RU41157U1 - MULTIFUNCTIONAL DIGITAL COMPUTING DEVICE FOR MEASURING AND GENERATION OF SIGNALS - Google Patents

Abstract

A multifunctional digital computing device for measuring and generating signals relates to measuring and computing equipment and can be used to measure the parameters of electrical circuits and study the spectral characteristics of signals. The device contains analog-to-digital converters of the input channels A and B of the oscilloscope, a synchronization block, digital-analog channels C and D of the generator, a synchronization block, a clock generator, a RAM block of the oscilloscope, a programmable logic matrix in which the RAM of the generator is implemented. Due to the use of the external memory of the oscilloscope, the memory capacity is increased, which allows you to store a large amount of data and perform complex functional transformations.

Description

The utility model relates to measuring and computing technology and can be used in oscillography to measure the parameters of electrical circuits and study the spectral characteristics of signals.

Known two-channel digital oscilloscope by ed. St. USSR No. 1705749, publication date 1/15/1992

A device is known according to the patent No. 3337 for a utility model "Multifunctional digital computing device for measuring and generating signals" OSCIGEN ", (priority date 06/20/2003, publication date 10/10/2003), which is taken as a prototype.

The device according to the utility model patent No. 3337 contains analog-to-digital converters of input channels, a programmable logic matrix, RAM, a synchronization unit, digital-to-analog converters, a clock generator, and a personal computer with a standard interface.

The disadvantage of the prototype device is its lack of speed for some special tasks of signal processing.

The objective of the utility model is to conduct complex measurements of electrical signals in a wide frequency range and study the characteristics of electrical circuits. The problem is solved by creating a universal measuring device that combines a two-channel digital oscilloscope with a two-channel oscillator with modulation capabilities. A distinctive feature of this device is that the random access memory of the generator is implemented in a programmable logic matrix, moreover, a circuit that implements direct digital frequency synthesis is used for the generator, which makes it possible to dispense with a significantly smaller amount of memory. The memory of the oscilloscope is external, of a large volume, which allows you to store a large amount of data and perform complex functional transformations, including fast Fourier transform, wavelet analysis and fractal signal analysis. This solution improves the metrological characteristics of the device.

Figure 1 shows a simplified block diagram of a device. In figure 1, the following notation:

1 - standard interface such as LPT or USB 2.0 with a personal computer (PC);

2 - programmable logic matrix containing a communication interface with a PC, which controls the device with

using commands coming from a PC; arithmetic units, signal buffers, address registers, generator random access memory, programmable frequency divider.

3 - analog-to-digital Converter channel A of the oscilloscope;

4 - analog-to-digital Converter channel B of the oscilloscope;

5 - the block of RAM of the oscilloscope;

6 is a synchronization unit that controls the scan (scan addresses of RAM) upon the occurrence of a synchronization event;

7 - digital-to-analog converter channel C generator;

8 - digital-to-analog converter channel D generator;

9 - clock generator.

Figure 2 shows a simplified diagram of a programmable logic matrix (block 2 in figure 1).

In figure 2, the following notation:

2.1 - programmable frequency divider;

2.2 - block of memory addresses;

2.3 - random access memory of channel C of the generator;

2.4 - random access memory channel D generator;

2.5 - decoder;

2.6 - programmable delay;

2.7 - memory management unit;

2.8 - communication unit.

The device operates as follows. The measurement cycle begins with entering from PC 1 via the LPT or USB interface the current measurement process parameters. The generator blocks 2.3 and 2.4 of the C and D channels of the generator through the address block of memory 2.2 enter the tables of generated signals of a given shape and set the phase increment that determines the frequency of the generators in direct digital synthesis scheme. As the parameters of the oscilloscope, the values of the programmable delay of data recording after the synchronization event, the division coefficient of the programmable frequency divider determining the time resolution, and the synchronization mode are set. To do this, use the communication unit 2.8, located in the programmable logic matrix 2 and the necessary registers that determine the operation of the device in each of the programmable modes. Data for digital-to-analog converters 7 and 8 of the generator are read from the blocks of the RAM of the generator 2.3 and 2.4. The digitized data of channels A and B of the oscilloscope from blocks 3 and 4 through the decoder 2.5 are entered at the addresses of the RAM 5 of the oscilloscope. This process can be repeated many times. The repetition frequency is set by a clock 9 and a programmable frequency divider 2.1, located in the programmable logic matrix 2. If a synchronization event occurs, allocated by the synchronization unit 6, the memory address continues to increase to a value determined by the programmable

2.6 delay, then the data recording process is stopped, and the data accumulated in the oscilloscope’s RAM 5 are sent via PC 2.8 to PC 1. Data can also be transferred without a synchronization event when the address reaches a certain (maximum) value. Data can be processed in programmable logic matrix 2 in a continuous flow mode when a sequence consisting of the results of processing a given number of samples by a selected averaging algorithm is selected from the primary samples from the analog-to-digital converters of the channels of channels A and B of the oscilloscope (blocks 3 and 4). This data sequence is transmitted to PC 1, and the primary data is cyclically stored in the RAM 5 of the oscilloscope. In PC 1, the data is processed and displayed on the monitor of PC 1. Then, the data processing cycle is repeated.

The process of digitization, processing and display of data can be carried out in continuous mode. At the same time, it is possible to stop the process with a specified block of 2.6 delay after the synchronization event and to view the data fragment before and after the event with a higher resolution in time by entering samples from the blocks of RAM 5 of the oscilloscope.

Due to the high functionality of the data processing programs and the use of the local random access memory of the generator and the external RAM of the oscilloscope, metrological improvements

characteristics of the device, due to which the device can be used in various systems, including educational-methodical and scientific research, medicine, automatic control systems.

Claims (1)

A multifunctional digital computing device for measuring and generating signals, containing analog-to-digital converters of the input channels A and B of the oscilloscope connected to a programmable logic matrix, a memory block of the oscilloscope, a synchronization block, digital-analog channels C and D of the generator connected to a programmable logic matrix and outputs C and D devices, a clock generator, the output of which is connected to a programmable logic matrix, a personal computer with a standard interface, while m the RAM of the generator is local and implemented in a programmable logic matrix.