DD265746A1 - METHOD FOR EVALUATING PULSE GROUPS - Google Patents

Abstract

The invention relates to a method for evaluating pulse groups, in particular pulse groups of pulses with random pulse repetition frequencies. According to the invention, the pulses of each of the pulse groups are counted asynchronously without prior limitation of the maximum frequency in a single counting stage. figure

Description

Field of application of the invention

The invention serves for the activation of pulse groups, in particular pulse groups with statistically distributed pulse repetition frequencies, such as those provided by secondary electron multipliers, for which the ratio of the number of pulses of at least two pulse trains is to be determined. For a comparison of the pulse groups, the individual pulses jeo.> R impulse group are paid.

Characteristics of the known state of the art It is known to count pulse sequences by means of suitable payer and with suitable facilities such as arithmetic units or

similar to the Impulszahlverhlltnis form. Usually payers are used whose maximum Zählfroquenz is greater than or equal to the highest frequency to be paid. (Kühn / Schmied TTL manual; Hetze / Schenk

Halbleiterschaltungetechnik). If, in the application, the pulse frequency is higher than the maximum counting frequency of the counting arrangement, then either occurs

different size error si <f or it is with an increase in the cost of a counter with a correspondingly high

Counting frequency to use. For the intended application cSsr counter in an arrangement for automatic adjustment of at least one Item according to WP 158824 (G 02 B21 / 18) is due to different ZAhKeIr ¹ ^ ₁ error in comparing the Pulse numbers too big. When limiting the maximum frequency by low-pass pulses, single pulses with a pulse repetition frequency in the range

This maximum frequency is not detected with certainty in each pulse group, so that errors in the absolute values are different. Counter with extremely consistent counting rates / to realize or highly accurate to the respective

As well as a counting device in the gigahertz range with one

economically unreasonable effort connected.

Object of the invention

Aim of the invention is the improvement of the reproducible accuracy of the pulse group evaluation as well as the reduction of the technical and economic expenditures ».

Explanation of the essence of the invention

The invention is based on the object of detecting and evaluating as many pulses of the pulse group as possible with little evaluation effort, the pulses, in particular in critical ranges of the maximum evaluation frequency, having the same influence on the absolute value of the count result to be provided for the pulse group comparison in all pulse group cycles should own.

According to the invention, this object is achieved in a method for evaluating pulse groups, in particular pulse groups of pulses with statistically distributed pulse repetition frequencies, wherein for the comparison of the pulse groups in each case the pulses of each pulse group werdon, achieved in that the pulses of each pulse groups uhne previous limitation dnr maximum frequency be counted asynchronously in a single counting stage. According to the invention, a single asynchronous counter is used which, as has been shown, initially realizes a low-pass behavior. The pulses of all pulse groups are detected in this counting stage, wubel the maximum frequency In each pulse train is determined by the always the same limit frequency of the asynchronous counting. At the same time it is ensured that all pulses are evaluated at a pulse repetition frequency at this Grenzfraquenz of the counting process in each pulse group, so that as many individual pulses of each pulse group are taken into account for the determination of the result for a given accuracy. The counting processes of the prior art are based on obtaining a lowest possible absolute value for each counting operation of an arbitrary pulse group. Nevertheless, the relative deviations of the absolute values are too high for each impulse group acquisition. In contrast, the invention is not based on the absolute errors of the individual counting operations, but it is independent of the individual absolute amounts of the evaluation of each pulse group created equal conditions for all counts, so that t'otz absolute error, the relative error deviation for all counts is extremely low , This method allows a very accurate ratio formation

pulses of the pulse groups to be evaluated, wherein the individual pulse has the same influence on the absolute value of the result formation due to its pulse train sequence in each pulse group. This effect is achieved in a surprisingly simple manner, without complex frequency-dependent counter or filter can be realized.

exemplary The inventive method will hereinafter with reference to an embodiment shown in the drawing Schaltungsanordnunn v \ t Evaluation of pulse groups of pulses with statistically distributed Impulsfolgefrequenxen be explained in more detail. At an input E1 are the output pulses of Überslchtsgründen not shown in the drawing Secondary electron multiplier (with amplifier and pulse shaper), on the light passing by cyclically Measuring window of an arrangement gomaß WP158824 falls. The input E1 is via a gate 1 with the counter input one

Asynchronous counter 2 in connection, in which the incoming pulses of the photomultiplier are counted.

An input E 2 dia information about the beginning and end of two measurement windows are fed, d. H. Start · and Stoppin ipulse of two pulse trains. With the beginning of the first pulse train, the gate 1 is opened via a control unit 3. The asynchronous counter 2 counts the pulses on Input E1, if they are below oelner cutoff frequency. If the pulse repetition frequency is higher, the respective Impuhe not detected and not included in the count. At the end of the first pulse sequence controlled by the control unit 3, the gate 1 is blocked and the count of the counter 2 in

a first output register 4 taken. The counter 2 can be preset to an initial value at this time.

With the beginning of the second pulse train in turn the gate 1 is opened via the control unit 3, so that the pulses at the input E1

are counted asynchronously with the same criteria of pulse detection as in the first pulse train in counter 2. At the end of the second pulse train controlled by the control unit 3, the gate 1 locked and the Z8I 'result of the counter 2 in order

Itnpirisgruppeiiauswertung transferred to a Ausgangeregister 5. Zweck'näßigerweise are then reset by the control unit 3, the counter 2 and a not shown Evaluation reported the presence of two related pulse group count results. Thereafter, a new counting cycle may begin in the operated manner.

Claims (1)

Method for evaluating pulse groups, in particular pulse groups of pulses with randomly distributed pulse repetition frequencies, the pulses of each pulse group being counted for comparison of the pulse groups, characterized in that the pulses of each pulse group are counted asynchronously without prior limitation of the maximum frequency in a single counting stage become. For this 1 page drawing