JP2004032405A - Apparatus and method for transmitting telemeter data - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify the setting of a data transmitting time of a slave station and to relieve the data when a collision occurs. <P>SOLUTION: A storage unit 4 stores the presence or absence of a data retransmission request from a master station by the on/off control of a retransmission request receiving state, a storage unit 5 stores a transmittable start time when a transmission of the data to the master station becomes possible, and a storage unit 6 stores a maximum transmission delay allowing time from the transmission start time. A transmission timing detector 1 calculates a real transmission time based on a random number, transmittable start time and the maximum transmission delay allowing time when the retransmission request receiving state is on and stores the actual transmission time in a storage unit 7. The detector 1 detects the data transmission timing by comparing the present time with the actual transmission time. A data transmitter 8 transmits telemeter data to the master station when a command is received from the transmission timing detector. A data receiver 9 turns off the retransmission request receiving state of the storage unit 4 when the retransmission request signal is not received from the master station, and turns on the retransmission request receiving state when the retransmission request signal is received. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to transmission of telemeter data, and more particularly, to transmission of telemeter data from a slave station to a master station in a telemeter control system in which a master station collects measurement values from a plurality of slave stations and remotely controls the operation.
[0002]
[Prior art]
As is well known, a telemeter system is composed of slave stations installed at various locations for various purposes such as observation and measurement, and a master station that collects and collectively manages data from the slave stations. An example of this type of telemeter system is described in JP-A-8-307964 as a "telemeter / telecontrol system".
[0003]
This telemeter system relates to a case where data is transmitted from a master station to a slave station. Upon receiving the synchronization signal from the slave station, the master station transmits data to the slave station in accordance with the stored intermittent reception timing. If data is lost due to collision or the like, the master station retransmits the data. In this case, the transmission timing is shifted from the original transmission timing by a time corresponding to the random number value. The slave station also shifts the original reception timing by the time corresponding to the random number value. This reduces the probability of data collision. Since the master station is always in the continuous reception state, the timing when data is transmitted from the slave station to the master station does not need to be particularly considered.
[0004]
[Problems to be solved by the invention]
In the above-described related art, since the master station is always in the continuous reception state, the timing when data is transmitted from the slave station to the master station does not need to be particularly considered. However, when the number of slave stations increases, the amount of data transmitted from the slave station to the master station increases, so that the processing load of the master station during data collection increases. Therefore, there is a problem that the setting of the transmission time in each slave station needs to be dispersed and set in advance, and when the number of slave stations is large, it is necessary to spend much time for setting.
[0005]
Further, assuming that the above-described conventional technique is diverted to the transmission of data from the slave station to the master station, the dispersion of the timing by the random value only reduces the probability of collision, and the relief in the event of a collision actually occurs. No.
[0006]
Therefore, a first object of the present invention is to simplify the setting of the data transmission time of the slave station by automatically distributing the data transmission time of the slave station, and to reduce the processing load of the master station during data collection. It is an object of the present invention to provide a telemeter data transmission device and a telemeter data transmission method that reduce the problem.
[0007]
It is a second object of the present invention to provide a telemeter data transmitting apparatus and a telemeter data transmitting method for relieving when a data collision occurs.
[0008]
[Means for Solving the Problems]
A telemeter data transmitting device according to the present invention is a telemeter data transmitting device in a telemeter system for transmitting telemeter data from a plurality of slave stations to a master station. ), A random number generation unit (3 in FIG. 1) for generating random numbers, and a retransmission request reception storage unit (3 in FIG. 1) for storing the presence / absence of a data retransmission request from the master station by ON / OFF of a retransmission request reception state. 4), a transmission start time storage unit (5 in FIG. 1) that sets and stores a transmission start time at which data can be transmitted to the master station, and sets a maximum transmission delay allowable time from the transmission start time. A maximum delay time storage unit (6 in FIG. 1) for storing, an actual transmission time storage unit (7 in FIG. 1) for storing an actual transmission time at which data is actually transmitted to the master station, When, random number, transmission start time A transmission timing detection unit (1 in FIG. 1) for calculating an actual transmission time based on the maximum transmission delay allowable time and detecting a data transmission timing by comparing the current time with the actual transmission time; A data transmission unit (8 in FIG. 1) for transmitting telemeter data to the master station upon receiving a data transmission command from the timing detection unit, and a retransmission request signal from the master station within a predetermined time after data transmission. A data receiving unit (9 in FIG. 1) for turning off the retransmission request reception state of the retransmission request reception storage unit and turning on the retransmission request reception state of the retransmission request reception storage unit when a retransmission request signal is received. It is characterized by the following.
[0009]
In the present invention, first, the retransmission request reception state by the master station is acquired from the retransmission request reception storage unit, and it is determined whether the retransmission request reception state is ON. When the retransmission request reception state is ON, the maximum transmission delay allowable time is obtained from the maximum delay time storage unit, and a random number is obtained from the random number generation unit. The obtained random number is divided by the maximum allowable transmission delay time, and the remainder is used as the transmission delay time. Then, the transmission start time is acquired from the transmission start time storage unit, and the actual transmission time, which is a time after the transmission delay time from the transmission possible start time, is obtained and stored in the actual transmission time storage unit. Next, the current time is obtained from the clock unit and compared with the actual transmission time. If both times are the same, the telemeter data is transmitted to the master station. If the data transmitted to the master station is normally received, the retransmission request reception state is turned off, and if the data is not normally received, the retransmission request reception state is turned on.
[0010]
[Action]
According to the present invention, since the data transmission time is automatically calculated based on the transmission start time, the maximum transmission delay allowable time, and the random number, the transmission start time and the maximum transmission delay allowable time are respectively transmitted. Just by setting the start time storage unit and the maximum delay time storage unit, the data transmission time from each slave station to the master station can be automatically set at a time dispersed within a predetermined time.
[0011]
Also, the presence / absence of a data retransmission request due to data reception abnormality at the master station is stored in the retransmission request reception storage unit, and when a data retransmission request is issued, the data transmission time is newly calculated. The data transmission time can be obtained in consideration of the data reception state on the station side.
[0012]
Further, since the data transmission time from the slave station to the master station can be dispersed, the load on the master station at the time of data collection can be reduced even in a telemeter system having a large number of slave stations.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0014]
FIG. 1 is a block diagram showing one embodiment of the telemeter data transmission device of the present invention. Referring to FIG. 1, this telemeter data transmission device includes a transmission timing detection unit 1, a clock unit 2, a random number generation unit 3, a retransmission request reception storage unit 4, a transmission start time storage unit 5, a maximum delay time storage unit 6, It comprises a transmission time storage unit 7, a data transmission unit 8, and a data reception unit 9. Each of a plurality of slave stations equipped with such a telemeter data transmission device transmits telemeter data to a master station.
[0015]
The clock unit 2 is a system timer that displays the current time by ticking the time.
[0016]
The random number generator 3 generates a random number used for calculating the transmission delay time. The random number can be, for example, a numerical value from 0 to 10,000.
[0017]
The retransmission request reception storage unit 4 stores the presence / absence of a data retransmission request from the master station as ON / OFF of the retransmission request reception state. The data retransmission request is a request for retransmission of data performed by the master station to the slave station when data from the slave station is not received by the master station. In this case, there is a possibility that data transmission from the slave station to the master station may not be normally received by the master station due to packet collision or the like. When the system is activated, the retransmission request reception state is set to be ON.
[0018]
The transmission start time storage unit 5 sets and stores a transmission start time (hereinafter, referred to as a “transmission start time”) at which data can be transmitted to the master station. The transmission start time is set to, for example, 5:00 every hour.
[0019]
The maximum delay time storage unit 6 sets and stores the maximum allowable transmission delay time (hereinafter, referred to as “maximum delay time”) from the transmission start time set in the transmission start time storage unit 4. The maximum delay time is set to, for example, 10 seconds.
[0020]
The actual transmission time storage unit 7 stores an actual transmission time at which data is actually transmitted to the master station. The actual transmission time is a time obtained by adding a transmission delay time obtained from the random number and the maximum delay time to the transmission start time.
[0021]
The transmission timing detection unit 1 is a core part of the telemeter data transmission device, and calculates an actual transmission time at which data is actually transmitted and detects a transmission timing.
[0022]
First, the retransmission request reception status is acquired from the retransmission request reception storage unit 4, and it is determined whether the actual transmission time needs to be updated. When updating the actual transmission time, a transmission delay time is obtained from the random number obtained from the random number generation unit 3 and the maximum delay time obtained from the maximum delay time storage unit 6, and the transmission delay time is obtained from the transmission start time storage unit 5. The actual transmission time is calculated in addition to the time, and stored in the actual transmission time storage unit 7.
[0023]
Further, the current time acquired from the clock unit 2 is compared with the actual transmission time acquired from the actual transmission time storage unit 7, the transmission timing is detected based on the coincidence, and a data transmission command is issued to the data transmission unit 8. .
[0024]
When receiving a data transmission command from transmission timing detecting section 2, data transmitting section 8 transmits data to the master station.
[0025]
If the data receiving unit 9 does not receive the retransmission request signal from the master station within a predetermined time after the data transmitting unit 8 has transmitted the data, the data receiving unit 9 turns off the retransmission request receiving state of the retransmission request When a signal is received, the retransmission request reception state of the retransmission request reception storage unit 3 is turned ON.
[0026]
Next, the operation of this embodiment will be described with reference to the processing flowchart of the telemeter data transmission device shown in FIG.
[0027]
When the system is started, the transmission timing detection unit 1 acquires the retransmission request reception state from the retransmission request reception storage unit 4 (step S1 in FIG. 2), and determines whether the retransmission request reception state is ON (step S2). As described above, since the retransmission request reception state is set to ON when the system is activated, the transmission timing detection unit 1 acquires the maximum delay time A (second) from the maximum delay time storage unit 6 (step S3). ). Further, a random number B is obtained from the random number generator 3 (step S4).
[0028]
Next, the transmission timing detection unit 1 divides the obtained random number B by the maximum delay time A, and sets the remainder as a transmission delay time C (second) (step S5). Further, the transmission timing detection unit 1 acquires the transmission start time D from the transmission start time storage unit 5 (Step S6). Then, the actual transmission time E (minutes, seconds), which is the time after the transmission delay time C (seconds) from the transmission start time D (minutes), is obtained (step S7) and stored in the actual transmission time storage unit 7 (step S7). S8).
[0029]
Next, the transmission timing detection unit 1 acquires the current time F (minutes, seconds) from the clock unit 2 (step S9) and compares it with the actual transmission time E (minutes, seconds) (step S10). As a result, if both times are the same, the transmission timing detecting section 1 sends a data transmission command to the data transmitting section 8, and the data transmitting section 8 transmits the data to the master station (step S11). If the times are different, the transmission timing detection unit 1 acquires the current time F from the clock unit 2 again and compares it with the actual transmission time E (step S9).
[0030]
If the data transmitted to the master station is normally received, there is no request for retransmission from the master station (NO in step S12), and the data receiving unit 9 receives the retransmission request from the retransmission request reception storage unit 4. The state is turned off (step S13). In this case, since the retransmission request reception state of the OFF state is acquired at the time of the next data transmission (step S1), the transmission timing detecting unit 1 does not update the actual transmission time (NO in step S2 and step S3). If the obtained current time matches the actual transmission time (step S9) (YES in step S10), the data transmission to the master station (step S11) is repeated.
[0031]
On the other hand, if the data transmitted to the master station is not normally received, there is a retransmission request from the master station (YES in step S12), and the data receiving unit 9 receives the retransmission request from the retransmission request reception storage unit 4. The state is turned on (step S14). In this case, at the time of the next data transmission, the retransmission request reception state of the ON state is acquired (step S1), so that the transmission timing detection unit 1 updates the actual transmission time (steps S3 to S8). If the obtained current time (step S9) matches the updated actual transmission time (YES in step S10), data transmission to the master station (step S11) is repeated.
[0032]
Next, a specific numerical value will be described as an example. Now, assuming that the data of the slave station should be transmitted to the master station every hour from 5:00 to 5:09 seconds, the transmission start time storage unit 5 stores the data for 5 minutes and the maximum delay time storage unit 5 stores the data. Is set to 10 seconds.
[0033]
The transmission timing detection unit 1 acquires the maximum delay time 10 (seconds) from the maximum delay time storage unit 6 (Step S3). It is also assumed that the transmission timing detection unit 1 has acquired the random number “1567” from the random number acquisition unit 3 (Step S4). The transmission timing detector 1 divides the random number “1567” by the maximum delay time 10 (seconds) and sets the remainder “7” as the transmission delay time (seconds) (step S5). Further, a transmission start time 5 (minute) is obtained from the transmission start time storage unit 5 (step S6). Then, 5 minutes and 7 seconds after the transmission delay time of 7 (seconds) from the transmission start time of 5 (minutes) are set as the actual transmission time (step S7) and stored in the actual transmission time storage unit 7 (step S8).
[0034]
Next, the transmission timing detection unit 1 acquires the current time F (minutes, seconds) from the clock unit 2 (step S9) and compares it with the actual transmission time of 5 minutes and 7 seconds (step S10). If the times are the same, the transmission timing detection unit 1 sends a data transmission instruction to the data transmission unit 8, and the data transmission unit 8 transmits the data to the master station at 5 minutes and 7 seconds (step S11).
[0035]
If the data transmitted to the master station in 5 minutes and 7 seconds is received normally (NO in steps S12 and S2), the data transmission one hour later is also performed in 5 minutes and 7 seconds. This is because, since the data was normally received, the actual transmission time of 5 minutes and 7 seconds was timed, and it was not necessary to change the actual transmission time.
[0036]
Similarly, when the random number is “5151”, 5 minutes and 1 second, when the random number is “6195”, 5 minutes and 5 seconds, and when the random number is “8888”, 5 minutes and 8 seconds, The data is transmitted to each station (step S11). Since the random number generated in the slave station is at random, the probability that the actual transmission time of data to the master station overlaps is low. Further, even if the actual transmission times from a plurality of slave stations overlap and a data collision occurs, a retransmission request is issued from the master station, so that the retransmission of the data after updating the actual transmission time can be relieved.
[0037]
In the above numerical example, the maximum delay time is set to 10, but when the maximum delay time is set to 1, the transmission delay times of all the slave stations, and therefore the actual transmission times, are the same. This is because, regardless of the random number of any value, the remainder of 1 which is the maximum delay time is 0, so that the transmission delay time does not occur. In this case, if the processing capability of the master station can be increased to reduce the probability of data collision, collection of telemeter data from all slave stations can be expedited.
[0038]
The above-described telemeter data transmission method can also be performed by causing a computer constituting the transmission timing detection unit 1, the data transmission unit 8, and the data reception unit to execute a program. The program controls the computer to perform the same processing as in the flowchart shown in FIG.
[0039]
【The invention's effect】
The first effect of the present invention is that the data transmission time is automatically calculated based on the transmission start time, the maximum transmission delay allowable time, and the random number. By simply setting the data in the transmission start time storage unit and the maximum delay time storage unit, the data transmission time from each slave station to the master station can be automatically set at a time dispersed within a predetermined time.
[0040]
A second effect of the present invention is that the presence / absence of a data retransmission request accompanying a data reception abnormality at a master station is stored in a retransmission request reception storage unit, and when a data retransmission request is issued, the data transmission time is newly added. Since the calculation is performed, the data transmission time can be obtained in consideration of the data reception state on the master station side.
[0041]
The third effect of the present invention is that the data transmission time from the slave station to the master station can be dispersed, so that the load on the master station during data collection can be reduced even in a telemeter system having a large number of slave stations. That you can do it. .
[Brief description of the drawings]
FIG. 1 is a block diagram showing one embodiment of a telemeter data transmitting apparatus according to the present invention; FIG. 2 is a flowchart showing the operation of the embodiment shown in FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Transmission timing detection part 2 Clock part 3 Random number generation part 3 Retransmission request reception storage part 5 Transmission start time storage part 6 Maximum delay time storage part 7 Actual transmission time storage part 8 Data transmission part 9 Data reception part

Claims (6)

In a telemeter data transmission device in a telemeter system that transmits telemeter data from a plurality of slave stations to a master station,
A clock section that displays the current time by ticking the time,
A random number generator for generating random numbers,
A retransmission request reception storage unit for storing the presence or absence of a data retransmission request from the master station by ON / OFF of a retransmission request reception state;
A transmission start time storage unit that sets and stores a transmission start time at which data transmission to the master station is enabled;
A maximum delay time storage unit that sets and stores a maximum allowable transmission delay time from the transmission start time,
An actual transmission time storage unit that stores an actual transmission time at which data is actually transmitted to the master station;
When the retransmission request reception state is on, the actual transmission time is calculated based on the random number, the transmission start time, and the maximum allowable transmission delay time, and the current time is compared with the actual transmission time to obtain data. A transmission timing detection unit that detects transmission timing;
A data transmission unit that transmits telemeter data to the master station when receiving a data transmission command from the transmission timing detection unit,
When the retransmission request signal is not received from the master station within a predetermined time after the transmission of the data, the retransmission request reception state of the retransmission request reception storage unit is turned off, and when the retransmission request signal is received, the retransmission request reception storage unit is turned off. A data receiving unit for turning on the retransmission request reception state of the telemetry data. When the retransmission request reception state is ON, the transmission timing detection unit calculates the actual transmission time by adding a remainder obtained by dividing the random number by a maximum transmission delay allowable time to the transmission available start time, and calculates the retransmission request. The method according to claim 1, wherein when the reception state is off, the calculation of the actual transmission time is not performed, and the transmission timing of the data is detected by comparing a current time with the actual transmission time. Telemeter data transmission device. The telemetry data transmission device according to claim 1 or 2, wherein the actual transmission time is fixed. 4. The telemeter data transmission device according to claim 3, wherein the maximum transmission delay allowable time is set to one. A telemeter data transmission method in a telemeter system for transmitting telemeter data from a plurality of slave stations to a master station,
A procedure for acquiring the retransmission request reception state by the master station from the storage unit and determining whether the retransmission request reception state is ON;
When the retransmission request reception state is ON, a procedure for obtaining the maximum transmission delay allowable time from the storage unit, a procedure for obtaining a random number from the random number generation unit, and dividing the obtained random number by the maximum transmission delay allowable time A procedure for setting the remainder as a transmission delay time, a procedure for obtaining a transmission available start time from a storage unit, and obtaining an actual transmission time that is a time after the transmission delay time from the transmission available start time, and storing the actual transmission time in the storage unit. Steps to
A procedure for obtaining the current time from the clock unit and comparing the current time with the actual transmission time;
A procedure for transmitting the telemeter data to the master station if both times are the same,
Turning off the retransmission request reception state if the data transmitted to the master station is normally received, and turning on the retransmission request reception state if the data is not normally received. Telemeter data transmission method. A program executed by a computer constituting a telemeter data transmission device in a telemeter system for transmitting telemeter data from a plurality of slave stations to a master station,
Acquiring the retransmission request reception state by the master station from the storage unit, and determining whether the retransmission request reception state is ON,
When the retransmission request reception state is ON, obtaining the maximum transmission delay allowable time from the storage unit, obtaining the random number from the random number generation unit, and dividing the obtained random number by the maximum transmission delay allowable time Setting the remainder as a transmission delay time, obtaining a transmittable start time from a storage unit, obtaining an actual transmission time that is a time after the transmission delay time from the transmittable start time, and storing the actual transmission time in the storage unit. Steps to
Obtaining the current time from the clock unit and comparing it with the actual transmission time;
Transmitting the telemeter data to the master station if both times are the same;
Turning off the retransmission request reception state if the data transmitted to the master station is normally received, and turning on the retransmission request reception state if the data is not normally received. And the program.

Images