JPH0627658B2 - Flow rate display method of flow rate display device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a flow rate display method for a flow rate display device that can be widely mounted on flow meters having different flow rate ranges.

[Conventional technology]

And [Problems to be Solved by the Invention] Conventionally, when the flow rate of the flow meter is digitally displayed when the flow rate of the flow meter is different because the discharge rate per flow rate pulse is different and the range of flow rate that can be measured with predetermined accuracy is different Due to the limitation of the number of digits to be displayed in each part, it is impossible to manufacture the flow rate display part common to all the device types, and the flow display part dedicated to each device type is inevitably manufactured. For this reason, it is necessary to have an inventory for each device type, and the number of inventories increases, which causes a drawback such as an increase in the cost of the device.

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned drawbacks, an object of the present invention is to provide a flow rate display method of a flow rate display device common to all kinds of flow meters having different discharge rates per flow rate pulse and different flow rate ranges. There is.

[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 instantaneous flow rate and its decimal point digit of the boundary value of the flow rate range that is determined for each flow meter and can be measured with predetermined accuracy, the flow rate per flow rate pulse and its decimal point digit, and the maximum display digit number are stored in RAM. Remember.

2) At the same time as inputting all of the above information, search for the number of non-zero digits of the maximum instantaneous flow rate from the maximum digit side, subtract the digit number from the maximum display digit number, and further determine the decimal point digit of the maximum instantaneous flow rate. Add to calculate the temporary decimal point in RAM,
This is stored in RAM.

3) When the temporary decimal point digit is other than 0, 1, 2, subtract 3 from the temporary decimal point digit.

4) Return to step 3) with the subtracted value as the decimal point digit.

5) When the temporary decimal point position is either 0, 1, or 2, it is stored in the RAM as a decimal point digit.

6) Wait for the flow rate pulse to be input. When the flow rate pulse is input, the time measurement value of the cycle measurement counter is stored by this flow rate pulse.

7) The frequency is calculated from this time measurement value, this frequency is multiplied by the conversion value K to calculate the instantaneous flow rate, and this instantaneous flow rate and its decimal place are stored in RAM.

8) Call the decimal point digit, subtract the provisional decimal point digit from this value, and add 1 to this to calculate the lowest display digit.

9) The numerical value of the instantaneous flow rate in the RAM is called for the maximum number of display digits in order from the least significant display digit, sent to the display drive section, displayed on the display section, and returned to 6).

Is configured.

[Action]

In the flow rate display device, before the work is started, the discharge amount per flow rate pulse and its decimal point digit, the maximum instantaneous flow rate of the boundary value of the flow rate range that enables measurement with predetermined accuracy, the decimal point digit and the maximum display digit number Is stored in RAM. At the same time, R
The decimal point digit of the maximum instantaneous flow rate stored in the RAM is obtained from the information stored in the AM, and is stored in the RAM as a temporary decimal point position. The position of the decimal point is 0,
If either 1 or 2, it is stored in the RAM as a decimal point digit. If the tentative decimal point digit is other than 0, 1, 2, 3 is subtracted from the tentative decimal point digit, and the determination is repeated using the subtracted value as the tentative decimal point digit.

After that, when a flow rate pulse is input from the flow meter, the time measurement value of the cycle measurement counter is temporarily stored in the RAM. The cycle of the flow rate pulse is calculated from the time measurement value, and the instantaneous flow rate is calculated by multiplying this cycle by the conversion value K obtained from the discharge rate per flow rate pulse and / h of the display unit, and this instantaneous flow rate and its decimal place. Is stored in RAM. The temporary decimal point digit is subtracted from the decimal point digit of the instantaneous flow rate, and 1 is added to this to calculate the lowest display digit of the instantaneous flow rate. R
It is possible to call the numerical value of the instantaneous flow rate in the AM for the maximum number of display digits in order from the lowest display digit, send this to the display drive unit, and display the maximum number of display digits on the display unit. At this time, the decimal point of the display unit is displayed in a digit corresponding to the decimal point digit stored in the RAM, and the display unit can select an easy-to-read display unit according to the instrument type of the flow meter, and the effective digit. Only numbers of numbers can be displayed.

〔Example〕

Embodiments will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes four flow rate pulses oscillated for one rotation from a rotor of a flow meter (not shown) according to the flow rate of the 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 frequency-divided flow rate pulse is sent to an internal counter (not shown) of the one-chip microcomputer 5 (hereinafter, referred to as a computer) which is a display control unit of the flow rate display device 1 and is configured to be integrated. There is. The computer 5 calculates the total integrated flow rate from the count value of the internal counter and the integrated flow rate from a predetermined time point, sends the calculated integrated flow rate to the display drive unit, and displays the total integrated amount and the integrated amount from the predetermined time point on the display unit. Is configured. In addition, the second ROM is stored in the ROM (not shown) inside the computer 5.
As shown in Fig. A, 1) The flow rate per flow rate pulse and the decimal point digit input from the input unit 8 described later are calculated by RA in the computer 5.
Store in M.

2) When the maximum instantaneous flow rate of the boundary value of the flow rate range that is determined by the flow meter and can be measured with a predetermined accuracy and its decimal point digit are input from the input unit, these are stored in the RAM.

3) The maximum display digit number input from the input unit 8 is stored in the RAM.

4) At the same time that all the information is input, the number of non-zero digits of the maximum instantaneous flow rate is searched from the maximum digit side, the digit number is subtracted from the maximum display digit number, and the decimal point digit of the maximum instantaneous flow rate is further calculated. Addition is performed to calculate a temporary decimal point digit in the RAM, and this is stored in the RAM.

5) When the provisional decimal point digits are other than 0, 1, 2, subtract 3 from the provisional decimal point digits.

6) The subtracted value is used as a temporary decimal point digit and the process returns to 5).

7) When the temporary decimal point digit is either 0, 1, or 2, it is stored in the RAM as the decimal point digit.

8) A decimal point digit calculation program consisting of "end" is stored. Further, the ROM stores a display control program for alternately displaying these data on the display unit 7 in the order of an instantaneous flow rate, a frequency division rate, the number of elements oscillating a flow rate pulse, and a meter factor, which will be described later.

Further, the divided flow rate pulse is configured to be sent to the control timing unit of the computer 5, and when the flow rate pulse is input, the instantaneous flow rate display program stored in the ROM is executed to calculate the instantaneous flow rate. Then, this is sent to the display drive unit 6 and displayed on the display unit 7. The instantaneous flow rate display program is the second
As shown in FIG. E, 1) Wait for the flow rate pulse to be input, and when the flow rate pulse is input, the flow rate pulse latches the period measurement counter (not shown) and Store in RAM.

2) Reset the cycle measurement counter.

3) The period measurement counter is started and the number of time measurement pulses from the oscillator (not shown) is measured.

4) Call the time measurement value in RAM.

5) The frequency is calculated by calculating the reciprocal of the time measurement value, this frequency is multiplied by the conversion value K to the instantaneous flow rate / h, and the calculated value and its decimal place are stored in the RAM.

6) Call the decimal point digit, subtract the provisional decimal point digit from this value, and add 1 to this to calculate the lowest display digit.

7) The numerical value of the instantaneous flow rate in the RAM is called for the maximum number of display digits in order from the least significant display digit, and this is called the display drive unit 6
Sent to and displayed on the display 7.

8) The decimal point digit stored in the RAM is called, and the display instruction of the decimal point of the digit of the display section corresponding to this is displayed.
Send to and return to 1).

Is configured.

In addition, the ROM includes a total integrated amount, an integrated amount from a predetermined time point, an instantaneous flow rate, and a frequency division according to signals from the input unit 8, the mode switch 9, the reset switch 10 and the changeover switch 11 connected to the computer 5. A program for recalling the rate, the number of elements, and the meter factor and setting them from the input section 8 is stored.

In the above flow rate display device, the discharge rate per flow rate pulse (cc / h), its decimal point digit, and flow rate meter are set in advance in the RAM of the computer 5 and the boundary of the flow rate range that enables measurement with a predetermined accuracy. Value of maximum instantaneous flow rate (
/ h) and its decimal point digit and maximum display digit number are stored. At the same time, the number of non-zero digits is searched and the RAM
This digit number is subtracted from the maximum display digit number in the above, and a calculated value obtained by adding the decimal point digit of the maximum instantaneous flow rate to this subtracted value is obtained as a temporary decimal point digit of the maximum instantaneous flow rate and stored in these RAMs. To be done. (See FIG. 3) When this temporary decimal point digit is other than 0, 1, 2, 3 is subtracted from the temporary decimal point digit, and this subtracted value is determined as the temporary decimal point digit in the same manner as the previous time.

When the provisional decimal point digit has a value of 0, 1 or 2,
This is stored in the RAM as a decimal point digit.

After that, the flow rate pulse transmitted from the flow meter is counted by the internal counter, and when the display command signal is received, the count value is multiplied by the meter factor to calculate the total integrated flow rate or the integrated flow rate from a predetermined time, This is sent to the display drive unit 6 and displayed on the display unit 7.

On the other hand, when the flow rate pulse from the flow meter is input to the control unit of the computer 5, the instantaneous flow rate display program is executed, the period measurement counter starts, the time measurement pulse from the oscillator is measured, and the period of the flow rate pulse is measured. 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 period measurement counter is reset,
The next time measurement will start. Then, the time measurement value is called, a cycle is calculated from this time measurement value, and a frequency is calculated from this cycle. The coefficient K obtained from the discharge amount per pulse and the display unit (/ h)
The instantaneous flow rate is calculated by multiplying by and the instantaneous flow rate and the decimal point digit are stored in the RAM.

Furthermore, the temporary decimal point digit stored in the RAM is called,
This provisional decimal point digit is subtracted from the decimal point digit of the instantaneous flow rate, and 1 is added to this to calculate the minimum display digit of the instantaneous flow rate stored in the RAM. From the minimum display digit, the numerical value of the instantaneous flow rate is called up in order from the minimum display digit, which is sent to the display drive unit 6 and displayed on the display unit 7. At this time, the display
The decimal point digit of 7 is displayed based on the decimal point digit stored in the RAM, and the display unit 7 is capable of displaying the numerical value of the predetermined effective digit number by selecting the display unit according to the instrument type of the flow meter. , The operator can definitely read the instantaneous flow rate.

In the embodiment, the instantaneous flow rate is displayed for each one flow rate pulse, but if a subtraction counter (not shown) is used to make the display easier to read, the instantaneous flow rate is displayed for every N flow rate pulses. You can also do it.

〔The invention's effect〕

As described above, according to the present invention, even in the case of a flow meter in which the discharge amount per one flow pulse or the flow rate range which can be measured with a predetermined accuracy is different, the maximum display digit is obtained from these information and the decimal point position is read by the indicated value. It is configured so that it can be easily moved and changed to a display unit that is easy to read, the instantaneous flow rate is calculated from the flow rate pulse oscillated from the flow meter, and only the effective digit value of this instantaneous flow rate is displayed on the display unit. Therefore, only one type of flow rate display device needs to be prepared regardless of the type of flow meter, and there is an advantage that a flow rate display device with extremely high versatility can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram for explaining the whole of the present invention, and FIG. 2a
Is a flow chart showing a decimal point digit calculation program according to the present invention, FIG. 2b is a flow chart showing an instantaneous flow rate display program according to the present invention, and FIG. 3 is an address map of the internal RAM 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 display control unit for counting a flow rate pulse oscillated from a rotor of a flow meter according to a flow rate of a liquid to calculate a flow rate of the liquid, and sending the calculated flow rate to a display drive unit for display on a display unit. In the equipped flow rate display device, 1) The maximum instantaneous flow rate and its decimal point digit, the flow rate per pulse and its decimal point digit, and the maximum display are determined from the flow rate range that is determined for each flow meter and can be measured with predetermined accuracy. The number of digits is stored in RAM. 2) At the same time that all of the above information is input, search for a non-zero digit of the maximum instantaneous flow rate, subtract the digit number from the maximum display digit number, and further add a decimal point digit of the maximum instantaneous flow rate, Calculate the temporary decimal point in the RAM and store it in the RAM
Remember. 3) When the temporary decimal point digit is other than 0, 1, 2, subtract 3 from the temporary decimal point digit. 4) Return to step 3) with the subtracted value as the decimal point digit. 5) When the temporary decimal point position is either 0, 1, or 2, it is stored in the RAM as a decimal point digit. 6) Wait for the flow rate pulse to be input. When the flow rate pulse is input, the time measurement value of the cycle measurement counter is stored by this flow rate pulse. 7) The frequency is calculated from this time measurement value, this frequency is multiplied by the conversion value K to calculate the instantaneous flow rate, and this instantaneous flow rate and its decimal place are stored in RAM. 8) Call the decimal point digit, subtract the provisional decimal point digit from this value, and add 1 to this to calculate the lowest display digit. 9) The numerical value of the instantaneous flow rate in the RAM is called for the maximum number of display digits in order from the least significant display digit, sent to the display drive section, displayed on the display section, and returned to 6). A flow rate display method characterized by the above.