JP2010136285A - Telemeter system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a telemeter system which sets the optimum baud rate according to a meter connected thereto, and avoids any communication trouble due to degradation or variations of the meter with time passage or by an ambient temperature change or the like. <P>SOLUTION: In the telemeter system including a terminal NCU connected to a center NCU via a communication network and a microcomputer meter of a message type with predetermined bits wired to the terminal, one bit length in communication between the terminal NCU and the microcomputer meter can be set to be shifted for increment or decrement, for example, in 3 usec units from one bit length (3.333 msec) corresponding to a standard communication speed of the predetermined bits of the microcomputer meter. Thus even when the microcomputer meter is subjected to an environmental change such as a temperature change, and time-passage degradation, the terminal NCU communicates with the microcomputer meter without any troubles. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a telemeter system constituted by a terminal NCU connected to a center NCU via a communication network and a telegram-type microcomputer meter having a predetermined bit connected to the terminal by wire.

  In a telemeter system developed for meters such as gas and water, a fixed value set in advance on the terminal side is used for communication with an 8-bit telegraphic gas or water meter connected to the 8-bit port of the terminal. Communication is performed at a baud rate (about 300 baud). In addition, 5-bit data used in a 5-bit telegram type water meter is transmitted and received at a communication speed of a fixed baud rate (about 200 baud). Moreover, the water meter of a pulse signal output system is a meter which outputs a pulse signal for a certain period of time every time a fixed amount is increased, for example, every time a flow rate of 100 L is detected. In view of this, a centralized meter reading system and its relay transmission device have been proposed that can perform meter reading via a relay transmission device corresponding to the communication method of each meter even when meters of different communication methods are installed in each dwelling unit. (See Patent Document 1).

However, the baud rate, which is the modulation speed at the time of communication, can be switched between baud rates using a 5-bit telegram meter or an 8-bit telemeter meter, but it can be changed to an 8-bit telemeter-type microcomputer meter connected to an 8-bit port. On the other hand, only a fixed baud rate determined in advance corresponding to the 8 bits is possible, and it is not possible to adjust from the predetermined baud rate.
JP 2007-249893 A

  When the meter connected to the 8-bit port of the terminal NCU is a water meter, the communication baud rate is 300 baud as a standard, but in reality the baud rate at which communication is possible is biased in the positive or negative direction. It is not always best to set the communication baud rate on the terminal side to 300 baud. This is because if the communicable range of the meter is biased in either the positive direction or the negative direction with respect to 300 baud, even if communication is possible at the beginning of the connection, communication will be hindered due to deterioration of the meter over time, variations, ambient temperature changes, etc. This is because there is a possibility of causing illness. Therefore, it is considered necessary to be able to set an optimum baud rate according to the connected meter.

  In order to solve this problem, a telemeter system according to the present invention comprises a terminal NCU connected to a center NCU via a communication network, and a telegram system micrometer with a predetermined bit connected to the terminal by wire. The setting process for shifting the transmission 1-bit length in the communication between the terminal NCU and the microcomputer meter from the 1-bit length corresponding to the standard communication speed corresponding to the predetermined bit of the microcomputer meter is enabled. Made up of.

  According to this telemeter system, when a microcomputer meter such as a water meter is connected to a predetermined port such as an 8-bit port of the terminal NCU, 1 bit length corresponding to a standard baud rate (for example, (3.333 msec) has a function capable of shifting the transmission 1-bit length. Therefore, even if the microcomputer meter has an environmental change such as a temperature change or aged deterioration, the terminal NCU does not interfere with the communication with the microcomputer meter.

  Moreover, in this telemeter system, it is preferable that the setting process can set a transmission 1-bit length optimum for communication with the microcomputer meter. In this case, the optimum transmission 1-bit length can be determined based on the shortest 1-bit length and the longest 1-bit length that allow communication with the microcomputer meter. The shortest 1-bit length and the longest 1-bit length are 1-bit length that enables communication with the microcomputer meter when the transmission bit length is sequentially increased or decreased by a predetermined length. The shortest length and the longest length can be set. The shortest 1-bit length and the longest 1-bit length are communication with the microcomputer meter when the transmission bit length is sequentially changed by a predetermined width from the outermost side of a certain transmission bit length range. Can be set with the shortest length and the longest length of 1 bit.

  Furthermore, in this telemeter system, the setting process is automatically performed by an input device such as a button provided in the terminal, by an external setting device that can be connected to the terminal, or by a maintenance notification function that periodically checks the meter connection state. It is preferable to have a function of enabling execution.

  According to the telemeter system of the present invention, it is possible to set a 1-bit length suitable for the type of microcomputer meter such as a water meter connected to the port of the NCU, and it is possible to automatically set an optimal transmission 1-bit length, Stable communication is possible regardless of the type of meter connected.

  Embodiments of a telemeter system according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view showing an embodiment of a telemeter system according to the present invention. The telemeter system shown in FIG. 1 is a T-NCU (hereinafter referred to as NCU) connected to a center 102 connected to a host computer (hereinafter referred to as host) 101 and a wireless network such as a telephone line 105 or FOMA network. 103 and a meter 104 such as gas or water supply connected to the cable by wire.

  FIG. 2 is a block diagram of the NCU shown in FIG. The NCU incorporates a nonvolatile memory 202 for holding settings of a terminal such as a microcomputer meter, and includes a DIPSW 208 as an input device, a button 209, and the like. The CPU 203 has a clock and timer function.

  Now, it is assumed that a microcomputer meter (an 8-bit telegram-type microcomputer meter used for measuring usage of gas, water, etc.) is connected to the NCU, and data is transmitted from the NCU to the meter connected to the NCU. Originally, it should be transmitted at a communication baud rate of 300 baud as specified, but the center value of the baud rate range that can be communicated with the connected 8-bit meter is not exactly 300 baud, and is shifted in the plus or minus direction from there. Therefore, a value of 300baud is not an appropriate value.

  Therefore, when the communication baud rate of the meter is deviated from 300baud in either the positive direction or the negative direction, the information is notified to the terminal from the center 102 or the setting machine by a message. Then, the terminal transmits by shifting the baud rate, that is, 1 bit length (the time length required to communicate 1-bit information amount) by a certain length in the plus or minus direction according to the contents of the message. For example, the terminal can set 1 bit length of 3.333 msec, 3.275 msec, 3.275 msec, 3.400 msec, and a message from the center or setting machine. For example, if the setting value in the setting message is 0, 3.333 msec. 1 bit length that is most compatible, such as 3.275 msec for 1, 2 and 3.400 msec for 2, and so on, can be selected according to the connected meter. An example of the bit length selection message is shown in FIG.

  However, in the above method, only an appropriate setting value is selected from values prepared in advance in accordance with the deviation of the communicable 1-bit length range of the meter. Although it can be close, it is not optimal. Therefore, as shown in FIG. 4, the 1-bit length transmitted to the meter can be set at a value sufficiently smaller than the 1-bit length of 3.3333 msec, which is 300 baud, for example, every 3 usec (microseconds). By sending a setting message from the machine, the transmission 1-bit length can be arbitrarily set. In this way, an optimal 1-bit length can be set for the meter connected to the terminal.

  In addition to being able to set the transmission 1-bit length from the center or external setting machine to the meter, it is automatically optimized by pressing an input device such as a button 209 (see FIG. 2) provided on the NCU. There is also a technique for setting a single 1-bit length. For example, when the input button 209 is pressed, the NCU shifts to a mode for setting a 1-bit length called a 1-bit length measurement mode. When shifting to this mode, the NCU changes the bit length little by little within a certain range of, for example, 3.250 msec to 3.400 msec, and transmits a message to the meter, and the communicable range of the connected meter Search for.

  As shown in FIG. 5, when the NCU transmission 1-bit length range is 3.250 msec to 3.400 msec, a short interval (from 3.250 msec as the lower limit to 3.400 msec as the upper limit) is used. For example, there is a means for transmitting a message to the meter while changing the bit length every 3 usec or 6 usec). That is, FIG. 5 is a flowchart for explaining one method for searching for a communicable range of the meter.

  When the input button 209 (see FIG. 2) is pressed (step 1; abbreviated as “S1”, the same applies hereinafter), initialization is performed so that the shortest 1 bit length = 0 and the longest 1 bit 1 length = 0 (S2). The transmission 1-bit length is set to 3.250 msec (S3). It is determined whether or not the transmission 1-bit length is 3.400 msec (S4). If the determination is negative, an activation message is transmitted to the 8-bit meter (S5), and whether or not there is a reply from the 8-bit meter. Is determined (S6). If there is a reply from the 8-bit meter, it is determined whether or not the minimum 1-bit length is 0 (S7). If the determination is correct, the minimum 1-bit length is set to the current transmission 1-bit length. (S8) After the setting, and when the determination of S7 is negative, the transmission 1-bit length is updated to a length obtained by adding 3 usec to the current transmission 1-bit length (S9). It returns to determination (S4).

  In the initial flow of this flow, the determination in S4 is no. If there is no reply from the meter in S6 after transmission to the meter in S5, the process proceeds to S10. Since the shortest 1-bit length remains the initial value 0, the process proceeds to S9 where the transmission 1-bit length is set longer by 3 usec. This is repeated, and after the transmission to the meter in S5, when there is the first reply from the meter in S6, the determination in S7 is right, so in S8 the minimum 1-bit length is the transmission 1 at that time. Set to bit length. Thereafter, if the transmission 1-bit length is set longer by 3 usec in S9, in the next loop, if S4 is NO, even if there is a reply from the meter in S6, the shortest 1-bit length in S7 is 0. It is determined whether or not, and the update of the shortest 1-bit length is not performed in S8. When the transmission 1-bit length becomes gradually longer and no reply is received from the meter in S6, the process proceeds to S10. This time, the shortest 1-bit length is not the initial value 0. If the loop is repeated 50 times from S4 to S9, the transmission 1-bit length becomes 3.400 mec. If it is determined in S4 that the transmission 1-bit length is 3.400 msec, the process proceeds to S10.

  If there is no reply from the 8-bit meter in the determination of S6 and if the determination of S4 is correct, it is determined whether or not the minimum 1-bit length = 0 (S10). Except for the initial stage of the flow, since the shortest 1-bit length = 0 is not usually 0, the determination is negative, and the longest 1-bit 1 length = current transmission 1-bit length−3 usec (S11). That is, the last (longest) transmission 1-bit length returned from the 8-bit meter is set as the longest 1-bit 1 length. It is determined whether or not the shortest 1-bit length = 3.250 msec and the longest 1-bit 1 length = 3.400 msec (S12). If the determination in S12 is negative, the transmission 1-bit length is set to the average bit length of the shortest bit length and the longest bit length (S13). That is, the average of the shortest value and the longest value in the range of bit lengths returned from the 8-bit meter is set as the transmission 1-bit length. If the determination in S12 is correct, that is, if there is a reply from the 8-bit meter in the entire range of 1 bit length = 3.250 msec to 3.400 msec, the transmission 1 bit length is set to 3.333 msec.

  The transmission message to the meter may be a meter activation message. Send a message to the meter using that method and check if there is a reply from the meter. If there is a reply from the meter to the NCU as in the above-described flow, it can be determined that the connected meter can receive with the 1-bit length. Then, the next bit length is set and the same process is performed again. This is performed up to the point where communication with the meter is disabled within the above range. 3. If there are all replies in the range from 250 msec to 3.400 msec, 3.333 msec is set to 1 bit length.

  As another search method, there is also a method as shown in FIG. This is a method of obtaining a communicable range by narrowing the range from both ends of the 1-bit length range. For example, after the lowest limit, communication is performed at the maximum limit value, and when both cannot be communicated, the range is further narrowed. If the communicable range of the connected meter is found by the search, the center value of this communicable range is set to 1 bit length. If all communication within the search range is possible, it is determined that there is no deviation, and 3.333 msec at which the baud rate is 300 baud is set to 1 bit length. In this way, an ideal 1-bit length can be set for the connected meter.

  FIG. 6 is a flowchart for explaining another method for searching for the communicable range of the meter. When the input button is pressed (S21), the shortest 1 bit length = 3.250 msec, the longest 1 bit 1 length = 3.400 msec, the shortest 1 bit length found flag = FALSE, and the longest 1 bit length found flag = FALSE. Initialization is performed (S22). Next, the transmission 1 bit length = the shortest 1 bit length is set (S23), and it is determined whether the shortest 1 bit length found flag is ON or OFF (S24). If the shortest 1-bit length found flag is OFF, an activation message is transmitted to the 8-bit meter (S25). It is determined whether or not there is a reply from the 8-bit meter (S26). If it is determined in S26 that there is a reply, the shortest 1-bit length found flag is set to ON (S27), and the determination in S26. If it is determined that there is no reply, 3 usec is added to the shortest 1-bit length to the current transmission 1-bit length (S28). Thus, S23 to S28 correspond to the search for the lowest limit of the 1-bit length range.

  If it is determined in S24 that the shortest 1-bit length found flag is ON, and after S27 and S28, it is determined whether the longest 1-bit length found flag is ON or OFF (S29). If the determination in S29 is OFF, the transmission 1-bit length is set to the longest 1-bit length (S30), and then it is determined whether the longest 1-bit length found flag is ON or OFF (S31). If it is determined in S31 that the longest 1-bit length found flag is ON, the process immediately proceeds to S24 (determining whether the shortest 1-bit length found flag is ON or OFF). If it is determined in S31 that the longest 1-bit length found flag is OFF, an activation message is transmitted to the 8-bit meter (S32). It is determined whether or not there is a reply from the 8-bit meter (S33). If it is determined in S33 that there is a reply, the longest 1-bit length found flag is set to ON (S34), and the determination in S33. If it is determined that there is no reply, the maximum 1-bit length is subtracted from the current transmission 1-bit length by 3 usec (S35). After S34 and S35, the process proceeds to S23. Thus, S30 to S35 correspond to the upper limit search in the 1-bit length range.

  In the determination (S29), if the longest 1-bit length found flag is ON, it is determined whether or not the shortest 1-bit length = 3.250 msec and the longest 1-bit 1 length = 3.400 msec (S36). If the determination in S36 is negative, the transmission 1-bit length is set to the average bit length of the shortest bit length and the longest bit length (S37). If the determination in S36 is affirmative, the transmission 1-bit length is set to 3.333 msec. (S38).

  As a trigger for implementing this function, there is a method of using an external setting machine that can be connected to the NCU in addition to the input device such as the above-described button. In addition, it is conceivable that the NCU uses a maintenance function for periodically checking the connectivity with the meter, and only once when checking the connectivity. In this case, the optimum value is automatically set without any operation by the user himself / herself.

1 is a system diagram of a wireless telemeter system according to an embodiment of the present invention. It is a block diagram of NCU concerning an embodiment of the present invention. It is a structure of the bit length selection message concerning embodiment of this invention. It is explanatory drawing of 1 bit length setting concerning embodiment of this invention. It is a flowchart figure of 1 bit length setting concerning embodiment of this invention. It is another flowchart figure of 1 bit length setting concerning embodiment of this invention.

Explanation of symbols

101 Host computer 102 Center NCU
103 T-NCU 104 Meter 105 Telephone line 201 8-bit meter I / F
202 Non-volatile memory for data registration 203 CPU
204 ROM
205 RAM
206 Battery 207 Input unit 209 such as a display unit 208 DIPSW for displaying a communication result, etc. Input device such as a button

Claims (8)

In a telemeter system constituted by a terminal NCU connected to the center NCU via a communication network and a telegram-type microcomputer meter of a predetermined bit connected to the terminal by wire,
It is possible to perform setting processing for shifting a transmission 1-bit length in communication performed between the terminal NCU and the microcomputer meter from a 1-bit length corresponding to a standard communication speed corresponding to the predetermined bit of the microcomputer meter. Telemeter system.   2. The telemeter system according to claim 1, wherein the setting process is capable of setting a transmission 1-bit length optimum for communication with the microcomputer meter.   3. The telemeter system according to claim 2, wherein the optimum transmission 1-bit length is determined based on a shortest 1-bit length and a longest 1-bit length that allow communication with the microcomputer meter.   4. The telemeter system according to claim 3, wherein the shortest 1-bit length and the longest 1-bit length are communication with the microcomputer meter when the transmission bit length is sequentially increased / decreased by a predetermined length. A telemeter system consisting of a shortest length and a longest length of 1 bit length that were possible.   4. The telemeter system according to claim 3, wherein the shortest 1-bit length and the longest 1-bit length are changed by sequentially narrowing the transmission bit length by a predetermined width from the outermost side of a fixed transmission bit length range. A telemeter system comprising a shortest length of 1 bit and a longest length that can be communicated with the microcomputer meter.   The telemeter system according to claim 1, wherein the setting process is automatically executed by an operation of an input device such as a button provided in the terminal NCU.   6. The telemeter system according to claim 1, wherein the setting process is automatically executed by an external setting device connectable to the microcomputer meter.   6. The telemeter system according to claim 1, wherein the setting process is automatically executed by a maintenance notification function for periodically checking a connection state of the microcomputer meter.

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