JPS62233900A - Digital signal transmitter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to a digital signal transmission device that can transmit measured digital data through a small number of signal paths and convert the signal at a necessary scale.

[Prior art and its problems]

When operating a large plant, it is necessary to measure various data such as temperature and pressure in each part of the plant and transmit it to a long distance, but in order to improve accuracy and noise resistance, digital quantities are used instead of analog quantities. It is desired to transmit these measurement data by Therefore, in the past, these measured signals converted into data were transmitted through a large number of signal paths. However, in this case, the circuit for scaling the transmitted data on the receiving side is complicated, and furthermore, it has various drawbacks, such as requiring a large number of transmission paths in accordance with the quantization of the signal.

[Purpose of the invention]

The present invention relates to a digital signal transmission device that can transmit scaled measurement data using a few signal transmission paths and a simple circuit.

[Key points of the invention]

This invention doubles the cycle by connecting in series pulse distributors that alternately distribute input pulse trains to output a pulse train in which the pulses do not overlap and the pulse interval is twice that of the input pulses. Two sets of circuits are prepared to generate a signal that converts the data into a frequency using this signal, transmit the measurement data and scale data through separate transmission paths, and then use a receiving circuit consisting of a counter to convert the data from both data. It attempts to detect a scaled digital quantity.

[Embodiments of the invention]

FIG. 1 is a block diagram showing an embodiment of the present invention, in which a transmitting circuit 2 converts input measurement data and scale data into frequencies, and receives the signals through two signal transmission paths 3. Send to circuit 4. The receiving circuit 4 is composed of a counter and is designed to read the scaled digital amount from the two input signals.
These details will be explained below.

FIG. 2 is a block diagram showing the configuration of the transmitting circuit 2 in the embodiment shown in FIG. In FIG. 2, when the clock pulses output from the clock oscillator 7 are input to the pulse distributor 8, the pulse distributor 8 receives the input clock pulses so that the pulses do not overlap each other and the pulse period is equal to that of the input clock pulse. Two sets of pulse trains having twice the period are output. Therefore, the 2 output from this pulse distributor 8
N sets of pulse distributors 11, 12 . . . one of the sets of pulse trains are connected in series. . . . 13 to generate N reference clock signals by inputting them to the pulse distributor 11 located at the beginning of the pulse divider 11. Furthermore, M sets of pulse distributors 21, 22 . ...Pulse distributor 21 at the beginning of 23
M reference clock signals are created by inputting the input signal to M reference clock signals.

FIG. 3 shows a pulse distributor 8 shown in the transmitting circuit shown in FIG.
FIG. The pulse distributor shown in FIG. 3 is composed of two D-type flip-flops 31 and 32, two AND elements 33 and 34, and one inverting element 35.
When a pulse train signal such as a clock pulse is input to the input terminal 36, pulse train signals having a cycle twice that of the input pulse train signal are output from the two output terminals 37 and 38. Each pulse of the pulse train outputted from the output terminal 38 and each pulse of the pulse train outputted from the output terminal 38 are designed not to overlap with each other.

FIG. 4 is a waveform diagram showing the waveforms of the input signal and output signal of the pulse distributor shown in FIG. figure(
b) is the waveform of the pulse signal applied to the output terminal 37,
FIG. 4(c) shows the waveforms of the pulse signals applied to the output terminal 38.

In the transmission circuit shown in FIG. 2, the conversion circuit 14 is connected to pulse distributors 11, 12 . . . . N pulse trains whose periods are doubled are input from 13, and scale data is input from input terminal 2B, so the transmission signal converted to frequency is input from conversion circuit 14 to output terminal 2C. Hail.

FIG. 5 is a circuit diagram of the conversion circuit described in the transmission circuit shown in FIG. 2. In this FIG. 5, N AND elements 51
,52. . . 53 respectively calculate the AND of the clock signal from the pulse distributor and the scale data, and the 0 element 54 calculates the AND of these N pieces of AND elements 51, 52 .・・・
- By calculating the logical sum of the outputs of 53, the conversion circuit outputs a transmission signal converted into a frequency.

Similarly, in the transmitting circuit shown in FIG.
pulse distributors 21, 22 . By inputting M reference clock signals from 23 and measurement data via two input terminals, the conversion circuit 24 converts the frequency to the output terminal 2D via the divider 25. A transmission signal will be output.

FIG. 6 is a waveform diagram of the transmission signal in the embodiment circuit shown in FIG. 1, in which FIG. Sorry, but the receiving circuit 4 in FIG. 1 is composed of a counter, and this FIG. 6 ((+
The scaled digital quantity can be read from the two signals shown in (b).

FIG. 7 is a block diagram showing an application example of the present invention in which a plurality of pieces of data are measured and digital signals scaled at respective scales are transmitted. In the above-described embodiment, measurement data of one point is digitized and transmitted, but in reality, a large number of data must be measured, so the configuration shown in FIG. 7 is adopted.

In the application example circuit shown in FIG. 7, a selection signal from a control circuit 74 is applied via a control bus 73, so that one of a plurality of detected values is selected by a selector circuit 61, and the selection signal is sent via a sample and hold circuit 62. A/D conversion circuit 6
3 is input. The A/D conversion circuit 63 converts the input analog signal into a digital signal and sends it to the transmitting circuit 2, and the circuit configuration of the transmitting circuit 2 of C has already been explained in FIG. Similarly, the scale data is selected by the selector circuit 71 and sent to the transmitting circuit 2 via the sample and hold circuit 72.

The transmission signal is sent from the transmission circuit 2 to the decoder circuit 64 via the two signal transmission paths 3, and the sample and hold circuit 6
5 to the counter circuit 66. This counter circuit 66 converts the input transmission signal into display data and outputs it to the display circuit 67. Since this display data is scaled, a desired unit symbol can be attached to it.

〔Effect of the invention〕

According to this invention, a pulse distributor is used to create multiple reference clocks, and digital data is converted into a frequency and transmitted using these clocks. Since the frequency is converted to , there is no need for numerical processing of the digital signal, and the circuit can be made extremely simple. Furthermore, since the transmission signal contains information in its frequency, only two pulses and two signal transmission lines are needed to count them, so the number of signal transmission lines is significantly reduced compared to the past. This has the advantage of greatly contributing to reducing the cost of the entire device.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG.
The figure is a block diagram showing the inside of the transmitting circuit in the embodiment shown in FIG. 1, FIG. 3 is a circuit diagram of a pulse distributor described in the transmitting circuit shown in FIG. 2, and FIG. 4 is a block diagram showing the inside of the transmitting circuit in the embodiment shown in FIG. FIG. 3 is a waveform diagram showing waveforms of an input signal and an output signal of a distributor. FIG. 5 is a circuit diagram of a conversion circuit described in the transmission circuit shown in FIG. 2 1ζ, and FIG. 6 is a waveform diagram of a transmission signal in the embodiment circuit shown in FIG. 1. Further, FIG. 7 is a block diagram showing an application example of the present invention in which a plurality of data are measured and digital signals scaled at respective scales are transmitted. 2... Transmission circuit, 3... Signal transmission path, 4... Receiving circuit, 7... Clock oscillator, 8. II, 12, 13
゜21.22,23...Pulse distributor, 14.24.
... Conversion circuit, 25... Frequency divider, 31, 32... D
Type flip-flop, 33.34...AND element, 3
5... Inversion element, 51, 52.53... AND element, 54... 0 element, 61, 71... Selector circuit, 62° 65.72... Sample hold circuit, 63
... A/D conversion circuit, 64 ... Decoder circuit, 66
...Counter circuit, 67...Display circuit, 73...
Control bus, 74...Figure 1 C) Irikichi @
. Figure 5 Figure 6

Claims (1)

[Claims] 1) In a device that transmits measured digital data, a plurality of pulse distribution means are connected in series to output a pulse train whose pulses do not overlap with the input pulse train and whose pulse intervals are twice the input pulse train. a first pulse train generating means configured to input clock pulses from the clock oscillating means to the first pulse distributing means; and a first pulse train generating means configured to input clock pulses from the clock oscillating means to the first pulse distributing means, and a first pulse train generating means configured to convert scale data into a frequency using the pulse train output from the first pulse train generating means. a data conversion means;
a second pulse train generating means configured in the same manner as the first pulse train generating means; a second data converting means for converting measurement data into a frequency using a pulse train output from the second pulse train generating means; and a first data converting means for converting the measured data into a frequency. A digital signal transmission device comprising: a counter that receives the output signal of the second data conversion means and the output signal of the second data conversion means and detects a scaled digital quantity.