SU1499288A1 - Logic optical tester - Google Patents

Abstract

The invention relates to instrumentation technology and can be used in the setup, maintenance and operation of fiber-optic paths for receiving and transmitting information. The purpose of the invention, the enhancement of functionality, is achieved by measuring the dynamic characteristics. The logical optical tester contains an optoelectronic converter 1, a switching unit 2, a peak value extracting unit 3.5, a level-binding unit 4, an indication unit 7, a square pulse generator 8, a correction unit 9, a driver 10, a voltage source 11, a block 12 comparison, the electron-optical converter 13 and allows to control in the dynamic mode the maximum and minimum permissible powers of the optical signal at the input of the fiber-optic receiver, at which no logical switching of the signal occurs. drove at the electrical output, the maximum allowable optical signal power at the input of the fiber optic receiver, which ensures reliable switching of the logical signal at the output of the fiber optic receiver, optical power at the output of the fiber optic transmitter, corresponding to the logical "1" state and logical "0". 5 il.

Description

14y

The invention relates to instrumentation technology and can be used in the setup, maintenance and operation of fiber-optic paths for receiving and transmitting information.

The purpose of the invention is the expansion of functional capabilities due to the possibility of measuring dynamic characteristics.

Figure 1 shows the block diagram of the logical optical tester; FIG. 2a, b are timing diagrams with

and

measuring the logical levels of a fiber optic transmitter; figa, b - time diagrams of signals when determining the maximum allowable optical signal power at the input of a fiber-optic receiver, corresponding to logical at .4a, b - time diagrams of signals when determining the minimum allowable power of an optical signal at the input of a fiber-optic receiver corresponding to the logic in fig. 5a, b are the time diagrams of the signals when determining the maximum permissible power of the optical signal at the input of the fiber-optic receiver corresponding to the logic Eco 1. Logical optical tester co. holds an optoelectronic converter 1 serving to convert a test sequence of optical signals from a fiber optic transmitter or line to an electrical one, the input of optoelectronic i converter 1 is the optical input of a logical optical tester, and the output is connected to the first input of the Z block switching, the output of block 2 is commuted and connected to the combined inputs of the first block 3 of the peak value, which serves to determine the level of logic 1, and block 4 of the binding level, which serves to reduce the logic level to zero potential and decrease by the same amount of logic level 1, the output of the second peak extracting unit 5, used to determine the amplitude of the pulses coming from the output of the level clamping unit 4, is connected to the first of the two inputs of the differential amplifier 6, the second input of which is connected to the output of the first unit 3

14929288

th g

five

0

0

five

five

0

the peak value, the output of the differential amplifier 6 is connected to the first input of the display unit 7, which serves to display the values of the measured and set values. A generator of 8 rectangular pulses, which is used to set the frequency of the test pulse train, is connected to the first bp of correction block 9, which serves to pass pulses of only one (positive) polarity, the second input of which is intended to connect an external oscillator, and the output is connected to the first the input of the generator 10, which serves to form at the output of the signal with predetermined (adjustable) values of the logic levels O and 1, the second and third inputs of the generator 10 are connected respectively to the first and second outputs of the source 11 reference; voltage, the third and fourth outputs of the source 11 of the reference voltage are connected to the combined inputs, respectively, the second and third, block 7 indykadii and perzoku and second -... the codes of unit 12 comparison "Third. Comparison unit 12 is considered to be an electrical electrical input of a logical op-ex tester and serves to connect an electrical output of the test fiber to its substitute 2C}: ng to it; The first and second outputs of the comparison unit 12 are connected respectively to the 4th and 5th inputs. indication glare 7, the 6th input of the indication unit 7 is connected to the output of the first block 3 of the peak value. The second output of the driver 10 is the electrical output of the optical logic tester, and the first output is connected to the combined second input of the switching unit 2 and the input of the electro-optical converter 3, which serves to convert the test sequence of electric pulses to the optical output of the optical optical converter 13 tester and serves to connect the optical input of the test fiber to it. equestrian receiver.

Logical optical tester works as follows.

The output of a monitored fiber optic transmitter is connected to the input of a logical optical tester, i.e. optoelectronic converter 1. An optical signal converted into an electrical signal is supplied through a switching unit 2, which has a mode switch and is in the optical signal measurement mode, to the input of the first peak value selection unit 3, where the value obtained from the optoelectronic converter is determined level of logical I; On figa 2a level of logical 1 is designated VI. To measure the magnitude of an optoelectric transducer. 1 logic level O signal from the output of switching unit 2 enters the level A supply block A, where the logic 1 and logical O levels decrease by an amount equal to the logic level O, C of the level 4 logic level signal goes to the second block 5 selection of the peak value. FIG. 26 its value is denoted as V2. In the Differential Amplifier, the signals received from blocks 3 and 5 of the peak measurement are mapped. The value of the VO level of the logical O, calculated as the difference between the values VI and V2, and the value VJ are fed to the display unit 7.

The generator 8 rectangular impulses sets the frequency of the test pulse sequence and delivers the generated signal to the correction unit 9, which passes pulses of only positive polarity. In order to extend the frequency range of the logical optical tester, it is possible to connect a foreign generator to the correction unit 9, and the correction unit 9 has a switch for switching the received signal either from the generator 8 rectangular

0

five

measurement of parameters of a given electrical signal. In the electro-optical converter 13, the signal is converted into a test sequence of optical pulses applied to the optical input of the fiber-optic receiver under test, from whose electrical output the test pulse sequence arrives at the input of the comparison unit 12 and, further, to the display unit. Fig. 3a shows an example of a timing diagram of a test sequence of optical pulses when determining the maximum allowable power of an optical signal at the input of a fiber optic receiver corresponding to a logical signal O. Lree. The power of the optical signal P1 is switched by switching the electrical signal at the input of a fiber optic receiver to logical 1. (Fig.36). Fig. 4a 5 shows an example of a timing diagram of a test sequence of optical pulses in determining the minimum permissible power of the optical signal at the input of a fiber-optic receiver corresponding to logic

0

0

five

0 g

cic signal i. When the optical signal is lowered below P2, the electrical signal at the output of the fiber-optic receiver switches to the logical value O (Fig. 46). FIG. 5a shows an example of a timing diagram of a test sequence of optical pulses. when determining the maximum allowable optical signal at the input of a fiber-optic receiver, at which it has not yet occurred. ditsya his naschenie. By increasing the power of the optical signal of the RE, the fiber-optic receiver goes into saturation state and stops switching. The electrical signal at its output all the time corresponds to the level of logic 1. When

a horse-optical transmitter, corresponding to the logic levels O and 1, the amplitude of the test sequence of pulses, or from an external generator g measuring the optical power of the hair, C of the correction unit 9, the signal goes to the formatter W, where the required amplitude of the signal is set.

 The pulses produced by the generator unit 10 remain constant and can be set in accordance with the characteristics of the logic devices used.

The test pulse train received in the shaper 10 is fed to the combined inputs of the electro-optical converter 13 and the switching unit 2, the mode switch of which is in the position

55

From block 10 shaper testov

equestrian transmitter, corresponding to the levels of logic O and 1, the amplitude of the test sequence measuring the optical power of the

55

From block 10 shaper testov

a sequence of pulses is fed to the electrical input of the fiber-optic transmitter under test, from the optical output of which the signal is fed to the optical input of the opto-electronic converter 1.

The logical optical tester allows you to dynamically determine the following parameters of fiber optic elements of receiving and transmitting discrete information: the maximum allowed optical signal power at the input of a fiber optic receiver, corresponding to a logical O at the fiber optic receiver output, at which the signal on the electrical output of the fiber-optic receiver to the state of the logical minimum allowable power of the optical signal at the fiber-optic input optical receiver corresponding to the logical

 M on the fiber optic receiver VOKOD, at which the signal at the electrical output of the fiber optic receiver does not switch to the state of the logical maximum allowable power of the 6ptic signal at the input of the fiber optic receiver, corresponding to logical 1 at the output of the fiber optic receiver, which ensures reliable switching at the output of the fiber-optic receiver from the logical 1 state to the logical optical power at the optical fiber output transmitter, corresponding to the state of logical 1 and logical O.

Claims (1)

In addition, the logical optical tester allows to obtain the dependence of the specified parameters of the optical-optical elements of the reception and transmission of discrete information from the clock frequency of the discrete signal, A logical optical tester containing an optoelectronic converter, a switching unit, an indication unit, a differential amplifier, a driver, the first output of which 15 - 20 25 35 m 30 -. Q th ь. 50 connected to the input of an electro-optical converter, the output of which is the optical output of a logical optical tester, is also distinguished by the fact that, in order to expand its functionality by measuring the dynamic characteristics, the first level block and the second peak value selection block are introduced , square pulse generator, correction unit, reference voltage source, comparison unit, the output of an optoelectronic converter, whose input is the optical input of a logical opt A cheche tester is connected to the first input of the switching unit, the output of which is connected to the input of the first block of the peak value selection and the input of the block of the level lock, the output of which is connected to the first input of the differential amplifier through the second input of the differential amplifier with the output of the first block of the peak value, and the output with the first input of the display unit, the first input of the correction unit is connected to the output of the square pulse generator, the second input is the connection input outside generator, and the output of the correction unit is connected to the first input of the generator, the second and third inputs of which are connected respectively to the first and second outputs of the source of reference voltages, the second input of the display unit is connected to the first input of the comparator and the third output of the source of reference voltages, the fourth the output of which is connected to the third input of the display unit and the second input of the comparison unit, the third output of which is the electrical input of the logic tester, the first and second outputs of the comparison unit are connected to Responsibly with the fourth and fifth inputs of the display unit, the sixth input of which is connected to the second input of the differential amplifier, the second output of the driver is the electrical output of the logical optical tester, the first output of the driver is connected to the second input of the switching unit. Vf v ( Y4 ; .. fci / - tf "f tfiJ 0tta4 Fig