JPH0760103B2 - Calibration device for physical quantity measuring instrument - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention uses a physical quantity-electric quantity converter for converting a physical quantity such as load, pressure, displacement, acceleration, torque, strain, temperature, etc. into an electric quantity. The present invention relates to a calibration device in a physical quantity measuring instrument that calibrates a relative quantity output from the physical quantity-electric quantity converter during measurement into an absolute quantity.

(B) Conventional Technology In general, when a physical quantity is measured by using a physical quantity-electric quantity converter (hereinafter referred to as “converter”), it is necessary to calibrate (calibrate). As a method for calibrating the load measuring device to which the load converter using the above is connected, as shown in FIG. 8, a bridge for calibration is provided in the middle of the primary coil of the input transformer 81 to which the output of the measuring bridge 80 is applied. 82 is inserted so that the carrier alternating current from the carrier alternating current power source 83 applied to the measurement bridge 80 is also supplied to the calibration bridge 82 through the coupling transformer 84, and one side of the calibration bridge 82 is provided with a calibration resistor. A method in which 85 is connected in parallel by a switch 86 only during calibration to obtain a calibration output, or a cross-shaped circuit 87 is formed instead of the calibration bridge as shown in FIG. 9 and is connected between its adjacent ends. Method of obtaining a calibration output use resistor 88 was inserted by the switch 89 has been used.

In the latter case, in the former case, the problem that the influence of the occurrence of unbalance due to the aging of the calibration bridge 82, the temperature change, etc. appears as an error in the calibration value. It has been resolved.

However, in any of these methods, since a method of inserting a resistor to generate a calibration value,
Even if a plurality of resistors are combined in parallel as shown in the figure and synthesized, the obtained calibration value is practically limited to a few points, and an arbitrary calibration value could not be selected.

Therefore, conventionally, when performing calibration, for example, 4000 με (40
A strain gauge that generates a calibration value of (00 × 10 ⁻⁶ strain) is connected as a measurement gauge to a load cell having an output voltage of 3950 με at 10 t (which is shipped with such a calibration value in advance). When used with (4000/3950) x 1
Calculate the load corresponding to 4000με as 0 ≒ 10.13 (t), and output the calibration value output (waveform) of 4000με is 10.13 (t).
As a result, the measurement output was calibrated.

As described above, the conventional device has the inconvenience of being forced to perform a complicated proportional calculation when the converter is used, and this calibration needs to be performed every time the gain of the measuring device is changed by changing the measurement range or the like. It should be easy to do.

Therefore, in order to solve the above-mentioned problem, the present applicant first
A calibration device for a strain measuring instrument as shown in FIG. 10 has been proposed (see Japanese Laid-Open Patent Publication No. 57-161604).

That is, as shown in FIG. 10, the previously proposed calibration device has a carrier bridge AC power supply voltage generated by a carrier wave AC power supply 83 via a power supply transformer 90 to a measurement bridge 80 composed of a resistance bridge using a strain gauge. Is applied, the output obtained from the measurement bridge 80 is sequentially supplied to the carrier amplifier 91 and the detection carrier filter circuit 92 via the input transformer 81 to be amplified and detected, and the detection output from which the carrier component is removed is supplied to the DC amplifier 93. It is a strain measuring instrument which is amplified by and is supplied to the meter 94, and the measured output is displayed by the meter 94. Measuring bridge 80
To the first coupling transformer 96 for extracting a voltage from a carrier voltage supply path for the digital switch and the digital switch receiving the reference voltage from the secondary side of the first coupling transformer 96.
D / A converter 97 that inputs the digital output of 95 and this D / A
A changeover switch 99 which receives the analog output of the converter 97 through an amplifier 98 and changes its polarity in accordance with an external operation, and the output of this changeover switch 99 is passed through a second coupling transformer 100 to the primary side of the input transformer 81. And a circuit for injecting the same into the digital camera, and is configured so that an arbitrary calibration value can be set by the digital switch 95.

Therefore, according to this calibration device, the problem of the proportional calculation described above is solved, so that simplification of the calibration work is realized.

However, in the case of this calibration device, the calibration value and rated capacity, etc. are read from the test result table etc. attached to the converter, the read calibration value is set in the digital switch 95, and the polarity ( Whether it is compression or expansion), set the changeover switch 99 to the appropriate polarity, and then set the measurement range and meter.
In order to adjust 94 to full scale, input transformer 81,
An operation procedure of operating (adjusting) the detection output voltage obtained through the carrier wave amplifier 91 and the detection carrier filter circuit 92 of the DC amplifier 93, for example, a variable resistor 93a that can be operated externally is required. If you were not familiar with, the operation was never easy.

(C) Purpose The present invention has been made in view of the above circumstances, and its purpose is to reduce the inconvenience, the specialized knowledge, and the experience required to perform a complicated proportional calculation when a converter is used as in the related art. Provides a calibration device for a physical quantity measuring instrument that can easily and quickly perform accurate calibration and measurement even for those who do not have specialized knowledge or experience, while those who tended to make mistakes in reading and calculation of calibration values To do.

(D) Configuration In order to achieve the above-mentioned object, the present invention provides a load, pressure,
A physical quantity measuring instrument that measures a physical quantity using a physical quantity-electric quantity converter that converts a physical quantity such as displacement, acceleration, torque, strain, and temperature into an electric quantity, including a calibration value specific to the physical quantity-electric quantity converter. An optical scanner that optically reads a bar code directly or indirectly attached to the physical quantity-electric quantity converter in which individual information is converted according to a predetermined code rule, and a bar code character obtained from this optical scanner. According to the above code rule, a bar code reader comprising a bar code decoder, coefficient calculating means for calculating a coefficient corresponding to a calibration value included in individual information obtained by the bar code reader, and coefficient calculating means. The coefficient output from the means is received as a digital control signal, and the output signal of the physical quantity-electric quantity converter is multiplied by the coefficient. A coefficient adding means having a variable gain amplifier whose gain is controlled by the coefficient; an analog / digital conversion generating means for converting an analog signal obtained by the coefficient adding means into a digital signal; And control means for controlling the coefficient adding means so that the calculated coefficient is input to the coefficient adding means and the output signal of the physical quantity-electric quantity converter is multiplied by the coefficient, and transferred from this control means. And the display means for displaying the measurement data output from the analog / digital conversion means.

Hereinafter, the gist of the present invention will be described in detail based on examples.

FIG. 1 is a block diagram showing the configuration of an embodiment of a calibration device in a physical quantity measuring instrument according to the present invention.

In the figure, 1 is a physical quantity-electric quantity converter (hereinafter, simply referred to as "converter") for converting a physical quantity into an electric quantity, and as an example, a pressure transducer using a strain gauge as a conversion element, a load There is a converter, etc. 1a is a measurement bridge composed of strain gauges, and 1b is a power supply for the measurement bridge. 2 is a predetermined code rule, such as 3of9, in which the type, calibration value and rated capacity of the converter 1 are used as individual information of the converter 1.
It is a bar code pattern coded by a code (so-called Code 39) and is generally displayed on the front surface of a tag whose back surface is coated with an adhesive. Reference numeral 3 is an optical scanner for reading the bar code pattern 2, and 4 is a serial electric signal (a) obtained from the optical scanner 3 which is decoded according to the above code rule and converted into an ASCII code 8 Bit barcode data output (b-1)
The optical scanner 3 and the barcode decoder 4 constitute a barcode reader 5 as individual information reading means.

The signals (c-1) and (c-2) are control signals for the bar code decoder unit 4.

On the other hand, 6 electrically adjusts the output signal from the converter 1 to 1
A preamplifier for outputting [με] = 1 [μv], 7 is a coefficient adding circuit as a coefficient adding means for calibrating the output signal (d) of the preamplifier 6, and has a variable total gain A, The total gain A is controlled by the latch signal (e) and the 8-bit control data signal (f). Reference numeral 8 is an A / D conversion circuit as an analog / digital conversion means for converting the analog output signal (g) obtained from the coefficient adding circuit 7 into a digital signal. In this example, the maximum analog input voltage is 10 [v] (Ie full scale 10 [v]). Reference numeral (h) is a response signal, (i) is an 8-bit digital output signal, and (j) is a control signal. 9,10 and
Reference numerals 11 are first, second and third input / output devices (hereinafter referred to as "first I / O", "second I / O" and "third I / O"), respectively. An 8-bit data bus 12, a control signal line 14 as a plurality of status signal lines, and a response signal line 15 are connected. The response signal (h) from the A / D conversion circuit 8 and the 8-bit digital output signal (i) are input to the first I / O 9, and the control signal (j )
Is output. A latch signal (e) and a control data signal (f) are output from the second I / O 10 to the coefficient adding circuit 7. In the third I / O 11, the barcode decoder output (b-1) is input from the barcode decoder unit 4, and the control signals (c-1) and (c-2) are sent to the barcode decoder unit 4. The output signal (b-2) of the keyboard 11a serving as the operation panel is input. Reference numeral 16 is a digital display as a display means for displaying the individual information and the measured value shown in the barcode pattern 2, for example,
It consists of a 10-digit red light emitting diode.
Reference numeral 17 is a so-called 8-bit CPU as a central processing unit, 18 is a so-called ROM as a fixed storage device, and 19 is a so-called RA as a readable / writable storage device.
It is M. Digital display 16, CPU17, ROM18, RAM described above
A data bus 12, an address bus 13, a control signal line 14, and a response signal line 15 are connected to 19 respectively. The first I / O
9, second I / O10, third I / O11, digital display 16, ROM
18 and RAM 19 are called peripheral devices of CPU 17, and these peripheral devices and CPU 17 constitute a so-called microcomputer as a control means.

Next, the configurations of the bar code reader 5 and the coefficient adding circuit 7, which are the main parts of the device of the present invention, will be described.

FIG. 2 is a block diagram showing the configuration of the barcode reader 5, in which the configuration of the optical scanner 3 and the configuration of the barcode decoder unit 4 are drawn together. Reference numeral 20 is a reflection type optical sensor including a light emitting diode 20a as a light emitting portion and a phototransistor 20b as a light receiving portion. Reference numeral 21 is a waveform shaping circuit that adjusts the output signal of the optical sensor 20 to a logic level to remove disturbance. Reference numeral 22 is an edge detection circuit for detecting the rising and falling edges of the pulse output signal corresponding to the bar code pattern of the waveform shaping circuit 21, that is, the output signal (a) of the optical scanner 3. Reference numeral 23 is a serial output signal from the edge detection circuit 22, which is read, decoded and converted into an ASCII code to form an 8-bit parallel signal (b ').
It is a barcode decoder that outputs as. The control signals (c-1) and (c-2) from the CPU 17 are input to the bar code decoder 23 via the third I / O 11, and when an error occurs during bar code reading. , A 7-bit error information signal (k ') for indicating the type of error is output. Reference numeral 24 denotes a buffer circuit having eight so-called 3-state buffers having a high impedance state, which is connected to the 8-bit output signal (b ') of the bar code decoder 23 in a one-to-one manner and has a negative logic. The control signal (c-2) is input to the control input. Reference numeral 25 denotes an output terminal of the bar code decoder 23 whose first input terminal outputs a 7-bit error information signal (k ').
A gate circuit composed of seven NAND gates connected to pair 1 and commonly connected to all the second input terminals to receive a control signal (c-2), each output terminal outputting an output signal (k) Are connected to the error display circuit 26 in a one-to-one relationship. 27a to 27g are light emitting diodes for error display.The correspondence with each error state is 27a is a checksum error, 27b is a start character error, 27c is a stop character error, 27d is a message overflow, 2
7e is scan speed unsuitable (too slow), 27f is scan speed unsuitable (too fast), and in the above 27a to 27f, when all are lit, it means a defective state, while 27g shows a read completion , When off, means an error. That is,
When the light emitting diode 27g is turned off, any one or more of the error indicating light emitting diodes 27a to 27f are turned on. 28
Is a sounding body and is driven by the oscillation circuit 29. And
Reference numeral 30 is one of the NAND gates constituting the oscillation circuit 29. One input end of the NAND gate 30 is connected to the cathode side of the light emitting diode 27g through the inverter 30a. At the time of lighting, the oscillator circuit 29 is controlled to the operating state.

FIG. 3 is a diagram showing a specific circuit configuration of the coefficient adding circuit 7.

In the figure, the coefficient adding circuit 7 is roughly divided into five parts. Reference numeral 31 is a digit shift unit, 32 is a coefficient adding unit, 33 is a Zero voltage inserting unit, 34 is an inverting unit, and 35 is a selecting unit, and the above units constitute a variable gain amplifier having a variable total gain A. Reference numeral 36 is an input terminal connected to the output terminal of the preamplifier 6, and 37a to 37e and 38a to 38d are analog switches. In the figure, I is a signal input terminal, O is a signal output terminal, and C is ON-. OFF Indicates the control input terminal. When this ON-OFF control input terminal C becomes H level, the input terminal I and the output terminal O are connected to be in ON state, and when it becomes L level, it is in OFF state. Reference numerals 39a to 39d are analog switches having transfer contacts, in which B is a normally closed contact input end, M is a normally open contact input end, T is a common contact output end, and C is an ON-OFF control signal input end. The input to this ON-OFF control signal input terminal C is H
At the level, the normally closed contact B is opened and the normally opened contact M is closed, and at the L level, the normally closed contact B is closed as shown in FIG. All of 40, 41a to 41d, 42, 43 are operational amplifiers, and are all configured as inverting amplifiers. 44,4
Reference numerals 5 and 46 are binary-octal decoders, and only one of the eight output terminals Y _{0 to} Y ₇ is selected in response to 1of8, that is, a 4-bit input signal. Is also composed of positive logic. In the decoder 44, the output terminals Y _{0 to} Y ₄ among the output terminals Y _{0 to} Y ₇ are used, and the decoder 45
Output terminals Y _{0 to} Y ₅ are used in the above, and the output terminals Y ₀ are not used in the decoder 46, but Y _{1 to} Y ₄ are used. 47, 48a to 48d, 49, 50 are all latches.

Now, the structure of each of the above parts will be described. First, the girder moving part 31
In the figure, 51 is a feedback resistor, which is connected between the inverting input terminal and the output terminal of the operational amplifier 40. The non-inverting input of this operational amplifier 40 is grounded to form an inverting amplifier. 52 to 56 are all input resistances, where R is the resistance value of the feedback resistance 51, the input resistance 52 is 100R, the input resistance 53 is 10R, the input resistance 54 is R, and the input resistance 55 is 0.1R. Are configured to have a relationship of 0.01R. Further, the output terminals O of the analog switches 37a to 38e and one ends of the input resistors 52 to 56 are connected in series, and the other ends are all connected in common and connected to the inverting input terminal of the operational amplifier 40,
The input terminals I of the analog switches 37a to 37e are all commonly connected to the input terminal 36. Further, the latch 4 is connected to the ON-OFF control input terminal C of the analog switches 37a to 37e.
The seven latch output terminals Q _{0 to} Q ₄ are connected in a one-to-one relationship. Further, the output terminals Y _{0 to} Y _{4 of} the decoder 44 and the input terminals D _{0 to} D _{4 of the} latch 47 are connected in a one-to-one manner, and the input terminals of the decoder 44 are
The lower 4 bits of the control data signal (f), that is, the lower nibble (f-1) is connected to D _{0 to} D ₃ in a one-to-one relationship.

Next, in the coefficient adding unit 32, 57a to 57d are feedback resistors, which are 8000 [Ω], 800 [Ω], and 80 [Ω], respectively.
[Omega] and 8 [Omega], and the respective operational amplifiers 41a to 41d form an inverting addition amplifier. 58 to 61 are input resistors, 8 [Ω] and 4 respectively
It has an integral multiple value of [Ω], 2 [Ω], and 1 [Ω]. The output terminals O of the analog switches 38a to 38d are connected to input resistors 58 to 61, respectively.
Are connected to the inverting input terminal of the operational amplifier 41a via the respective. Further, the input terminals I of the analog switches 38a to 38d are commonly connected and connected to the output terminal of the operational amplifier 40. Here, the portion formed by the analog switches 38a to 38d and the input resistors 58 to 61 and enclosed by the broken line in the figure is called a coefficient switching circuit 62a. Reference numerals 62b to 62d denote coefficient switching circuits having the same configuration as the coefficient switching circuit 62a, and although not shown, ON-OFF control input C of each analog switch is provided.
Are connected to different latches 48b-48d, respectively. ON of analog switches 38a-38d −
The OFF control input terminal C has a one-to-one correspondence with the output terminals Q _{0 to} Q ₃ of the latch 48a.
Connected to the latches 48b-48d and coefficient switching circuits 62b-6.
Correspondence with 2d is also the same. Therefore, in the coefficient adding unit 32, the coefficient switching circuit 62a, the feedback resistor 57a, and the operational amplifier 41a.
The 1000th coefficient circuit is formed by the inverting and adding amplifier, and the coefficient switching circuit 62b, the feedback resistor 57b, and the operational amplifier 41b.
And the coefficient switching circuits 62c and 62d, the feedback resistors 57c and 57d, and the operational amplifiers 41c and 41d constitute the 10th and 1st coefficient circuits, respectively. The input terminals of the latches 48a to 48d
The lower nibble signal (f-1) of the control data signal (f) is connected to D _{0 to} D ₃ in a one-to-one manner.

Next, in the Zero voltage inserting unit 33, 63 is a feedback resistor, which is connected between the inverting input terminal and the output terminal of the operational amplifier 42. 64a to 64d are input resistors, all feedback resistors
It has the same resistance value as 63. Further, one ends of the input resistors 64a to 64d are connected to the common contact output ends T of the analog switches 39a to 39d, respectively, and the other ends thereof are connected in common to form an operational amplifier.
It is connected to the inverting input terminal of 42. Further, the normally-closed contact input terminals B of the analog switches 39a to 39d are connected to the output terminals of the operational amplifiers 41a to 41d, that is, 1000th, 100th, 1st, and 1st.
All of the normally open contact output terminals M are connected to the 0th and 1st coefficient circuits and are grounded to hold the Zero potential.

On the other hand, the lower nibble signal (f-1) of the control data signal (f) is input to the input terminals D _{0 to} D ₃ of the decoder 46 on a _one-to-one basis, and the output terminals Y _{1 to} Y _{4 of the} decoder 46 are connected. Latch 50 input
D ₀ to D ₃ are connected in a one-to-one, the latch output Q ₀ to Q ₃ of the latch 50 is connected to the ON-OFF control input C and one-to-one analog switch 39a-39d.

Next, in the inverting section 34, 65 is a feedback resistor and 66 is an input resistor, both of which have the same resistance value, and together with the operational amplifier 43 form an inverting amplifier having a gain of 1. And operational amplifier
The output terminal of 43 is connected to the output terminal 67.
Is connected to the input terminal of the A / D conversion circuit 8 at the next stage.

Finally, in the selection unit 35, the upper 4 bits of the control data signal (f), that is, the upper nibble signal (f-2) is connected to the input terminals D _{0 to} D ₃ of the decoder 45 in a one-to-one correspondence. Output terminals Y _{0 to} Y ₅ of the latch 49 are one-to-one with input terminals D _{0 to} D ₅ of the latch 49.
The latch signal (e) is input to the latch input terminal LT of the latch 49. The output terminals Q _{0 to} Q ₅ of the latch 49 are respectively the latch 50 of the Zero voltage inserting section 33,
Latch input terminals LT of the 1st place circuit latch 48d, the 10th place circuit latch 48c, the 100th place circuit latch 48b, the 1000th place circuit latch 48a, and the digit moving unit 31 latch 47 of the coefficient adding unit 32.
It is connected to the.

Fig. 4 shows the structure of the bar code symbol.
Is a start margin that is normally white in a part where nothing is printed, 69 is a start character consisting of a bar / space indicating the start of a message, 70 is a message that is information to be transmitted, and 71 is a message , A checksum character (not used in this embodiment) for detecting an erroneous reading added as an option, 72 is
A stop character 73, which indicates the end of the symbol, is a stop margin where nothing is printed. The start character and the strap character have an asymmetrical sequence and can be scanned in both left and right directions in the figure. The format of the message 70 is shown in 74 to 77, where 74 is a type display section that represents the type of converter in alphabetical letters, and
Is a pressure converter, L is a load converter, A is an acceleration converter, D
Is a displacement converter, T is a torque converter, and M is a temperature converter. Reference numeral 75 is a calibration value display section that represents a calibration value in units of [με], 76 is a partition section that represents a partition with a hyphen, and 77 is a rated capacity display section, of which 77
Reference numeral a is a numerical value portion representing the rated capacity, and 77b is a unit display portion representing the unit of the rated capacity. For example, T is ton, K is kilogram, and G is gram. In general, barcode symbols are broadly classified into two types according to the encoding method, a module width encoding method and a NRZ (Non-Return-to-Zero) encoding method.The module width encoding method is mainly used for industrial applications. On the other hand, the NRZ encoding type is usually used in many commercial applications. In the present embodiment, of the module width encoding methods, a code system called 3of9Code is used. Explaining the outline of this 3of9Code, the characters that can be handled are:
Numbers 0-9, alphabets A-Z, 7 special characters,
With a total of 44 start / stop characters, one character consists of 9 bars (black part) and spaces (white part), and the bar / space consists of wide W element and narrow N element, Of the nine elements, there are necessarily three W elements.

FIG. 5 is a flow chart showing the outline of the operation of the bar code decoder 23 for decoding the bar code defined as described above, but the description of the configuration is omitted because it overlaps with the operation description described later.

FIG. 6 is a diagram showing the bit definition of the control data signal (f), showing the upper nibble (f-2) and the lower nibble (f-1) expressed in hexadecimal, and the corresponding functions,
In the higher nibble (f-2), OH (hexadecimal numbers are marked with H to distinguish them from decimal numbers) designates the Zero voltage insertion unit 33, and 1H is the coefficient switching circuit of the first place of the coefficient addition unit 32. 62d is designated, 2H to 4H are similarly designated to designate the 10th to 1000th coefficient switching circuits 62c to 62a of the coefficient adding section 32, and 5H is designated to designate the digit moving section 31. The function of the lower nibble (f-1) is classified into three cases depending on which part is selected in the upper nibble (f-2). For example, the coefficient addition unit
When 32 is selected, 1H-9H correspond to the coefficients 1-9,
When the digit shift part 31 is selected, 0H is 1/100 times, 1H is 1/1
Designate a circuit (resistor) of 0x, 2H is 1x, 3H is 10x, and 4H is 100x. Further, when the Zero voltage inserting section 33 is selected, 1H corresponds to the first coefficient circuit, and 2H to 4H hereinafter correspond to the tenth to 1000th coefficient circuits. Therefore, for example, the digit moving unit 31
Control data signal (f) is set to 52
Set it to H.

FIG. 7 is a schematic flowchart of the operation of the entire apparatus of the present invention, but the description of the configuration will be omitted because it duplicates the operation description described later.

Now, the operation of this embodiment configured as described above will be described.

First, the outline of the operation will be described with reference to FIG. In the figure
It is started from START, and the instruction to the CPU 17 is read from the keyboard 11a of the operation panel via the third I / O 11, and it is determined whether the instruction content is the measurement operation or the bar code reading operation. If not, the operation returns to the instruction reading operation. If the instruction is a barcode reading operation, the control signal (c-1) to the barcode decoder section 4 is instantaneously dropped to the L level via the third I / O 11 and the barcode data is output to the barcode decoder 23. (B-
1) is requested (may be interpreted as a notification of acceptance preparation completion), and the control signal (c-2) is held at L level to activate the buffer circuit 24 and open the gate circuit 25. Bar code decoder 23 which has received the control signal (c-1)
Sends the barcode data output (b-1) to the CPU 17 via the third I / O 11 according to the flowchart shown in FIG. 5 (details will be described later). Bar code data output (b-
The CPU 17 having received 1) judges whether the content of the barcode data output (b-1) is error information or data obtained by reading a barcode, and if it is error information, the digital display 16 (first A predetermined error message is displayed in (Fig. 1) and the process returns to the instruction reading routine again. If it is not the error information, the barcode information, that is, each data of the type of the converter, the calibration value and the rated capacity is temporarily stored in the RAM 19 and the above three data are displayed on the display 16.

Next, the coefficient is calculated from the bar code information now stored in the RAM 19, and the control data signal (f) and the latch signal (e) are output to the coefficient adding circuit 7 via the second I / O 10 based on the result. Then, each part of the coefficient adding circuit 7 is set to a predetermined state. Then, in the measurement operation, the CPU 17 outputs the control signal (j) to the A / D conversion circuit 8 via the first I / O 9, and the A / D
After receiving the response signal (h) of the conversion circuit 8, the 8-bit digital output signal (i) of the A / D conversion circuit 8 which is the measured value converted into the digital signal is received, and the measured value is displayed on the digital display 16 Then, the process returns to the instruction reading routine again.
On the other hand, as a result of the instruction reading, when the instruction is the measurement operation, the process branches to the coefficient calculation routine, and the routine returns to the instruction reading routine again through the above-mentioned routine. Explaining the means for exchanging data and signals between the CPU 17 and peripheral devices, the CPU 17 reads out the operation contents pre-written in the ROM 18 one by one and performs the above-mentioned operation. Data and signal exchange will be described as an example. CPU1
7 outputs the address data in which necessary data is stored to the address bus 13 and outputs one of the plurality of control signal lines 14.
The book is sent to the ROM 18 as a device selection signal (not shown). The ROM 18 outputs the data corresponding to the above address data to the data bus 12 and outputs a response signal on the response signal line 15 to inform the CPU 17 that the data currently on the data bus 12 is from the ROM 18. . The CPU 17 receives the data on the data bus 12 by the response signal on the response signal line 15. The above is the basic operation, and the operation of exchanging data with peripheral devices other than the ROM 18 is almost the same, so description thereof will be omitted.

Next, the operations of the bar code reader 5 and the coefficient adding circuit 7, which are the main parts of the device of the present invention, will be described in detail. First,
The operation of the bar code reader 5 will be described with reference to the block diagram of FIG.
A description will be given based on the schematic operation flowchart of the figure and FIG. The bar code decoder 23 controls the control signal (c-1).
Is instantly brought to the L level and is activated by START. When the operator scans the optical scanner 3 on the barcode pattern 2, the light emitted from the light emitting diode 20a is reflected by the barcode pattern 2 and enters the phototransistor 20b. The reflected light is output from the phototransistor 20b as an electric signal having a level difference due to the difference in the reflectance due to the space (white portion) and the bar (black portion) of the barcode pattern 2 and is input to the waveform shaping circuit 21 to change the signal level. The signal is shaped into a TTL level such as uniformization and removal of disturbance, and is input to the edge detection circuit 22. The edge detection circuit 22 detects the rising and falling edges of the W element and the N element, which are components of the barcode pattern, and outputs them to the barcode decoder 23 as serial edge signals. The bar code decoder 23 measures the interval of the edge signal by a built-in timer and determines whether it is a W element or an N element. Now, returning to the flowchart of FIG. 5, after the bar code decoder 23 is activated, first, the start margin indicating the start of the bar code symbol is started.
It is determined whether 68 is a valid length (time interval), and if invalid, this operation is repeated. That is, this state is either because the predetermined start margin 68 is not secured in the bar code pattern which is being read, or the operator has not yet scanned the optical scanner 3 on the bar code pattern 2. . Now, assuming that the operator is operating the optical scanner 3, the pulse width of the bar or space sequentially input from the edge detection circuit 22 is measured in the next bar / space length acquisition, and compared with the reference value to obtain N. If it does not belong to either element or W element, the first operation is start margin valid? Return to. One bar / space like this
While judging whether the spelling is valid or not, it is judged whether or not the first character is the start character 69, and if it is invalid, the process returns to the first motion through the operation of the error information output E2. If the start character 69 is valid, a message decoding routine is entered. First, in the bar / space length capture, check the element and width as above,
If it is invalid, the operation returns to the first operation after the operation of error information output E3, E5, E6. When it is valid, the logic value of each element is determined and sequentially shifted, and the above operation is repeated until 9 bits are formed, that is, until one character is formed.
When one character is detected, it is determined whether or not there are three elements in W in 9 bits (9 elements) which is a characteristic of 3of9Code. If there are not three, the operation returns to the first operation via the error information output E2 '. When it is confirmed that there are three W elements, the stop character 72 is next determined, and when the stop character 72 is detected, the bar code data 8-bit parallel signal (b ') is output in the data output.
Is output. If the stop character 72 is not detected yet, the internal ASCII code table is referenced to convert the input character into an ASCII code corresponding to the input data, and the character data is stored in the internal output buffer until the stop character 72 is detected. However, if the number of characters in the message exceeds 29, including the checksum character, is the message too long? , And returns to the first operation via the error information output E4. On the other hand, although not shown, the bar code decoder 23 performs an initialization operation immediately after activation to set the 8-bit parallel signal (b ') to 00H, indicating that the CPU 17 is preparing for output. And the first operation, which is the start margin, is effective? Then, in the character data storage, the message stored in the output buffer is sequentially output as an 8-bit parallel signal (b ') in the data output, and the control signal (c-2) from the CPU 17 is set to the L level. As a result, the buffer circuit 24 is activated and the third I / O 1 is output as the barcode data output (b-1).
Transferred to CPU 17 via 1.

Here, the operation of the error information outputs E2, E3, E5, E6, E2 ', E4 will be described. When any of the above errors is detected, the bar code decoder 23 outputs a 7-bit error information signal (k '), and when the control signal (c-2) becomes L level, the error information signal (k) indicates an error. Drive circuit 26 and 8
A predetermined error code is output to the bit parallel signal (b '). The error display circuit 26 receiving this output turns on the light emitting diode 27b in the error information output E2, E2 ',
In the following error information outputs E3, E5, E6 and E4, the light emitting diodes 27c, 27e, 27f and 27d are turned on. And
When the bar code is correctly read without any error, the 7-bit error information signal (k ') for driving only the light emitting diode 27g is output. At this time, the light emitting diode 27g is turned on and, at the same time, the NAND gate 30 is turned on through the inverter 30a.
In the N state, the oscillation circuit 29 becomes the operating state and the sounding body 28 is driven. Therefore, the converter 1 connected to the device of the present invention
Is a load converter having a rated capacity of 10 [t] and a calibration value of 3950 [με], the operator now specifies the bar code reading operation with the keyboard 11a of the operation panel, and the optical scanner 3 displays the bar code pattern 2 on the bar code pattern 2. If the bar code information is read correctly, the sounding body 28 sounds and the light emitting diode 27g lights up to indicate that the bar code reading is completed. The digital display 16 displays the indications 74 to 77 in FIG. Is formed.

Next, the operation of the coefficient adding circuit 7 will be described. After displaying the bar code information by the bar code data output (b-1) as described above, the CPU 17 shifts to the coefficient calculation operation (seventh step).
See figure). Since the preamplifier 6 of this embodiment outputs the output signal (d) of 1 [με] = 1 [μV], in the case of the converter 1, the output signal (d), that is, the coefficient adding circuit 7 is output. When the input voltage is Ei, the maximum analog input voltage of the A / D conversion circuit 8 is 10V, so Ei = (3950 × 10 ⁻⁶ / 10000) · W (1) holds, and Ei · A = 10 (2) holds, where W is the load that the converter 1 receives. From the equations (1) and (2), the total gain A required for the coefficient adding circuit 7 is A = 10000 × 10/3950 × 10 ⁻⁶ × W (3), where W = 10 [Rated capacity] t] in equation (3)
Substituting into ∴A ₁₀ = 2532 (4), and in order to calibrate load converter 1 with rated capacity 10 [t] and calibration value 3950 [με], the total gain of coefficient addition circuit 7 becomes 2532 times. I understand that it is all right. Therefore,
The CPU 17 performs the operations of the above equations (1) to (4), and then executes the second operation according to the bit definition of the control data signal shown in FIG.
The control data signal (f) and the latch signal (e) are output to the coefficient adding circuit 7 through the I / O 10 of. First, 00H is output as the control data signal (f), and the latch signal (e) is instantly set to the H level. The upper nibble signal (f-2) of the control data signal (f) is the input terminal D ₀ of the decoder 45 of the selection unit 35.
Is input to to D _3, its output Y ₀ is selected, the latch 49 is in the H level the output of the latch output terminal Q ₀ output from the output terminal Y ₀ of the decoder 45 by the latch signal (e) . On the other hand, the lower nibble signal (f-1) is input to the input terminals D _{0 to} D ₃ of the decoder 45 of the Zero voltage inserting section 33, and the output of the output terminal Y ₀ is H level.
However, since the output terminal Y ₀ is not connected to anything, the outputs of the output terminals Y _{1 to} Y ₄ remain at the L level. Since the latch 50 latches the L level data by the output from the output terminal Q ₀ of the decoder 49, each output terminal Q _{0 of the} latch 50.
The outputs in ~ Q ₃ all hold the L level. As a result, the analog switches 39a to 39d are all normally closed contacts B.
Is closed and the output terminals of the operational amplifiers 41a to 41d are connected. That is, in the equation (4), which is the above calculation result,
Zero (0) is not included in A ₁₀ = 2532.
The voltage inserting unit 33 is set in the non-operating state.

Next, the CPU 17 outputs 12H as the control data signal (f). Since the upper nibble signal (f-2) is 1H, only the output of the output terminal Y ₁ of the decoder 45 becomes H level, and only the output terminal Q _{1 of the} latch 45 is held at H level by the latch signal (e) ( At this point, the H level of Q ₀ is released). On the other hand, the lower nibble signal (f-1) having a value of 2H
Is latched by a latch 48d, the output of the output terminal Q ₀ of the latch 48d is at L level, the output of the output terminal Q ₁ is at H level,
Similarly, the outputs of the output terminals Q ₂ and Q ₃ are held at the L level. As a result, the coefficient "2" is set in the coefficient switching circuit 62d (details will be described later). Thereafter, in the same procedure, as control data signal (f), 23H, 35H, 42
Output H and set the coefficients from 10th to 1000th to "3", "5", and "2", respectively. Now, the operation of the coefficient switching circuit 62a will be described in detail. When the above 42H is output as the control data signal (f), the data signal applied to the input terminals D _{0 to} D _{3 of} the latch 48a is latched and its output terminal is output. The output of Q ₁ is at H level, and the outputs of output terminals Q ₀ , Q ₂ and Q ₃ are at L level.
Hold on to the level. As a result, analog switch 38b
Only closed. Therefore, since the input resistance 59 is 4 [Ω] and the feedback resistance 57a is 8000 [Ω], assuming that the gain in this 1000th circuit is A ₀ , A ₀ = 8000/4 = 2000, and so on. If the gain of the _1st circuit is A ₁ , the gain of the 10th circuit is A ₂ , and the gain of the 1st circuit is A ₃ , then A ₁ = 500, A ₂
= 30, A ₃ = 2, and the Zero voltage insertion unit 33 is in the non-operating state, so it operates as a mere inverting adder, and A ₀ + A ₁ + A ₂ + A ₃
= 2532.

Next, the CPU 17 sets the digit moving unit 31 to a predetermined state, but the coefficient adding unit 32 can set only four digits from the 1000th place to the 1st place. It is determined whether the first digit is 4 digits, and the digit moving unit 31 is set to have 4 digits. By the way, in the load transducer with the calibration value of 3950 [με], the rated capacity is 1000 [t] and 10 respectively.
In case of 0 [t], 10 [t], 1 [t], 100 [kg],
The total gain required for the coefficient adding circuit 7 is calculated by the equations (1) to (4) as 253164, 25316, 2532, 253.2, 2 respectively.
Since it is 5.32, the digit moving unit 31 is 0.01 times and 0.1 times, respectively.
It should be set to 1x, 1x, 10x, 100x.
Therefore, in the case of the present embodiment, 52H is output to the coefficient adding circuit 7 as the control data signal (f) in order to set 1 time. The decoder 45 outputs 5H as the higher nibble signal (f-2).
Is decoded, the output of the output terminal Y ₅ becomes H level, and the output Q _{5 of the} latch 49 is held at H level by the latch signal (e). On the other hand, 2H as the lower nibble signal (f-1) is decoded by the decoder 44, the output terminal Y ₂ becomes H level, the input signal of the latch 47 is latched by the output signal of the output Q ₅ of the latch 49, and the latch 47 The output terminal Q _{2 of} is held at the H level. As a result, the analog switch 37c is closed, and the input resistor 54 is connected between the input terminal 36 and the inverting input terminal of the operational amplifier 40. Since both the input resistor 54 and the feedback resistor 51 have the same resistance value R, they operate as an inverting amplifier with a gain of 1. The inverting section 34 is an inverting amplifier having a gain of 1, and is only for matching the polarities of the input signal and the output signal of the coefficient adding circuit 7.

After setting the coefficient adding circuit 7 as described above, the CPU 17
The control signal (j) is applied to the / D conversion circuit 8 to convert the analog output signal (g) of the coefficient adding circuit 7 into a digital value and
It is instructed via the first I / O 9 to output as the bit output signal (i). The A / D conversion circuit 8 notifies the CPU 17 of the end of conversion with the response signal (h), and the CPU 17 notifies the CPU 8 at that time.
Captures bit output signals and displays the data on a digital display
Display on 16. After that, the CPU 17 returns to the instruction reading operation and repeats the above-described operation according to the operator's instruction.

As described above, since the device of the present invention includes the bar code reader 5, it is not necessary for the operator to visually read the rated capacity, the calibration value and the like from the test result table and the like attached to the converter as in the conventional example. Moreover, since the coefficient adding circuit 7 is automatically set by the CPU 17, the basic operation for calibration is greatly improved, and even an operator who has no special knowledge can easily perform the operation of calibration and measurement. In other words, what the operator should operate is only the instruction of measurement or barcode reading and scanning of the optical scanner 3 on the barcode pattern 2. Therefore, it is possible to concentrate on the work such as the analysis of the measurement result, and the efficiency of the measurement / analysis work can be improved.

Needless to say, the present invention is not limited to the embodiment described above and shown in the drawings, and various modifications can be made. For example, it is possible to provide a terminal for taking out the output signal of the coefficient adding circuit 7 and connect it to an analog recorder, a so-called pen recorder or the like, or connect it internally to a meter or the like and display it in analog form. is there. On the other hand, the CPU 17 is not limited to an 8-bit data bus, but 16 bits
Bits are also possible, first I / O9, second I / O9
It is also possible to omit O10 and the third I / O11 and directly connect to the data bus 12.

(E) Effect As described above in detail, according to the present invention, a barcode (pattern) obtained by converting individual information including a calibration value specific to a physical quantity-electric quantity converter according to a predetermined code rule is stored in advance as the physical quantity. -By attaching the bar code directly or indirectly to the electrical quantity converter and reading the bar code with the optical scanner, the bar code decoder reverses the bar code character obtained from the optical scanner according to the code rule. Then, the calibration value included in the individual information is decoded, the coefficient calculation means receives the control of the control means, calculates the coefficient corresponding to the decoded calibration value, and outputs it as a digital signal to the coefficient addition means. Under the control of the control means, the variable gain amplifier as the addition means changes the gain so that the output signal of the physical quantity-electric quantity converter is multiplied by the coefficient, and the coefficient addition means is added. The analog signal obtained by the above is converted into a digital signal by the analog / digital conversion means, and the display means is configured to display the individual information attached to the bar code and the measurement data output from the analog / digital conversion means. Therefore, it has been troublesome to read the calibration value and the like from the test result table etc. attached to the converter, which has been a problem of the conventional calibration device, to perform the comparison calculation, and to set the read numerical value with the switch. In order to detect this and the possibility of reading errors, to know the polarity from the above test result table, set the selector switch to the appropriate polarity, then set the measurement range and set the meter to full scale. Familiar with the device, requiring complicated adjustments such as operating a variable resistor that can operate the voltage externally of the DC amplifier. It is possible to solve problems such as that it can not be operated easily by only those who have done it,
In particular, it is possible to calibrate quickly without error by a simple operation of reading the bar code attached to the physical quantity-electric quantity converter with a bar code reader, and the calibration value is converted into the corresponding coefficient to obtain the physical quantity. Since the gain is changed by transferring it to the coefficient adding means consisting of the variable gain amplifier inserted in the measuring system of the measuring instrument, the cost increase due to the common use of members can be suppressed and a large number of calibration values can be obtained. In addition, it is possible to provide a calibration device that can measure the above-mentioned value and can use a bar code reader that is generally commercially available in large quantities as a reading means, and can suppress the cost increase to the minimum also in this respect.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention,
FIG. 2 is a block diagram showing the configuration of the bar code reader,
FIG. 3 is a circuit diagram showing an embodiment of the coefficient adding circuit, and FIG.
FIG. 5 is a block diagram of a bar code symbol, FIG. 5 is a schematic operation flowchart of a bar code decoder, FIG. 6 is a view showing bit definitions of control data signals, and FIG. 7 is an operation of the entire apparatus of the present invention. 8 is a schematic flow chart for explaining the above, FIG. 8 is a circuit diagram showing a configuration of a conventional example, and FIG.
FIG. 8 is a circuit diagram showing a configuration of another conventional example in which the circuit of FIG. 8 is improved, and FIG. 10 is a circuit diagram showing a configuration of another conventional example in which the circuit is further improved. 1 ... Converter, 1a ... Measuring bridge, 1b ... Measuring bridge power supply, 2 ... Bar code pattern, 3 ... Optical scanner, 4 ... Bar code decoder section, 6 ... Preamplifier, 7 ... coefficient addition circuit, 8 ... A / D conversion circuit, 9 ... first I / O, 10 ... second I / O, 11 ... third I / O, 11a ... keyboard , 12 …… 8-bit data bus, 13 …… 16-bit address bus, 14 …… control signal line, 15 …… response signal line, 16 …… digital display, 17 …… CPU, 18 …… ROM, 19… ... RAM, 20 ... Optical sensor, 21 ... Wave shaping circuit, 22 ... Edge detection circuit, 23 ... Bar code decoder, 24 ... Buffer circuit, 25 ... Gate circuit, 26 ... Error display circuit, 28 …… Sound generator, 31 …… Digit shift part, 32 …… Coefficient addition part, 33 …… Zero voltage insertion part, 34 …… Inversion part, 35 …… Selection part, 37a to 37e, 38a to 38d, 39a 39d ...... analog switches, 40,41A～41d, 42, 43 ...... operational amplifier, 44 to 46 ...... decoder, 47,48A～48d, 49, 50 ...... latch, 62a to 62d ...... factor switching circuit.

Claims (1)

[Claims] 1. A physical quantity measuring instrument for measuring a physical quantity using a physical quantity-electric quantity converter for converting a physical quantity such as load, pressure, displacement, acceleration, torque, strain, and temperature into an electric quantity. An optical scanner that optically reads a bar code directly or indirectly attached to the physical quantity-electric quantity converter by converting individual information including a calibration value specific to the quantity converter according to a predetermined code rule, and the optical scanner. Formula Bar code reader which converts the bar code character obtained from the scanner according to the above code rule, and the coefficient corresponding to the calibration value contained in the individual information obtained by this bar code reader. And a coefficient output from the coefficient calculating means as a digital control signal to output the physical quantity-electric quantity converter. Coefficient adding means whose gain is controlled by the coefficient so that the signal is multiplied by the coefficient, an analog / digital converting means for converting an analog signal obtained by the coefficient adding means into a digital signal, Control means for causing the coefficient calculating means to calculate the coefficient and for inputting the calculated coefficient to the coefficient adding means to control the coefficient adding means so as to multiply the output signal of the physical quantity-electric quantity converter by the coefficient. , The data transferred from this control means and the analog /
A calibration device in a physical quantity measuring instrument, comprising: a display device for displaying measurement data output from a digital conversion device.