JPS636814B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for controlling an electronic weighing machine.

Conventional weighing machines currently have one control switch for each function, such as an auto-zero command switch, a hold command switch for displaying weight values, a hold release switch, and a zero point check switch. It is. However, it is not only uneconomical to provide various switches for each function, which are not used repeatedly, but also has low operability, which can lead to erroneous operations.

Therefore, the present invention provides a control method that allows one switch to be used for multiple functions.

The control method according to the present invention will be explained below based on one embodiment. Figure 1 shows the configuration of the charge scale, where 1 is an analog-to-digital converter (hereinafter referred to as A/DCOV.), which converts the output signal of load converter 2, which outputs an analog signal corresponding to the weighed value, into a digital signal. Convert to D. 3 is a timing signal generator, R ₁ ~
Scanning signals are sequentially and repeatedly output to the three output lines of _R3 . 4 is a set unit price reading section, which has four input lines K ₁ , K ₂ , K ₄ , K ₈ and the above three output lines.
An input device consisting of a matrix circuit of R ₁ , R ₂ , and R ₃ reads the signal from the numeric keypad 5 and outputs unit price data Da. 6 is an auto-zero circuit, which includes a memory section 7 that stores the digital value of the A/DCOV.1 output at the time when auto-zero is commanded;
Corrected weighing value data Dg by subtracting the memory contents from the digital value of A/DCOV.1 output at that time
and an arithmetic unit 8 which outputs. Reference numeral 9 denotes a full price calculation unit which calculates the price of the object to be weighed from the unit price data Da and weighed value data Dg, and outputs price data _DM . 10 is the digital value D of the output of A/DCOV.1
This is a comparator that determines whether the value corresponds to the zero point of the weight value. For example, if the resolution of A/DCOV.1 is
15000, the output is inverted to the logic level "H" in the range of 0<D<200, and the output remains at the logic level "L" when D<0 or D<200. Reference numeral 11 denotes a timer circuit, which has a trigger input terminal T for controlling the start of the timer, and a reset terminal R for clearing the timer at logic level "H" regardless of the state of the trigger input terminal T. T has input line _K8 and output line
A trigger signal is input at the timing when the self-resetting pushbutton switch S of the numeric keypad 5 provided between R3 and _R3 is operated, and the reset terminal R is connected to the comparator
Connected to 0 output. Note that when the timer circuit 11 starts counting, the output is inverted to logic level "H", and automatically returns to logic level "L" after a specified time t has elapsed. A waveform shaping circuit 12 shapes the waveform of the AND gate 13 output of the input line _K8 and the output line _R3 , and outputs a set signal to the trigger input terminal T of the timer circuit 11. 14 outputs the AND of the waveform shaping circuit 12 output and the comparator 10 output;
In the AND gate that controls the updating of the memory section 7 of the auto-zero circuit 6, when the output of the comparator 10 is at the logic level "H" and the push button switch S is operated, the output level is inverted to the logic level "H". The memory unit 7 is commanded to update the stored contents. 15 is a display unit that digitally displays unit price data Da, weight value data Dg, and price data D _M as unit price, weight, and price, respectively, and a control terminal that holds the display by setting the logic level to "H". The control terminal C is connected to the output of the timer circuit 11.

Next, the operation will be explained based on the flow sheet diagram shown in FIG. 2, taking as an example the operation immediately after the power is turned on.
After turning on the power, if the digital signal D of A/DCOV.1 output is within the range of 0<D<200 near the zero point,
The output of the comparator 10 is inverted to logic level "H",
Since the timer circuit 11 is in the reset state, the control terminal C of the display section 15 is at the logic level "L". Therefore, the display section 15 shows a display corresponding to the digital signal D from time to time.

When the pushbutton switch S is operated, the AND gate 14 output is inverted to logic level "H", the contents of the memory section 7 are updated to the digital value of A/DCOV.1 at that time, and the weight value data Dg is calculated. The weight value is set to zero. As a result, the display content on the display unit 15 changes to the content obtained by correcting the digital signal D. If the pushbutton switch S is repeatedly operated in this state, the contents of the memory section 7 are updated to the respective digital values as needed. Load the object to be measured and output the digital signal D.
is out of the range of 0<D<200, the comparator 10
The output returns to the logic level "L", and the reset state of the timer circuit 11 is released. The same pushbutton switch S that was then commanded to auto-zero
When the output line _R3 is scanned, the timer circuit 11 is set and the display section 15 is displayed.
The control terminal C of is inverted to logic level "H", and the display contents are held. At this time, since the output of the comparing section 10 is at the logic level "L", the AND gate 14 is in an OFF state, and even if the push button switch S is operated, no update command is issued to the memory section 7. When the timer circuit 11 is set and starts timing, for example, a specified time of 10 seconds has elapsed, the timer circuit 11 detects time-up, the control terminal C of the display section 15 returns to the logic level "L", and the display is no longer held. The hold is released, and the display unit 15 displays the time when the hold is released. In addition, when an abnormal situation occurs in which the digital signal D is out of the range of 0<D<200 near the zero point immediately after the power is turned on, the reset of the timer circuit 11 is released, so the pushbutton switch S is operated. However, unlike the case described above, the memory section 7 of the auto-zero circuit 6 is not commanded to update, and the timer circuit 11 is immediately set and the display section 15 goes into a hold state to notify the operator of this abnormal situation.

In the above embodiment, the timer circuit 11 is provided so that the hold on the display is automatically released after a predetermined period of time has elapsed, but as shown in FIG. The same effect can be achieved even if the hold is released by operating the push button switch S again. Further, as shown in FIG. 4, an RS flip-flop 17 may be provided, and a hold release switch 18 may be provided separately from the push button switch S. Furthermore, in the above embodiment, display hold control is performed, but clearing of tare weight, clearing of unit price,
It is also possible to control print commands, release of holds on binary counters and combination displays.

Further, in the above embodiment, the set unit price reading section 4, auto-zero circuit 6, amount calculation section 9, etc. were provided separately.
These can be implemented by the CPU 19 as well.

As explained above, according to the control method of the present invention,
Depending on whether or not the weight value is near the zero point, one switch can be used as an auto-zero command switch and for controlling the operation of a circuit other than the auto-zero circuit, so one switch is provided for each function. This is not necessary and can eliminate the possibility of erroneous operation. As a result, operability is significantly improved.

[Brief explanation of the drawing]

The drawings show one embodiment of the control method according to the present invention; FIG. 1 is a block diagram of a fare scale, FIG. 2 is a flow sheet diagram, and FIGS. 3 and 4 are other embodiments. DESCRIPTION OF SYMBOLS 1...Analog-digital converter, 2...Load converter, 5...Numeric keypad, 6...Auto zero circuit, 7...Memory section, 10...Comparator, 11...Timer circuit, 15
...Display section, 16...J-K flip-flop, 17
...R-S flip-flop, S...push button switch [multi-function switch].

Claims (1)

[Claims] 1 If one multi-function switch is operated with the weight value signal within a predetermined range near the zero point, the auto-zero circuit will operate, and if the multi-function switch is operated with the weight value signal outside the predetermined range, the auto-zero will be activated. A method for controlling an electronic weighing machine, characterized in that the signal is used as an operation control signal for a circuit other than the circuit.