JPS6029048B2 - Digital weighing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a digital weight measuring device that converts a weight value into a pulse number and displays it digitally.

Generally, a digital weight measuring device detects weight using a sensor such as a load cell, amplifies the weight detection output in an amplifier, and then converts it into a pulse number signal corresponding to the output level by an A/D converter. The pulse number signal is input to a data processing device and converted into weight data, which is then displayed digitally.

Conventionally, when manufacturing two weight measuring devices with different weighing capacities in such digital weight measuring devices, for example, it is necessary to replace the weight sensor, adjust the amplification degree of the amplifier, or disassemble the A/D converter. If you try to use one weighing device as two weighing devices by changing its weighing capacity, it will take the same amount of process time and cost as manufacturing two weighing devices. there were.

This invention was devised to solve these problems, and it is possible to easily obtain two scales with different weights or precisions by a simple switching operation, and is highly economical. It is an object of the present invention to provide a digital weight measuring device in which each scale can perform proper auto-zero processing.

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a weight detecting section consisting of a load cell or the like, and this detecting section 1' outputs a voltage signal corresponding to the weight of the object to be weighed.

The voltage signal output from the weight detecting section 1 is amplified by a differential amplifier 2, and furthermore, high frequency components such as noise are cut by a low-pass filter 3, and then input to an A/D converter 4. There is. The A/D converter 4 is of a double integration type, for example, and outputs a digital signal corresponding to the input voltage while repeating sampling IJ once every 200 seconds. For example, it is adjusted so that a digital signal of 2 pulses per 1 pulse is output. The digital weight data sampled by the A/D converter 4 is supplied to a data processing device 6 via a 1/0 port 5. The data processing device 6 includes a CPU (Central Processing Unit) 7, a RAM (Random Access Memory) 8, and a ROM (Read Only Memory).
memory) 9, these CPU7, RAM8, RO
M9 and the 1/0 port 5 are coupled by a data bus 10 and an address bus 11 so that data can be exchanged. In addition, the CPU 7, RAM 8, ROM
9 is also connected to a display and keyboard controller 14 for controlling a display 12 and a keyboard 13 via the data bus 10 and address bus 11, so that data can be exchanged. A signal is input to the 1/0 boat 5 from a 15k9 to 6k9 changeover switch 15. As shown in FIG. 2, the RMM 8 has, for example, a 16×16 256-word structure, each word consisting of 4 bits, and forms various registers, various flag memories, and the like. The main memory configuration of the prefix AM8 is described by indicating each word as M[X, Y] and each bit as <>. M[F, 1] is used to set the unit of one scale. M[F,2] to M[0
, 2] are formed into an accumulation layer, and M[F, 4] to M
[0,4] is formed in the queue buffer.
Also, M[F,5] to M[A,5] are formed as price display registers, M[9,5] to M[5,5] are formed as unit price display registers, and M[4,5] to M [0,5] is formed in the weight table register, M[F,6] to M[0,6] are formed in the working register, and M[F,9] to M[0,9]
The display contents are memorized and formed into registers. Also M [F
, A] to M[B, A] are formed in the net weight count register, M[A, A] to M[6, A] are formed in the weight count value input register, and M[E, B] to M [A, B] is set to zero weight value and formed into a register, and M[4, B] to M[0
, B] are formed on the outside of the beautiful weight count register. Also, M[8,C] to M[4,C] are formed in a tare weight count register, and M[F,C], M[E,C], M[2,D]
〜M[0,D] is the true weight value and formed into the same shape, M[7,
D] to [3, D] are formed into stable weight count registers. Furthermore, M[C, D] to M[8, D] are transferred to the weight count register, M[F, D] to M[D, D], M[1
, E], M[0, E] as weight count register 'B',
M [6, E] ~ M [2, E] in the weight count register {
q, M [B, E] ~ M [7, E] as weight count register 'D}, M [F, E] ~ M [C, B], M [0, F]
into the weight count register (E}, M[5,F] to M[1
, F] to the weight count register 'F', M[A, F]~
M [6, F] is set to the weight count register (G}, M [F,
F] to M[B, F] are respectively formed on the weight count register plate. Furthermore, M[0,3]<1> is a zero point over flag memory, M[0,3]<2> is a weight over flag memory, M[3,3]<2> is a 15k9 flag memory, M[3, 3] <3> is formed in the 6k9 flag memory.

The CPU 7 controls the RAM 8 based on the program set in the ROM 9, and the main program control is performed based on the flowchart shown in FIG.

In other words, when the power is turned on and the process is started, preprocessing (■) is performed first, followed by key processing (■), count data importing from the A/D converter 4 (■), flicker processing (■), auto-zero processing (■), and display processing (■) in sequence. After the display process (2) is completed, turn to the key process (2). Thereafter, the routine from key processing (1) to display processing (2) is repeated, and when a key input or count data is received, the routine is on standby so that processing can be performed immediately. In the pre-processing (2), everything in the RAM 8 is cleared, all digits on the display are displayed as zero, and the display is checked.

Subsequently, count data is taken in from the A/D converter 4, the data is subjected to flicker processing, the true weight value is taken in to the register, and finally the weight is set to zero and the data is taken in to the register as zero value data. In the next key process (2), especially when the zero key (key for determining the zero point) is operated, the process based on the flowchart shown in FIG. 4 is performed.

That is, when the zero key is operated, first the upper limit of the zero range outside the accumulator is loaded. This is for example ROM9
For example, plus 300 counts are loaded as the upper limit value as the range for setting the zero point. Next, “
Check whether "1" is set. If "1" is set, check whether the count value currently stored in the weight purchase price register is greater than or equal to 300 counts stored in the accumulator. .Also, even if it is “0”, the accumulator count data is 2.
Multiply the current weight by 5 and check whether the stored count value is greater than or equal to the accumulator count value. Through this check, if the count value of the weight purchase price register is smaller than the count value of the accumulator, it is determined that there is no problem with the upper limit, and then the accumulator is set to minus 30, which is the lower limit of the zero range.
Load 0 count. In this case as well, it is checked whether "1" is set in the 15k9 flag memory, and if it is "1", the contents of the accumulator are left as they are, and if it is "0", the contents of the accumulator are changed to 2.
It makes three sounds. Then, the magnitude of the absolute value of the count value of the weight true value and the count value of the register and the absolute value of the count value of the accumulator is checked. Then, if the true weight value and the current value are smaller than the accumulator value, it is determined that there is no problem with the lower limit, and the true weight value and the counter data at that time are set to zero weight value, stored in the register, and the value is set to zero. shall be. Therefore, for example, when the changeover switch 15 is ON, the true weight value and the count contents of the register are absolute value 300.
If it is within the range, zero setting is possible by operating the zero key. In terms of weight, one scale is 5 meters and the absolute value at 10 counts is +300, so it is a range of 30 scales, that is, an absolute value of 150 meters. Further, when the switching switch 15 is in the OFF state, if the true weight value and the count contents of the register are within the range of the absolute value ±750 by the 2.3 tone processing, zero setting is possible by operating the zero key. In terms of weight, this means 4 counts x 2 in 1 scale and 2 meters.
Since the absolute value at 5 = 10 counts is 750, it is 7.
This means a range of 5 scales, or 150 units of absolute value. In this way, even if the weight is 1 yen, 6k9
Even in this case, the zero setting by operating the zero key will be an absolute value of ±150 degrees. In addition, in the process (2) of taking in the count data from the A/D converter 4, the count data from the A/D converter is taken into the weight count value input registers M[A,A] to M[6,A].

In addition, in flicker processing (■), the count data taken into the weight count value input register is sequentially taken into the weight count register (■) ~ weight count register pan, and the changes before and after the count data taken into each weight count register are compared. Stable weight count register M [
Flickering is prevented by changing the contents of [7, D] to M[3, D] or keeping them as they are. The contents of the tare weight count register are subtracted from the contents of the stable weight count register, and the result is the true weight value and is stored in the register.
If the 15k9 flag memory is "0" when the count data is taken into the true weight register, the count data is set to 2. It starts to make a tingling sound. Also auto zero processing■
As shown in FIG. 5, first, the ON/OFF state of the 15k9/6k9 selector switch 15 is read. And when switch 15 is ON, 15k9 flag memo IJI
This is set to "1" and 5 evenings is set in the 1 scale register, and when the switch 15 is OFF, the 15x9 flag memory is cleared to "0" and 2 evenings is set in the 1 scale register. In this way, when the changeover switch 15 is ON, one scale is 1 in 5 meters as the second measuring means.
A scale with a count of 0 and a weight of 15k9 (30,000 counts) is formed, and the changeover switch 1 to 5 is turned off.
At this time, a scale is formed as the first measuring means, with one scale having 4 counts in 2 days and a weighing capacity of 6k9 (12,000 counts). Next, the contents of the 15k9 flag memory are checked. If it is "1", then the contents of the 6k9 flag memory are checked. When checking the flag memory of 6k9, if it is "1", the weight is zero, and the count number of the register is divided by 2.
Clear the 9 flag memory to “0”. This is the process when the selector switch 15 is switched to 15 kg. Further, when the 6k9 flag memory is "0", it remains unchanged. Also, in the above, when the 15k9 flag memory is "0", it is processed as a 6k9 weigher, that is, the weight is set to the true value, the count value of the jister is multiplied by 2.5, and the weight is set to zero, and the count value of the jister is multiplied by 2.5. and further stores “ in the 6k9 flag memory.
1" is performed. When this process is completed, the absolute value of the difference between the weight zero value register contents and the weight true value register contents is within 5 counts of the auto zero processing range. It is checked whether it is or not.
In this case, even if a weighing item with a weight of 15k9 is used, the weight is 6k9.
Even when using a 6k9 scale, the auto-zero processing range is performed with a uniform count of "5". This is solved by measuring the sound. If the absolute value of the difference is within 5 counts, the weight is set to the true value, the contents of the register are converted to a weight zero value, and the contents of the register are transferred to the register to set a new zero point. Also, the contents of the actual weight count register are cleared to zero. Further, if the absolute value of the difference is greater than 5 counts, the above new zero point setting process is not performed. When such processing is completed, it is then checked whether the new zero point is within a preset zero range. This check is performed in the same manner as when the zero key is operated, except that the zero point over flag is processed and the object of comparison is the zero weight value and the contents of the register. That is, first load the upper limit of the zero range into the storage register. followed by 1
It is checked whether the 5k9 flag memory is "1" or not, and if it is "0", the contents of the accumulator are multiplied by 2.5. If it is "1", the contents of the accumulator are held as they are. Next, compare the contents of the accumulator with the zero weight value and the contents of the register, and if the zero weight value and the contents of the register exceed the contents of the accumulator, set the zero point over flag to ``1''. If the contents of the register are smaller than the contents of the accumulator, the zero point over flag memory remains "0".Then, load the lower limit of the zero range into the accumulator.Then check whether the 15k9 flag memory is "1" or not. do.
If the 15kg flag memory is "0", the contents of the accumulator are multiplied by 2.5.

If it is "1", the contents of the accumulator are held as they are. Compare the absolute value of the contents of the accumulator with the zero weight value and the absolute value of the contents of the register, and if the weight is zero and the contents of the register are greater than or equal to the contents of the accumulator, set the zero point over flag to "1". , if it is smaller than the contents of the accumulator, the zero point overflow flag memory remains at "0". In this way, the process moves to the next display processing routine. In the display process (■), as shown in Figure 6, 5 counts are added to the count data of the 5-digit beauty weight count register, rounded down to 4, and then 15k.
9 Check flag memory.

When this flag memory is "1", it means that the scale is 15k 9/5 digits, so calculate the weight value by calculating the 5 digits of the 1 scale register into the upper 4 digits of the actual weight count register, and use that value as the weight. Transfer to display register. Also, the flag memory is “0”
'', the scale is 6 kg/2 weight, so 2 weight is added to the upper 4 digits of the actual weight count register, and the value is transferred to the weight display register.Next, the zero point over flag memory is set to ``. 1" and the weight over flag memory is set to "1". If either one is set to "1", the display 12 goes out. Note that the weight over flag memory becomes "1" when the weight of the object to be weighed exceeds the weighing value of the scale.Also, when both flag memories are "0", the count data of the weight display register is not loaded. After setting a zero suppression code such as "F" to the upper digits that are not present, the contents of the weight display register are displayed on the display 12. Therefore, if the content of the weight display register is "00200J", then "F
F200" and the display becomes "200". In this way, the two measuring means of 15k9/5 (10 counts) and 6k9/2 (4 counts) with different weighing values and 1 scale can be easily switched and operated by switching the changeover switch 15.

After this changeover, there is no need to replace the weight detector 1 or adjust the differential amplifier 2 or A/D converter 4, so there is no need to increase the number of parts used or troublesome work, improving economic efficiency. can do. Also, the accuracy is the same for both the 15k9/5 scale scale and the 6kg/2 scale scale because the number of scales is 3000 and the scale resolution as a scale is the same. Also 15
When the k9/5 scale is selected, the auto zero processing range is set to within 5 counts of the absolute value, and when the 6k9/2 scale is selected, the auto zero processing range is set to the absolute value ± If the weight value is set within 2 counts and the weight value is zero in any case, and the weight value is less than half of one scale based on the register count value, the weight value will always be displayed as zero, so proper auto-zero processing cannot be performed. can operate stably.

In the above embodiment, the case where one scale is 4 counts and 10 counts has been described, but the present invention is not limited to this. For example, one scale may be 2 counts and 5 counts, or 5 counts and 10 counts, etc. .

In short, the smaller number of counts per scale should be 2 or more. Also, the number of counts on one scale is 4 counts and 1
In case of 0 count, 2 count and 5 count, A
= state and B = arc, and in the case of 5 counts and 10 counts, the relationship of A = N + 1 and B = 2 (N + 1) is satisfied. Note that in the above, N is a positive integer. When B is an odd number, such as when the number of counts on one scale is 2 counts and 5 counts, the auto zero processing range is the absolute value ± 2/2 = 1 count or less and the absolute value 1/2
(5-1) = 2 counts or less, and when A is an odd number such as 5 counts and 10 counts, the auto zero processing range is absolute value 1/2 (5-1) = 2 counts or more and absolute value ±10 /2=5 counts or less. In addition, in the above embodiment, a device that can switch between 15k 9/5 evening and 6k 9/2 evening is described, but it is not necessarily limited to this. For example, 15k 9/5 evening and 15kg
It is also possible to select and switch between scales with the same weight but different scale resolution, such as the /10 scale.

Furthermore, in the above embodiment, the 15k9 flag memory is "1" in the key processing routine and the auto zero processing routine.
” is not set, that is, when the scale is 6k9, the upper and lower limit values of the zero point loaded into the accumulator are each multiplied by 2.5 times, but this is not necessarily limited to 2.3 times. Sound processing may be omitted; in this case, the zero point range will be 300 counts in absolute value as in the case of the 15k9 scale, so the weight will have an absolute value of ±60 over 30 scales of 1 scale and 2 scales.

In other words, this means that the zero point range is set at the same rate as when the zero point range is divided by the absolute value calculator 150 in the 15k9 scale. As described in detail above, according to the present invention, in a digital weight measuring device that converts a weighed value into a pulse number and displays it digitally, one scale is counted as A count (here, AZ2) by the number of pulses.

) to calculate the weight value by calculating the number of pulses generated during measurement ÷ the weight value on the A count When the number is odd, the first measuring means sets the auto-zero processing range to the absolute value of (A-1)/2 or less, and when measuring, one scale is set to B counts (however, B>A) with the number of pulses. Number of generated pulses ÷ B count x 1
When calculating the weight value by weighing the weight value on the scale, if B is an even number, the auto zero processing range is set to B/2.
or, in the case of an odd number, a second measuring means that sets the auto-zero processing range to be less than or equal to the absolute value of (B-1)/2, so that the above-mentioned two measuring means can be selectively switched to operate. Therefore, there are two types with different weighing or accuracy.
It is possible to provide a digital weight measuring device that can easily obtain scales on a stand by a simple switching operation, is highly economical, and allows each scale to be switched to perform appropriate auto-zero processing. .

[Brief explanation of the drawing]

The figures show an embodiment of the present invention. Figure 1 is a block diagram showing the circuit configuration, Figure 2 is a diagram showing the RAM memory configuration, Figure 3 is a flowchart of the main program, and Figure 4 is the key processing. In particular, FIG. 5 is a flowchart of the zero key processing, FIG. 5 is a flowchart of the auto zero processing, and FIG. 6 is a flowchart of the display processing. 1... Weight detection unit, 4... A/D converter,
7...CPU (central processing unit), 8...
...RAM (Random Access Memory), 9...
・・ROM (Read Only Memory), 15...
15kg/6kg switch. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Scope of Claims] 1. In a digital weight measuring device that converts a measured value into a number of pulses and displays it digitally, one scale is set to A count (however, A≧2) with the number of pulses. Calculate the weight value by weighing the number of pulses ÷ A count x 1 scale, and if the above A is an even number, set the auto zero processing range to A/2.
or, when the number is odd, the auto-zero processing range is set to be less than or equal to the absolute value of (A-1)/2, and one scale is counted by the number of pulses B (where B>A). ) and calculate the number of pulses generated during measurement ÷ B count ×
Calculate the weight value by weighing the weight value of 1 scale, and if the above B is an even number, set the auto-zero processing range to the absolute value of B/2 or less, or if it is an odd number, set the auto-zero processing range to (B-1) 1. A digital weight measuring device, comprising: a second weighing means for determining the absolute value of /2 or less, and capable of operating by selectively switching between the two weighing means.