JPH0627659B2 - Flow rate display method of flow rate display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is a flow rate display device that can be widely installed in flow meters having different flow rate ranges, and in particular, the minimum instantaneous flow rate of the instantaneous flow rate can be easily changed. The present invention relates to a flow rate display method for a flow rate display device configured to properly perform zero display.

[Prior Art] and [Problems to be Solved by the Invention] Recently, in order to reduce the number of inventory of the flow rate display device, a common flow rate display device is attached to flow rate meters having different flow rate ranges. When displaying the instantaneous flow rate, this flow rate display device measures the period between two flow rate pulses, calculates the frequency from this, and multiplies this frequency by a meter factor K to calculate the instantaneous flow rate. In this case, since the flowmeter has a range that can be measured with a predetermined accuracy as the flow rate range, if the instantaneous flow rate is less than or equal to the minimum instantaneous flow rate of the flow rate range, the value is displayed without displaying zero. Is configured.

In this type of flow rate display device, when displaying the instantaneous flow rate of flow meters with different flow rate ranges with the same flow rate display device, the minimum instantaneous flow rate differs depending on the type of flow meter, so there is a difference between flow rate pulses. It is necessary to determine whether or not the instantaneous flow rate is zero due to different cycles, and there is a demand for a flow rate display method for a display device that makes these determinations.

The present invention was devised in accordance with the above-mentioned demand, and is a flow rate display device common to all instrument types of flow meters having different flow rate ranges, and the cycle of zero display can be easily changed according to each instrument type. It is an object of the present invention to provide a flow rate display method for a flow rate display device that can be used.

[Means for Solving the Problems]

In order to solve the above problems, the display control unit that calculates the flow rate of the liquid by counting the flow rate pulses transmitted from the rotor of the flow meter that rotates according to the flow rate of the liquid and sends this to the display drive unit is ) The maximum cycle corresponding to the minimum instantaneous flow rate is calculated from the minimum instantaneous flow rate at the boundary value of the flow rate range that is determined for each flow meter and can be measured with predetermined accuracy and the meter factor K of the flow meter, and stored in RAM. To do.

2) Wait for the flow rate pulse to be input.When the flow rate pulse is input, the flow rate pulse stores the time measurement value of the cycle measurement counter as the detection cycle, resets the cycle measurement counter, and Start cycle measurement.

3) This detection cycle is compared with the maximum cycle, and when the detection cycle is larger than the maximum cycle, the instantaneous flow rate is set to zero and R
It is stored in AM and is called to the display drive,
Display on the display and return to 2).

4) When the detection cycle is smaller than or equal to the maximum cycle, the frequency is calculated from the detection cycle, and this frequency is multiplied by the meter factor K of the flow meter to calculate the instantaneous flow rate, which is stored in RAM and Is called on the display drive unit, is displayed on the display unit, and the process returns to 2).

Is configured.

[Action]

In this flow rate display device, when the minimum instantaneous flow rate of the boundary value of the flow rate range that is determined for each flow meter and enables measurement with a predetermined accuracy is input before the work is started, this is stored in the storage unit. The frequency corresponding to the minimum instantaneous flow rate is calculated from the minimum instantaneous flow rate and the meter factor K of the flow meter, the maximum period is calculated from this frequency, and this is stored.

On the other hand, when the flow rate pulse is input after waiting for the flow rate pulse to be transmitted from the flow meter, the time measurement value of the time measurement counter is stored as the detection cycle. Further, the next time measurement is started at the same time when this time measurement counter is reset. The detection cycle is compared with the maximum cycle, and when the detection cycle is larger than the maximum cycle, the instantaneous flow rate is stored in the RAM as zero, and this is called by the display drive section to display zero of the instantaneous flow rate on the display section. .

On the other hand, when the detection cycle is shorter than the maximum cycle, the frequency is calculated from the previous detection cycle, and the instantaneous flow rate is calculated by multiplying the frequency by the meter factor K of the flowmeter, and the instantaneous flow rate is stored in the RAM. It is called by the display drive unit and displayed on the display unit.

〔Example〕

Embodiments will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes four flow rate pulses transmitted from a rotor of a flow meter (not shown) for one rotation according to the flow rate of liquid, and the integrated value and the instantaneous flow rate are calculated from the measured values. It is a flow rate display device that calculates and displays these. The flow rate display device 1 is configured to be sent to an OR circuit and a Schmitt circuit 3 via an amplifier 2 for amplifying the flow rate pulse, and further sent to a frequency dividing circuit 4 for frequency division. The divided flow rate pulse is sent to a control unit (not shown) of a one-chip microcomputer 5 (hereinafter, referred to as a computer) which is a display control unit of the flow rate display device 1 and an internal counter of the computer 5 (see FIG. (Not shown), and is configured to be integrated. The computer 5 calculates the total integrated flow rate from the count value of the internal counter or the integrated flow rate from a predetermined time point according to a display command signal of the total integrated flow rate from the mode switch 9 described later or a display command signal of the integrated flow rate from a predetermined time point. Then, this is sent to the display drive unit 6, and the total integrated amount and the integrated amount from a predetermined time point are displayed on the display unit 7. Further, in the computer 5, the ratio input section of the maximum instantaneous flow rate and the minimum instantaneous flow rate of the boundary value of the flow rate range of the flow meter operated by the mode switch 9 and the changeover switch 11, the maximum instantaneous flow rate input section, and each flow meter An input unit 8 which is a meter factor input unit for inputting a corresponding meter factor K is connected. On the other hand, the computer 5 has a calculation unit for calculating the minimum instantaneous flow rate from the maximum instantaneous flow rate and the ratio of the maximum instantaneous flow rate and the minimum instantaneous flow rate, and this calculation unit includes both the maximum instantaneous flow rate input unit and the ratio input unit. It constitutes the minimum instantaneous flow rate input means.
Further, the computer 5 has calculating means for calculating the maximum period of the flow rate pulse corresponding to the minimum instantaneous flow rate from the minimum instantaneous flow rate of the boundary value and the meter factor K, and means for storing the output value of this calculating means. In addition, an instantaneous flow rate display program is stored in the internal ROM (not shown). This instantaneous flow rate display program is, as shown in FIG. 2, 1) calculating the minimum instantaneous flow rate from the ratio of the flow rate range of the flow meter input from the input section 8 described later and the maximum instantaneous flow rate,
This is stored in RAM (not shown).

2) The maximum cycle corresponding to the minimum flow rate is calculated from the minimum instantaneous flow rate and the meter factor K input from the input unit 8 according to the flow meter, and stored in the RAM. 3) Waiting for the input of the flow rate pulse, and when the flow rate pulse is input, the period measurement counter (not shown) is latched by this flow rate pulse and the time measurement value is stored in the RAM.

4) Reset the cycle measurement counter.

5) Start the period measurement counter and measure the time measurement value from the oscillator (not shown).

6) Call the time measurement value in RAM.

7) This detection cycle is compared with the maximum cycle, and when the detection cycle is larger than the maximum cycle, the instantaneous flow rate is set to zero and the RAM is set.
Remember.

8) When the display command signal of the instantaneous flow rate is transmitted from the mode switch 9, the zero display is called to the display drive unit 6,
Display the instantaneous flow rate at zero on display 7 and return to step 3).

9) When the instantaneous flow rate display command signal is not transmitted from the mode switch 9, return to 3).

10) When the detection period is less than or equal to the maximum period,
The frequency is calculated from the detection cycle, this frequency is multiplied by the meter factor K to calculate the instantaneous flow rate, and this is stored in the RAM.

11) When the instantaneous flow rate display command signal is transmitted from the mode switch 9, the zero display is called to the display drive unit 6,
This is displayed on the display unit 7, and the process returns to 3).

12) When the command signal for displaying the instantaneous flow rate is not transmitted from the mode switch 9, return to 3).

Is configured.

Further, in the ROM, in response to a display command signal from the mode switch 9, the instantaneous flow rate, the frequency division rate, the number of elements for transmitting the flow rate pulse, and the meter factor are used to call these data from the RAM to the display drive section 6. Display this 7
A control program that is displayed alternately with is stored. In addition, the ROM has an input section connected to the computer 5.
8, according to the signals from the mode switch 9, the reset switch 10 and the changeover switch 11, the total integrated amount, the integrated amount from a predetermined time point, the instantaneous flow rate, the frequency division ratio, the number of elements and the meter factor are called and input from the input section 8. A program that can be set is stored.

In the above flow rate display device, the ratio of the maximum instantaneous flow rate to the minimum instantaneous flow rate at the boundary value of the flow rate range that is determined according to the type of flow meter and can be measured with a predetermined accuracy, and the maximum instantaneous flow rate are input from the input unit 8. Then, the minimum instantaneous flow rate is calculated,
It is stored in RAM. The frequency corresponding to this is calculated from this minimum instantaneous flow rate, the maximum period is calculated from this frequency, and this is stored in the RAM.

On the other hand, when the flow rate pulse is input after waiting for the flow rate pulse to be transmitted from the flow meter, this is counted by the internal counter. When the display command signal of the total integrated flow rate or the integrated flow rate from a predetermined time point is transmitted from the mode switch 9, this count value is multiplied by the meter factor K to calculate the total integrated flow rate or the integrated flow rate from the predetermined time point. At the same time, the total integrated flow rate or the integrated flow rate from a predetermined time point is called up by the display drive section 6 and displayed on the display section 7.

On the other hand, when the flow rate pulse is input to the control unit of the computer 5, the time measurement pulse from the oscillator is measured and the cycle of the flow rate pulse is measured. When the next flow rate pulse is input, the period measurement counter is latched and the time measurement value is temporarily stored in the RAM. At the same time, the cycle measurement counter is reset and the next time measurement is started. Then, the time measurement value is called, a detection cycle is calculated from the time measurement value, and the detection cycle is compared with the maximum cycle. When this detection cycle is larger than the maximum cycle, the instantaneous flow rate is stored as 0 in the RAM. When the display command signal of the instantaneous flow rate is transmitted from the mode switch 9, the display drive unit 6 calls the zero display, and the display unit 7 displays the instantaneous flow rate zero.

When the detection cycle is smaller than the maximum cycle, the frequency is calculated from the detection cycle, and the instantaneous flow rate is calculated by multiplying the frequency by the meter factor K. The instantaneous flow rate is RA.
Stored in M. When the instantaneous flow rate display command signal is transmitted from the mode switch 9, the instantaneous flow rate will be displayed.
Called by 6 and displayed on display 7.

In the embodiment, the minimum instantaneous flow rate input section is composed of the maximum instantaneous flow rate input means, the ratio input section of the maximum instantaneous flow rate and the minimum instantaneous flow rate at the boundary value of the flow rate range, and the calculation section of the minimum instantaneous flow rate. Alternatively, a minimum instantaneous flow rate input section that operates by the mode switch 9 and the changeover switch 11 may be provided to directly input the minimum instantaneous flow rate.

〔The invention's effect〕

As described above, the present invention determines the flow rate corresponding to the minimum instantaneous flow rate from the minimum instantaneous flow rate at the boundary value of the flow rate range determined by the flow meter and capable of measuring the liquid with a predetermined accuracy and the meter factor K of the flow meter. The maximum pulse period is calculated to calculate the zero display unit, and when the flow rate pulse with a period greater than this maximum period is measured, the instantaneous flow rate is displayed as zero. It is only necessary to prepare one kind of display device, and it is possible to provide not only a highly versatile flow rate display device, but also a device that can easily change the zero display unit of the instantaneous flow rate and is extremely easy to handle. There are advantages such as

[Brief description of drawings]

FIG. 1 is a block diagram for explaining the whole of the present invention, and FIG. 2 is a flow chart showing an instantaneous flow rate display program according to the present invention. 1 ... Flow rate display device, 2 ... Amplifier, 3 ... OR circuit and Schmitt circuit, 4 ... Division circuit, 5 ... One-chip microcomputer, 6 ... Display drive unit, 7 ... Display unit, 8 …… Input section, 9 …… Mode switch, 10 …… Reset switch, 11 …… Change switch,

Claims (1)

[Claims] 1. A flow rate display device comprising a display control section for counting a flow rate pulse transmitted from a rotor of a flow meter according to a flow rate of the liquid to calculate a flow rate of the liquid and sending the calculated flow rate to a display drive section. , 1) Calculate the maximum period corresponding to the minimum instantaneous flow rate from the minimum instantaneous flow rate at the boundary value of the flow rate range that is determined for each flow meter and enables measurement with a predetermined accuracy, and the meter factor K of the flow meter, and RAM Remember. 2) Wait for the flow rate pulse to be input.When the flow rate pulse is input, the flow rate pulse stores the time measurement value of the cycle measurement counter as the detection cycle, resets the cycle measurement counter, and Start cycle measurement. 3) This detection cycle is compared with the maximum cycle, and when the detection cycle is larger than the maximum cycle, the instantaneous flow rate is set to zero and R
It is stored in AM and is called to the display drive,
Display on the display and return to 2). 4) When the detection cycle is smaller than or equal to the maximum cycle, the frequency is calculated from the detection cycle, and this frequency is multiplied by the meter factor K of the flow meter to calculate the instantaneous flow rate, which is stored in RAM and Is called on the display drive unit, is displayed on the display unit, and the process returns to step 2). A flow rate display method characterized by the above.