JP2009192515A - Surveillance device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance a visibility on a meter in an important monitor range of an electric current value of a motor. <P>SOLUTION: This surveillance device 100 carries out a digital conversion of the measured value of the motor by an A/D conversion part 1 and conducts operation processing using predetermined operation expression by an operation part 2. In operation processing, a fixed coefficient is multiplied to the input value in an ordinary monitor range, but in the important monitor range, more larger coefficient than the coefficient is multiplied to the input value. The output measured value is carried out analog conversion by D/A conversion part 3 and outputs as a current driving a pointer 8 of a meter 4. Thereby, the measured value of the motor in the important monitor range is displayed on the meter with in the expanded state rather than the measured value in the ordinary monitor range, therefore, visual inspection of fall and rise of the current of the motor is carried out in detail and easily. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a monitoring device that measures a load state of an electric motor such as a motor and other electric devices based on a current value thereof and monitors a state of the motor and a machine using the motor.

  Recently, monitoring the operation status of production machines and the like so that managers can easily see them in factories or the like is called “visualization” or the like, and is being implemented by various companies. For example, many motors are used in production lines, processing machines, loaders, robots, and the like that constitute the production line. By measuring the current of the motor, the life of the motor itself can be determined, and the motor load can be determined. The state of the machine ahead of the motor can be determined from the state.

Generally, when measuring a motor current in detail using a DC current measuring device, the magnification of the measuring device is set to a predetermined value, and the display of the magnification displayed on the meter is read. A scale is displayed on the meter for each predetermined magnification (for example, a survey meter described in Patent Document 1).
Japanese Patent Laid-Open No. 06-109857

  However, even if the magnification of the measuring instrument can be changed, it is only displayed at that magnification throughout the meter.For example, if the measured value exceeds the upper or lower limit of the range measurable by the magnification, the pointer moves. There was a problem that the current value could not be determined due to the absence or shaking of the light. On the other hand, when the magnification is set so as to display the entire range of current values that can be input, there is a problem in that it is difficult to visually recognize the range to be intensively measured.

Means for Solving the Invention

  The present invention has been made to solve the above-described problems, and includes a meter having a pointer and a scale, and in a monitoring device for measuring the current or voltage of an electric motor or other electrical equipment, the scale is An analog that has an enlarged display area that is displayed larger than the normal display area, that is displayed continuously in the normal display area and the enlarged display area, and that converts the measured value input from the motor into a predetermined digital value. / Digital conversion means, calculation means for performing calculation processing so that the measurement value in the priority monitoring range among the digitally converted measurement values is expanded relative to the measurement value in the normal monitoring range, and the calculation means And a digital / analog conversion means for converting the measured value calculated in step 1 into a current for moving the pointer. Specifically, the calculation means multiplies the measurement value of the priority monitoring range digitally converted by the analog / digital conversion means by a coefficient larger than the measurement value of the normal monitoring range, and calculates the calculated measurement value. The digital / analog conversion means performs analog conversion again, whereby the pointer moves greatly when displaying the measurement value of the focus monitoring range, and the scale corresponding to the focus monitoring range is larger than the normal display area. Displayed (enlarged display area), the measured value can be enlarged and displayed in the focus monitoring range.

  Further, in the present invention, the present invention further includes setting means for setting the priority monitoring range, and the setting means includes input means for inputting an upper limit value and / or a lower limit value of the priority monitoring range, and the upper limit value and And / or an arithmetic expression obtaining means for obtaining an arithmetic expression from the lower limit value.

  In addition, the present invention further includes setting means for setting an enlarged display area in the above invention, the setting means including input means for inputting an upper limit value and / or a lower limit value of the enlarged display range, and the upper limit value and And / or an arithmetic expression obtaining means for obtaining an arithmetic expression from the lower limit value.

  In addition, the present invention is characterized in that, in the above-mentioned invention, the apparatus includes a plurality of the meters and a corresponding unit that associates measured values of the plurality of electric devices with the corresponding meter for each electric device. As a specific example, the corresponding means selects a predetermined arithmetic expression based on the plurality of meters, determination data providing means for adding determination data for each electric device to measurement values of the plurality of electric devices, and the determination data. It comprises a selection means and a classification output means for classifying the measured value after calculation by the calculation means for each electric device and outputting it to the corresponding meter.

  Further, according to the present invention, in the above-described invention, the meter, determination data providing means for adding determination data for each electric device to measurement values of a plurality of electric devices, and a predetermined arithmetic expression are selected based on the determination data A selection means for selecting, a measurement value after calculation by the calculation means for each electrical device, and a selection output means for output, and a selection for selecting a specific output from the output from the classification output means and sending to the meter Means.

  In the invention described above, the enlarged display area and the normal display area are displayed in different colors.

(Embodiment 1)
FIG. 1 is an external perspective view showing a monitoring apparatus according to Embodiment 1 of the present invention. FIG. 2 is a configuration diagram illustrating the monitoring apparatus illustrated in FIG. 1. The monitoring apparatus 100 includes an input unit that inputs a DC current (or DC voltage) of an electric motor such as a motor to be measured, and an analog / digital conversion unit 1 that converts the input DC current from an analog value to a digital value ( A / D conversion unit 1), a calculation unit 2 that performs a predetermined calculation process on the digitally converted measurement value, and a digital / analog conversion unit 3 (D / D) that reconverts the calculated digital value into an analog value. A conversion unit 3), an analog meter 4 for displaying the measurement value subjected to the arithmetic processing, a setting unit 5 for setting the arithmetic expression of the arithmetic processing of the arithmetic unit 2, a power source 6 of the monitoring device 100, a predetermined A storage unit 10 such as a ROM (Read Only Memory) that stores the above program and an alarm unit 12.

  On the front surface of the housing 50 of the monitoring device 100, a dial 51 constituting the meter 4 and the setting unit 5, a power switch 52 of the power source 6, and the like are arranged. Further, an input terminal to which a motor to be monitored and other electric motors are connected is provided at the lower part of the housing 50 (not shown). Note that the dial 51 may be provided inside the housing 50. Further, the outer shape of the housing 50 and the arrangement of the dial 51 and the like shown in FIG. 1 are merely examples, and other forms can be appropriately adopted.

  The meter 4 is a moving coil type measuring instrument, and includes a moving coil, a permanent magnet, a pointer 8, a scale plate 9, and the like. The scale 7 displayed on the scale plate has a fan shape in which a specific range is enlarged and displayed. The scale 7 displays, for example, 0A to 100A as a whole measurement range, and the range of 40A to 60A (emphasis monitoring range) among them is enlarged and displayed (enlarged display area 7a). Specifically, with respect to all the scales, the left 1/3 portion is a portion (normal display area 7b) for displaying the range of 0A to 40A (normal monitoring range), and the central 1/3 portion is 40A. ˜60A range (priority monitoring range) is displayed (enlarged display area 7a), the right 1/3 part is displayed 60A-100A range (normal monitoring range) (normal display area 7b), As a whole, the range of 40A to 60A is enlarged and displayed as compared with the other ranges, and the scale of the normal display area 7b and the scale of the enlarged display area 7a are continuously displayed.

  In other words, the display of 0A to 40A is assigned to the left third part of the whole scale, for example, the part is divided into 40 equal parts, and one scale is attached every 5A, and the central third part is 40A to 40A. Allocate the display of 60A, for example, divide the part into 20 equal parts, attach 1 scale every 5A, assign the display of 60A-100A to the 1/3 part of the right, for example, divide the part into 40 parts By attaching one scale every 5A, the priority monitoring range is enlarged and displayed.

  The scale 7 is provided with different colors for the enlarged display area 7a and the normal display area 7b. Specifically, the enlarged display area 7a of 40A to 60A means normal operation of the electric motor, and is displayed in green, for example. On the other hand, the normal display area 7b is displayed in red, for example, because there is a high possibility that some problem (for example, no load or overload) has occurred in the electric motor. The color arrangement is not limited to green and red as long as the enlarged display area 7a and the normal display area 7b can be easily distinguished visually and the pointer 8 is easily visible.

  The A / D converter 1 converts the input current from an analog value to a digital value. The number of divisions at the time of digital conversion should be a number that does not make the fluctuation of the pointer 8 awkward, but if the number of divisions is too large, the calculation process becomes complicated, so the entire measurement range is considered. It should be a reasonable number of divisions. For example, if the monitoring target is a motor, specifically, it is preferable to divide 512, 1024, 2048, or 4096.

  The computing unit 2 multiplies the measured value converted into the digital value by a predetermined coefficient. That is, the input value in the priority monitoring range is multiplied by a coefficient (for example, a factor of four times) larger than the input value in the normal monitoring range. FIG. 3 is a chart for explaining the calculation method. The horizontal axis shows the input value, and the vertical axis shows the output value. In the range of 0A to 40A where the input value is the normal monitoring range and the range of 60A to 100A, the input value is multiplied by a certain coefficient (for example, coefficient “0.5”), but the priority monitoring range is 40A to 40A. In the range of 60 A, a coefficient larger than the coefficient (for example, coefficient “2”) is multiplied. The ratio of this coefficient (slope in the chart) is the enlargement ratio. This coefficient may be any value in the normal monitoring range and the priority monitoring range, but is at least a value such that the measurement value in the priority monitoring range is expanded relative to the measurement value in the normal monitoring range. There must be.

  The storage unit 10 stores an arithmetic expression for performing the enlargement. The D / A converter 3 converts the measured value after the calculation into an analog current for driving the meter 4. In addition, the casing 50 is provided with an alarm device 53 (such as a buzzer) that warns when the upper limit value is exceeded or the lower limit value is exceeded. The alarm device 53 operates based on a signal from the alarm unit 12 when the measured value exceeds the priority monitoring range. If the energization of the alarm device 53 is cut off for a few seconds after the power is turned on, the alarm device 53 will not sound even if the measured value falls below the lower limit value when the power is turned on. Further, when the power is turned off, the alarm device 53 will not sound if the power to the alarm device 53 is cut off at the same time.

  Next, the operation of the monitoring apparatus 100 of the present invention will be described. For example, a production line of a foundry or a direct current motor that drives a machine is monitored. A motor that needs to be monitored is connected to an input terminal of the monitoring device 100. When the motor is in an unloaded state, the current value decreases, and when an overload is applied, the current value increases. By monitoring this current value, normality / abnormality of the motor itself or the machine driven by the motor, etc. Can be judged. For example, when the motor is operating normally, the current value is in a range of 40A to 60A, and a direct current within the range is input to the input unit as a measured value. This measured value is digitally converted by the A / D converter 1 and sent to the calculator 2.

  The computing unit 2 reads an arithmetic expression stored in advance in the storage unit 10 into a temporary memory (not shown), and performs arithmetic processing on the measurement value using the arithmetic expression. The arithmetic processing is performed by a method as shown in FIG. That is, when the input value is the normal monitoring range of 0A to 40A and the range of 60A to 100A, the input value is multiplied by a constant coefficient (for example, coefficient “0.5”). In a range larger than 40A and less than 60A, which is the monitoring range, a coefficient larger than the coefficient (for example, coefficient “2”) is multiplied and output.

  Next, the output measurement value is converted into an analog signal by the D / A converter 3 and output as an appropriate current for driving the pointer 8 of the meter 4. The pointer 8 of the meter 4 operates based on this current value. As a result, the measured value of the motor in the priority monitoring range is displayed enlarged on the meter than the measured value in the normal monitoring range.

  As described above, in the monitoring apparatus 100, the range of the measurement value to be monitored with priority is enlarged and displayed, so that the reduction and increase in the current for driving the motor can be visually confirmed in detail and easily. If the pointer 8 approaches or exceeds the upper limit value or the lower limit value of the priority monitoring range, the monitor can determine that an abnormality has occurred in the motor or the production apparatus that is the driving target of the motor.

  Further, the setting unit 5 can freely change the setting of the priority monitoring range. For example, as shown in FIG. 1, a dial 51H for setting an upper limit value and a dial 51L for setting a lower limit value are provided on the front surface of the casing 50 of the monitoring apparatus 100, and the lower limit value and the upper limit value are set using these dials. Are set ("input means"). For example, as shown in FIG. 4, the lower limit value of the priority monitoring range can be set to 35A and the upper limit value can be set to 65A, or the lower limit value can be set to 45A and the upper limit value can be set to 55A. The setting can be set in units of 5A, for example.

  Since the upper limit and the lower limit (M1.M2) of the output value for the meter 4 are fixed and the input values (I1, I2) are variable, when the input value is set by the setting unit 5, the input values (I1, I2) ), The slopes of the priority monitoring range and the normal monitoring range are obtained from the output values (M1, M2), and this is stored in the storage unit 10 as an arithmetic expression corresponding to the set input value. The setting unit 5 includes a storage unit 5a that stores a program for generating (or selecting) the arithmetic expression from the upper limit value, the lower limit value, and the fixed output value, and generates (or selects) the arithmetic expression. And a processing unit 5b for acquiring a specific arithmetic expression ("arithmetic expression acquiring means").

  For example, as shown in FIG. 4A, when the lower limit value of the input value is set to 35A and the upper limit value is set to 65A, the output values M1 and M2 are fixed. The slopes of the respective arithmetic expressions in the range and the priority monitoring range are obtained. This calculation formula is stored in the storage unit 10 and is read into a temporary memory of the calculation unit 2 at the time of calculation.

  Similarly, as shown in FIG. 4B, when the lower limit value of the input value is set to 45A and the upper limit value is set to 55A, the output values M1 and M2 are fixed. The slopes of the respective arithmetic expressions in the range and the priority monitoring range are obtained. This calculation formula is stored in the storage unit 10 and is read into a temporary memory of the calculation unit 2 at the time of calculation. The display of the lower limit value and the upper limit value on the scale is preferably changed electrically or mechanically in conjunction with the switching of the dial 51.

  Further, each arithmetic expression is created in advance for each combination of the upper limit value and the lower limit value of the input value and stored in the storage unit 10, and the arithmetic expression acquiring means stores the memory by switching the dial 51 as the input means. A corresponding arithmetic expression may be selected from the unit 10 and read by the arithmetic unit 2. In this case, the storage unit 10 may be a non-writable one such as a ROM.

  In this way, it is possible to set an appropriate priority monitoring range according to the characteristics of an electric motor such as a motor to be monitored or a machine using the electric motor.

  FIG. 5 is an explanatory diagram showing a modification of the scale display form. The scale 7 of the meter 4 may have a three-quarter arc shape as shown in FIG. 5 instead of a quarter arc shape as shown in FIG. 1 or FIG. Visibility can be enhanced by widening the display range of the scale 7 and increasing the movement of the pointer 8 of the meter 4 accordingly. The shape of the meter 4 may be any shape as long as the normal monitoring range and the priority monitoring range are displayed on different scales. Although not shown, the scale 7 may be displayed in a straight line instead of an arc, and the pointer 8 may move linearly with respect to the linear scale 7.

  FIG. 6 is an explanatory diagram showing a calculation method when an enlarged display area is set. As shown in the figure, the input values (I1, I2) may be fixed and the upper limit value and the lower limit value (M1, M2) of the enlarged display area may be set. The setting unit 5 includes a storage unit 5a that stores a program for generating (or selecting) the arithmetic expression from the upper limit value, the lower limit value, and the fixed input value, and generates (or selects) the arithmetic expression. And a processing unit 5b for acquiring a specific arithmetic expression ("arithmetic expression acquiring means").

  For example, as shown in FIG. 6A, when the lower limit value of the enlarged display area is set to M1b and the upper limit value is set to M2b, the slope of the arithmetic expression in the priority monitoring range increases, and the enlargement rate of the input value is further increased. Can be big. On the other hand, the inclination of the normal monitoring range is reduced. Also in this case, the slopes of the priority monitoring range and the normal monitoring range are obtained from the input values (I1, I2) and the output values (M1, M2) by the arithmetic expression acquisition means, and this corresponds to the set input value. It is stored in the storage unit 10 as an arithmetic expression. At the time of calculation, the data is read into a temporary memory of the calculation unit 2.

  Also, as shown in FIG. 6B, when the lower limit value of the enlarged display area is set to M1a and the upper limit value is set to M2a, the slope of the arithmetic expression in the priority monitoring range becomes small. In this case, since the inclination of the normal monitoring range becomes large, monitoring in this normal display area becomes easy. Also in this case, similarly to the above, the slopes of the priority monitoring range and the normal monitoring range are obtained from the input values (I1, I2) and the output values (M1, M2) by the arithmetic expression acquisition unit, and these are set as the input. The calculation unit corresponding to the value is stored in the storage unit 10. At the time of calculation, the data is read into a temporary memory of the calculation unit 2.

  Moreover, when setting the output value on the meter side, the display of the scale 7 must be changed accordingly. For example, as shown in FIG. 7, in the monitoring device 150, a switch 54 for selecting a range setting target (input value (I 1, I 2) or output value (M 1, M 2)) on the front surface of the housing 50. The upper limit value setting dial 51H and the lower limit value setting dial 51L are shared by the input value setting and the output value setting. If the switch 54 is set to IN, the lower limit value I1 and the upper limit value I2 of the input value can be set by the upper limit value setting dial 51H and the lower limit value setting dial 51L. If the switch 54 is set to OUT, the upper limit value setting is performed. The lower limit value M1 and the upper limit value M2 of the output value can be set by the dial 51H for setting and the dial 51L for setting the lower limit value. Note that the dial 51 and the switch 54 may be provided inside the housing 50. Further, the forms of the upper limit value setting dial and the lower limit value setting dial are not limited to those shown in FIG.

  Further, an upper limit value dial 55 and a lower limit value dial 56 for adjusting the full scale width of the enlarged display area are provided on the upper portion of the housing 50, respectively. By rotating the dials 55 and 56, the display line 57 for the lower limit value and the display line 58 for the upper limit value move mechanically or electrically in a substantially horizontal arc direction. Although not shown, when this is realized mechanically, for example, the normal display area is a fan-shaped display plate, the rotation of the dials 55 and 56 is transmitted by a gear or the like, and the rotation center of the pointer 8 of the meter 4 is the center. What is necessary is just to make it rotate. If the color of the display plate is changed, the normal display area and the enlarged display area can be color-coded. Further, in the case of electrical realization, a plurality of LEDs are arranged in an arc along the scale 7, or the scale 7 is displayed by liquid crystal or EL, and the display range is changed by the dials 55 and 56. good.

  Further, as a simple method, as shown in FIG. 8, scale plates 13 having different display lines 57 for the lower limit value and display lines 58 for the upper limit value are prepared, and the scale plate 13 is exchanged to enlarge the display. The full scale width of the area may be changed. Specifically, as shown in FIG. 8A, the scale full width of the enlarged display area 7a is larger than the standard, and as shown in FIG. 8B, the enlarged display area 7a is larger than the standard. Prepare one with a smaller scale overall width. In this way, the normal display area 7b and the enlarged display area 7a can be easily changed. In addition, the adjustment means of the scale width of the enlarged display area 7a is not limited to the above means.

  Moreover, as shown in FIG. 9, you may enable it to measure electric motors, such as a motor driven by alternating current. Specifically, an alternating current (AC) / direct current (DC) converter 11 is provided in the input unit of the monitoring apparatus shown in FIGS. The AC / DC converter 11 includes a rectifier and a smoother (not shown). By providing the AC / DC converter 11 in the input unit, it is possible to monitor the AC motor. Other configurations are the same as those of the monitoring apparatus 100 shown in FIGS.

  As mentioned above, according to the monitoring apparatus 100 concerning Embodiment 1 of this invention, since the range of the measured value to monitor preferentially is displayed as an important monitoring range expanded rather than another range, visibility becomes high. For this reason, it is easy to judge normality / abnormality of the electric motor and the production machine using the electric motor. Further, although not shown, normal / abnormality of the electric motor or the like may be monitored using a voltage applied to the electric motor as an input value.

(Embodiment 2)
FIG. 10 is a block diagram showing a monitoring apparatus according to the second embodiment of the present invention. The monitoring device 200 is characterized in that it is configured to monitor a plurality of motors M, compared to the configuration of the monitoring device 100 shown in the first embodiment. That is, a feature is that a plurality of input units are provided, a motor M to be monitored is connected to each input unit, and a meter 4 is provided for each motor M. The input switching unit 204 switches the input from each input unit to one and sends it to the A / D conversion unit 201. If the input units are not insulated from each other, an insulation amplifier is provided for each input (not shown). The A / D conversion unit 201 digitally converts the measurement values of each motor M, and adds a header for determining which motor M current for each measurement value of each motor M (“discrimination data addition”). means").

  The calculation unit 202 sequentially calculates the digitally converted measurement values. The type of the motor M, the machine using the motor M, and the like have different priority monitoring ranges. For this reason, arithmetic expressions corresponding to each motor M are stored in the storage unit 10, and the arithmetic expressions are read in advance by the arithmetic unit 202 and temporarily stored in the memory. Based on the header given to the digitally converted measurement value, the calculation unit 202 determines which motor M the measurement value belongs to, and selects an arithmetic expression used to calculate the measurement value of the motor M ("Selecting means"), and arithmetic processing is performed based on the arithmetic expression concerned.

  The calculation result for each motor M is sent to the D / A converter 203 and converted again into analog, and output as an appropriate current for driving the pointer 8 of the meter 4. The output switching unit 205 discriminates which motor M the calculation result is based on the header, and outputs each calculation result to the meter 4 corresponding to the corresponding motor M (“sort output means”). ). A hold amplifier 206 for fixing the output is provided between the output switching unit 205 and each meter 4. Each meter 4 moves the pointer 8 based on the output current. The scale 7 of each meter 4 has an enlarged scale displayed in the priority monitoring range. In this way, a plurality of motors M can be monitored by one monitoring device 200. Furthermore, even when the characteristics of the motor M and the range to be monitored are different, they can be monitored simultaneously.

  In the above, the calculation result based on the procedure for switching the input by the input switching unit 204, the procedure for assigning a header to the measured value of each motor M in the A / D conversion unit 201, and the header in the output switching unit 205 The measured value of each motor M is output to the corresponding individual meter according to the procedure for discriminating which motor M belongs to, but the measured value of motor M and meter 4 correspond one-to-one. The means for causing ("corresponding means") is not limited to this. For example, switching between input and output may be synchronized so that the switching is performed at high speed. Further, if the D / A conversion unit 203 is provided corresponding to each meter 4, the output switching unit 205 and the hold amplifier 206 are unnecessary.

(Embodiment 3)
FIG. 11 is a block diagram showing a monitoring apparatus according to the third embodiment of the present invention. The monitoring device 300 is characterized in that a single meter 4 is configured to monitor a plurality of motors M with respect to the configuration of the monitoring device shown in the second embodiment. The monitoring apparatus 300 has a configuration in which a display selection unit 206 is provided at a subsequent stage of the output switching unit 205 and a display selection dial 301 for operating the output switching unit 205 is provided on the front surface of the meter 4. Since other configurations are the same as those of the monitoring apparatus 200 according to the second embodiment, description thereof is omitted. In this monitoring apparatus 300, when the user selects the number of the motor M that the user wants to monitor with the display selection dial 301 (for example, “1”), the input switching unit 204 linked with the display selection dial 301 displays only the current value of the motor M1 as A. / D conversion unit 201.

  When the user selects another motor M number (for example, “2”) using the display selection dial 301, the input switching unit 204 sends only the current value of the motor M <b> 2 to the A / D conversion unit 201. In this way, a single meter 4 can monitor a plurality of motors M, and different types of motors M can be monitored within an optimum range. This is particularly effective when the space for installing the meter on the housing 50 or when the installation location is small when the meter is used alone.

  In the first to third embodiments, the motor is described as an example of the electric device, but the monitoring target of the monitoring device is not limited to the motor. For example, a power source, a generator, and the like can be monitored.

  BRIEF DESCRIPTION OF THE DRAWINGS It is an external appearance perspective view which shows the monitoring apparatus concerning Embodiment 1 of this invention.   It is a block diagram which shows the monitoring apparatus shown in FIG.   It is a chart for demonstrating the calculating method.   It is a chart for demonstrating the calculating method.   It is explanatory drawing which shows the modification of the display form of a scale.   It is explanatory drawing which shows the calculation method at the time of setting an enlarged display area.   It is an external appearance perspective view which shows the monitoring apparatus which enabled the setting of the enlarged display area.   It is explanatory drawing which shows an example of a scale plate.   It is a block diagram which shows the modification of the monitoring apparatus shown in FIG.   It is a block diagram which shows the monitoring apparatus concerning Embodiment 2 of this invention.   It is a block diagram which shows the monitoring apparatus concerning Embodiment 3 of this invention.

Explanation of symbols

100 Monitoring Device 1 A / D Conversion Unit 2 Calculation Unit 3 D / A Conversion Unit 4 Meter 5 Setting Unit 7 Scale

Claims (7)

A monitoring device comprising a meter having a pointer and a scale, and measuring a current or a voltage of an electric motor or other electric device,
The scale has an enlarged display area displayed in an enlarged manner than the normal display area, and is continuously displayed in the normal display area and the enlarged display area.
Analog / digital conversion means for converting a measurement value input from an electric device into a predetermined digital value;
Arithmetic means for performing arithmetic processing so as to expand the measurement value of the priority monitoring range among the digitally converted measurement values relative to the measurement value of the normal monitoring range;
Digital / analog conversion means for converting the measured value calculated by the calculation means into a current for moving the pointer;
A monitoring device comprising: Furthermore, a setting means for setting the priority monitoring range is provided, and this setting means includes:
Input means for inputting an upper limit value and / or a lower limit value of the priority monitoring range;
An arithmetic expression acquisition means for acquiring an arithmetic expression from the upper limit value and / or the lower limit value;
The monitoring apparatus according to claim 1, further comprising: Furthermore, a setting means for setting an enlarged display area is provided, and the setting means includes:
An input means for inputting an upper limit value and / or a lower limit value of the enlarged display area;
An arithmetic expression acquisition means for acquiring an arithmetic expression from the upper limit value and / or the lower limit value;
The monitoring apparatus according to claim 1, further comprising:   The apparatus according to any one of claims 1 to 3, further comprising a plurality of the meters, and a corresponding unit that associates the measurement values of the plurality of electric devices with the corresponding meters for each electric device. Monitoring device. Further, the handling means includes:
Discrimination data giving means for giving discrimination data for each electrical device to the measurement values of a plurality of electrical devices;
Selection means for selecting a predetermined arithmetic expression based on the discrimination data;
The measurement value after calculation by the calculation means is classified for each electric device, and the classification output means for outputting to the corresponding meter,
The monitoring apparatus according to claim 4, further comprising: And the meter
Discrimination data giving means for giving discrimination data for each electrical device to the measurement values of a plurality of electrical devices;
Selection means for selecting a predetermined arithmetic expression based on the discrimination data;
A classification output means for classifying and outputting the measurement value after calculation by the calculation means for each electric device;
Selection means for selecting a specific output from outputs from the sorting output means and sending it to the meter;
The monitoring device according to claim 1, further comprising:   The monitoring apparatus according to claim 1, wherein the enlarged display area and the normal display area are displayed in different colors.

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