T_j]/[T_j+S_j_+_
1])^-^1 However, N_j≧1 Here, T_j_-_1: Counter count value obtained by converting the time between the j-th counted pulse and the immediately preceding counting cycle pulse into the number of clock pulses T_j: j+1st counted pulse Counter count value S_i, which is the time between a pulse and the immediately preceding counting period pulse converted into the number of clock pulses: Counter count value S_j_+_1, which is the time between the j-th counted pulse and the immediately following counting period pulse, which is converted into the number of clock pulses : Counter count value obtained by converting the time between the j+1st pulse to be counted and the immediately following counting period pulse into the number of clock pulses N_j: Counter count value of the counting period pulse included in the period of the pulse to be counted