SU762172A1 - Multichannel frequency to code converter - Google Patents

Description

681.325 (088.8)

(72) Authors

inventions G. S. Magdanov, Yu. V. Voronin and V. D. Shershukov

*

(71) Applicant -

(54) MULTICHANNEL DEVICE OF FREQUENCY IN CODE

CONVERSIONS

PTB

The invention relates to a measurement technique, can be used in automated systems of operational monitoring and control of technological processes on the basis of a computer to enter information from frequency sensors.

There are known conversion devices containing an input driver connected to a “-digit counter of periods of the measured frequency, a decoder and a key, connected to the input of the reference frequency counter [1].

The disadvantage of the device is intermittent regulation and complexity.

In addition, a multichannel 15 frequency-to-code conversion device is known, which contains a driver, a counter, and a decoder connected to counting channels consisting of a key, a counter, and logic elements [2]. 20

The disadvantages of this device is the complexity of the switching nodes, as well as the fact that the sampling resolution is a constant value specified by the number of channels. In addition, it is intended 25 to measure only low-frequency oscillations.

In order to simplify and extend the functionality of a multichannel frequency conversion device

the code containing the driver connected to the counter and the decoder whose outputs are connected to the inputs of the corresponding counting channels consisting of a key whose input is connected to the input busbar and the output to the counter of the reset driver and the elements AND, a control unit is entered, performed on the register and keys, and in each channel - a delay element and an inverter, the register control unit inputs are connected to the control buses, and the outputs are connected to the decoder inputs via the corresponding keys, while the other inputs of the cells The control unit is connected to the counter outputs, in addition, the input of each counting channel is connected to the reset pulse shaper, through the delay element to the other key input and through the inverter to the first inputs of the And elements, the second inputs of which are connected to the outputs of the counter, and the outputs of the elements And connected to the corresponding output tires.

FIG. 1 shows a block diagram of the device, FIG. 2 (a, b, c) is a timing diagram of his work.

The device contains an input driver 1, connected to the counter 2 periods of the measured frequency} _x , control unit 762172

3

3 measurement interval and sampling resolution, which includes a “-bit register 4, the outputs of which are connected to the control inputs of the corresponding keys 5ι — 5 _П , connected between the corresponding outputs of counter 2 and the inputs of the decoder 6, counting channels 7ι — 7 ₂ ^п , each of which comprises a delay element 8, driver 9 a reset pulse to the "O", the inverter 10, key 11 connected to the input of the counter 12, the reference frequency, the aND 13ι-13, _etc. The control bus 14 and output busses (outputs) 15, input 16 reference frequency.

The apparatus operates continuously, ie. E. Counter 2 counts pulses of the measured frequency generator 1 cyclically from 0 to (2 ⁿ -1) with a period of 2 ^minutes · Τ _Χ, wherein the duration of one cycle of the counter 2 is equal to one period of the measured frequency / _g .

Consider one cycle of operation of the ith counting channel 7ί (all keys 5 are open). When installed in the counter 2 of the code of the / -th channel, at the / -th output of the decoder 6, the output voltage drops from a high level “1” to a low “0” (Fig. 2), which through the delay element 8 closes the key 11, fixing the measurement result in the counter 12, and simultaneously through the inverter 10 opens the elements And 13ι — 13 _t , allowing the issuance of information from the counter 12 to the output bus 15 of the device. After a time equal to one period of the measured frequency, or one clock of counter 2 with the code of the next (/ + 1) -th channel set in it, the low level signal from the / -th output of the decoder 6 returns to its original state, i.e. level "1". This differential (“0” - “1”) starts the reset pulse shaper 9 into the “0” of counter 12, through delay element 8 (for the duration of pulse formation and reset of counter 12) opens key 11, allowing the passage of reference frequency pulses to counter 12, and through the inverter 10 it closes the AND 13ι — 1 З _t elements, prohibiting the removal of information from the 7th counting channel 7ι into the output buses of the 15th device. The counting process (conversion in the counter 12 of the reference frequency of the / -th channel 7) ends with the arrival, as already described above, of the difference "1" - "0", i.e. with the installation in the counter 2 again the code of the considered / -th counting channel 7, but in the next cycle. Thus, a measuring interval is formed, equal to T _i = (2 ”-1) T _x .

The remaining channels 7 of the device work in the same way, with the only difference that the cycle of measurement and removal of the received code (7 ,, + G) of each subsequent channel 7 is shifted with respect to the previous one by one period of the measured frequency, equal to

reading interval (sampling resolution) T _c - T _x .

The selection of the measurement interval and the setting of the sampling resolution occur by writing, for example, from a computer, through the device control buses 14 (before starting its operation) to the register 4 of the control code word, which, using the keys 5ι —— 5 _П, blocks the outputs of the junior or senior code of this word) the counter discharges 2 periods of the measured frequency. As can be seen from FIG. 2b, blocking the lower digits leads to a change in the sampling resolution and a slight change in the measurement interval, and blocking the higher digits (Fig. 2, c) leads to a change in the measurement interval (in a ratio that is a multiple of two) with a constant sampling ratio.

The device can also implement a method for converting frequency to code, based on measuring the number of pulses of the measured frequency over a given time interval. For this, it is necessary to send signals of the measured frequency to the input 16 of the reference frequency, and to the input of the last one - the pulses of the time interval equal to the reading interval.

By introducing counting channels 7ι — 7 ₂ ", the device is simplified, and the presence of a control unit for measuring intervals and a sampling resolution allows effectively selecting the latter for measuring stationary, slowly varying and rapidly varying processes in a wide frequency range.

Claims (1)

Claim A multichannel frequency conversion device in the code containing the driver connected to the counter, and the decoder, the outputs of which. connected to the inputs of the corresponding counting channels consisting of a key, the input of which is connected to the input bus and the output with a counter, reset pulse shaper and elements AND, characterized in that, in order to simplify the expansion of functionality, a control unit is introduced register and keys, and in each channel - the delay element of the inverter, and the inputs of the register of the control unit are connected to the control buses, and the outputs through the corresponding keys are connected to the inputs of the decoder, if this other inputs of the keys are The control is connected to the counter outputs, in addition, the input of each counting channel is connected to the reset pulse shaper, via the Delay Element - to another key input and through the inverter - to the first inputs of the And elements, the second inputs of which are connected to the outputs of the counter, and the outputs of the X elements connected to the corresponding output tires. 762172 five