JP2002039816A - Flowmeter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flowmeter capable of measuring various flow rates such as integrated flow rate and momentary flow rate of a target fluid, and outputting a BCD output signal corresponding to these flow rates to the outside equipment without using a BCD output signal converter. SOLUTION: Various flow rates such as integrated flow and momentary flow of the target fluid are measured, and when a latch signal is received from a sequential controller 9, a BCD control signal from the sequential controller 9 is taken out one digit by one digit from each flow rate as the flow rate classified signal and a digit instruction signal according to these signals, and the taken out signal is outputted to the sequential controller 9. Therefore, the various flow rate can inexpensively, correctly be outputted to the sequential controller 9 far from an installation place of the flow meter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow meter configured to measure various flow rates such as an integrated flow rate and an instantaneous flow rate of a liquid to be measured and to output these to an external device such as a sequential controller.

[0002]

2. Description of the Related Art Recently, various flow meters have been digitized, and the flow rate of a liquid to be measured has been digitized. Along with this, the flow rate of the liquid to be measured is output to an external device such as a sequential controller that controls plants in which the flow meter is incorporated, and these are used for various controls.

[0003]

SUMMARY OF THE INVENTION In this type of flow meter,
Various flow rates such as integrated flow rate and instantaneous flow rate are calculated.
To output these flow rates to a sequential controller, a BCD output signal converter for converting the flow rate into a BCD output signal suitable for data transfer is required. For this reason, various flow rates such as an integrated flow rate and an instantaneous flow rate can be converted into a BCD output signal at a preset timing, and these can be accurately output to the control device. However, the cost of the flow meter increases accordingly. There are drawbacks.

An object of the present invention is to eliminate the above-mentioned drawbacks and measure various flow rates such as an integrated flow rate and an instantaneous flow rate of a liquid to be measured, and output a BCD output signal corresponding to these flow rates without a BCD output signal converter. To provide a flow meter configured to output to an external device.

[0005]

A flow meter having a control unit for measuring the flow rate of a liquid to be measured and calculating various flow rates such as an integrated flow rate and an instantaneous flow rate, and an external device for transferring the flow rates to the outside. When the latch signal is received from the external device, the BCD control signal of the external device is used as a flow type signal and a digit instruction signal while the latch signal is output. The control unit is configured to extract a value for each digit and output the value to an external device.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a flow meter for measuring a flow rate of a liquid to be measured, and a counter 3 for integrating a flow rate pulse transmitted from a sensor unit 2 in accordance with the flow rate of the liquid to be measured, and a value of the counter 3 for inputting. A control unit 5 that reads in via the output unit 4 and calculates a flow rate according to a desired flow rate display mode; a storage unit 6 that stores the calculated flow rate; an operation unit 7 that selects a desired flow rate display mode; The display unit 8 displays a flow rate or the like according to the flow rate display mode. A sequential controller 9 which is an example of an external device that outputs various command signals via the input / output unit 4 is connected to the control unit 5.

The control section 5 is configured to temporarily store the integrated flow rate and the instantaneous flow rate when receiving the latch signal from the sequential controller 9. The control unit 5 reads the four BCD control signals of the sequential controller 9 as one flow type signal and three digit indication signals while the latch signal is output from the sequential controller 9, and outputs the flow type signal. It is configured to output the integrated flow rate and the instantaneous flow rate to the sequential controller 9 for each digit according to the signal (the integrated flow rate at the time of the “0” level signal, the instantaneous flow rate at the “1” level signal) and the digit instruction signal. I have. The BCD control signal may be increased to correspond to three or more flow rates.

Further, upon receiving the latch signal, the control unit 5 immediately outputs the value of the digit indicated by the three-digit instruction signal from the temporarily stored integrated flow rate to the sequential controller 9 from its own BCD output terminal. Then, when the flow type signal is a "0" level signal, every time the digit indicating signal changes, the value of the digit indicated by the digit indicating signal is changed from the integrated flow to eight digits, and the flow type signal is a "1" level signal. In the case of (1), it is configured to sequentially select up to five digits from the instantaneous flow rate and output this to the sequential controller 9.

The sequential controller 9 receives the value of each digit from the control unit 5 as an integrated flow up to eight digits, and receives the subsequent five digits as an instantaneous flow rate, and performs various controls such as flow rate control of the liquid to be measured based on these flow rates. Is configured to do so.

In the above-mentioned flow meter, the flow rate pulse transmitted from the sensor unit 2 in accordance with the flow rate of the liquid to be measured is integrated in the counter section 3, and the integrated flow rate and the instantaneous flow rate are calculated from the value of the counter section 3 each time. . These calculated flow rates are stored in the storage unit 6 and displayed on the display unit 8 at predetermined time intervals in a flow rate unit corresponding to a desired flow rate display mode.

During this time, as shown in FIG. 2, a latch signal is sent from the sequential
At the same time, the latest integrated flow rate and the instantaneous flow rate stored in the storage unit 6 are temporarily stored, and at the same time, whether or not the flow rate type signal from the BCD control terminal of the sequential controller 9 is a “0” level signal is determined. Will be determined. When this flow rate type signal is a “0” level signal, the other three BCs
Each time the digit indicating signal consisting of the D output signal changes, the value of the digit indicated by the digit indicating signal is called from the integrated flow rate and output to the sequential controller 9. This is repeated up to the eighth digit, and the values of all digits of the integrated flow rate (2, 9, 5,
1, 4, 1, 3, 0) is the sequential controller 9
Is output to Thereafter, when the flow rate type signal becomes the "1" level signal, the instantaneous flow rate is called up, and similarly, the value of the digit indicated by the digit indication signal is called up from the instantaneous flow rate and output to the sequential controller 9. This is repeated up to the fifth digit, and the values of all digits of the instantaneous flow rate (0, 0, 0, 4,
2) is output to the sequential controller 9. Upon receiving the values of each digit of the integrated flow rate and the instantaneous flow rate, the sequential controller 9 can perform various controls such as flow rate control of the liquid to be measured based on these values. Thereafter, when the latch signal is turned off, the calculation of the flow rate of the liquid to be measured is repeated.

[0012]

As described above, the present invention measures various flow rates such as an integrated flow rate and an instantaneous flow rate of a liquid to be measured and, when receiving a flow rate type signal and a digit indicating signal from an external device, responds to these signals. Since values are extracted digit by digit from each flow rate and output to external devices, there is an advantage that various flow rates can be accurately and inexpensively output to external devices.

[Brief description of the drawings]

FIG. 1 is a schematic view of a display device of a flow meter according to the present invention.

FIG. 2 is a signal waveform diagram of input / output signals between a control unit and a sequential controller according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flow meter 2 Sensor unit 3 Counter part 4 Input / output part 5 Control part 6 Storage part 7 Operation part 8 Display part 9 Sequential controller

Claims (1)

[Claims] 1. A flowmeter comprising: a controller for measuring a flow rate of a liquid to be measured and calculating various flow rates such as an integrated flow rate and an instantaneous flow rate; and an external device for performing predetermined control based on the flow rate. When the latch signal is received, the BCD control signal of the external device is used as a flow type signal and a digit instruction signal while the latch signal is output. A flowmeter characterized in that a control unit is configured to take out and output this to an external device.