SU1307440A1 - Range meter of sequentially counted time intervals - Google Patents

Abstract

The invention relates to instrumentation engineering and can be used in pulsed and computer engineering, industrial electronics for measuring time intervals in a wide range with increased accuracy. The aim of the invention is to improve the accuracy and speed and enhance the functionality due to the possibility of cyclic measurements. The device contains - a shaper 2 control pulses, a delay line 3 with p-taps, p-flip-flops 5.1-5.P memory, p-gels 4.1-4.P coincidence, selector 6 on a coarse scale. In order to achieve the set goal, the element OR 11, the code decoder 9, the precise reference scale selector 8, the write pulse shaper 10 are entered, new connections are formed. The shaper 10 write pulses contains a multi-input element OR. 1 3.p. f-ly, 2 ill. (L

Description

The invention relates to instrumentation engineering, in particular, to the measurement of time intervals, and can be used in pulsed and information technology, digital measuring devices and tracking systems, in signal analysis equipment, in general physics, in industrial electronics. for measuring time intervals over a wide range with increased accuracy.

The purpose of the invention is to improve the accuracy and speed and enhance the functionality due to the possibility of cyclic measurements.

Figure 1 shows the functional diagram of the meter; Fig. 2 shows time diagrams for explaining the operation of the time interval meter.

The meter contains an input bus 1, a driver 2 for control pulses, a delay line 3 with p-taps, p-elements 4,1-4. N coincident p-flip-flops 5.1-5. P memory, a selector 6 of the coarse reading scale, which can be executed on a two-input coincidence element, a rough count counter 7, an exact count scale selector 8 that can be implemented on the inverter, a decoder 9 of a code whose cells from the first to the n-th inclusive can be executed on a two-input coincidence element, driver 10 pulse write, performed on many ovom OR element, an OR 1.

In FIG. 2, there are indicated: 12 — measurable (modulating) temporal inter

shafts lasting f, and

- ism

 t

,,, /

H

with the measurement period where to is the division value of the coarse reading scale (in particular, taken as a unit of the epurea scale); 13 - borderline plot from N-ro to (# -1) -th division of the coarse reading scale, in particular, coinciding simultaneously with the pulses t aw aw. and tu ,, in mas45

50

Shaper 2 control input. The pulses are connected to the input bus 1, the pins of the pins 3 delays with the taps are connected to the first inputs of the corresponding elements 4.1–4, match 3) their moves are connected to the S-inputs of the corresponding triggers 5.1–5 memory, direct output The nth memory trigger is connected. the first input of the mudflow: torus 6 of the coarse counting scale, the output of which is connected to the counting input of the counter 7 of the coarse counting, the input bus 1 is connected to the input of the selector 8 and the exact counters and the combined R-inputs of the n-flip-flops .5 ,. -5 .p memory, direct outputs of which from to 5. (n-1) are connected to the first inputs of the corresponding cells of the decoder 9 code, the direct output of the trigger 5, (n-1) is also connected to the first input of the n Whose ", the headquarters of the division price of a unit of exact

reference 14 - the scale of the exact reference with the price division tg / n, where n is the number of taps of the delay line; 15 is a graph of the distribution function of the absolute from the coder of the 9 coz decoder, the inverse errors At-from the discrete outputs of the flip-flops 5.2-5, n are connected once a single output path of the ut section to the second inputs of the decoder cells using the classical sequential method: first in ( n-1), and the inverse output counting a in the known measuring device 5.p of the memory is connected,

5 o

five

five

0

tal x, for example, with rounding off the fractional readings of the reference to the real integer by fault, inverted for consistency; 6 is a normal distribution curve for adjacent quantization intervals at the center of which is the expectation point; 17 is the shifted scale of the exact reading of the gauge, which coincides with the points of expectation of a continuous random magnitude in a given area; I8 is a plot of the absolute error distribution function ut, from sampling of a single measurement of a plot for the case of using the rule of correct rounding of the measurement error of the fractional part of the actual decimal number in the meter, inverted for consistency; 19 - the pulse at the output of the selector 8 of the scale of the exact reference; 20 - pulses at the outputs of the corresponding elements 4.1-4. An coincidence; 2 - pulses of the inverse single parallel code of the memory triggers 5 at the time of the end of the measurement; 22 - pulse signal Record at the output of the imager 10 | 23 is the measurement result recorded by the coarse count counter 7; 24 is the output signal of the decoder 9 code

Shaper 2 control input. pulses are connected to the input bus 1, the pint lines 3 delays with taps are connected to the first inputs of the corresponding elements 4.1–4, n matches 3 c) whose strokes are connected to the S inputs of the corresponding triggers 5.1–5 of memory, direct output n th memory trigger is connected. the first input of the mudflow: torus 6 of the coarse reading scale, the output of which is connected to the counting input of counter 7 of coarse reading, the input bus 1 is connected to the input of the selector 8, the exact reading counters and the combined R inputs of the n-flip-flops .5 ,. -5 .p memory, direct outputs of which from to 5. (n-1) are connected to the first inputs of the corresponding. 9 decoder cells, direct trigger output 5, (p-1) is also connected to the first input of the 5th circuit of the 9 kotz decoder, inverted outputs of trigger numbers 5.2-5, n are connected to the second inputs of the decoder cells first to ( p-1), and the inverse output of the memory tripper 5.p is connected,

Moreover, with the second input of the 5th cell of the decoder code 9, the outputs of which are precision output buses and connected to the inputs of the drive 10 write pulse, the output of which is connected to the output write bus, the output of the coarse scale selector 6 is connected to the first element input OR 11, the second input of which is connected to the output of the generator 2 of control pulses and the installation input of the counter 7 of a rough countdown, and the output to the input of the delay line 3, the output of which is connected to the second input of the coarse selector 6, and the output of the selector 8 of the exact reading scale is connected to the second combined inputs of elements 4.1-4. Matching.

The meter works as follows.

The leading edge of the measured input pulse enters through the shaper 2 to the input of the line 3 delays with taps, during movement in which it consistently forms at the outputs of the graduation scale of the exact counting Total Total delay of t of line 3 at the last tap corresponds to the coarse count unit.

After time t, the leading edge of the measured pulse arrives at the selector 6 of the coarse.calcuit scale 6, opened at the second input by a high potential from the direct output of the nth trigger, if the measured duration is longer than the duration t, that is, the result from the output the selector 6, the pulse will go to the counting input of the counter 7 of the coarse readout and through the element OR 11 to the input of the delay line 3, in which it repeats the path of the preceding, but already completed, input pulse.

The presence of a single potential pulse of a measured duration at the second input of the selector 6 supports the circulation of a coarse unit in the delay line 3, thus forming continuously accurate and coarse scales on the corresponding trigger outputs, which are synchronized

The leading edge of the input pulse is wired. These pulses transfer the ratio of the measured duration at the output of the driver 2 control pulses. Moving pulses from the taps j of the delay line 3 through the corresponding elements 4.1-4. The coincidence on the S-inputs of the trigger 5.1-5. The terminal does not pass, therefore it is not taken into account when measuring time intervals commensurate with or exceeding the duration of the coarse reference unit. as all the combined inputs of elements 4.1-4. The coincidence elements are under the zero (low) potential of the selector 8 of the exact reference scale performed on the inverter.

The selector 8 at the same time plays the function of a temporary gate for accurate counting pulses in a short interval of time.

The capacity of the measured time interval is determined by the expression

(- N. - im

+ it

d)

1 regde N - the number of counting pulses, which are counted by counter 7;

t is the division price of the coarse reading scale;

ut is the absolute error of the rough measurement or the fractional part of the measurement result, which is measured using an accurate reference scale.

By a single level of the measured pulse, all the triggers are transferred to the single state, which corresponds to the preliminary parallel recording of the redundant array of information into the triggers 5.1–5.p. In this case, the information in the negative (reverse) code is considered reliable, in particular, from the inverse outputs of the 5.1-5.5 memory triggers. At all inputs of the code decoder 9, the low (zero) level is not formed, so the digit of the exact reference is not formed, the level of the recording signal at the output of the imaging unit 10 will be zero (low), i.e. the recording signal will not be generated.

After the input pulse of the measured duration is terminated by a single (high) potential from the output of the selector 8 of the exact reading scale, the coincidence elements are opened, the second inputs of which are successively fed the last pulse of the coarse reading scale, the corresponding elements of the coincidence pass the precise counting pulses to the R inputs of the same trigger 5 .

corresponding triggers to the zero state, i.e. will erase the pre-recorded in-ing information.

For a moving pulse from the last retraction of the delay line 3, the passage of a rough count to counter 7 is prohibited by a zero potential at the forward output of the nth trigger 5.p.

From this moment on, the mode of measuring intervals of small duration or fractional part of the measurement result At the exact reference point begins. In this case, the counter / stops and its last pulse forms the extreme division of the coarse scale. If the moment of the end of the measured pulse coincides with the moment of time, when the last pulse of counter 7 of the rough count (or the end of the pulse if t is in the g-th section, then its further movement will cause the appearance and fixation of the pulses on the t on the nth line 3 delays,

In order to reduce the dimensionality of the absolute error of single-sample discretization — twice to iO, 5 units of reference, the proposed meter uses the rule of rounding the fractional part of At in the uncertainty interval, using half-rounds at the same time within all consecutive reading intervals. The graphs of the distribution of the absolute error of discretization of a single measurement for such a rounding are presented in the plot of Fig. 2.8. The transfer of the index O or the approximation of successive reading indexes of the scale to the beginning of the measurement allows the circuit to implement the mathematical rule of correct rounding of the fractional part of the decimal number, i.e. allows to use the rounding error of a single measurement, using the equality of the direct count,;

ut mxt./n

(2)

For this, in the meter, the signal delay from the first tap of the delay line 3 is tp / 2n, the signals from the other tapes are shifted by

tp / n, which makes it possible to optimally use a mathematical rule in relation to rounding off the systematic error of the meter.

For example, if the end of the measured pulse falls on the segment between the tm and (t + 1) -m taps, then

50

shortening the first reading interval to t (, / 2.n, which is equivalent to approaching the start of measurement of all outputs of the shifted scale, the end of the measured time interval will be artificially automatically transferred to the (pN-1) -th section (Figs. 2, 7) .

This causes the appearance of moving pulses of an offset scale.

Exact reading on the outputs from (t + 1) -th to the nth inclusive. In the triggers, the presence of a pulse at the taps from the first to the t-th will be detected, and the following will change the information, which slows down the duration of the real measurement cycle to the adjacent (N + l) -ro coarse-reading pulse. At the same time, with (N + l) -ro pulse in the meter, the value measured in series with a coarse and precise scale is recorded; the real value of the input time interval is equal to

0

Shh N-t ,, (3)

with a finite absolute error of discreteness not more than ± 0.5 units of exact count.

When decoding, displaying and reading the measurement result recorded by the 5.1-5-5 triggers in a parallel unit code, Katf will require some kind of finite time in the (N + 2) -ro interval of the coarse count,

therefore, in the cyclic measurement mode, following the first measurement. impulse tj, will be skipped. .

To increase the measurement speed,.

those. to obtain the measurement result, without waiting for the end of the movement of the precision counting pulse to the end of the delay line 3, the state of the triggers 5.1-5 is decoded in the meter using the decoder 9. Using the decoder 9 allows instantaneous transition from parallel code to serial In this case, an individual decimal digit of the consecutive exact counting in the fractional part btj was determined uniquely and rapidly, without waiting for the end of the movement in line 3.

The cells of the decoder 9 are made on a two-input coincidence element 4. The inputs of the first to (n-1) -th cells are connected to the forward output of the corresponding trigger 5.1-: 5 "(n-1) and, accordingly, to the inverse output of the adjacent trigger followed by the number , and for the pth cell, the inputs are connected to the inverse output of the nth trigger and the forward output (n-1) of the first trigger, the combined S-inputs of the trigger 5.1-5.p are connected to the input bus of the meter. The outputs of the decoder 9 are connected to the corresponding inputs of the pulse signal generator 10 Record, which can be used for automatic processing of information from the memory trigger outputs by internal circuits of the interfaced computer or for its census into the digital tracking system.

Claims (2)

1. A band meter for sequential counting, containing a driver of control pulses, the input of which is connected to the input bus of the meter, a delay line with p-taps and a total delay time t, and the delay between signals from neighboring taps is tg / n, line taps the delays are connected to the first inputs of the corresponding n-elements of coincidence, the outputs of which are connected to the S-inputs of the corresponding memory triggers, the direct output of the fiveth memory trigger is connected to the coarse-scale selector, the output cat The ogo is connected to the counting input of a coarse count counter, the output of which is a coarse count output bus meter, characterized in that, in order to improve accuracy and speed and enhance functionality, an OR or code decoder is introduced into it. an exact reading scale selector and a write pulse shaper, the meter input bus is connected to the precision reference scale selector input and to the combined R-inputs of memory triggers, the first outputs of memory triggers from the first through (n-1) -th connection ; us to the first inputs of the corresponding cells of the code decoders, and direct the output (p-1) of the memory trigger is also connected to the first input of the pth cell of the code decoder; the inverse outputs of the memory trigger, starting from the second to the pth, are connected to the second the inputs of the code decoder code with numbers one less than that of memory triggers, and the inverse output of the n-th memory trigger is connected, in addition, with the second input of the n-th cell code decoder whose outputs are precision output buses and connected to the inputs of the write pulse generator, the output of which is connected to the output write bus, the output of the coarse count selector switch to the first input of the OR element, the second input of which is connected to the output of the control driver pulses and setup the input of the coarse count counter, and the output to the input of the delay line, the output of which is connected to the second input of the coarse count selector, and the output of the precision count selector connected to the second combined inputs. Dami all items match. 2. The meter according to claim 1, characterized in that the recording pulse generator contains a multi-input element OR, whose inputs are connected to the input of the imaging unit, and the output - with the output of the recording pulse formatizer. Fi $. Z Compiler L.Pletneva Editor N.Kishtulinets Tehred I.Popovich Proofreader A.Obruchar j ,, | c-, -, -, 1-1 - 1, l ,, UJ LL -IrTn.nWT. I--.-. - --.-. - - -. . - - - - Order, 1630/48 Circulation 371 Subscription VNIIPI USSR State Committee for inventions and discoveries. I3035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, Projecto st., 4