JP5874895B2 - measuring device - Google Patents

Description

  The present invention relates to a measurement apparatus, and more particularly, to improvement in reproducibility of a measurement signal based on measurement data stored after being compressed.

  One type of measuring apparatus is a paperless recorder as described in Patent Document 1 in which a two-dimensional display is regarded as recording paper.

  FIG. 2 is a block diagram showing an example of a conventional paperless recorder. In FIG. 2, an analog measurement signal related to a physical quantity to be measured such as temperature, pressure, voltage, and current is input to the input unit 1.

  The measurement unit 2 converts an analog measurement signal related to the physical quantity to be measured input to the input unit 1 into a digital signal by an A / D converter driven by a sampling clock having a predetermined measurement period T1, and measures measurement data. Get.

  The measurement data converted into a digital signal by the measurement unit 2 is selected as a maximum value and a minimum value from within a display period T2 (> T1) that is sufficiently longer than the period T1 of the sampling clock, and is temporarily stored as compressed data. 5 is stored. The measurement unit 2 compares the measurement data to be sequentially converted with the minimum value and the maximum value in the display cycle T2 stored in the temporary storage memory 5, and updates and stores it as a new minimum value if it is smaller than the minimum value, If it is larger than the maximum value, it is updated and stored as a new maximum value.

  The display data creation unit 4 acquires current time data from the real time clock 3 as sampling time data for each display cycle T2. The sampling time data and the minimum value and the maximum value stored as compressed data in the temporary storage memory 5 at that time are written in the acquisition memory 6 as display data set data and stored in the temporary storage memory 5. Clear the minimum and maximum values.

  The display unit 8 has a height from the minimum value min to the maximum value max and a width of the display cycle T2 as shown in the enlarged view of the part A based on the display data stored as set data in the acquisition memory 6. A graph waveform is drawn as an aggregate of a plurality of rectangles.

  In the enlarged view of the portion A, a solid line B shows an actual waveform based on the measurement data. Here, paying attention to the relationship between the display resolution of the display unit 8 constituting the paperless recorder and the display cycle T2, even when the time axis is expanded to the maximum, several dots on the display screen are approximately equal to the display cycle T2. If it expands so far, the aggregate | assembly which several rectangles continued like the enlarged view can be confirmed.

  The display data stored as set data in the acquisition memory 6 can be copied to the memory card 7 as necessary, and the data can be referred to by a PC or the like. In this case, a display resolution higher than that of the display unit 8 can be obtained depending on the PC monitor used.

Patent Document 1 describes a technique related to a paperless recorder.
Patent Document 2 describes a technique related to a measurement data storage device that stores measurement data in a form that reflects a level variation of an analog measurement signal between acquisition periods.

JP 2003-149008 A JP 7-128084 A

  According to the conventional configuration shown in FIG. 2, by recording the minimum value and the maximum value and the set data sampling time as set data for each display cycle in the acquisition memory 6, all measurement data is recorded and displayed. The waveform can be displayed with less set data compressed, and can be reliably displayed without losing the minimum and maximum values measured in each display cycle.

  However, it is impossible to accurately grasp at what point the minimum value and maximum value forming the rectangle of each display period are generated on the time axis of each rectangle. In order to observe these generation times in more detail, it is necessary to speed up the display cycle. In order to obtain the time at which the minimum value and the maximum value are actually observed, the display cycle must be equal to the measurement cycle, which is not realistic.

  The present invention solves these problems, and an object of the present invention is to display the minimum value and the maximum value in each display cycle in a form reflecting the time information at which the minimum value and the maximum value are measured. It is to realize a measuring apparatus capable of displaying an enlarged waveform approximate to an actual waveform based on the above.

In order to achieve such a problem, the invention according to claim 1 of the present invention is:
An analog measurement signal related to the physical quantity to be measured is sampled at a measurement cycle T1 and converted into a digital signal as measurement data, and the minimum and maximum values of these measurement data are connected by line segments at a display cycle T2 (> T1). In a measuring device configured to display,
A storage means for storing the minimum and maximum values and the latest value of the measurement data together with the respective sampling times is provided,
The minimum value, the maximum value, and the latest value of the measurement data are arranged according to respective sampling times, and the minimum value, the maximum value, and the latest value of the measurement data that are adjacent to each other are connected and displayed by line segments. .

The invention of claim 2 is the measuring apparatus according to claim 1,
The display form of the measurement data is a graph waveform display as an aggregate of a plurality of rectangles having a height from a minimum value to a maximum value and a width of a display period according to a display magnification ratio, and at least the measurement data The minimum value, the maximum value, and the latest value are arranged in accordance with each sampling time, and the minimum value, the maximum value, and the latest value of the measurement data that are adjacent to each other are switched to a form that is connected by a line segment .

  As a result, an enlarged display waveform approximated to the actual waveform is obtained based on the compressed data in each display cycle.

It is a block diagram which shows one Example of this invention. It is a block diagram which shows an example of the conventional paperless recorder.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, an analog measurement signal related to a physical quantity to be measured such as temperature, pressure, voltage, and current is input to the input unit 11.

  The measurement unit 12 converts an analog measurement signal related to the physical quantity to be measured input to the input unit 11 into a digital signal by an A / D converter driven by a sampling clock having a predetermined measurement period T1, and measures measurement data. Get.

  For the measurement data converted into a digital signal by the measurement unit 12, two values, a maximum value and a minimum value, are selected from within a display period T2 (> T1) that is sufficiently longer than the period T1 of the sampling clock. Are stored in the temporary storage memory 15 together with the current time data acquired as sampling time data. The measurement unit 12 compares the measurement data to be sequentially converted with the minimum value and the maximum value in the display cycle T2 stored in the temporary storage memory 15. If the measurement data is smaller than the minimum value, the measurement unit 12 sets a new minimum value as the new minimum value. It is updated and stored together with the current time data acquired as sampling time data, and if it is larger than the maximum value, it is updated and stored together with the current time data acquired as sampling time data from the real-time clock 13 as a new maximum value.

  The display data creation unit 14 acquires current time data from the real time clock 13 as sampling time data for each display cycle T2. Then, the sampling time data and the minimum and maximum values stored in the temporary storage memory 15 are written to the acquisition memory 16 as display data set data, and the latest value of the measurement data at that time is also sampled from the real-time clock 13. Along with the current time data acquired as data, it is written into the acquisition memory 16 as display data set data. Note that the minimum value and the maximum value stored in the temporary storage memory 15 are cleared when they are written to the acquisition memory 16.

  The display data stored as set data in the acquisition memory 16 can be copied to the memory card 17 as necessary, and the data can be referred to by a PC or the like.

  The display unit 18 is shown by an alternate long and short dash line C in the enlarged view of the part A based on the display data of three points including the minimum value, the maximum value, and the latest value stored as set data in the acquisition memory 16 for each display cycle T2. As shown, the display data of these three points are arranged in the order of the sampling time data, and adjacent measurement data are connected with a straight line and displayed. Here, if the latest value is smaller than the stored minimum value, it becomes the new minimum value, and if it is larger than the maximum value, it becomes the new maximum value. In these cases, the set data is the minimum value and the maximum value. 2 points.

  The waveform of the new method indicated by the alternate long and short dash line C is indicated by a solid line B, as compared with the conventional graph waveform as an assembly of a plurality of rectangles having a height from the minimum value min to the maximum value max and a width of the display period T2. It is very close to the actual waveform.

  Thereby, information such as the context of the time at which the minimum value, maximum value, and latest value in each display period T2 are measured can be read from the waveform of the new method indicated by the alternate long and short dash line C.

  Note that the display data according to the present invention includes all information of conventional display data. Therefore, the waveform of the display data based on the present invention can be displayed by the same drawing method as before.

  This also makes it possible to selectively use the waveform drawing method for the conventional display shown in FIG. 2 and the new display data shown in FIG. 1 in accordance with the waveform enlargement ratio on the display screen of the display unit 18.

  That is, for example, when the display cycle T2 of the enlarged display waveform is equal to or less than a few dots of pixels on the display screen of the display unit 18, the height from the minimum value min to the maximum value max and the width of the display cycle T2 are set as before. A waveform is drawn and displayed as an aggregate of a plurality of rectangles.

  On the other hand, when the display cycle T2 of the enlarged display waveform becomes longer than several dots of pixels on the display screen of the display unit 18, the display method is switched to the method of the present invention, and the minimum value, maximum value, and latest value are changed. These three points are rearranged in the order of measurement time and connected by a straight line to be drawn and displayed.

  The drawing method of the present invention increases the amount of data processing compared to the conventional method. However, by switching the display method according to the display enlargement ratio, if the conventional method is selected and enlarged display is not performed, drawing with the same performance as before can be performed.

  In the above embodiment, an example in which the measurement apparatus is a paperless recorder has been described. However, the present invention is not limited to this, and a data logger that continuously captures multi-point measurement data at a plurality of measurement locations at a predetermined measurement cycle, It is also effective for a waveform measuring apparatus that captures and records waveform measurement data in

  As described above, according to the present invention, the minimum value and the maximum value in each display cycle can be displayed in a form reflecting the time information at which the minimum value and the maximum value are measured, and an actual waveform based on the compressed data is displayed. A measuring device capable of displaying an approximated enlarged waveform can be realized.

DESCRIPTION OF SYMBOLS 11 Input part 12 Measurement part 13 Real time clock 14 Display data creation part 15 Temporary storage memory 16 Acquisition memory 17 Memory card 18 Display part

Claims (2)

An analog measurement signal related to the physical quantity to be measured is sampled at a measurement cycle T1 and converted into a digital signal as measurement data, and the minimum and maximum values of these measurement data are connected by line segments at a display cycle T2 (> T1). In a measuring device configured to display,
A storage means for storing the minimum and maximum values and the latest value of the measurement data together with the respective sampling times is provided,
The minimum value, the maximum value, and the latest value of the measurement data are arranged according to respective sampling times, and the minimum value, the maximum value, and the latest value of the measurement data that are adjacent to each other are connected and displayed by line segments. measuring device. The display form of the measurement data is a graph waveform display as an aggregate of a plurality of rectangles having a height from a minimum value to a maximum value and a width of a display period according to a display magnification ratio, and at least the measurement data The minimum value, the maximum value, and the latest value are arranged in accordance with each sampling time, and the minimum value, the maximum value, and the latest value of the measurement data adjacent to each other are switched to a form that is connected by a line segment. Item 2. The measuring device according to Item 1.