JP3251357B2 - Remote meter reading system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless meter reading system for remotely reading meter data such as the amount of electricity, gas, and water used, and more particularly to a communication system for transmitting the meter data. Things.

[0002]

2. Description of the Related Art A wireless meter reading system for remotely measuring quantity data such as electricity, gas, and water consumption as an object of the present invention is conceptually described later. It has a meter reading unit for the quantity data to be processed and a processing unit for the quantity data to be processed. On the meter reading unit side, a wireless device (transmission side) connected by wire is provided. Also, a wireless device (receiving side) connected by wire is provided, and the quantity data obtained at the meter reading unit side is wirelessly transmitted to the processing unit side for processing. This type of technical means is, in the conventional case, Not yet established.

[0003] Therefore, in the prior art in this case, one technical means which can be simply inferred as a similar type or a similar type will be described.

[0004] That is, the conventional technical means that can be inferred from this type include, for example, a transmitting terminal unit and a transmitting wireless device.
In addition, the receiving terminal unit and the receiving wireless device are connected by a wired line, respectively, and the transmitting wireless device and the receiving wireless device are connected by a wireless line. One example is a mode set to the double transmission system.

Therefore, in the case of this conventional transmission system,
Regarding the transmission of numerical data between the transmitting terminal and the transmitting radio and between the receiving terminal and the receiving radio,
The data error rate is low for wired lines and high for wireless lines. In the spread spectrum wireless communication system between the wireless devices, the longer the period (chip length) of the transmitted PN code, the greater the process gain, the better the noise resistance, and the longer the communication distance. On the other hand,
With such a long chip length, the transmission speed is relatively slow,
In addition, the signal synchronization time between the transmission side and the reception side becomes long, and the total throughput, that is, the so-called processing capacity is reduced.

[0006]

[Problems to be solved by the invention]

Therefore, in the conventional quantity data transmission system, the input of the quantity data by wire from the transmitting terminal is waited for a certain period of time or until a certain amount of data is reached, and then the data is divided into one section. The quantity data is transmitted from the transmitting wireless device as a data packet, and the receiving wireless device determines whether the received packet is correct,
If it is correct, an ACK signal is returned to the transmitting unit, and the received quantity data is transmitted to the receiving terminal unit to perform necessary processing. If not, a NAC signal is transmitted to the transmitting unit. Will be returned.

[0008] When the transmitting unit receives the ACK signal, the transmitting unit transmits the next data packet and the NAC
When a signal is received, the previous data packet is
Resubmit. On the other hand, on the transmitting side, after the transmission of the data packet, an ACK signal or N
If the AC signal is not returned,
It is assumed that the transmitted data packet cannot be received, and the same data packet is transmitted again.

Therefore, in the conventional data transmission system, if the transmitting unit transmits a data packet for each section and fails to receive an ACK signal or a NAC signal within a predetermined time, the transmitting unit transmits the data packet. Before the receiving unit cannot determine whether the transmission packet could not be received, or whether it could receive and returned an ACK signal or NAC signal, but could not receive the transmission packet, The same data packet is transmitted again, so that even if the receiving unit receives the transmitted packet and returns an ACK signal or a NAC signal, the transmitting unit can receive it. If not, the receiving unit receives the same data again, which causes a problem that the transmission efficiency is extremely deteriorated.

Further, in the case of the conventional data transmission system, since the transmission error rate on the radio line is high, the receiving unit receives the transmission data from the radio line while receiving the transmission data from the radio line as described above. Is output, the data output to the wired line is interrupted while the data transmission on the wireless line is unsuccessful, so that a so-called timeout error may occur.

Further, when a spread spectrum wireless communication system is used in a conventional data transmission system, data transmission and reception are performed on the basis of noise predicted by the use environment, a chip length fixed by a communication distance, and a correlation determination value. Also, the correlation value of the transmission data is determined, but in the case of such a fixed chip length, when the noise in the use environment is extremely low or when the communication distance is short, a large process gain is not required. As a result, the transmission time is wasted. On the other hand, when the noise in the use environment increases or when the communication distance is long, a larger process gain is required, so that the transmission is not possible. There was a problem that it became possible.

SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem. It is an object of the present invention to provide a technique in which a transmitting section having a needle detecting section as a target to be inspected transmits a signal as an object to be processed. It is an object of the present invention to provide a wireless meter reading system of this kind, which can transmit quantity data to a receiving unit having a processing unit by a wireless line in a good and efficient manner.

[0013]

In order to achieve the above object, a wireless meter reading system according to the present invention provides a wireless communication system between a meter reading unit for quantity data to be measured on a transmitting unit and a transmitting wireless device. , And a processing unit of the quantity data as an object to be processed on the receiving side and a receiving side wireless device are connected to each other by a wired line, and a mutual connection between the transmitting side wireless device and the receiving side wireless device is established. In addition to being connected by a wireless line, each of these wired and wireless lines is configured to be of a half-duplex transmission system, and the transmitting section is equivalent to one packet of quantity data input from the meter reading section for quantity data. , And the receiving unit determines the data block received by the receiving radio and transmits the quantity data as follows. On the receiving unit side, when it is determined that the received data block is a normal reception, the block number corresponding to the received data block is returned to the transmitting side and transmitted to the processing unit. If the receiving unit determines that the received data block is abnormal reception, the transmitting unit determines that the time corresponding to the end of the return of the previous block number has elapsed. Thereafter, the data block and the subsequently input data block are transmitted together again, and the receiving unit returns the block number of the data block that has been normally received, and the data is normally received. The process is repeatedly performed in order.

[0014]

Therefore, in the remote meter reading system according to the present invention, the receiving unit of the data block including the quantity data from the transmitting unit is connected to the transmitting unit and the receiving unit through the wireless line. The transmission to the receiving side and the return of the block number corresponding to the response for each data block transmission from the transmitting side to the receiving side can be performed quickly and accurately.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a remote meter reading system according to the present invention will be described below in detail with reference to FIGS.

FIG. 1 is a system configuration diagram showing an outline of a remote meter reading system to which one embodiment of the present invention is applied.

That is, in the configuration of the system of this embodiment, the meter reading section of arbitrary quantity data at the transmission section side A, for example, in this case, meter reading by appropriate means and read usage of electricity, gas and water And a wireless device (hereinafter, referred to as a transmitting-side wireless device) A2 of the meter-reading portion A1 (corresponding to a transmitting side) of the quantity data to be measured. And a processing unit for the quantity data received at the receiving side B, for example, in this case, confirmation of the usage of electricity, gas and water, and receipt of bills for collecting usage fees. A processing unit (hereinafter, simply referred to as a processing unit) B1 for the quantity data to be processed and a wireless device (hereinafter, referred to as a receiving wireless device) B2 on the processing unit B1 side (corresponding to a receiving side) B2 To each wired line A
3, B3, and these transmitting-side radios A
2. The receiving-side wireless device B2 is connected to each other by a wireless line C3, and each of the wired lines A3, B3 and the wireless line C3 adopts a half-duplex transmission method.

Therefore, also in the data transmission system according to this embodiment, between the meter reading section A1 of the transmission section A and the transmission side radio A2, and between the processing section B1 of the reception side B and the reception side radio, Regarding the transmission of numerical data between B2 and B2, the data error rate is low because of the connection by the wired lines A3 and B3, and the transmission between the transmitting radio A2 and the receiving radio B2 is not performed. Since the connection is made by the wireless line C3, the data error rate becomes high. In the spread spectrum wireless communication system between the wireless devices A2 and B2 on the transmitting side and the receiving side, the data is transmitted. P
The longer the one cycle (chip length) of the N code, the larger the process gain, the better the noise resistance, and the longer the communication distance. However, if the chip length is long, The transmission speed is relatively slow, and the signal synchronization time between the transmitting unit A and the receiving unit B is prolonged, so that the total throughput, that is, the processing capacity is reduced.

Next, a protocol for simultaneous transmission and reception of quantity data in the embodiment system having the above configuration will be described.

FIGS. 2 and 3 are explanatory diagrams respectively showing states of data transmission in the system of the above-described embodiment at the time of normal transmission and reception of quantity data and at the time of abnormal transmission and reception.

At the time of normal transmission / reception of quantity data in the system of this embodiment, as shown in FIG.
, The wired line A3 from the meter reading unit A1 of the quantity data
When the predetermined quantity data is input, the transmission-side radio A2 transmits the input of the quantity data as a “data block 1” corresponding to one packet to the reception-side radio B2 via the radio line C3.

Then, on the receiving side B, the receiving side radio B2 judges the received "data block 1". In this case, since this is a normal reception, its block number, that is, "block 1" No. 1 "is returned as an ACK signal to the transmitting-side wireless device A2 via the wireless line C3, and the received" data block 1 "corresponding to one packet and, consequently, the corresponding predetermined quantity data are transmitted to the wired line B3.
To perform the required processing by transmitting to the processing unit B1, and repeat this.

In addition, when the quantity data is abnormally transmitted / received in the system of this embodiment, as shown in FIG. When the quantity data is input, the transmission-side radio A2 transmits the input of the quantity data as “data block 1” to the reception-side radio B2 via the radio line C3.

Then, in the receiving side B, the receiving side wireless device B2 judges the received "data block 1" as described later. In this case, since this was not received normally, In the device B2, the transmitting-side wireless device A
No ACK signal is sent back to 2 (corresponding to * 1 in FIG. 3).

For this reason, in the transmitting side radio A2, after the lapse of the time corresponding to the end of the return of the ACK signal in the case of the normal reception, the “data block 1” and the “data block 1” input up to that time are renewed. The data block 2 "is combined, and this is combined with" data block 1 + 2 "corresponding to one packet.
Similarly, the receiving-side wireless device B2 is connected via the wireless line C3.
Then, the receiving-side radio B2 can normally receive even the end of the packet when there are a plurality of data blocks in one received packet, that is, when it is “data block 1 + 2”. Even if there is no block number, the block number that can be normally received, for example, if the normal reception portion is only "data block 1", only the corresponding "block No. 1" is transmitted to the transmitting side radio A2 as an ACK signal It returns via the wireless line C3, and similarly transmits the normally received quantity data to the processing unit B1 via the wired line B3 to perform required processing (corresponding to * 2 in FIG. 3). However, if one packet is interrupted during reception or data becomes abnormal, the reception-side radio B2 waits for the maximum time required for reception of one packet to elapse, and then returns the quantity data received normally. Return only the block number of

Further, as described above, in the receiving-side radio B2, after the data block, for example, "data block 2" is normally received, the corresponding block number, that is, "block No. 2". Is returned as an ACK signal to the transmitting wireless device A2 via the wireless line C3. If the corresponding block number cannot be normally received by the transmitting wireless device A2, the transmitting wireless device A2 transmits
Similarly to the above, after the lapse of the time corresponding to the end of the return of the ACK signal in the case of the normal reception, the previous “data block 2” and the previously input “data block 3” are combined again. Then, this is transmitted as a “data block 2 + 3” corresponding to one packet to the receiving-side wireless device B2 via the wireless line C3, and subsequently, the receiving-side wireless device B2 has a plurality of data blocks in one received packet. In the case, that is, in the case of “data block 2 + 3”, if both can be normally received, the block number, that is, “block No. 2 + No. 3” is ACKed.
The signal is returned as a signal to the transmitting side wireless device A2 via the wireless line C3 (corresponding to * 3 in FIG. 3), and the received predetermined quantity data as the “data block 2 + 3” is processed by the wired line B3 through the processing unit B1. To perform necessary processing separately.

In this case, if at least one of the transmitted "data blocks 2 + 3" cannot be normally received and the subsequently transmitted "data block 2 + 3 + 4" can be normally received, Discard already received data and use only newly received data.

However, in the preceding paragraph, the receiving-side radio B2
However, if all of the “data block 2 + 3” corresponding to one packet cannot be normally received, the previous “data block 2 + 3” and the “data block 4 And transmits this as a “data block 2 + 3 + 4” corresponding to one packet to the receiving-side wireless device B2 via the wireless line C3,
Subsequently, in the receiving-side radio B2, if there are a plurality of data blocks in one received packet, that is, if “data block 2 + 3 + 4” is received, if both can be received normally, the block number In this example, “Block No. 2 + No. 3 + No.
A CK signal is returned to the transmitting side wireless device A2 via the wireless line C3 (corresponding to * 4 in FIG. 3), and the received predetermined quantity data as the "data block 2 + 3 + 4" is processed by the wired line B3. The data is transmitted to B1 to perform necessary processing separately. However, in this case, the block numbers are returned for all the normally received block numbers.

The structure of the data packet is, for example, as shown in FIG. 4, OPF (opening flag as open mark), RXID
(Identification of transmission destination), TXID (identification of transmission source), BNO (block number), {quantity data}, CRC (cyclic redundancy check), and CRF (closing flag as a close mark).

Next, regarding the connection between the wireless line C3 and the wired lines A3 and B3 in the system of this embodiment, the communication speed of the wireless line C3 is higher than the communication speed of the wired lines A3 and B3. , To the receiving side radio B2,
For example, by providing a data buffer (not shown),
After buffering the reception data corresponding to the corresponding time in which the retry of the wireless communication is predicted to occur, the processing unit B1
It is preferable that the data buffer can be transmitted over a wired line B3. At this time, the capacity of the data buffer is determined, for example, by measuring the time during which the first data block is normally transmitted and received, and at the same time, By estimating the time required for the retry, it is possible to easily set the buffer amount until the data is output to the wired line B3.

Next, the chip length in the spread spectrum wireless communication system in the system of this embodiment is shown in FIG.
Can be set automatically, as shown in

That is, at the start of wireless communication, the transmitting-side wireless device A2 transmits start-up data, that is, a start-up message with the longest chip length that can be provided by this system.
The receiving-side radio B2 also waits for and receives the activation message with the longest chip length. The activation message includes the shortest chip length used for data transmission, in other words, the expected minimum length. ， Required chip length,
This includes data on whether or not to automatically set the chip length.

When receiving the activation message, the receiving-side radio B2 returns an ACK signal with the longest chip length of the activation message, and waits for a confirmation signal with the minimum number of chips of the activation message. to go into.

After receiving the ACK signal, the transmitting-side radio A2 transmits an acknowledgment signal with the minimum number of chips, and after transmitting the acknowledgment signal, fails to receive the ACK signal even after a predetermined period of time. In this case, the acknowledgment signal is transmitted again with the same number of chips. If the ACK signal cannot be received even after the lapse of a predetermined time, the number of chips is further increased by one step. The operation is repeated, and when the ACK signal is received, the quantity data is transmitted based on the chip length at that time.

On the other hand, when receiving the confirmation signal in the standby state, the receiving-side radio B2 returns an ACK signal with the same chip length and cannot receive the next quantity data even after a predetermined time. In step (1), the chip length is increased by one step so as to wait for the confirmation signal, and when the next quantity data is received, the quantity data is thereafter received according to the chip length at that time.

The correlation value in the spread spectrum wireless communication system in the system of the embodiment can be automatically set and controlled as shown in FIGS.

That is, if there is a certain degree of correlation between the received PN code and the synchronization PN code from the synchronization PN code generator 11, a synchronization signal is output from the correlation determiner 12, and this synchronization signal is output. When the correlation determination value is too low, the count value becomes extremely large, and when the correlation determination value is too high, the count value becomes almost zero. By controlling so as to fall within an appropriate range, the correlation determination value here can be easily set.

If the synchronization detection from the correlation determiner 12 is output, for example, for more than a few pits, it is considered that the PN code is actually being received. If the detection is output for more than a few pits, and then the synchronization is lost, this may be due to noise, attenuated communication radio waves, or a high correlation value. The correlation determination value is not changed because it is unclear whether it is too high.

Therefore, in the system of this embodiment, the transmitting side having the meter reading section of the quantity data as the object to be inspected and the receiving section having the processing section of the quantity data as the object to be processed are connected to the transmitting side and the receiving side. The transmission of the data block including the quantity data from the transmission unit to the reception unit and the transmission of the individual data block from the transmission unit are performed in spite of the fact that the wireless units are connected by a wireless line. The return of the block number corresponding to the response to the receiving section can be performed quickly and accurately, and the quantity data at the meter reading section can be easily processed at the processing section.

[0040]

As described above in detail with reference to the embodiments,
ADVANTAGE OF THE INVENTION According to the remote meter-reading system which concerns on this invention, between the meter-reading part of a meter object as a to-be-measured object in a transmission part side, and the transmission side radio | wireless machine, and the quantity data as a to-be-processed object in a receiving part side The processing unit and the receiving-side wireless device are connected to each other by a wired line, and the transmitting-side wireless device and the receiving-side wireless device are connected to each other by a wireless line,
Each of these wired and wireless lines is configured in a half-duplex transmission system, and on the transmitting side, the quantity data input from the meter reading section of quantity data is converted into a data block equivalent to one packet, and the transmission side wireless device is used. , And the receiving unit determines the data block received by the receiving wireless device and transmits the quantity data as follows. If it is determined that the data block is normally received,
When the block number corresponding to the received data block is returned to the transmitting side and transmitted to the processing unit for processing, and the receiving unit determines that the received data block is abnormal reception. After the time corresponding to the end of the return of the previous block number elapses on the transmitting unit side, the data block and the subsequently input data block are transmitted again together, and the receiving unit side transmits The block number of the received data block is returned, and this is repeated in order until the data is received normally, so that the transmitting unit and the receiving unit are connected by a wireless line. The transmission of the data block including the quantity data from the transmission unit to the reception unit, and the transmission of the block number corresponding to the response for each data block transmission from the transmission unit side Each of these can be quickly and accurately sent back to the receiving side. When conceptually viewed as a data transmission system of this type, the transmission efficiency deteriorates and a time-out error occurs, as in the case of a conventional similar system. , Or has an excellent feature that the transmission time can be wasted and the possibility of transmission failure can be very easily prevented and avoided.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram showing an outline of a remote meter reading system to which an embodiment of the present invention is applied.

FIG. 2 is an explanatory diagram showing a state of data transmission during normal transmission and reception of quantity data in the system of the embodiment.

FIG. 3 is an explanatory diagram showing a state of data transmission at the time of abnormal transmission and reception of quantity data in the system of the embodiment.

FIG. 4 is an explanatory diagram showing a configuration example of a data packet in the system of the embodiment.

FIG. 5 is a time chart for explaining automatic setting of a chip length in a spread spectrum wireless communication system in the system of the embodiment.

FIG. 6 is a block diagram showing control means for a correlation value in the spread spectrum wireless communication system in the system of the embodiment.

FIG. 7 is a time chart for explaining automatic setting of a correlation value in the spread spectrum wireless communication system in the system of the embodiment.

[Explanation of symbols]

 A Transmitter side A1 Meter reading unit for quantity data A2 Transmitter wireless unit A3 Wired line B Receiver unit B1 Processing unit for quantity data B2 Receiver wireless unit B3 Wired line C3 Wireless line 11 PN code generator for synchronization 12 Correlation determiner 13 Counter 14 Controller

──────────────────────────────────────────────────続 き Continuing on the front page (72) Kazuo Yoshida, 3-6 Tsukioka-cho, Toyama-city, Toyama Pref. Inside (72) Kaoru Ikeya 3-6-6 Tsukioka-cho, Toyama-shi, Toyama Tateyama Kagaku Kogyo Co., Ltd. (72) Inventor Motoharu Takada 3-6 Tsukioka-cho, Toyama City, Toyama Prefecture Inside Tateyama Science & Technology Co., Ltd. (72) Inventor Sada Toi 3-6-6 Tsukiokacho, Toyama City, Toyama Prefecture Tateyama Chemical Industry Co., Ltd. (56) References JP-A-58-56200 (JP, A) JP-A-3-104496 (JP, A) JP-A-1-97647 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04Q 9/00-9/16 G08C 15/00 H04L 1/16

Claims (2)

(57) [Claims] The present invention relates to a method of measuring a quantity of data to be measured on a transmitting unit between a reading radio unit and a transmitting-side wireless device, and a process of processing quantity data to be processed on a receiving unit and a receiving radio. And the transmitter and receiver are connected by a wireless line, and both the wired and wireless lines are half-duplex transmitted. In the transmitting unit, the transmitting unit transmits the quantity data input from the meter reading unit of the quantity data as a data block corresponding to one packet, and receives the data in the receiving unit. A remote meter reading system characterized in that a data block received by a side wireless device is determined and quantity data is transmitted as follows.
If the receiving unit determines that the received data block is a normal reception, the block number corresponding to the received data block is returned to the transmitting side and transmitted to the processing unit. If the receiving unit determines that the received data block is abnormally received, the transmitting unit determines that the time corresponding to the end of the return of the previous block number. After the lapse of time, the data block and the subsequently input data block are transmitted together, and the receiving unit returns the block number of the data block that has been normally received. Iteratively and repeatedly until it becomes. 2. The remote meter reading system according to claim 1, wherein a data buffer having a predetermined capacity is provided in the receiving-side wireless device.