KR100355959B1 - Multi-functional measurement device with settable module for converting the object of measurement and method for correcting error of measurement - Google Patents

Abstract

The present invention relates to a multifunctional measuring apparatus capable of measuring various objects and a method of correcting a measurement error by replacing a signal converter.

The multi-function measuring apparatus of the present invention may be replaced according to a measurement target, and includes a signal conversion unit for converting at least one or more input signals according to a sensing result or a measurement target signal of the measurement target into a signal that can be processed therein. The control unit receives a selected conversion signal from one or more conversion signals output from the signal conversion unit, and generates a digital measurement signal representing a corresponding measurement value, and at least one output control signal for controlling an operation of the selected output target. . The display unit receives the digital measurement signal and the output control signal of the controller and displays the corresponding measurement value from the outside. The output unit receives the digital measurement signal and the output control signal of the controller to transmit and receive data with an external device. The power supply unit receives AC power and converts the AC power into internal power required for the operation of the signal conversion unit, the control unit, the display unit, or the output unit, and provides the same to the corresponding portion.

Description

MULTI-FUNCTIONAL MEASUREMENT DEVICE WITH SETTABLE MODULE FOR CONVERTING THE OBJECT OF MEASUREMENT AND METHOD FOR CORRECTING ERROR OF MEASUREMENT}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to various measuring apparatuses, and more particularly, to a multifunctional measuring apparatus capable of measuring various objects and a method of correcting a measurement error by replacing a signal conversion module.

Currently, various digital instruments are used in industrial fields depending on the application. For example, alternating current voltmeters and direct current voltmeters for measuring voltage, alternating current ammeters and direct current ammeters for measuring current, and thermometers, power meters, counters, or timers are digital instruments frequently used in industrial fields. In addition, various types of digital instruments such as frequency meters, power factor meters, communication systems, instrumentation signal receivers, tachometers, speedometers, pressure gauges, hygrometers, flow meters, and accelerometers are required for various fields.

Digital instruments come in a wide variety of products because of the different order specifications for the consumers who need them.

1 illustrates a general configuration diagram of an AC voltmeter among various digital instruments.

Referring to FIG. 1, the voltage divider 12 inside the AC voltmeter 10 divides the input voltage to a low voltage and provides the voltage to the A / D converter 14. The A / D converter 14 converts a low voltage input signal into a digital signal and provides it to the display unit 16, and the display unit 16 displays the digital signal corresponding to the input voltage to be recognized externally. In general, since the input range of the A / D converter 14 is within 1 V, the level of the input signal may be adjusted thereto. The display unit 16 is composed of a display device such as seven segments or a liquid crystal display (LCD). The power supply unit 18 converts an AC power source into a DC voltage, and supplies a voltage necessary for the operation of each of the parts 12, 14, and 16 constituting the AC voltmeter 10.

2 shows a configuration diagram of a general ammeter.

Referring to FIG. 2, a shunt 22 having a resistance connected in parallel to an input terminal of the ammeter 20 converts an input current into a voltage. The voltage converted through the shunt 22 is converted into a digital signal through the A / D converter 24 and displayed on the display unit 26. The power supply unit 28 converts an AC power supply into a DC voltage to provide a voltage required at each component part 22, 24, 26.

3 shows a configuration diagram of a general frequency meter.

Referring to FIG. 3, the frequency / voltage converter 32 inside the frequency meter 30 converts an input frequency signal into a voltage, and converts an analog voltage into a digital signal in the A / D converter 34. The display unit 36 displays the voltage corresponding to the input frequency so as to be recognized externally. The power supply unit 38 converts an AC power supply into a DC voltage to provide a voltage used in each of the component parts 32, 34, and 36.

4 shows a configuration diagram of a general counter system.

Referring to FIG. 4, in the counter system 40, the pulse shaping unit 42 shapes an input pulse signal. In the shaped pulse signal, the pulse is counted in the counter section 44. The display unit 46 displays the signal counted by the counter unit 44 so as to be recognized externally. The power supply unit 48 converts the input power into voltages required by the components 42, 44, and 46, and supplies them. At this time, when a proximity sensor is used for the input terminal, the power supply unit 48 supplies a DC voltage or an AC voltage thereto.

Figure 5 shows the configuration of a general weighing scale.

Referring to FIG. 5, the weight detector 52 of the weight scale 50 measures a weight of an object or a person to be weighed and generates a signal corresponding to the weight. The weight sensing unit 52 generally uses a weight sensor. The A / D converter 54 receives a signal corresponding to the weight and converts it into a digital signal. The display unit 56 displays the digital signal so as to be recognized externally. The power supply unit 58 converts an AC power supply into a DC voltage to provide an appropriate voltage to each of the component parts 52, 54, and 56.

6 shows a block diagram of a comprehensive control instrument having various measurement functions.

Referring to FIG. 6, the signal converter 61 of the integrated control instrument 60 receives a current, a voltage, or other signals and converts the signals into signals that can be processed in the instrument. The A / D converter 62 converts the signal converted by the signal converter 61 into a digital signal. The controller 63 receives the digital signal and adjusts the switching unit 69 to change the output direction. The output signal may be displayed on the display unit 65 or externally provided through the communication unit 66. In addition, an output signal may be transmitted through the D / A converter 67 or the control output unit 68. The power supply unit 64 receives an AC power and converts the voltage into a voltage to be used in each component.

7 graphically illustrates each component for various digital instruments.

Referring to FIG. 7, the digital meter includes an AC voltmeter, an AC ammeter, a DC voltmeter, a DC ammeter, a frequency meter, a power factor meter, a thermometer, a power meter, a counter, a timer, a communication system, a tachometer, a line speed meter, a pressure gauge, a hygrometer, a flow meter, an accelerometer, and the like. There are so many kinds. Each of the digital instruments includes an input signal unit for receiving an input signal, a signal processor for converting the input signal, a control unit for controlling the flow of signals, a display unit for displaying an output signal, a power unit required for the operation of the digital instrument, and an output signal. It includes an output for transmitting to another device. At this time, the operation of each component is different according to the type of digital instrument, and each component is different depending on its operation.

The input signal part has different components depending on a measurement target such as voltage, current, frequency, pressure, or weight. In general, there are about 60 types of input signal units such as voltage divider, shunt, proximity sensor, pt100Ω, temperature sensor, pressure sensor, weight sensor, optical sensor, AC frequency sensor, and acceleration sensor. In addition, depending on the type of signal to be converted, the signal processing unit has about 6 types such as parallel A / D (Analog to Digital) converter, serial A / D converter, voltage / frequency converter, frequency / voltage converter, pulse width modulation or charge / discharge. There is a kind. The control unit may be composed of about four types, including an instrument using 8 bits, 16 bits or 32 bits, or no separate control unit. The display unit has a displayable digit according to the range of output values, and there are about seven types of digital instruments. The display size of the output value displayed on the display unit varies from 0.4 inch to 8.0 inch depending on the type of digital instrument used, and there are generally 11 types. The power supply can be classified into about 10 types according to portable power such as DC 5V, DC 12V or rated power such as AC 100V or AC 220V, and the output part can be divided into relay or communication output. It can be divided into three types.

As such, considering all the measuring devices for the signal to be measured, more than 100 components are required. In the case of considering the types of components shown in FIG. 7, a product including an input signal part, a signal processing part, a control part, a display part, a display size, a power supply part, and an output part includes 60 × 6 × 4 × 7 × 11 ×. 10 x 3 = 3,359,400 products can be configured.

Therefore, in order to manufacture such a digital product, a separate circuit is developed for each product, and each component needs to be assembled separately. In addition, since the work process is different for each product, there is a problem that the cost of the work guidance and production tools are expensive. In addition, since these digital products are produced in small quantities, the productivity is low and the short-term delivery is difficult. In particular, in order to produce such products, the production of the product is possible only by providing separate work instructions and model classification instructions for each product.

In addition, the digital products up to now have a narrow measuring range, and thus, when the measured value exceeds this range, it is often impossible to express it properly. For example, when using an A / D converter having a measurement range up to 1999, when the measured value is 2400, 0240 is displayed. In addition, the general speedometer can express a value of 1800 RPM (Revolution Per Minute), but can not express a speed of more than 2,400 RPM. Therefore, to express this, separate hardware must be accompanied or a separate application program must be supported.

In addition, various digital products have different magnitudes of signals to be adjusted for each board, and therefore, each product must be accompanied by hardware for adjusting the signal.

In addition, since the measured value changes according to the change of the ambient temperature, the digital product must be equipped with separate dedicated hardware. However, these temperature compensation products are often more expensive than digital measuring instruments. Therefore, there is a problem in that the cost of the product increases when using hardware for temperature compensation.

The present invention has been made to solve the above problems, and comprises a multi-function measuring device and a method of correcting the measurement error using a removable module that can implement a measurement function for various uses by configuring a single substrate, replacing a specific single module The purpose is to provide.

1 is a general configuration diagram of an AC voltmeter.

2 is a configuration diagram of a general ammeter.

3 is a block diagram of a general frequency meter.

4 is a configuration diagram of a general counter system.

5 is a block diagram of a general weighing scale.

6 is a configuration diagram of a comprehensive control type instrument having various measurement functions.

7 is a diagrammatic representation of each component for various digital instruments.

8 is a block diagram of a multi-function measuring apparatus using a removable module according to a preferred embodiment of the present invention.

9 is a diagram illustrating an internal configuration of a signal converter in the multifunction measuring apparatus according to the preferred embodiment of the present invention.

10 is an internal configuration diagram of a control unit in the multifunction measuring device according to the preferred embodiment of the present invention.

11 is an internal configuration diagram of a display unit in the multifunction measuring device according to the preferred embodiment of the present invention.

12 is an internal configuration diagram of a power supply unit in the multifunction measuring device according to the preferred embodiment of the present invention.

13 is an internal configuration diagram of an output unit in the multifunction measuring apparatus according to the preferred embodiment of the present invention.

14 is an internal circuit diagram of a communication output unit in the multifunction measuring apparatus according to the preferred embodiment of the present invention.

15 is a circuit diagram of a control output unit in the multifunction measurement apparatus according to the preferred embodiment of the present invention.

16 is a circuit diagram of a D / A output unit in the multifunction measuring apparatus according to the preferred embodiment of the present invention.

17 is a diagram showing signals used in the multifunction measuring apparatus according to the preferred embodiment of the present invention.

18 shows display values of an output signal in accordance with an input frequency signal;

Fig. 19 is a diagram showing each component of a digital instrument in the case of using the multifunctional measuring apparatus of the present invention.

20A is a product configuration diagram of a conventional digital measurement device.

20B is a product configuration diagram of a multifunction measuring apparatus according to a preferred embodiment of the present invention.

(Name of the code for the main part of the drawing)

100: main bus 200: signal conversion unit

300: control unit 400: display unit

500: power supply unit 600: output unit

210: magnification selector 220: rectifier

230: zero crossing detection unit 240: chattering prevention unit

250: waveform shaping

310: voltage / frequency converter 320: EEPROM

330: microprocessor

410: 7 segment 610: communication output unit

620: control output unit 630: D / A output unit

612: RS232 driver 614: RS485 driver

632: DA conversion unit

In order to achieve the above object, the multi-function measuring device using the removable module of the present invention can be replaced according to the measurement target, and can process at least one or more input signals according to the sensing result or the measurement target signal of the measurement target therein. A signal converting unit for converting the signal into a predetermined signal, a digital measuring signal receiving a converted signal selected from one or more converted signals output from the signal converting unit and indicating a corresponding measurement value, and at least for controlling an operation of the selected output target. A control unit generating one or more output control signals, a display unit receiving the digital measurement signal and the output control signal of the control unit so as to externally recognize corresponding measurement values, and a digital measurement signal and output control signal of the control unit. Output to send and receive data with external devices Portion and, by receiving the AC power converted by the internal power required for the signal converting unit, a control unit, a display or output of the operation, may include a power supply that provides a portion corresponding to this.

The signal converter may further include a detector that detects a measurement target and converts the measured object into one or more input signals.

The signal converter may include a DC voltage generator for converting a signal selected from one or more input signals into a DC voltage and outputting the signal, a digital signal generator for outputting a signal selected from one or more input signals as a high state or a low state signal; It may include a pulse signal generator for converting the selected signal from the above input signal in the form of a pulse to output.

The DC voltage generator may include a magnification selector for changing the magnitude of the input signal to a size suitable for internal operation, and a rectifier for converting the DC signal to a DC signal when the output signal of the magnification selector is an AC signal.

The digital signal generator may further include a chattering prevention unit for reducing chattering of an input signal.

The pulse signal generator may further include a waveform shaping unit for shaping an input signal.

The control unit receives a frequency converter for converting the DC voltage of the signal converter into a frequency corresponding to the voltage magnitude, and receives a frequency signal of the frequency converter and an output signal of the signal converter and digitally measures the signal input by the internal processing. A processor for generating a signal, a transmission / reception signal for transmitting a signal to an external device, and one or more output control signals for controlling an operation of an output target, and a reference value connected to the processor to store a reference value for compensating for an error in a measurement value. And a switching unit connected to the processor and configured to change an operation mode of the processor or a reference value stored in the memory.

The switching unit may include a switch for controlling an operation mode of a processor, a switch for changing a storage location of a reference value stored in a memory, and a switch for changing a size of a reference value stored in a memory.

The transmission and reception signal may further include a transmission and reception control signal for selecting data transmission to or from the external device.

The output control signal may further include an alarm signal for notifying the outside when the measured value is out of the display range.

The display unit may include one or more display devices for displaying a measurement value to be recognized externally, and one or more display controllers for controlling the operation of the one or more display devices.

The display device may be at least one of seven segments, a liquid crystal display, a light emitting diode, or an electron tube.

The output unit may include a communication output unit for transmitting and receiving data with an external device, a control output unit for controlling an external load, and a D / A output unit for supplying a DC voltage or a DC current to the external device.

The communication output unit may include an RS232 driver for RS232 communication and an RS485 driver for RS485 communication.

The control output unit may include an excess state alarm unit for notifying the outside of the display when the measured value exceeds the display range of the display unit, and a under state alarm unit for notifying the outside when the measured value is less than the display range of the display unit. have.

The over state alarm unit and the under state alarm unit may include a delay circuit.

The D / A output unit includes a DA converter for converting a digital measurement signal of the controller into an analog signal corresponding thereto, an amplifier for amplifying the analog signal of the DA converter with a predetermined voltage, and an output voltage of the amplifier. It may include a DA output control unit for controlling the output signal supplied to the external device.

The DA converter may include a plurality of resistors connected to each bit signal of the digital measurement signal.

The amplifier may include a reference signal generator for generating a reference signal, an OP amplifier receiving the output signal and the reference signal of the DA converter from the inverting input terminal, and outputting the output signal to the non-inverting input terminal through the DA output controller. Can be.

The DA output controller may include a switching device in which on / off is controlled according to an output signal of an amplifier, and one or more resistors and diodes connected in series between the switching means and a power supply.

The switching device may be a transistor.

The output unit may include a first converter converting AC power into a power source for driving a D / A output unit, and a second converter converting AC power source into a power source for driving a signal converter, a controller, a display unit, a communication output unit, or a control output unit. 2 may include a conversion unit.

In addition, the removable signal conversion device of the present invention receives a signal and a digital measurement signal representing a corresponding measurement value, and a control unit for generating at least one output control signal for controlling the operation of the selected output target, and the control unit of the A display unit for receiving a digital measurement signal and an output control signal to display a corresponding measurement value externally, and an output unit for receiving and receiving data from an external device by receiving the digital measurement signal and output control signal of the controller; A measuring device comprising a power supply unit receiving an AC power and converting the signal into an internal power source for operation of the signal converter, the controller, the display unit, or the output unit, and providing the same to a corresponding part, wherein the selected signal is selected from one or more signals. DC voltage generator for converting and outputting a voltage, at least one And a digital signal generator for outputting a signal selected from among signals of a high state or a low state, and a pulse signal generator for converting and outputting a signal selected from one or more signals into a pulse form.

In addition, the removable signal conversion device of the present invention may further include a detection unit for detecting the measurement target and converting it into one or more input signals.

In addition, the measurement error correction method of the present invention calculates a reference value for the measurement value compensation, storing the reference value and the mirror reference value, respectively, measuring the numerical value for the measurement target, if there is a variation in the measured numerical value The method may include changing the mirror reference value by the change value of the measured value, comparing the changed mirror reference value with the reference value, calculating a difference value, and changing the measured value by the difference value.

The reference value can be calculated by the following equation.

Here, f _x represents the frequency of the signal input to the microprocessor, f _h represents a frequency higher by a certain amount than the f _x frequency, f _l represents a frequency lower than the frequency by f _x , and Y _max is f _h represents a display value at the frequency, Y _min represents a display value at the f _l frequency.

The changing of the measured value may further include setting the changed measured value as a reference value.

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

Figure 8 shows a block diagram of a multi-function measuring apparatus using a removable module according to a preferred embodiment of the present invention.

Referring to FIG. 8, the multifunction measurement apparatus of the present invention includes a main bus 100 to transmit signals between the respective configuration modules 200, 300, 400, 500, and 600. The main bus 100 receives an input signal and provides it to the signal converter 200, and transmits a control signal or a data signal between each module. The main bus 100 is manufactured as a substrate to insert each module. Can be.

In addition, it includes a signal converter 200 for converting the input signal to process different input signals in accordance with the intended use to be measured. The signal converter 200 converts the input signal Input received through the main bus 100 into a signal of 1 V or more so that the controller 300 can process the input signal.

The controller 300 converts the voltage signal converted by the signal converter 200 into a frequency signal, and generates an output signal by calculating and processing the same in an internal processor. At this time, the conversion of the voltage signal to the frequency signal is simple, the internal structure of the V / F converter, and the price is low, and even if a low input signal is input, a wide range of output signals can be generated to facilitate the processor control Because. However, it will be apparent that the processor can be directly controlled using the voltage signal without converting it into a frequency signal.

The display unit 400 may use a liquid crystal display, a light emitting diode, an electron tube, or the like, and displays the output signal of the controller 300 so as to be externally recognized.

The power supply unit 500 is for supplying power for the operation of each module 200, 300, 400, 600 in the multifunction measurement apparatus of the present invention. In this case, the power supply unit 500 may be configured to supply power to the signal converter 200 and the controller 300 differently from the power supplied to the output unit 600. This is because the influence of the output unit 600 due to the noise caused by the input signal or the noise caused by the power source can be reduced, thereby improving the reliability of the product.

The output unit 600 is for outputting a signal by arithmetic processing of the control unit 300 to the outside, a control output for controlling an external load, a communication output for communication and D for data processing with external data. / A output, and so on.

9 is a block diagram of a signal converter for voltage and current in the multifunction measuring apparatus according to the preferred embodiment of the present invention.

Referring to FIG. 9, the signal converter 200 may be a signal Out1,..., And Out4 that may process the signals Input1,..., And Input4 that are input through the main bus 100. The conversion is provided to the controller 300 through the main bus 100. The magnification selector 210 is generated by reducing the size of the first input signal Input1 according to the selected magnifications 1: 1, 10: 1,... In this case, when the first input signal Input1 is an AC signal, the first input signal Input1 may be converted into a direct current through the rectifying unit 220. The first conversion signal Out1 is generated with a DC voltage of 1 V or more. The first converted output signal Out1 may be used when the multifunctional measuring device of the present invention is used as an instrument such as an ammeter, a voltmeter, or a tachometer.

The chattering prevention unit 240 receives the first input signal Input2 input in a high or low state, such as an on / off signal, and receives the second converted signal Out2 in a high or low state. It prevents chattering from happening. The second converted signal Out2 may be used when the multifunctional measuring device of the present invention is used as an instrument such as a counter or a timer.

The waveform shaping unit 250 receives the third input signal Input3 input in the form of a pulse, such as a frequency signal, and shapes the waveform of the input signal to provide it to the controller 300. In this case, the zero crossing detection unit 230 may receive the first input signal Input1 having an alternating current through the magnification selector 210 and supply it to the third converted signal Out3. Accordingly, the third switch output signal Out3 is generated by selecting the output signal of the waveform shaping unit 250 or the zero crossing detection unit 230 by the switch SW11. The third converted signal Out3 may be used when the multifunctional measuring apparatus of the present invention is used in a speedometer or a frequency meter.

The fourth input signal Input4 is directly provided as the fourth converted signal Out4 without undergoing a separate intermediate process.

As such, the signal conversion unit 200 is configured to convert the measured value into a signal according to an object to be measured, for example, temperature, speed, weight, etc., so that it is easy to change the configuration of the signal conversion unit 200 according to the measurement object. will be.

10 is a block diagram of the controller in the multifunction measuring apparatus according to the preferred embodiment of the present invention.

Referring to FIG. 10, the control unit 300 receives the converted signals Out1, ..., Out4 of the signal converter 200 through the main bus 100, and controls each signal according to the purpose of the measurement device. The microprocessor 330 may be configured to output the result through the display unit 400 or the output unit 600.

When the CONT terminal of the microprocessor 330 is in the low state, the first conversion signal Out1 is applied to the voltage / frequency converter 310 through the first switch SW1. The voltage / frequency converter 310 receives a power supply voltage Vcc1, outputs a frequency corresponding to the input first converted signal Out1, and provides the frequency to the T-IN terminal of the microprocessor 330. The microprocessor 330 receives the frequency signal corresponding to the first conversion signal Out1, converts the signal into a value displayed on the display unit, and displays the external signal through the display unit 400 so as to be recognized externally.

18 illustrates display values of an output signal according to an input frequency signal.

Referring to FIG. 18, the first converted signal Out1 converted by the microprocessor 330 and displayed through the display unit 400 may be expressed as Equation 1 below.

Here, f _x is a frequency input through the T-IN terminal of the microprocessor 330, and f _h and f ₁ represent frequencies higher and lower by a predetermined magnitude than f _x frequency. In addition, Y _max and Y _min represent display values at f _h and f ₁ frequencies, respectively.

At this time, the EEPROM (Electrically Erasable Programmable Read Only Memory) 320 connected to the DOUT, DIN, CS, and CK terminals memorizes a constant reference value to perform a calibration operation. Perform temperature compensation.

The correction process of the measurement error according to the temperature change will be described as an example.

First, a reference value for the calibration operation is calculated through (Equation 1). That is, assume that a voltage of a predetermined magnitude is applied to the voltage / frequency converter 310 by the resistors R0 and R1 connected in series at room temperature of 25 ° C., and the value obtained by Equation 1 is 1,000. At this time, a high state signal is output from the CONT terminal of the microprocessor 330, and the second switch SW2 is turned on so that the mirror reference value equal to the reference value 1,000 and the reference value is equal to the EEPROM 320. Are stored in.

Then, the first switch SW1 is operated to perform a measurement operation on the first input signal Input1. The first input signal Input1 is converted into the first converted signal Out1 through the signal converter 200 and provided to the microprocessor 330 through the voltage / frequency converter 310. At this time, when the value measured by Equation 1 is 2,500, it is assumed that the ambient temperature is changed and the measured value is converted from 2,500 to 2,505. When the measured value is changed, the second switch SW2 is operated through the CONT terminal of the microprocessor 330 to change the mirror reference value from 1,000 to 1,005. Therefore, the changed mirror reference value 1,005 may generate a difference value of 5 from the reference value 1,000 stored in the EEPROM 320. By using the difference value 5, the current measured values 2,505 are compensated (2,505-5), thereby displaying the correct measured values 2,500. The displayed value is again stored in the EEPROM 320 and used as a reference value for subsequent measurement.

As such, the values measured by the microprocessor 330 may be displayed on the display unit 400 so that the display signals A, B, C, D, E, F, G, DP, COM1, COM2, COM3, and COM4 may be displayed. ) Or provided to the output unit 600.

On the other hand, the fifth to eighth switches (SW5, ..., SW8) connected to the microprocessor 330 is for changing the set value of the microprocessor (330). The fifth switch SW5 is for determining the operation mode of the microprocessor 330, and the sixth switch SW6 is a moving key for changing the position of the edit data. In addition, the seventh switch SW7 is for changing the value of data stored in the EEPROM, and the eighth switch SW8 is for determining the data change. In FIG. 10, the case of four switches SW5,..., And SW8 has been described as an example, but may be configured of two or more switches according to the operation of the microprocessor 330.

In addition, the TXD signal, the RXD signal, and the R / T signal are signals provided to an output unit for RS232C or RS485 communication with an external device, and the HO signal and LO signal are signals provided to an output unit for controlling an external load. . In addition, the DA signal is a signal composed of a plurality of bits, which is converted into an analog signal to provide a current or voltage signal to the outside.

11 is a block diagram of a display unit in the multi-function measuring apparatus according to the preferred embodiment of the present invention.

Referring to FIG. 11, the display unit 400 may receive output signals A, B, C, D, E, F, G, and DP from the microprocessor 330 of the controller 300 to externally recognize them. And a display device 410 having a plurality of digits for display, and control means Q1, Q2, Q3, Q4 for controlling the operation of the display device 410.

Although FIG. 11 illustrates a display device 410 having seven segments as an example, a general display device such as a liquid crystal display, an electron tube, or a light emitting diode may be used. Of the signals A, B, C, D, E, F, G, and DP provided from the microprocessor 330, the A, B, C, D, E, F, and G signals are used to represent each segment of seven segments. The DP signal is a signal for indicating a point included in each segment.

Each segment is controlled according to the operation of each transistor Q1, Q2, Q3, Q4 driven by COM1, COM2, COM3 or COM4.

12 is a block diagram of a power supply unit in the multifunction measuring apparatus according to the preferred embodiment of the present invention.

Referring to FIG. 12, the power supply unit 500 includes a transformer for receiving an AC power source of 110V or 220V and converting it into a voltage used in the measurement apparatus. In FIG. 12, in order to reduce noise of an input signal, power (+ Vcc2, -Vcc2) supplied to the D / A output unit in the output unit 600 and power supplied to portions other than the D / A output unit (+ For example, Vcc1 and -Vcc1) are separately shown.

13 is a block diagram illustrating an internal configuration of an output unit in the multifunction measuring apparatus according to the preferred embodiment of the present invention.

Referring to FIG. 13, the output unit 600 receives an output signal from the microprocessor 330, a communication output unit 610 for RS232 or RS485 communication, and a control output unit for controlling a load connected to the outside of the measurement device. 620 and a D / A output unit 630 for providing a current or voltage according to the measured value to the external device.

The communication output unit 610 receives the serial communication transmission signal TXD and the communication transmission / reception control signal R / T from the microprocessor 330 to perform RS232C and RS485 communication. In addition, when the communication output unit 610 receives a communication signal transmitted from the outside, the serial communication reception signal RXD is generated and provided to the microprocessor 330.

The control output unit 620 is mainly for controlling a load device such as a solid state relay (SSR), a silicon controlled rectifier (SCR), or an insulated-gate bipolar transistor (IGBT), and the HO or the HO provided by the microprocessor 330. Internal circuitry operates according to the LO signal.

The D / A output unit 630 receives an n-bit data signal DA of the microprocessor 330 through the main bus 100, converts the n-bit data signal DA into DC, and provides an output signal to an external device.

14 shows an internal circuit diagram of the communication output unit in the multifunction measuring apparatus according to the preferred embodiment of the present invention.

Referring to FIG. 14, the communication output unit 610 may have an RS232 driver 612 for RS232 communication and an RS485 driver 614 for RS485 communication. The RS232 driver 612 transmits the serial communication transmission signal TXD provided from the microprocessor 330 to the outside according to the operation of the third switch SW3. The received signal RXD applied from the outside is provided to the microprocessor 330 according to the operation of the fourth switch SW4.

On the other hand, the RS485 driver 614 converts the serial communication transmission signal TXD received according to the operation of the third switch SW3 into a signal R + / T + for RS485 communication, and provides the signal to the outside and applies the signal from the outside. The received signal R- / T- is converted into a signal RXD used internally and supplied to the microprocessor 330 according to the operation of the fourth switch SW4.

The operation of the RS232 driver 312 and the RS485 driver 314 is performed by a transmission and reception control signal (R / T) for communication. For example, when the communication transmission / reception control signal R / T is in a high state, it is a reception mode, and when it is a low state, it is a transmission mode.

15 is a circuit diagram of a control output unit in the multifunction measuring apparatus according to the preferred embodiment of the present invention.

Referring to FIG. 15, the control output unit 620 is for controlling an external load. When the HO signal is generated from the microprocessor 330, the fifth transistor Q5 is turned on and the first relay RLY1. The contacts of the sixth and seventh output terminals Output6 and Output7 are connected to each other. The HO signal is a signal generated when the measured value exceeds the reference value set by the fifth to eighth switches SW5, ..., SW8. Therefore, when the measured value exceeds the reference value, an alarm signal is generated that the measured value exceeds the reference value through the sixth and seventh output terminals Output6 and Output7. Accordingly, the user may change the displayable range on the display unit 400.

On the other hand, when the measured value is smaller than the lowest reference value, the LO signal is generated in the microprocessor 330, the sixth transistor Q6 is turned on, and the eighth and ninth outputs through the second relay RLY2. The contacts of terminals (Output8, Output9) are connected. Accordingly, an alarm signal indicating that the minimum reference value is less than the eighth and ninth output terminals Output8 and Output9 is generated, and the user can change the displayable range on the display unit 400. At this time, it will be obvious that other switching elements such as FET (Field Effect Transistor) can be used in addition to the BJT.

16 is a circuit diagram of a D / A output unit in the multifunction measuring apparatus according to the preferred embodiment of the present invention.

Referring to FIG. 16, the D / A output unit 630 converts an n-bit measurement signal DA generated by the microprocessor 330 into an analog signal through the D / A converter 632 and then operates an OP amplifier. The D / A converter 632 converts the analog signal into a signal having a predetermined size. When the signal amplified by the OP amplifier is greater than or equal to the threshold voltage of the seventh transistor Q7, the seventh transistor Q7 is turned on to generate an output signal through the eleventh output terminal Output11. . In addition, the D / A output unit 630 is independent of the power supply (+ Vcc1, -Vcc1) used in the signal conversion unit 200, the control unit 300 or the display unit 400 to reduce noise caused by the input signal. (independent) Use a different power supply (+ Vcc2, -Vcc2). FIG. 16 shows a D / A output unit in the case of using a general D / A converter 632 and an OP amplifier amplifier.

17 is a diagram showing signals used in the multifunction measuring apparatus according to the preferred embodiment of the present invention.

Referring to FIG. 17, + Vcc1 and -Vcc1 generated by the power supply unit 500 are analog power supplies for internal operation of the multifunction measuring apparatus of the present invention, and + Vcc2 and -Vcc2 are used to reduce noise of an input signal. A power source used for the D / A output unit 630. In addition, the Input1 to Input5 signals are input signals applied to the main bus 100, and Input5 is a ground input signal.

The signals Out1 through Out4 are converted signals of the input signals Input1, ..., Input4 in the signal converter 200, and COM1 through COM4 drive each segment with respect to the display unit 400 having four seven segments. It is a drive signal for this purpose.

DA0 to DA7 are data signals in the case of processing an 8-bit digital signal, and signals from DA0 to DA15 or DA0 to DA31 can be used when processing data in 16-bit or 32-bit.

The RXD signal represents a receiving signal or a receiving terminal that receives a signal from the outside in RS232 or RS485 communication, and the TXD represents an output signal or output terminal for transmitting externally. The R / T signal is a control signal for selecting transmission or reception at the communication output unit 610, and the HO and LO signals are alarm signals when the measured value is outside the range of the highest reference value and the lowest reference value, respectively.

On the other hand, the operation of processing the measured value in the multi-function measuring apparatus of the present invention may be performed by first installing the microprocessor 330 on the main bus or the main board, and inputs a programming signal or data through an external signal input terminal. . The SDA signal is an external data signal for applying to the microprocessor 330, and the SCK signal is an external clock signal.

19 is a diagram showing each component type of the digital instrument in the case of using the multi-function measuring apparatus of the present invention.

Referring to Fig. 19, in a digital instrument such as a voltmeter, ammeter, frequency meter, power factor meter, thermometer, power meter, counter, timer, communication system, tachometer, line speed meter, pressure gauge, level meter, hygrometer, flow meter, or accelerometer, In the case of forming an internal configuration like a multi-function measuring device, the signal conversion unit, the control unit, the display unit, the power supply unit, the output unit, and six parts of the main bus connecting the respective parts can be configured.

The signal converter may be configured in different configurations according to the type of signal to be measured, and when the measurement target is changed, the corresponding signal converter may be selected accordingly.

For example, the signal converter for measuring current may be unified with a shunt, and the signal converter for voltage measurement may be configured as a rectifier for rectifying a transformer and an alternating current with a direct current. In addition, the ohmmeter and the temperature sensor may be configured as one signal converter by measuring the magnitude of the current or the magnitude of the current flowing in the resistor according to the temperature. As such, the pulse input and the proximity sensor may be configured by the same signal converter, the displacement sensor and the acceleration sensor may be configured as one single part, and the pressure sensor and the weight sensor may be configured by the same part. The communication inputs can be used together with the communication outputs.

As described above, in the case of the configuration, about 60 input signal units and about 6 signal processing units may be configured by about 10 signal conversion units.

In addition, the control unit can be configured as one control unit as compared with the conventional four types by using the V / F converter for converting the voltage of the input signal into a frequency.

On the other hand, the display portion and the display size have the same display range and display method as those of the conventional display portion.

The power supply unit integrates a conventional input signal unit and a signal processing unit and constitutes a small number of signal conversion units, so that the power supply unit uses a DC 5V power supply unit, DC 12V, DC 24V, DC 48V, and AC 48V as compared to about 10 conventional methods. It can be reduced to about 5 types such as power supply unit using AC 100V and DC 100V together, power supply unit using AC 100V and AC 240V together, and prevolt power supply.

In addition, the output unit can be reduced to one by forming the communication output unit, the control output unit and the D / A output unit together to form a single output unit.

Therefore, although 3,359,400 types of products can be produced according to the conventional digital instrument, the signal conversion unit (10 types) × control unit (1 type) × display unit (7 types) (5 types) × output unit (1 type) = 350 kinds of modules can realize all kinds of digital instruments.

In particular, the multi-function measuring apparatus of the present invention does not change even if the measurement target is changed once the rest of the parts other than the signal conversion unit, that is, the control unit, the display unit, the power supply unit, the output unit and the main bus (main substrate), Can be manufactured as a fixed product. Therefore, all measurement instruments can be implemented by replacing about 10 signal converters in a measuring device including a control unit, a display unit, a power unit, an output unit, and a main bus.

FIG. 20A illustrates a product configuration diagram of a conventional digital measurement apparatus, and FIG. 20B illustrates a product configuration diagram of a multifunction measurement apparatus according to a preferred embodiment of the present invention.

Referring to FIG. 20A, a conventional digital measurement apparatus includes a power supply transformer 840 provided on a main substrate 800, a display module provided with a display element 810 for displaying a measurement value and an operation switch 820, and Outer various parts 830 are made. These various parts of the product varies depending on the object to be measured, the configuration of the measuring device accordingly.

Referring to FIG. 20B, in the multi-function measuring apparatus of the present invention, a power supply unit 980, a display unit 930, a controller 940, an output unit 950, and a signal converter 960 are installed on the main substrate 900, respectively. do. The signal converter 960 may have different components 970 for signal conversion depending on the object to be measured. The display unit 930 may include a display device 910 such as an LCD and an operation switch 920. As shown in FIG. 20B, the power supply unit 980, the display unit 930, the control unit 940, and the output unit 950 are fixed to the main substrate 900, and a signal conversion unit 960 suitable for the measurement target, as necessary. By installing), various measurement functions can be implemented. Therefore, the signal converter 960 is preferably manufactured in a module form so as to be easily installed and removed on the main substrate 900.

As described above, according to the multi-function measuring apparatus of the present invention, various measurement functions can be implemented using a single device by replacing only the signal conversion unit corresponding to the object to be measured. Therefore, since only the research and modification of the signal conversion unit needs to be made during the product change or development of a new product, the development or implementation time of the new product can be shortened and the cost can be reduced.

In addition, the multi-function measuring apparatus of the present invention can be replaced only the signal conversion module according to the measurement target, and other components can be fixed on the main board without having to replace, so that the measurement function of the Easy to switch

In addition, by reducing the type of the signal conversion module according to the measurement target, it is possible to reduce the cost and effort required to configure the measuring device of various functions.

In addition, the multi-function measuring apparatus of the present invention, when the measured value is out of the display range to display it externally so that the user can change the display range, it is convenient to use the product according to the measurement target.

In addition, the microprocessor is provided in the control unit for signal processing, and the operation of the processor can be controlled through a program, thereby reducing the production cost and development cost of the product according to the measurement target, and reducing the effort and time required for development. Can be reduced.

In addition, since the measurement error correction method of the present invention does not require a separate device for error compensation, it is possible to effectively prevent the measurement error due to the temperature change, it is possible to reduce the cost for error compensation.

In the above, preferred embodiments of the multi-function measuring apparatus and measuring error correction method of the present invention have been described in detail, but the contents are not limited to the field of the present invention described in the following claims. In addition, it will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the present invention.

Claims (34)

In the measuring device, A signal converting unit which is replaceable according to a measurement target and converts at least one or more input signals according to a sensing result of the measurement target or a signal to be measured into a signal that can be processed internally; A controller configured to receive a selected converted signal from one or more converted signals output from the signal converting unit, and generate a digital measurement signal representing a corresponding measurement value, and at least one output control signal for controlling an operation of the selected output target; A display unit which receives the digital measurement signal and the output control signal of the controller and displays the corresponding measured value so as to be recognized externally; An output unit configured to receive a digital measurement signal and an output control signal of the controller to transmit / receive data with an external device; And A power supply unit which receives AC power and converts it into internal power required for the operation of the signal conversion unit, the control unit, the display unit, or the output unit, and provides the same to the corresponding portion. Multifunctional measuring device using a removable module comprising a. The method of claim 1, The signal converter Sensing unit that detects a measurement target and converts it into one or more input signals Multifunctional measuring device using a removable module further comprising. The method of claim 1, The signal converter A DC voltage generator converting a signal selected from one or more input signals into a DC voltage and outputting the DC voltage; A digital signal generator for outputting a signal selected from one or more input signals as a high state or low state signal; And Pulse signal generator for converting the selected signal from one or more input signals into a pulse form and outputs Multifunctional measuring device using a removable module comprising a. The method of claim 3, The DC voltage generator A magnification selector for changing the magnitude of the input signal to a magnitude suitable for internal operation; And If the output signal of the magnification selector is an AC signal, the rectifier converts it to a DC signal. Multifunctional measuring device using a removable module comprising a. The method of claim 3, The digital signal generator Chattering prevention to reduce chattering of input signals Multifunctional measuring device using a removable module further comprising. The method of claim 3, The pulse signal generation unit Waveform Shaping to Shape the Input Signal Multifunctional measuring device using a removable module further comprising. The method according to claim 4 or 6, A zero crossing detector for converting an AC signal of the magnification selector into a pulse signal. Multifunctional measuring device using a removable module further comprising. The method of claim 1, The control unit A frequency converter converting the DC voltage of the signal converter into a frequency corresponding to the voltage magnitude; A digital measurement signal corresponding to a signal input by the internal processing by receiving the frequency signal of the frequency converter and the output signal of the signal converter, a transmission / reception signal for transmitting a signal to an external device, and one for controlling the operation of an output object. A processor for generating the above output control signal; A memory coupled to the processor for storing a reference value for compensating for an error in the measured value; And A switching unit coupled to the processor, the switching unit including one or more switches for changing an operation mode of the processor or a reference value stored in the memory Multifunctional measuring device using a removable module comprising a. The method of claim 8, The switching unit A first switch controlling an operation mode of the processor; A second switch for changing a storage position of the reference value stored in the memory; And Third switch for changing the size of the reference value stored in the memory Multifunctional measuring device using a removable module comprising a. The method of claim 8, The transmission and reception signal is Transmit / receive control signal for selecting data transmission to an external device or data reception from an external device Multifunctional measuring device using a removable module further comprising. The method of claim 8, The output control signal is Alarm signal to inform outside when measured value is out of display range Multifunctional measuring device using a removable module further comprising. The method of claim 1, The display unit At least one display device for displaying the measured value to be externally recognized; And One or more display controllers for controlling an operation of the one or more display devices Multifunctional measuring device using a removable module comprising a. The method of claim 12, The display device Multifunctional measuring device using a removable module which is at least one of a seven segment, a liquid crystal display, a light emitting diode or an electron tube. The method of claim 1, The output unit Communication output unit for transmitting and receiving data with an external device; A control output unit for controlling an external load; And D / A output for supplying DC voltage or DC current to external equipment Multifunctional device using a removable module comprising a. The method of claim 14, The communication output unit RS232 driver for RS232 communication; And RS485 driver for RS485 communication Multifunctional device using a removable module comprising a. The method according to claim 11 or 14, The control output unit An excess state alarm unit for notifying to the outside when the measured value exceeds the display range of the display unit; And Under-state alarm for notifying outside when measured value is out of display range Multifunctional measuring device using a removable module comprising a. The method of claim 16, The excess state alarm unit Multifunctional measurement device using a detachable module consisting of a delay circuit. The method of claim 16, The less than state alarm unit Multifunctional measuring device using a removable module composed of a delay circuit. The method of claim 14, The D / A output unit A DA converter converting the digital measurement signal of the controller into an analog signal corresponding thereto; An amplifier for amplifying the analog signal of the DA converter to a voltage having a predetermined magnitude; And DA output control unit for controlling the output signal supplied to the external device according to the output voltage of the amplifier Multifunctional measuring device using a removable module comprising a. The method of claim 19, The DA converter Multifunctional measuring device using a removable module composed of a plurality of resistors connected to each bit signal of the digital measurement signal. The method of claim 19, The amplification unit A reference signal generator for generating a reference signal; And OP amplifier that receives the output signal and the reference signal from the DA converter to the inverting input terminal, and the output signal is fed back to the non-inverting input terminal through the DA output controller. Multifunctional measuring device using a removable module comprising a. The method of claim 19, The DA output control unit Switching means for controlling on / off in accordance with an output signal of the amplifier; And At least one resistor and diode connected in series between said switching means and a power supply Multifunctional measuring device using a removable module comprising a. The method of claim 22, The switching means Multifunctional measuring device using removable module which is a transistor. The method of claim 1 or 19, The output unit A first converter converting AC power into a power source for driving the D / A output unit; And A second converter converting the AC power into a power source for driving the signal converter, the controller, the display, the communication output or the control output; Multifunctional measuring device using a removable module comprising a. A controller configured to receive a signal and generate a digital measurement signal representing a corresponding measurement value, and at least one output control signal for controlling an operation of the selected output object; A display unit which receives the digital measurement signal and the output control signal of the controller and displays the corresponding measured value so as to be recognized externally; An output unit configured to receive a digital measurement signal and an output control signal of the controller to transmit / receive data with an external device; A power supply unit which receives AC power and converts the internal power into an internal power required for the operation of the control unit, the display unit, or the output unit and provides the same to a corresponding part; And The signal transmission between the control unit, the display unit, the output unit, and the power supply unit is intermediated, and at least one input signal according to the sensing result of the measurement target or the measurement target signal is a signal that can be processed in the measurement apparatus. A main substrate to which a removable signal conversion device configured to be converted and provided to the control unit may be attached Multifunctional measuring device using a removable module comprising a. A control unit for receiving a signal and generating a digital measurement signal representing a corresponding measurement value, and at least one output control signal for controlling an operation of the selected output target, and receiving the digital measurement signal and output control signal of the control unit A display unit for displaying a corresponding measurement value to be recognized externally, an output unit receiving and receiving data from a digital measurement signal and an output control signal of the control unit, and transmitting and receiving data to and from an external device; In the measuring device having a power supply for converting the internal power required for the operation of the output unit, and providing it to the corresponding portion, and the main board connected to the control unit, the display unit, the output unit and the power supply, respectively, and relays signal transmission therebetween. In A converter configured to convert at least one input signal according to a sensing result of the measurement target or a signal to be measured into a signal that can be processed in the measurement apparatus; And Signal transmission unit for providing the converted signal to the control unit through the main board Removable signal conversion device comprising a. The method of claim 26, Sensing unit that detects a measurement target and converts it into one or more input signals Removable signal conversion device further comprising. The method of claim 26, A DC voltage generator converting a signal selected from one or more signals into a DC voltage and outputting the DC voltage; A digital signal generator for outputting a signal selected from one or more signals as a high state or low state signal; And Pulse signal generator for converting the selected signal from one or more signals into a pulse form and outputting Removable signal conversion device comprising a. The method of claim 28, The DC voltage generator A magnification selector for changing the magnitude of the input signal to a magnitude suitable for internal operation; And If the output signal of the magnification selector is an AC signal, the rectifier converts it to a DC signal. Removable signal conversion device comprising a. The method of claim 28, The digital signal generator Chattering prevention to reduce chattering of input signals Removable signal conversion device further comprising. The method of claim 28, The pulse signal generation unit Waveform Shaping to Shape the Input Signal Removable signal conversion device further comprising. Calculating a reference value for the measured value compensation, and storing the reference value and the mirror reference value, respectively; Measuring a numerical value for the measurement object; If there is a variation in the measured value, changing the mirror reference value by the variation in the measured value; Calculating a difference value by comparing the changed mirror reference value with the reference value; And Changing the measured value by the difference value Correction method of measuring error comprising a. 33. The method of claim 32, The reference value is Method for correcting the measurement error calculated by the following equation. From here, f _x represents the frequency of the signal input to the microprocessor, f _h represents a frequency higher than the frequency f _x by a certain amount, f _l represents a frequency lower than f _x by a certain amount, Y _max represents the displayed value at the f _h frequency, Y _min represents the displayed value at f _l frequency. 33. The method of claim 32, The step of changing the measured value Setting the changed measured value as the reference value Correction method of the measurement error further comprising.