KR100806935B1 - Apparatus for converting analog to digital signal based on VME bus used in safety system of nuclear plant - Google Patents

Abstract

The present invention relates to a VME bus-based digital / analog converter for use in a nuclear power plant safety system that simplifies circuits and minimizes malfunction of devices through digital / analog conversion of input / output signals.

The present invention provides an input unit for receiving a digital signal from the VME bus; A digital signal processing unit for comparing, analyzing and outputting the digital signal transmitted from the input unit according to a pre-stored program; A digital / analog converter converting the signal output from the digital signal processor into an analog signal; An isolation unit for isolating the analog signal converted by the digital / analog converter from interference with the digital signal and the power supply; A signal fixing unit for stably maintaining the analog signal output from the isolation unit; And a voltage / current converter configured to convert the voltage strength of the analog signal output from the signal fixing unit into a current of the analog signal and output the converted signal.

VME, Digital-to-Analog Conversion, Digital Signal Processing, Buffers, Nuclear Power, Power Plants

Description

Application for converting analog to digital signal based on VME bus used in safety system of nuclear plant}

FIG. 1 is a block diagram schematically illustrating a configuration of a VME bus-based digital / analog converter used in a nuclear power plant safety system according to an embodiment of the present invention.

FIG. 2 is a circuit diagram illustrating in detail the input unit illustrated in FIG. 1.

FIG. 3 is a circuit diagram illustrating in detail the digital signal processor illustrated in FIG. 1.

4 is a circuit diagram illustrating in detail the digital / analog converter shown in FIG. 1.

<Explanation of symbols for the main parts of the drawings>

10: VME bus 20: input unit

30: digital signal processor 40, 50: first and second output channel

42,52: First and second digital to analog converter

44,54: first and second isolation

46,56: first and second signal fixation

48,58: first and second voltage / current converter

The present invention relates to a Versa Module Eurocard (VME) bus-based digital / analog converter for use in a nuclear power plant safety system. Nuclear power plant safety that simplifies circuits and minimizes malfunction of devices through digital / analog conversion of input / output signals. The present invention relates to a VME bus-based digital-to-analog converter used in the system.

Numerous nuclear power plants are being constructed to cope with the recent surge in energy demands, but the maintenance and maintenance of such nuclear power plants requires a lot of cost and technology, and there is always a risk that a large-scale safety accident may occur. have.

In other words, in the nuclear power plant, it is necessary to have a control system that is very stable and reliably operated compared to other general plants or power plants due to the use of nuclear fuel, and the electronic control module used in such a control system malfunctions even in the environment of a high vibration power plant. This requires high reliability.

In particular, in a nuclear power plant, there is a problem that electronic circuit elements such as semiconductors are exposed to radiation and have a high probability of malfunction.

Despite the importance of stable operation of devices used in nuclear power plants as described above, in the conventional digital-to-analog converter, a plurality of NAND gates, transistors, amplifiers, and muxes are used to convert digital signals to analog signals. It requires a variety of devices such as), there is a problem that the probability of malfunction due to many of these devices.

In particular, such a digital-to-analog converter is widely used in the field of controlling control devices such as various motors and valves, so the volume and proportion of the system occupy a considerable amount of time and cost to maintain and manage it. There is a problem of being consumed.

The present invention is to solve the above-mentioned problems of the prior art, VME bus-based digital / analog conversion apparatus used in nuclear power plant safety system that simplifies the circuit through the digital / analog conversion of input and output signals and minimizes the malfunction of the device The purpose is to provide.

In order to achieve the above technical problem, a digital-to-analog converter based on a Versa Module Eurocard (VME) bus used in a nuclear power plant safety system according to the present invention includes: an input unit for inputting a digital signal from the VME bus; A digital signal processing unit for comparing, analyzing and outputting the digital signal transmitted from the input unit according to a pre-stored program; A digital / analog converter converting the signal output from the digital signal processor into an analog signal; An isolation unit for isolating the analog signal converted by the digital / analog converter from interference with the digital signal and the power supply; A signal fixing unit for stably maintaining the analog signal output from the isolation unit; And a voltage / current converter configured to convert the voltage strength of the analog signal output from the signal fixing unit into a current of the analog signal and output the converted signal.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

1 to 4 illustrate a configuration of a VME bus-based digital / analog converting apparatus used in a nuclear power plant safety system according to the present invention. FIG. 1 illustrates a nuclear power plant safety system according to an embodiment of the present invention. 2 is a block diagram schematically illustrating a configuration of a VME bus-based digital-to-analog converter. FIG. 2 is a circuit diagram illustrating in detail an input unit illustrated in FIG. 1, and FIG. 3 illustrates in detail a digital signal processor illustrated in FIG. 1. 4 is a circuit diagram illustrating in detail the digital-to-analog converter shown in FIG. 1.

The digital / analog conversion apparatus based on the Versa Module Eurocard (VME) bus used in the nuclear power plant safety system shown in FIGS. 1 to 4 includes a VME bus 10, an input unit 20, and a digital signal processor 30. First and second digital to analog converters 42 and 52, first and second isolators 44 and 54, first and second signal fixers 46 and 56, and first and second voltages / Current converters 48,58.

The VME bus 10 is preferably used for the VME bus system 3U, 19 ", P1 / J1.

The input unit 20 receives digital signals such as address signals, data, and control signals from the VME bus 10.

In this case, the buffer unit (not shown) receives an address signal from the VME bus 10 and provides it to the digital signal processing unit, and the transceiver unit (not shown) inputs and outputs a data signal to and from the VME bus 10 and inputs the data signal. To the digital signal processor.

The digital signal processor 30 compares and analyzes the digital signals transmitted from the input unit 10 according to a pre-stored program and outputs them to the first and second digital / analog converters 42 and 52, respectively.

In this case, it is preferable to use an erasable programmable logic device (EPLD) as the digital signal processor 30.

The first and second digital / analog converters 42 and 52 convert the signals output from the digital signal processor into analog signals.

That is, the first and second digital / analog converters 42 and 52 convert the 16-bit digital input signal into an analog signal of 0-+ 10V by the R-2R ladder circuit and output it.

The first and second isolators 44 and 54 isolate the analog signals converted by the first and second digital / analog converters 42 and 52, respectively, from interference with the digital signals and the power supply.

The first and second signal fixing parts 46 and 56 change the output signal according to the input signal of the channel when the output channels 40 and 50 in which the signal output from the digital signal processor 30 is processed are changed. Sample / Hold circuit is made to keep the voltage stable.

The sample / hold circuit consists of a capacitor, a switch, and a buffer. The switch is closed during the sampling time, so that the capacitor voltage is charged equal to the input voltage. The buffer maintains a constant voltage when the switch is opened. To print.

The first and second voltage / current converters 48 and 58 proportionally set the voltage strengths of the analog signals output from the first and second signal fixing parts 46 and 56 in proportion to a preset value of 4-20 mA. The output is converted to analog current.

Meanwhile, the first digital / analog converter 42, the first isolation unit 44, the first signal fixing unit 46, and the first voltage / current converter 48 connect the first output channel 40. And the second digital / analog converter 52, the second isolator 54, the second signal fixer 56, and the second voltage / current converter 58 form a second output channel 50. Configure.

That is, the digital signal output from the digital signal processor 30 is selectively converted into an analog signal through the first output channel 40 or / and the second output channel 50 and output.

Meanwhile, in another embodiment, one output channel may be used.

Those skilled in the art to which the present invention pertains will understand that the present invention can be implemented in other specific forms without changing the technical spirit or essential features. Therefore, the above-described embodiments are to be understood as illustrative in all respects and not as restrictive.

As described above, the VME bus-based digital / analog conversion apparatus used in the nuclear power plant safety system according to the present invention simplifies the circuit and minimizes malfunction of the device through digital / analog conversion of input / output signals.

It also isolates the supplied power supply, reducing mutual interference and improving reliability.

In addition, in case of malfunction due to defective device, deterioration, aging, etc., it is possible to replace the device easily by grasping the cause of failure.

Claims (6)

In the Versa Module Eurocard (VME) bus-based digital / analog converter for nuclear power plant safety systems, An input unit to receive a digital signal from the VME bus; A digital signal processing unit for comparing, analyzing and outputting the digital signal transmitted from the input unit according to a pre-stored program; A digital / analog converter converting the signal output from the digital signal processor into an analog signal; An isolation unit for isolating the analog signal converted by the digital / analog converter from interference with the digital signal and the power supply; A signal fixing unit for stably maintaining the analog signal output from the isolation unit; VME bus-based digital / analog converter used in the nuclear power plant safety system, characterized in that it comprises a voltage / current converter for converting the voltage strength of the analog signal output from the signal fixing unit to the current of the analog signal output . The method of claim 1, The input unit, A buffer unit which receives an address signal from the VME bus and provides it to the digital signal processor; A VME bus-based digital / analog converter for a nuclear power plant safety system, characterized in that it comprises a transceiver for inputting and outputting a data signal to and from the VME bus and providing the input data signal to the digital signal processor. The method of claim 1, The digital / analog conversion unit converts a 16-bit digital input signal into an analog signal of 0-+ 10V by a ladder circuit and outputs the digital signal based on the VME bus used in the nuclear power plant safety system. Analog inverter. The method of claim 1, The signal fixing section, When the channel to which the signal output from the digital signal processing unit is changed, the sample / hold circuit for stably maintaining the variation of the output signal in accordance with the input signal variation of the channel is used in the nuclear power plant safety system, characterized in that VME bus based digital / analog converter. The method of claim 4, wherein The sample / hold circuit is, A capacitor; A switch that is closed for a sampling time such that the capacitor voltage is charged equal to an input voltage; A VME bus based digital / analog converter used in a nuclear power plant safety system, characterized in that it comprises a buffer to maintain a constant voltage when the switch is opened. The method of claim 1, The voltage / current converter, VME bus-based digital / analog converter used in the nuclear power plant safety system, characterized in that for converting the voltage strength of the analog signal output from the signal fixing unit proportionally to the analog current of 4-20mA according to a preset value .

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