JPS6215128B2 - - Google Patents

Description

[Detailed description of the invention]

This invention is a method for weighing kilograms in load cell scales.
Regarding the pound conversion method. The weight units currently used in the world can be roughly divided into kilograms and pounds, and countries that use pound units are transitioning from pounds to kilograms. For this reason, it is desired that the scale unit be easily switched between kilograms and pounds. However, with conventional load cell scales, the maximum effective weighing value is, for example, 30 pounds, and that 30 pounds is
If you want to convert a pound scale that is adjusted to 30,000 pulses to a kilogram scale with a maximum effective weighing value of 15 kilograms, you must readjust it so that 15 kilograms is 30,000 pulses.
The drawback was that switching between pounds was troublesome. This invention was devised in order to eliminate such drawbacks, and it is possible to easily switch between kilograms and pounds with a simple operation, and there is no risk of deterioration in accuracy. The purpose is to provide a method. By the way, converting 30 pounds to kilograms is approximately
It becomes 13.608 kg. Therefore, for example, if 30 pounds is calculated as 30,000 counts, 15 kilograms is approximately 33,069 counts. If the accuracy of the scale is maintained at 1/3000, the minimum scale of a 30 pound scale is 0.01 pound, which is 10 counts. Also, the minimum scale of a 15 kg scale is 0.005 kg (5 grams), which is 11.02 counts. i.e. 30
As far as converting a pound scale to a 15 kilogram scale, the resolution of the minimum scale will increase. This is an important requirement for maintaining the accuracy of the scale. In other words, if you set 15 kilograms to 30,000 counts, 30 pounds is 13.608 kilograms, which is 27,216 counts, and the minimum scale is 0.01 pounds.
9.072, resulting in a decrease in resolution and a problem with the accuracy of the scale. Therefore, when switching between kilograms and pounds, the reference pulse number for the maximum effective weight value (30,000 pounds in the above example) is based on the smaller of the maximum effective weight values (30 pounds in the above example) of the kilogram measurement and pound measurement. ), and set the number of pulses for the larger maximum effective weight value (15 kg in the above example) to the maximum effective weight value of the reference pulse number above, 30 pounds =
It is important to set (33069 in the above example) in relation to 13.608 kg). This invention has been made based on the results of such investigation and is intended to accomplish the above-mentioned object. Embodiments of the present invention will be described below with reference to the drawings. Figure 1 is a block diagram showing the overall circuit configuration.
1 is a load cell that outputs an analog voltage signal according to the load of the object to be measured 2; 3 is this load cell 1
An analog-to-digital converter that digitally converts the output into pulses and counts the number of pulses, 4
is a numeric keypad for setting the unit price; 5 is a status switch equipped with a switch for setting the maximum weight value or whether the unit of measurement is in pounds or kilograms; 6 is a unit price display 7; A display device 10 includes a weight display 8 and a price display 9. A display device 10 displays unit price data set by the numeric keypad 4 on the unit price display 7, and also displays the number of pulses counted by the analog-digital converter 3. calculates the weight based on the settings of the status switch 5, displays the weight data on the weight display 8, calculates the price data from the unit price data and the weight data, and displays the price data. A microcomputer is used to display the price on the price display 8, and the computer 10 stores a ROM (read only memory) that stores the processing program and processing data.
RAM (Random Access Memory) is provided. The status switch 5 connects three switches 5a, 5b, and 5c to the input terminals of the microcomputer 10, as shown in FIG.
The switches 5a, 5b, and 5c are connected to D ₀ , D ₁ , and D ₂ respectively, and the maximum effective weighing value and weighing unit are set as shown in the table below by turning on and off the switches 5a, 5b, and 5c. There is.

[Table] As shown in FIG. 3, the RAM provided in the microcomputer 10 has a 4-bit, 1-digit configuration, including a 4-digit unit price memory 11 and a 5-digit weight memory 1.
2, 5-digit price memory 13, 1-digit weight decimal point position designation memory 14, 1-digit unit price, price decimal point position designation memory 15, 5-digit input register 16, 6-digit conversion constant register 17, 11-digit Conversion calculation registers 18 are formed respectively. The RAM is also provided with three 1-bit status memories A, B, and C. Then switch status memory A to status switch 5a.
, transfer status memory B to status switch 5.
In b, the status memory C is made to correspond to the status switch 5c, so that when the switch is on, "1" is set in the status memory, and when the switch is off, "0" is set in the status memory. As the load cell 1, when the maximum effective weighing value is 30 pounds and 15 kilograms, a one for 15 kilograms is used, and when the maximum effective weighing value is 15 pounds and 6 kilograms, a one for 15 pounds is used, and this exchange is performed as a unit. Since it uses a load cell, it can be easily carried out. The analog/digital converter 3 is, for example,
When load cell 1 for 15 kg is used, it is adjusted to count 30,000 pulses at a load of 30 pounds, and when load cell 1 for 15 pounds is used, it is adjusted to count 30,000 pulses at 6 kg.
This count pulse number becomes the reference pulse number _M1 . The microcomputer 10 is adapted to read a predetermined program from the ROM at the start of weighing and perform the following processes in the order of . , clear the RAM. , read status memories A, B, and C. , the count number is read from the analog-to-digital converter 3 and stored in the input register 16. , converts the count of the input register 16 based on the contents of the status memory, and stores the obtained result in the input register 16. Regular weight processing is performed based on the count number of the input register 16. When the process of ~ is completed, the unit price set in advance is multiplied by the weight obtained in the process of ~ above to calculate price data. The above processing process is shown in a flow chart as shown in FIG. The microcomputer 1
0 specifically performs the above processing as follows. First, it is checked whether status memory A is set to "1". If "1" is set, then it is checked whether status memory B shows "1" or not. If “1” is also set in this memory B, the maximum effective weighing value is
Treat as 30 pounds. Also, if "1" is not set in memory B, the count number of input register 16 is 30,000, which is the reference pulse number of 30 pounds.
(M ₁ ) is multiplied by the result of dividing by the number of pulses of 15 kilograms, 33069.336 (M ₂ ), and after storing the result in the input register 16, processing is performed assuming that the maximum effective weight value is 15 kilograms. Also status memory A
If "1" is not set in the status memory C, then it is checked whether "1" is set in the status memory C or not. If "1" is set in this memory C, processing is performed assuming that the maximum effective weighing value is 6 kilograms. Also, if "1" is not set in memory C, set the reference pulse number of 6 kilograms 30000 (M ₁ ) to the count number of input register 16 and set the number of pulses of 15 post.
The result of division by 34019.43 (M ₁ ) is multiplied, the result is stored in the input register 16, and processing is performed assuming that the maximum effective weight value is 15 pounds. The above processing steps are shown in a flowchart as shown in FIG. Specifically, the microcomputer 10 performs calculation processing when the status B is not set to "1" in the above processing, as shown in FIG. That is, first, 907184 (this is a value obtained by dividing 30000 by 33069.336 and omitting the decimal point) is set in the conversion constant register 17. Next, the count number of the input register 16 is multiplied by the above 907184, and the result is stored in the conversion calculation register 18. Then, 6 from the top of the conversion calculation register 18
The digits are rounded off and the upper five digits of the register 18 are shifted to the input register 16. Further, the microcomputer 10 specifically performs calculation processing when the status C is not set to "1" in the above processing as shown in FIG. That is, first, write the conversion constant register 17.
Set 881848 (this is the number obtained by dividing 30000 by 34, 019.43 and omitting the decimal point). Next, input register 1
The count number 6 is multiplied by the above 881848, and the result is stored in the conversion calculation register 18. Then, the sixth digit from the top of the conversion calculation register 18 is rounded off, and the top five digits of the register 18 are shifted to the input register 16. Furthermore, the microcomputer 10 rounds off the 30 pound processing to the first digit of the input register 16. The upper four digits of the input register 16 are shifted to the weight memory 12. 3 is set in the weight decimal point position designation memory 14. In addition, the 15 kilogram processing is performed by multiplying the value in the input register 16 by 5, and the result is stored in the conversion calculation register 18. The first digit of the conversion calculation register 18 is rounded off, and the upper five digits are shifted to the input register 16. The first digit of the input register 16 is processed in 5-gram steps. That is, when the first digit is 0, 1, or 2, it is set as 0, when it is 3, 4, 5, 6, or 7, it is set as 5, and when it is 8 or 9, it is set as 0 and the second digit is carried. The value in the input register 16 is transferred to the weight memory 12.
Shift to. Weight decimal point position specification memory 14
Set 4 to . I try to do it in this order. The microcomputer 10 also multiplies the value in the input register 16 by 2 to process 6 kilograms, and stores the result in the conversion calculation register 18.
The numerical value in the conversion calculation register 18 is shifted to the input register 16. The first and second digits of the input register 16 are subjected to bigram step processing. In other words, when these two digits are between 0 and 9, it is set as 00, when it is between 10 and 29, it is set as 20, when it is between 30 and 49, it is set as 40, when it is between 50 and 69, it is set as 60, when it is between 70 and 89, it is set as 80. When the number is between 90 and 99, the third digit is carried as 00. The upper four digits of the input register 16 are shifted to the weight memory 12.
4 is set in the weight decimal point position designation memory 14. In addition, the 15 pound processing is performed by multiplying the value in the input register 16 by 5, and the result is stored in the conversion calculation register 18. The first digit of the conversion calculation register 18 is rounded off, and the upper five digits are shifted to the input register 16. input register 1
Process the first digit of 6 in 0.005 pound steps. (This is the same as in the 5-gram step process described above) The value in the input register 16 is transferred to the weight memory 12.
Shift to. Weight decimal point position specification memory 14
Set 4 to . After performing such weight processing, the microcomputer 10 moves to a unit price x weight processing routine. Therefore, for example, when manufacturing a load cell scale that switches between 30 pounds and 15 kilograms, it is sufficient to use load cell 1 for 15 kilograms, and when manufacturing a load cell scale that switches between 6 kilograms and 15 pounds, load cell 1 is used. You can use one for 15 pounds. To create a scale with a maximum effective weighing value of 30 pounds using load cell 1 for 15 kilograms, a load of 30 pounds is required.
Adjust analog-to-digital converter 3 to count 30,000. In this state, status switches 5a and 5b are turned on. Note that the status switch 5c may be on or off. Since "1" is set in the status memories A and B, the microcomputer 10 performs the above-mentioned 30-pound processing. For example, the load of object 2 to be measured is 30
In the case of pounds, 30,000 is stored in the input register 16, of which the upper four digits are shifted to the weight memory 12. Thus, the microcomputer 10 causes the weight data stored in the weight memory 12 to be displayed on the weight display 8, and also causes the weight decimal point position designation memory 14 to be displayed.
The value 3 causes the decimal point to be displayed in the third digit. In this way, the weight display 8 shows "3", "0.", and "0".
The number "0" is displayed, indicating that it is 30 pounds. To switch this 30-pound scale to a scale with a maximum effective weighing value of 15 kilograms, turn off status switch 5b and status memory B.
It is sufficient to just set it to “0”. That is, by doing this, 907184 is set in the conversion constant register 17. Now the load is 30 pounds and the input register is 16.
Since 30000 is stored in , the value 27215520000 will be stored in the conversion calculation register 18. Here, the sixth digit from the top of this number is rounded off to 27216020000, and the top five digits of this number are further shifted to the input register 16. In other words, input register 16 has 27216
The value will be shifted. Then, the aforementioned 15 kg processing is performed. In other words, multiplication of 27216×5 is performed and the result is 136080
is stored in the conversion calculation register 18, the first digit is rounded off, and the upper five digits are shifted to the input register 16. Therefore, the value 13608 will be shifted into the input register 16. Next, 5-gram step processing is performed on the first digit "8" of 13608, and input register 1
The value of 6 is 13610. This input register 16
The numerical value is shifted to the weight memory 12 and 4 is set to the weight decimal point position designation memory 14. However, the weight display 8 shows "1", "3.", and "6".
The numerical values ``1'' and ``0'', i.e. 13.610, are displayed.
This means that a 30 pound scale has been converted to a 15 kilogram scale. Also, to create a scale with a maximum effective weighing value of 6 kg using load cell 1 for 15 pounds, 6
Adjust the analog-to-digital converter 3 to count 30,000 with a kilogram load. In this state, status switch 5a is turned off and status switch 5c is turned on. However, status memory A is “0”
is set and "1" is set in the status memory C, so the microcomputer 10 performs the above-mentioned 6 kg processing. For example, when the load is 6 kilograms, 30,000 is stored in the input register 16, and then multiplication by 30,000×5 is performed and the resultant value, 60,000, is stored in the conversion calculation register 18. This number 60000 is then shifted into input register 16. In this input register 16, the first and second digits are processed in 2-gram steps, and the upper four digits of the obtained value are shifted to the weight memory 12, and the weight decimal point position designation memory 14 is shifted to the weight memory 12.
is set to 4. Thus, the weight display 8 displays the numerical values "6.", "0", "0", "0", that is, 6.000, and 6 kilograms is displayed. To switch this 6 kg scale to a scale with a maximum effective weighing value of 15 pounds, it is only necessary to turn off the status switch 5c and set "0" in the status memory C. That is, by doing this, 881848 is set in the conversion constant register 17. The current load is 6 kg and 30000 is stored in the input register 16, so the conversion calculation register 18 is
The number 26455440000 will be stored. Here, the 6th digit from the top of this number is rounded off.
26455040000, and the upper five digits of this number are further shifted to the input register 16. In other words, the value 26455 is shifted into the input register 16. Then, the aforementioned 15 pound processing is performed. That is, a multiplication of 26455×5 is performed, the result 132275 is stored in the conversion calculation register 18, the first digit is rounded off, and the upper five digits are shifted to the input register 16. Therefore, the value 13228 will be shifted into the input register 16. and then
0.005 pound step processing is performed for the first digit "8" of 13228, and the value in input register 16 is
It becomes 13230. The numerical value in the input register 16 is shifted to the weight memory 12, and 4 is set in the weight decimal point position designation memory 14. Thus, the weight display 8 displays the numerical values "1", "3.", "2", "3", and "0", that is, 13.230, and the 6 kilogram scale is converted to a 15 pound scale. In this way, conversion from a 30-pound scale to a 15-kg scale or from a 6-kg scale to a 15-pound scale can be easily performed by operating the status switches 5a, 5b, and 5c. And 30
For conversion between a pound scale and a 15 kilogram scale, the maximum effective weighing value is 30 pounds, and the reference pulse number M ₁ = 30000.
, and when converting between a 6 kg scale and a 15 lb scale, the maximum effective weighing value is 6 kg, which has a small value, and the standard pulse number M ₁ = 30000 is set, so the scale can be switched to a 15 kg scale and a 15 lb scale, respectively. However, the accuracy can be maintained at a sufficiently high level without causing a decrease in resolution or accuracy. In the above embodiment, the numerical value in the input register 16 is multiplied by 5 when processing 15 kilograms and when processing 15 pounds, but the invention is not limited to this. For example, when processing 1 in FIG. Constant register 17
You may set the upper six digits of 907184 and 881848 multiplied by 5, that is, 453592 and 440924. In this way, 15 kg processing and 15
Multiplication, rounding, and shift processing from the conversion calculation register 18 to the input register 16 in pound processing can be omitted. As described in detail above, according to the present invention, in a load cell scale that displays the load amount as a digital quantity, the maximum effective measurement value is calculated based on the smaller of the maximum effective measurement value of kilogram measurement and pound measurement. Set the reference pulse number M ₁ and set the pulse number M ₂ for the larger maximum effective weight value of the reference pulse number M ₁ based on the proportional relationship to the smaller maximum effective weight value. When measuring the smaller maximum effective measurement value, the measurement value for the number of pulses obtained by measurement is the reference pulse number M ₁ above.
and its maximum effective measurement value, and when measuring the larger maximum effective measurement value, the measurement value for the number of pulses obtained by measurement is calculated by multiplying the number of pulses by M ₁ /M ₂ The measurement value per pulse obtained by dividing the reference pulse number M ₁ by the larger maximum effective measurement value is multiplied by a constant, and both measurement processes are selectively performed. Therefore, it is possible to easily switch between kilograms and pounds with a simple operation, and moreover, it is possible to provide a kilogram-pound conversion method in a load cell scale that does not pose a risk of impairing accuracy.

[Brief explanation of the drawing]

The figures show the implementation of the present invention, and Fig. 1 is a block diagram showing the overall configuration of a load cell weigher, and Fig. 2 is a block diagram showing the overall configuration of a load cell scale.
Figure 3 is a circuit diagram showing the configuration of the status switch, Figure 3 is a diagram showing the configuration of RAM, Figure 4 is a flowchart showing the measurement processing process, and Figure 5 specifically shows the processing in Figure 4. Flowchart, Figure 6 shows status memory B in Figure 5.
FIG. 7 is a flowchart specifically showing the multiplication processing section when the status memory C is not "1" in FIG. 5. FIG. DESCRIPTION OF SYMBOLS 1... Load cell, 2... Object to be measured, 3... Analog-digital converter, 5... Status switch, 6... Display device, 10... Microcomputer.

Claims (1)

[Claims] 1. In a load cell scale that is equipped with a load cell that converts the load amount into an electrical analog amount and an analog/digital converter that converts the analog amount output from the load cell into a digital amount, and displays the load amount as a digital amount. , set the reference pulse number M ₁ for the maximum effective measurement value based on the smaller of the maximum effective measurement values of kilogram measurement and pound measurement, and set the number of pulses for the maximum effective measurement value of the larger maximum effective measurement value.
M ₂ is set based on the proportional relationship to the smaller maximum effective measurement value of the reference pulse number M ₁ , and when measuring the smaller maximum effective measurement value, the The measured value is calculated proportionally from the relationship between the reference pulse number _M1 and its maximum effective measured value, and when measuring the larger maximum effective measured value, the measured value for the number of pulses obtained by measurement is, The number of pulses is multiplied by a constant of M ₁ /M ₂ , and then the reference pulse number M ₁ is divided by the larger maximum effective measurement value, and then multiplied by the measured value per pulse. A kilogram-pound conversion method in a load cell scale, characterized by being able to selectively perform both weighing processes.