JPH0319039Y2 - - Google Patents

Description

[Detailed description of the invention] The electronic water meter has a data sending function that allows telephone meter reading, but it is not possible to stop the sending operation midway through data sending. Therefore, even if the central reading device wanted to stop reading and start reading again for some reason, there was an inconvenience that reading could not be started again until all the data being sent had been sent out.

The purpose of this invention is to propose a data sending device that can eliminate the above-mentioned inconvenience by stopping the sending of data from the electronic meter by an operation from the reading device side, if necessary.

That is, in this invention, the reading side 10 and the electronic meter side 20 are interconnected by a line 30 having two electric wires, and the voltage of the starting signal transmitted from the reading side 10 to the electronic meter side through the two electric wires is transmitted. The electronic meter detects it with the detection circuit 22, activates the control circuit 25, opens and closes the sending switch 21 connected between the two electric wires, and sends meter reading data in a predetermined format to the line 30 as a serial digital signal. In the automatic meter reading system, a detection circuit 22 detects the H level and L level of the voltage between the two electric wires of the line 30 on the electronic meter side 20 and transmits it to the control circuit 25, and the sending switch is opened. A data sending device in an electronic meter, comprising: a control circuit 25 that immediately stops data sending if the voltage between the two electric wires is at L level while sending data, and returns to an initial state in which activation is possible. It is.

Next, it will be explained based on the drawings.

10 is a reading side, 20 is an electronic meter side, and both are connected by a line 30. The reading side 10 includes a power source 11, a start switch 12, a resistor 13, and a detection circuit 14. Note that the configuration of this reading side 10 is publicly known. The electronic meter side 20 includes a sending switch 21 inserted into the line, a detection circuit 22 that detects the level of the line and transmits it to a control circuit to be described later, and detects the rotation of a permanent magnet attached to a rotating part of the meter (not shown). It is equipped with a pulse input circuit 23 that transmits metering pulses from the rotation sensor to the control circuit, a display circuit 24 that receives and displays data from the control circuit such as meter integrated value, instantaneous value, etc., and a control circuit 25. Opening/closing operation of switch 21,
It has functions of controlling the display circuit 24, counting pulses from the pulse input circuit, and receiving signals from the detection circuit 22 to start and stop data transmission. Of course, this control circuit also has the function of automatically returning to its initial state after data transmission is completed, similar to conventionally known data transmission devices. Note that the initial state is a state in which activation can be accepted.

Now, when the sending switch 21 is open as shown and the electronic meter side 21 is in the initial state, when the start switch 12 on the reading side 10 is switched to the position shown, the voltage of the power source 11 is transferred to the electronic meter via the line 30. The information is transmitted to the meter side 20. This becomes a starting signal and is detected by the detection circuit 22, and the control circuit 25
is activated, opens and closes the sending switch 21, and sends meter reading data (meter integrated value) in a predetermined format to the line 30 as a serial digital signal.

This sent data is detected as a voltage signal by the detection circuit 14 at the receiving side resistor 13, and read by known means. If it is desired to stop reading during data transmission, the start switch 12 is switched from the illustrated position to the other position. Then, since the voltage of the power supply 11 is no longer supplied to the line, the detection circuit 22 detects the L level regardless of whether the sending switch 21 is opened or closed. When the start switch 12 is in the start position shown, the line is always at H level if the send switch 21 is open, but when the start switch is switched to the other position, even when the send switch 21 is open. Since the line is at the L level, the detection circuit 22 detects this, and the control circuit 25 makes a judgment to recognize that the start switch 21 has been switched to the other side, which is different from the one shown, and to immediately stop sending. The control circuit is activated to return to the initial state.

According to this invention, the electronic meter immediately recognizes the difference in conditions on the reading side, i.e., whether the start switch is in the start position shown in the diagram or the other stop position, while transmitting data, and determines whether the start switch is in the stop position. Since it is possible to stop data transmission midway through, there is a practical effect of shortening the time until restart during data transmission.

[Brief explanation of the drawing]

The drawing shows an automatic meter reading system using the data transmission device of this invention. 10...Reading side, 12...Start switch,
20...Electronic meter side, 21...Sending switch,
22...Detection circuit, 25...Control circuit.

Claims (1)

[Scope of utility model registration request] The reading side 10 and the electronic meter side 20 are interconnected by a line 30 having two electric wires, and the detection circuit 22 detects the voltage of the starting signal transmitted from the reading side 10 to the electronic meter side through the two electric wires. In an automatic meter reading system having an electronic meter, the control circuit 25 is activated, and the sending switch 21 connected between the two electric wires is opened and closed to send meter reading data in a predetermined format to the line 30 as a serial digital signal. , electronic meter side 2
At 0, the detection circuit 22 detects the H level and L level of the voltage between the two electric wires of the line 30 and transmits it to the control circuit 25. A data transmission device for an electronic meter, comprising a control circuit 25 that immediately stops data transmission when the voltage between electric wires is at L level and returns to an initial state in which activation can be accepted.