JP3307495B2 - Gas meter with communication function - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for switching a communication line with the outside of a gas meter equipped with a microcomputer and a communication system used for implementing the method.

[0002]

2. Description of the Related Art There is known a gas meter with a microcomputer gas shut-off device having a safety function for constantly monitoring a gas flow rate by a built-in microcomputer to secure safety.

[0003] The microcomputer with built-in gas meter is programmed with various abnormal use states when using gas. When an abnormal flow rate or abnormal use of gas occurs for a long time, the microcomputer quickly determines and closes the shutoff valve. ,
Cut off gas. In addition, it has a built-in seismic sensor and pressure sensor.
The gas is cut off immediately or the gas is cut off immediately when the supply gas pressure drops abnormally.

Further, in order to set various constants such as pulse units and instrumental difference correction coefficients in a microcomputer built in the gas meter, a predetermined electric signal is sent from the outside of the gas meter to the meter via a communication line to set the constant. In some cases, a request may be made to send the contents (information) such as constants and gas consumption stored in the microcomputer to the outside of the meter via a communication line. A gas meter with such a communication function is equipped with a lead wire for electrical connection to a communication line.The other end of the lead wire, one end of which is connected to a printed circuit board equipped with a microcomputer, is drawn out of the meter case. Have been.

Until the gas meter is installed in the customer and connected to the telephone network controller (NCU), the end of the lead wire drawn out is protected by covering with a heat shrink tube for insulation. I have.

The communication speed between the inside and the outside of the gas meter via the lead wire is 300 bps. In order to improve communication reliability, not only horizontal / vertical parity check but also special error control is performed.

[0007] The NCU has a photocoupler, and the photocoupler electrically insulates the communication line on the telephone station side from the communication line (lead wire) on the meter side.

Further, in this type of gas meter with a microcomputer gas shut-off device, a signal from a seismic sensor or a pressure sensor is applied between the time when the meter number is set and when a non-seismic interruption or a non-pressure interruption is performed. Equipped with a seismic / pressure mask mode that avoids shaking or pressure blocking. By setting this mode, it is possible to avoid interruption by the seismic sensor or pressure sensor when performing the flow rate test, and to improve the work efficiency. The release of the seismic / pressure mask mode is interrupted by a signal other than the vibration sensor or the pressure sensor.

In order to make various settings on the gas meter without using a telephone line and to read out the information in the gas meter, the leading end of the communication lead covered with the heat-shrinkable tube is cut off and the lead is put together. This is done by removing the insulation, stripping off the insulation coating, connecting the crocodile clip, which is a connector of a known setting device for setting reading, to the lead wire, and operating the setting device. At this time, if the polarity of the alligator clip is incorrectly connected, the gas meter has a structure in which the microcomputer closes the shutoff valve to shut off the gas. At this time, it must be left for 2 minutes as a return time. Further, when the setting is completed, the work of cutting off the insulating coating, covering with a heat shrinkable tube, and bundling the lead wires is performed.

In a gas meter with a microcomputer gas shut-off device, a test switch composed of a reed switch is provided on the front of the meter. By holding a permanent magnet close to this test switch for a certain period of time, the test switch becomes 0.2 When turned on for more than a second, the microcomputer is configured to close the shutoff valve to shut off gas, which is called test shutoff.

[0011]

In the conventional gas meter having a communication function, the lead wire to be connected to the telephone line was connected to the setting device and the setting device was operated, so that the heat shrink tube was covered. There has been a problem that the troublesome work of cutting off the tip of the lead wire, peeling off the insulating coating, connecting with the alligator clip, and attaching the heat-shrinkable tube to the lead wire again after the setting work has been involved has been a problem. In addition, there is another problem that the setting work becomes difficult because the lead wire becomes short.

Further, if the polarity of the alligator clip is incorrectly connected during the setting operation, the shutoff valve is closed, a predetermined return time is required, and the operation efficiency is deteriorated.

SUMMARY OF THE INVENTION It is a first object of the present invention to provide a gas meter with a communication function which can solve these problems at the time of setting work including reading of internal information of the gas meter.

Recently, multi-functions of gas meters with a communication function have been promoted, and the amount of information sent from the setting device to the gas meter and the amount of information sent from the gas meter to the setting device when performing setting work using the setting device tend to increase. In addition, there is also a problem that the time required for the setting operation increases and the operation efficiency deteriorates.

Therefore, a second object of the present invention is to provide a gas meter with a communication function that can solve such a problem.

[0016]

In order to achieve the first object, the invention according to claim 1 monitors a gas flow rate by a built-in microcomputer (2) and, when an abnormal use of gas occurs, shuts off a shut-off valve (3). ), A communication function including a microcomputer gas shutoff device having a switch (4) for shutting off gas and responding to magnetism from the outside, and a first communication line (9) for exchanging signals with the outside. A second communication line (7) connected to a light emitting diode (5) and a phototransistor (6) disposed outward of the meter, the first communication line (9) and a second communication line. A switching circuit (8) for switching and connecting the communication line (7) of
The switch (4) or the phototransistor (6)
And a control circuit (2) for switching the switching circuit (8) by judging the above signal.

Further, in order to achieve the second object,
The invention according to claim 2 is characterized in that, when the switching circuit (8) is switched to the second communication line (7), a clock frequency for controlling a communication speed is increased. It is a gas meter with a communication function of description.

[0018]

In a gas meter manufacturing plant or a place where a gas consumer is installed at a gas consumer, when exchanging signals by a setting operation using a setting device without using a first communication line, a magnetic coil of the setting device is used. The light-emitting diode and the phototransistor are arranged facing the switch (4), the phototransistor (6) and the light-emitting diode (5) of the gas meter, respectively.

Switch (4) according to predetermined operation of setting device
Alternatively, the control circuit (2) determines the signal of the phototransistor (6) and switches the switching circuit (8) to the second communication circuit.

Thus, signals are exchanged between the gas meter and the setting device by optical communication by the second communication circuit.
At this time, according to the second aspect of the present invention, the communication clock frequency is switched to a higher frequency, so that the setting operation signal is exchanged at a high speed.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 1 denotes a gas meter with a communication function provided with a microcomputer gas shut-off device, and a metering function section is omitted and not shown. Reference numeral 2 denotes a microcomputer, and reference numeral 3 denotes a shut-off valve provided at a gas inlet. The microcomputer 2 is programmed with various abnormal use states when the gas is used, and the microcomputer 2 determines when an abnormal use of the gas such as a flow rate abnormality occurs. And shut off the shutoff valve 3 to shut off the gas.

As described above, detecting an earthquake,
Although a seismic sensor and a pressure sensor for detecting an abnormal decrease in the supply gas pressure are provided, these are not shown. Reference numeral 4 denotes a test switch composed of a reed switch (lead SW), which is arranged on the front of the gas meter 1 and connected to the microcomputer 2.

Reference numerals 5 and 6 denote a light emitting diode (hereinafter abbreviated as an LED) and a phototransistor (hereinafter abbreviated as a photo Tr) arranged in parallel with the test switch 4 on the front of the gas meter 1 and are switched by a second communication line 7. It is connected to a circuit 8.

Reference numeral 9 denotes a first circuit having one end connected to the switching circuit 9.
The other end is drawn out of the gas meter 1 and connected to a telephone line 11 having a network control circuit (hereinafter abbreviated as NCU) 10. The NCU 10 has a built-in photocoupler 12 and electrically insulates the first communication line 9 on the gas meter side from the telephone line 11. Thus, the first communication line 9 and the telephone line 11
Are optically coupled by the photocoupler 12.

The telephone line 11 is connected to a known exchange,
Furthermore, it is connected to a computer of a meter reading center for automatic meter reading. The gas meter 1 is connected to the telephone line 11 via the NCU 10 as shown in the figure after the gas meter 1 is installed at a gas consumer, and is not connected until the installation. Therefore, until installation, the lead wire (electric wire) constituting the first communication line 9 is cut at a length slightly drawn from the gas meter 1 and covered with a heat-shrinkable tube to insulate the cut end. It is.

Therefore, in order to connect the lead wire (the first communication line 9) to the NCU 10 after the gas meter is installed, the lead wire on the NCU 10 side should be connected to the heat-shrinkable tube portion of the lead wire of the first communication line 9. Cut, peel off the insulation coating and connect.

Reference numeral 13 denotes a connection unit that connects the microcomputer 2 and the switching circuit 8. Reference numeral 14 denotes a personal computer, which forms a main body of the setting device, and configures the setting device 17 together with the setting device I / O section 15 and the connection line 16.

The setting device I / O unit 15 includes an electromagnet 19 wound with a magnetic coil 18, an LED 20, and a photo Tr 21. When performing a setting operation, as shown in the figure, the electromagnet 19, the LED 20, and the photo Tr 21 are used. However, the setting device I / O unit 15 is installed so as to face the test switch 4, the photo Tr 6, and the light emitting diode 5 of the gas meter 1, respectively.

Next, the setting operation by the setting device 17 will be described. Among the setting work procedures, the procedure on the setting device 17 side is programmed in the personal computer (14). At the beginning of the setting operation, the electromagnet 19 and the LED 20 are operated. The electromagnet 19 is turned on for 0.2 seconds or more, and during this ON time (strictly, immediately before the electromagnet 19 is turned on, the electromagnet 19 is turned on).
Flashes at a constant frequency. The operation of the electromagnet 19 and the LED 20 indicates the start of the setting operation.

When the test switch (reed switch) 4 is turned on by the operation of the electromagnet 19, the circuit and the program of the microcomputer 2 are determined so that the microcomputer 2 operates to turn on the power of the photo Tr 6. When the photo transistor 6 receives the light signal of the LED 20 on the setting device side by the blinking of the constant frequency, the microcomputer 2 determines that there is a communication request from the setting device 17 and switches the switching circuit 8 to the second communication line side. Switch to 7. Turning on the power of the photo Tr 6 is performed by the same process as switching the switching circuit 8 to the second communication line 7 side. In this manner, when the operation of operating the test switch 4 is performed, the microcomputer determines whether the operation is to activate a test shutoff function originally or to perform (request) communication for setting work. 2.

If it is determined that the operation is for communication for the setting operation, the switching circuit 8 is disconnected from the first communication line 9 and switched to the second communication line 7 as described above. Then, the clock frequency of the communication speed by the microcomputer 2 is switched to a higher frequency, and the operation waits. When it is determined that it is not for communication, the switching circuit 8 is configured to perform the original operation without switching.

Thus, the switching circuit 8 can be switched without canceling the original function of the seismic / pressure mask mode. The switching circuit 8 that has switched to the second communication line 7 returns to the first communication line 9 when it determines that communication with the setting device 17 has been completed, or after a certain time has elapsed.

As described above, when the power of the photo Tr 6 is turned on when the test switch 4 is turned on, the power consumption by the photo Tr 6 when the setting operation by the setting unit 17 is not performed is eliminated, and the gas meter 1 is turned off. To prevent the internal battery from being consumed.

After switching to the second communication line 7, 10
It waits for a message from the setting device in the message waiting state for seconds. There is no message in the last 10 seconds, or the high “H” state is 1
If there is more than one second, the switching circuit 8 is returned to the first communication line. The condition for returning to the first communication line is the same during the setting operation.

The switch 8 is returned to the first communication line 9 when the end message is received. It is the same as the second communication line. Further, when switching to the second communication line, the communication speed is increased, and there is no special error control, and only the horizontal / vertical parity check is performed. By doing so, the communication time can be further shortened, and the setting operation can be completed in a short time.

Such an operation is shown in a timing chart of FIG. In FIG. 2, ON and OFF of the meter-side photo Tr6 and the setter-side photo Tr21 mean the presence or absence of power supply to these transistors. Setting device side LED2
After the constant frequency of 0 disappears, communication data is first transmitted from the LED on the setter side as shown by a signal a after a predetermined standby time in FIG. To receive. Next, the meter side LED
5 transmits the communication data as indicated by the symbol C, and the setter-side photo Tr 21 receives the communication data as indicated by the symbol D. In this manner, the setting device 17 and the gas meter 1 exchange signals via the second communication line 7 and by optical coupling.

FIG. 3 is a timing chart when the setter 17 performs a normal shut-off operation. At this time,
The test switch 4 on the meter side is set to 0.2 by the electromagnet 19.
Turn ON for more than a second. The gas meter 1 has a test switch 4
Is turned on and the shutoff valve 3 is shut off 0.2 seconds after the gas is turned off to stop the gas. The test switch 4 is turned on for the power of the photo Tr 6
ON only for the first 0.2 seconds.

Next, a flowchart for performing the above operation will be described with reference to FIG. In step 101, the power of the photo Tr 6 is turned on, and the process proceeds to step 102.

In step 102, it is determined from the signal of the photo Tr6 whether or not there is blinking at a fixed period. If YES, a blinking flag is set in step 103, and
Move to 05.

If NO in step 102, the flashing flag is set to 0 in step 104, and the process proceeds to step 105. In step 105, it is determined whether or not 0.2 seconds have elapsed.
In the case of ES, the process proceeds to step 106. If NO, the process proceeds to the main routine.

At step 106, it is determined whether the blink flag is 1, and if YES, the routine proceeds to step 107. Step 1
At 07, the switching circuit is switched to the second communication line, and the flow shifts to the communication flow. If NO in step 106, the power supply of the photo Tr 6 is turned off in step 108, and the flow proceeds to the test interruption.

In the above embodiment, the electromagnet 19 is set at 0.
The LED 21 is operated for 2 seconds or more, and at that time, the LED 21 is blinked at a short cycle (constant frequency). From the signal of the test switch 4 and the photo Tr 6 at this time, the start of communication for the setting operation of the setting unit 17 is started. Although the microcomputer 2 determines that there is a signal and switches the switching circuit 8 to the second communication line 7 side, another method may be used as a signal for starting communication for setting work.

For example, by exciting the electromagnet 19 with alternating current, the test switch 4 is turned on and off at a constant frequency (ON.OF).
F), the microcomputer 2 may determine the signal and control the switching circuit 8 to switch to the second communication line. In this case, the program of the setting device and the circuit and the program of the gas meter become simpler than in the above embodiment.

[0044]

Since the gas meter with a communication function of the present invention is constructed as described above, various constants and the like are set in the gas meter at the time of shipment from a gas meter manufacturing factory or at the time of installation at a customer. When reading the contents of the microcomputer of the gas meter or performing so-called setting work, the I / O section of the setting device can be positioned close to the gas meter and exchanged by optical signals. The trouble of cutting or connecting with the alligator clip is eliminated, and work is not interrupted due to the wrong polarity of the alligator clip.

Further, since the communication between the setting device and the gas meter is performed in a non-contact manner by optical coupling, it is possible to avoid intrusion of noise or the like as in the case where a wire is connected to a lead wire as in the conventional case, and the setting operation is not performed. As a result, the quality of the gas meter is improved.

Further, since the clock frequency of the communication speed is switched to a higher value in accordance with the switching to the second communication line, the communication speed of the setting work is increased, and the setting work can be shortened from this aspect as well. it can.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of an embodiment of the present invention.

FIG. 2 is a timing chart of the embodiment of the present invention.

FIG. 3 is a timing chart of the embodiment of the present invention.

FIG. 4 is a flowchart of an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gas meter with communication function 2 Microcomputer, control circuit 3 Shut-off valve 4 Test switch (lead switch) 5 Light emitting diode 6 Phototransistor 7 Second communication line 8 Switching circuit 9 First communication line

──────────────────────────────────────────────────続 き Continuing from the front page (73) Patent holder 000116633 Aichi Watch Electric Co., Ltd. 1-2-70, Millennial, Atsuta-ku, Nagoya-shi, Aichi (72) Inventor Ikko Itsui 9-10 Misonodai, Fujisawa-shi, Kanagawa (72) Inventor Shigenori Okamura 4-1-2, Hirano-cho, Chuo-ku, Osaka City Inside Osaka Gas Co., Ltd. (72) Inventor Yukio Kimura 507-1 Shinhocho-cho, Tokai City, Aichi Prefecture Toho Gas Co., Ltd. (72) Inventor Tomio Kamitono 2-1-270, Millennial, Atsuta-ku, Nagoya City, Aichi Prefecture Inside Aichi Watch Electric Co., Ltd. .Cl. ⁷ , DB name) G01F 1/00-9/02

Claims (2)

(57) [Claims] A built-in microcomputer (2) monitors a gas flow rate, and when an abnormal use of gas occurs, closes a shut-off valve (3) to shut off the gas, and a switch (4) responsive to external magnetism. A gas meter with a communication function provided with a microcomputer gas shut-off device having a microcomputer and a first communication line (9) for exchanging signals with the outside, and a light emitting diode (5) disposed outside the meter and a photo A second communication line (7) connected to the transistor (6); said first communication line (9) and a second communication line (7)
A switching circuit (8) for switching the connection, and the switch (4) or the phototransistor (6)
And a control circuit (2) for switching the switching circuit (8) by judging the above signal. 2. The apparatus according to claim 1, wherein when the switching circuit is switched to the second communication line, a clock frequency for controlling a communication speed is increased. Gas meter with communication function.