SU798893A1 - Function generator - Google Patents

Description

(54) FUNCTIONAL GENERATOR

one

The invention relates to automation and computing and can be used, in particular, to form analog control signals in process control systems.

A function generator is known comprising an iltulse generator, a shift register, a reversible counter, a memory unit, a code comparison unit, a reversing distributor, a decoder, a trigger, an AND element and a code-analogue converter 1.

The lack of a generator is reduced reliability and a limited class of reproducible functions.

A function generator is also known, comprising a pulse generator, a control and synchronization unit, a multiplier, a controlled frequency amplifier, counters, a memory block, a reversible counter, a code comparison unit, and a code-analog converter 2.

The disadvantage of this generator is reduced reliability and complexity of the constructive implementation.

The closest to the proposed is a functional generator.

containing a pulse generator, a counter connected by a code output to an input of a memory unit connected by a first output to a first input of a subtractor connected by an output of a difference sign to a sign input of a reversible counter whose counter input is connected to an output of a controlled frequency divider, and a code output 0 s the second input of the subtraction unit and with the input of the output converter the code analog, the output of the zeroing of the subtraction unit connected to the input of the gating of the controlled divider

5 frequencies, the counting input of the counter and to the first input of the element I, connected by the second input with the output to the pulse generator, and the output - with. a counter input of a controlled frequency divider connected by a control input to the output of the code of the module of the difference of the subtraction unit e.

The disadvantage is reduced accuracy and a limited class of generated

5 functions.

The purpose of the invention is to improve the accuracy and expansion of the class of generated functions.

The goal is achieved by

0 that a functional trigger containing a pulse generator, a counter connected by a code output to an input of a blockhouse connected by a first output. The first input of a subtractor connected by an output of a difference sign to a sign input of a reversible counter whose counter input is connected to the output of a controlled frequency divider, and code output - with the second input of the subtraction unit and with the input of the output converter; code-analogue; a decoder and a multiplier, connected by the first input to the output of the pulse generator, are additionally introduced and the counting input of the counter, the setup input — which is connected to the second output of the memory unit, the input of the decoder and the control input of the controlled frequency divider connected by the counting input to the output of the multiplier, connected by the second input to the output of the module of the difference of the subtraction unit, the installation input and the installation control input of the reversible counter code are connected, respectively, to the first output of the memory unit and to the output of the decoder.

The drawing shows a block diagram of a function generator.

The functional generator contains a memory block 1 connected by the first output to the first input of subtractor 2 and to the installation input of the reversible counter 3. The second output of memory 1 is connected to the control input of the controlled frequency divider 4, the input of the decoder 5 and the installation input of the counter 6, which is connected by a code output to the input of memory block 1, and by a counting input to an output of a generator of 7 pulses and to a first input of a multiplier 8. A multiplier 8 is connected by a second input to an output of a code of a difference modulus module of a subtraction unit 2, and an output from an even input of a controlled splitter 4 frequency connected by an output to the counting input of a reversible counter 3, which is connected by a sign input to the output of the difference sign of the subtraction unit 2, a code setting control input — to the output of the decoder 5, and a code output — to the output of the output converter 9 analogue and with the second input of block 2 subtraction.

The functional generator implements the piecewise linear approximation method, where the device generates, at its output, linearly varying signals at each stretch of the approximation, the rate of change of which is directly proportional to the slope angles of the straight sections, replacing the corresponding portions of the curve to be approximated. The cells of block 1 store binary codes for the amplitudes P and the durations of the time intervals ti - ti for successive points of approximation of the generated function A (t). .

At the initial moment of time t of operation of the device, the counter b at its code output generates a signal for reading information from the first cell of the memory 1. By this signal, the binary amplitude code A from the first output of memory block 1 is fed to the first input of subtraction unit 2, to the second input of which at this time the amplitude code Ap equal to zero from the code output of the reversing counter 3 is fed. At the same time, the binary code of the time interval duration At from the second output of memory block 1 is fed to the control input of the divider 4 frequency, the installation input of the counter 6 and to the input of the decoder 5. The subtraction block 2 calculates the module and the sign of the difference, which determines the slope of the straight first segment, oh curve. The clock pulses from the output of the generator 7, the frequency of which can vary, are sent to the first input of multiplier 8, the output of which produces pulses whose number is directly proportional to A-code supplied to the second input of multiplier 8. The division factor of the divider 4 in the first section is proportional to t . Since the sign of the slope on the first segment is positive, the number, the binary code of which is contained in the reversible counter 3, increases by the magnitude of the amplitude increment A A over time l t.

To the moment of time t, the counting input of the counter 6 receives pulses from the generator 1, the number of which corresponds to the code of duration inter

0 shaft time d t

counter 6 will generate at its output a signal for reading information from the second cell of memory 1. This signal on the first and second outputs of memory block 1 generates codes of values A2 and t tj, which are fed to block 2 of subtraction and divisor 4, respectively. Block 2 subtracts A-Aj | A, -A, I and 1 on the slope for the second portion of the generated function. When the pulses from the generator 7 through the multiplier 8 and divider 4 to the counting input of the counter 3, the code of which increases by the value of d Ajj for the time d bji. Consequently, the value of the output signal of the converter 9 is code analog at time t (equal to Afj. By varying the frequency of the generator 7, it is possible to change the implementation time of function A (t) within wide limits.

If it is necessary to instantly change the altitude of the function A (t), for example, at the time t, the decoder is 5 according to the code bt-t, O, output from the third memory cell of the block

Claims (1)

Claim A functional generator containing a pulse generator, a counter connected by a code output to the input of a memory block connected by a first output to the first input of a subtraction block connected by a difference sign output to the sign input of a reversible counter, the counting input of which is connected to the output of a controlled frequency divider, and the code output - with the second input of the subtraction unit and with the input of the output converter, a code analog, characterized in that, in order to increase the accuracy and expand the class of generated functions, into the functional The decorator additionally introduces a decoder and a multiplier connected by the first input to the output of the pulse generator and to the counter input of the counter, the installation input of which is connected to the second output of the memory unit, the decoder input and with the upstream input of the controlled frequency divider connected by the counting input to the output of the multiplier connected to the second input with the output of the code of the module of the difference of the subtraction block, the installation input and the control input of the installation of the code of the reverse counter connected, respectively, to the first output of the block memory and to the output of the decoder.