JPH05197892A - Telemetry data transfer method - Google Patents

Abstract

(57) [Summary] [Purpose] A telemetry data transfer method for transferring measurement data measured by a terminal station to a master station is to reduce the amount of measurement data transferred from the terminal station to the master station. [Configuration] In a telemetry system that transfers measurement data to a master station only when a large change occurs in the measurement value measured at the terminal station, a change detection value and a measurement value for detecting a change in the measurement value at the terminal station When the measured value is received, a transmission condition storage unit 1a that stores an allowable upper limit value that is larger than the average value of the predetermined value and an allowable lower limit value that is smaller than the average value by the predetermined value, a previous measured value storage unit 2 that stores the previous measured value, , The absolute value of the difference between the received measurement value and the previous measurement value exceeds the change detection value, and at least one of the received measurement value and the previous measurement value exceeds the allowable upper limit value, or the allowable lower limit value. It is configured to include the transmission control unit 3 that transmits the measured value received when it is detected that the measured value is less than the measured value to the master station.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telemetry data transmission method for transferring measurement data measured by a terminal station to a master station, and more particularly, transferring measurement data only when a large change occurs in a measurement value measured at the terminal station. A method for transmitting telemetry data.

In recent years, measuring instruments and sensors have been installed in buildings and the like (hereinafter referred to as terminal stations) for measurement and monitoring, and the measured data are collected and centrally managed by a parent station (center). Telemetry systems such as building management systems are widely used.

In such a telemetry system,
In addition to the method of transferring the data measured at the terminal station to the master station each time, the newly received measurement value is larger than the previous measurement value in order to reduce the amount of data sent to the line and the amount of data processed by the master station. The method of transferring to the master station only when it changes is often used.

However, even if a method of transferring data only when the measured value has changed more than the previous measured value is used, the measured value may change frequently or the measured value may change greatly for some reason. In a certain system, when the change in the measured value becomes large, the amount of transferred data increases, and the host computer or the like that processes the measured value on the master station side may be overloaded.

Therefore, there is a need for a method of transferring telemetry data that is less likely to cause overload on the line or master station side.

[0006]

2. Description of the Related Art FIG. 4 is a diagram showing a pattern of changes in measured values. D _n in FIG. 4 is the current measured value, and D _n-1 is the previous measured value. Further, D _AV is an average value (or a reference value defined from past measured values) of measured values of a certain number of times. D _U and D _L are an upper limit value and a lower limit value which are appropriately determined to identify whether the measured value is within a certain range from the average value D _AV . Hereinafter, D _U is described as an allowable upper limit value, D _L is described as an allowable lower limit value, and a range of D _L or more and D _U or less is described as an allowable fluctuation range.

FIG. 4 shows that when the measured value D _{n of} this time is significantly different from the measured value D _{n-1 of the} previous time, specifically, the measured value D of this time is
The absolute value d _ij (i and j are identification numbers shown in FIG. 4) of the difference between _n and the previous measured value D _n-1 is a preset value Δ.
(Hereinafter, this value is referred to as an allowable change value) is exceeded, that is, d _ij = | D _n −D _n-1 |> Δ (Equation 1). ..

The pattern P _{1 in} FIG. 4 is the previously measured value D _n-1.
The measured value D _{n of} this time is also within the allowable fluctuation range. Pattern P ₂ is the last measured value D _n-1
There irrespective of what kind of value, a pattern that the current measurement value D _n exceeds the allowable upper limit value D _U, pattern P ₃ is also current measurement value D _n is less than the allowable lower limit value D _L Is the pattern.

The pattern P ₄ is a pattern in which the previous measurement value D _n-1 exceeds the allowable upper limit value D _U regardless of the current measurement value, and the pattern P ₃ is the same. This is a pattern in which the last measured value D _n-1 is less than the allowable lower limit value D _L.

In other words, the pattern P ₁ is within the permissible variation range of both the current measured value D _n and the previous measured value D _n-1 , but the patterns P _{2 to} P ₅ are at least the current measured value D _n . This is a pattern in which _one of the previously measured values D _n-1 is outside the allowable fluctuation range. In the conventional telemetry system that transfers measurement data to the master station when a large change occurs in the measurement value, the absolute value of the difference between the current measurement value D _n and the previous measurement value D _n-1 is the allowable change value. When Δ is exceeded, that is, when the condition of Expression 1 is satisfied, the current measurement value is unconditionally transferred. That is, all the patterns shown in FIG. 4 are transfer targets of the measurement data.

On the other hand, many remote measurement systems, such as a building management system, have measured values within a certain range. In such a system, the average value D _AV and the allowable variation range are the actual conditions. If there is no deviation, the measured value is often within the allowable fluctuation range. Further, in such a system, even if the measured value fluctuates slightly for some time, such as when some kind of adjustment is performed, if the measured value is within the permissible fluctuation range, as long as it is in the state of the pattern P _1. It is often unnecessary to send measurement data to the master station.

However, according to the conventional method, the current measured value D _n
And the difference between the previous measured value D _n-1 exceeds the allowable change value Δ,
Since the measurement data is transmitted even when the change in the measured value is within the allowable fluctuation range, congestion of the line and overload of the host computer of the master station often occur.

[0013]

In the prior art telemetry data transfer method for transferring measurement data to the master station when a large change occurs in the measurement value, both the previous measurement value and the current measurement value are within the allowable fluctuation range. Even if it is a value, if the difference in the measured values exceeds the allowable change value, the measured data is transferred, so the amount of transferred data increases and there is a possibility of overloading the host computer of the master station. there were.

An object of the present invention is to reduce the amount of measurement data transferred from a terminal station to a master station.

[0015]

FIG. 1 is a basic configuration diagram of the present invention, and FIG. 2 is another basic configuration diagram of the present invention. 1a in the figure
Nos. 4 to 4 are provided in a terminal station of a telemetry system that transfers measurement data to a master station (not shown) only when a large change occurs in the measurement value, and 1a is a change detection value for detecting a change in the measurement value. A transmission condition storage unit that stores an allowable upper limit value that is set to a value larger by a predetermined value from an average value of measured values for a certain period and an allowable lower limit value that is set to a value that is smaller than the average value by a predetermined value.

Reference numeral 2 is a previous measurement value storage means for storing the previous measurement value received from the measuring instrument, and 3 is a received measurement value and the previous measurement value storage means 2 when the measurement value is received from the measuring instrument. Calculate the difference between the stored previous measurement values,
Received when it is detected that the absolute value of the difference exceeds the change detection value and at least one of the received measurement value and the previous measurement value exceeds the allowable upper limit value or is less than the allowable lower limit value. It is a transmission control means for transmitting the measurement value as measurement data to the master station.

A reference numeral 4 receives the measured values from the measuring device, calculates the average value of the measured values when the measured values are received a predetermined number of times, and also determines the allowable upper limit value and the allowable lower limit value by a predetermined calculation method. The transmission condition calculation means 1b for calculating is a transmission condition storage means for storing the predetermined change detection value and receiving and storing the allowable upper limit value and the allowable lower limit value from the transmission condition calculating means 4.

[0018]

In FIG. 1, the transmission means storage means 1a stores a predetermined change detection value, an allowable upper limit value set to a value larger by a predetermined value from an average value of measured values of a predetermined number or a fixed period, and the average value. An allowable lower limit value set to a value smaller by a predetermined value is stored in advance.

Further, the last measured value storage means 2 stores the last measured value received from a measuring device (not shown) as the previous measured value. When a new measurement value (hereinafter referred to as the current measurement value) is received from the measuring device subsequent to the previous measurement value, the transmission control means 3 that has input the measurement value receives the transmission condition storage means 1a.
The predetermined change detection value, the allowable upper limit value, and the allowable lower limit value are input, and the previous measurement value is input from the previous measurement value storage means, and first the difference between the current measurement value and the previous measurement value is calculated. The absolute value is compared with the change detection value.

As a result of the comparison, if the absolute value of the difference between the current measurement value and the previous measurement value is smaller than the change detection value, the measurement data is not transmitted to the master station. It is checked whether at least one of the measured values exceeds the allowable upper limit value or is less than the allowable lower limit value.

As a result, if it is confirmed that the previous and present measured values do not exceed the permissible upper limit value and the permissible lower limit value, even if the difference between the present measured value and the previous measured value is Even if the absolute value is larger than the change detection value, the measurement data is not transmitted to the master station.

Further, when it is detected that at least one of the current measurement value and the previous measurement value exceeds the allowable upper limit value or less than the allowable lower limit value, the current measured value is transmitted to the master station.

In FIG. 2, the transmission condition calculating means 4 sequentially inputs the measurement values sent from the measuring instrument, calculates the average value of the measurement values when a predetermined number of times of the measurement values are received, and at the same time, determines a predetermined value. The allowable upper limit value and the allowable lower limit value are calculated by a calculation method (described in detail in the embodiments of the present invention). The calculated allowable upper limit value and allowable lower limit value are the transmission condition storage means 1
b, and is stored in the transmission condition storage means 1b. Further, the transmission condition storage means 1b separately stores the predetermined change detection values, but the state after storing these is exactly the same as the transmission condition storage means 1a in FIG.

Since the transmission condition storage means 1b has exactly the same operation as the transmission condition storage means 1a, the transmission control section 3 in FIG. 2 performs the same operation as in FIG. For this reason,
The description of the subsequent operation is omitted.

As described above, in FIGS. 1 and 2, the absolute value of the difference between the current measurement value and the previous measurement value is larger than the change detection value, and at least one of the previous measurement value and the current measurement value is Only when the allowable upper limit value is exceeded or the allowable lower limit value is exceeded, the current measured value is transmitted to the master station.

Therefore, in the configurations of FIGS. 2 and 3, even if the absolute value of the difference between the current measured value and the previous measured value exceeds the change detection value, the measured value is allowed to change. Measurement data will not be sent to the master station as long as it fluctuates within the fluctuation range. As a result, since the amount of data to be transmitted is reduced, the possibility of line congestion and overload of the host computer of the master station is reduced even if the above state continues for a while.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 3 is a block diagram of an embodiment of the present invention, showing a configuration of a measurement data transmitting device based on the basic configuration of the present invention shown in FIGS.

Throughout the drawings, the same symbols indicate the same objects. In the figure, 10 is a measurement data transmission device installed in a terminal station of a telemetry system, the following is its component part, and 1 is the FIG.
The transmission condition storage area 1a in the basic configuration diagram of FIG. 1 and the transmission condition storage area 4a and 4b that commonly realizes the transmission condition storage means 1b in the basic configuration diagram of FIG. 2 constitute the transmission condition calculation means 4 of FIG. Is a transmission condition calculation unit, 4b
Is a transmission condition calculation data storage area.

Further, 11 is a processor (hereinafter referred to as CPU), 12 is a random access memory (hereinafter referred to as RAM), 13 is a read-only memory (hereinafter referred to as ROM), 14
Is a measuring instrument interface unit, 15 is a communication control unit, 16 is an input / output interface unit, 17 is an input device, and 18 is a bus.

3 will be described below, but the measured value will be described using the change pattern of the measured value described in FIG. First, a description will be given of a different part between the basic configuration of FIG. 1 and the basic configuration of FIG.

In the case where FIG. 3 is an embodiment for realizing the basic configuration of FIG. 1, the transmission condition from the input device 17, that is, the permissible change value Δ, the permissible upper limit value D _U , and the permissible lower limit value are measured before starting the measurement. Enter D _L.

Among these, the allowable change value Δ is the absolute value d of the difference between the current measured value D _n and the previous measured value D _n−1 , where d = | D
It is used to determine whether or not _n −D _n−1 |> Δ. In addition, the allowable upper limit value D _U and the allowable lower limit value D _L are values used to determine whether or not to transmit the current measured value D _n , and take into consideration the usage of the telemetry system and the past fluctuation situation. Set to an appropriate value.

For example, when D _AV is the average value of the measured values for a certain number of times or for a certain period, D _{max is} the maximum value of the measured values during that period, and D _min is the minimum value, D _U = D _AV + (D _max −D _min ) × α (formula 2) D _L = D _AV − (D _max −D _min ) × α (formula 3), and D _U , D by using an appropriate value for α (for example, α <1)
Calculate _L.

The input transmission conditions are stored in the transmission condition storage area 1 in the RAM 12. In the case where FIG. 3 is an embodiment that realizes the basic configuration of FIG. 2, only the allowable change value Δ is input from the input device 17, and the other conditions, that is, the allowable upper limit value D _U and the allowable lower limit value D _L are initially set. The values and calculation formulas are programmed and stored in the ROM 13.

When the transmission of the measurement data is started, the CPU 11
The transmission condition calculation unit 4a reads the program from the ROM 13, but at the start of measurement, the initial values of the allowable upper limit value D _U and the allowable lower limit value D _L set in the program are RA.
It is stored in the transmission condition storage area 1 in M12.

Next, the transmission condition calculation unit 4a stores the measurement values input to the measurement device interface unit 14 from a measurement device (including sensors) (not shown) via the bus 18 in the transmission condition calculation data storage unit in the RAM 12. Store in 4b.

When the measured value reaches the number specified by the program after a certain period of time, the transmission condition calculation unit 4a reads out the measured value stored in the transmission condition calculation data storage unit 4b, and the average value D _AV , Allowable upper limit value D _U and allowable lower limit value D _L
To calculate. D _U and D _L can be calculated using the standard deviation value or the invariant variance by statistically processing the predetermined number of measured values, but from the convenience of explanation, it is calculated by Equation 2 and Equation 3. To do.

In this case, the transmission condition calculation unit 4a
A fixed number of measurement values read from the calculation data storage unit 4b
More average value D_AVAnd calculates the maximum of the measured values
Value D _maxAnd the minimum value D_minIs detected, and according to Equation 2 and Equation 3,
D_UAnd D_LIs calculated and the calculation result is sent to the RAM 12
It is stored in the case storage area 1. The value of α is
Shall be specified in grams.

Since the measurement is usually performed in a fixed cycle, a value calculated from a fixed number of received measurement values, for example, the average value D _AV is an average value of the measured values in a fixed period traced back from the current time point. ..

Thereafter, the transmission condition calculation unit 4a performs the above calculation each time a new measurement value is input or a specified number of measurement values is input by the specification of the program, and the transmission condition is stored. Update area 1 data.

After the transmission conditions have been calculated and stored in the transmission condition storage area 1 as described above, the embodiments having the basic configurations shown in FIGS. 1 and 2 operate in the same manner. explain.

When the measurement value D _n-1 is input from the measuring instrument to the measuring instrument interface section 14 while the transmission condition is stored in the transmission condition storage area 1, the CPU 11 performs necessary processing (processing content is the measured value D This will be described when inputting _n ), and the measured value D _n-1 is stored in the previously measured value storage area 2 in the RAM 12 as the previously measured value.

Next, when a new measurement value D _n is input, the transmission control unit 3 stores the previous measurement value D _n-1 from the previous measurement value storage area 2 and the transmission condition from the transmission condition storage area 1 as transmission conditions. The change detection value Δ, the allowable upper limit value D _U, and the allowable lower limit value D _L are read out, and first, the absolute value of the difference between the present measured value D _n and the previous measured value D _n-1 is compared with the change detected value Δ. .. As a result, if | D _n −D _n-1 | ≦ Δ (Equation 4), the current measurement value D _n is not transmitted to the master station (not shown) and the next measurement value is input.

If the comparison result is | D _n -D _n-1 |> Δ (Equation 5), it is checked whether any of the following four equations is satisfied.

D _n > D _U (formula 6) D _n <D _L (formula 7) D _n-1 > D _U (formula 8) D _n-1 <D _L (formula 9) As a result, any formula If it conforms to, the transmission control unit 3
Transmits the measured value D _n of this time as measured data to the master station via the transmission control unit 15, and if none of the expressions is met, the data of the measured value D _n of this time is not transmitted to the master station and Wait for input of measurement value of.

[0046] In other _{words, | D n -D n-1} | a> delta, and, if at least one of D _n or D _n-1 is greater than the allowable upper limit value D _U, below the allowable lower limit D _L If there is
That is, only when the measured value in the range shown by the mesh in FIG. 4 is detected, the data of the measured value D _n of this time is transmitted to the master station, and D _n ,
When both D _n-1 are both within the permissible lower limit value D _L and below the permissible upper limit value D _U (permissible fluctuation range), that is,
In the case of the pattern P _{1 in} FIG. 4, the measured value D _{n of} this time is not transmitted even if Expression 5 is satisfied.

As described above, in FIG. 3, the measurement data is not transmitted if the change in the measured value is within the allowable variation range even if the change is large, but in a general telemetry system, the variation is within the allowable variation range. Since the amount of measurement data transmitted to the master station decreases, the frequency of occurrence of line congestion and overload of the host computer of the master station decreases.

Although the embodiment of the present invention has been described above with reference to FIG. 3, it goes without saying that FIG. 3 merely shows an example of the present invention, and the present invention is not limited to the configuration of FIG.

For example, although only one input line of the measuring instrument is shown in FIG. 3, the number of measuring instruments and sensors is determined by the telemetry system to which the present invention is applied.
Of course, it is not limited to a specific number. Needless to say, when there are a plurality of measuring instruments, the measuring conditions are different for each measuring instrument.

The transmission conditions of equations 5 to 9 are: | D _n -D _n-1 | = Δ and D _n = D _U , D _n = D _L D _n-1 = D _U , D _{n- 1} = D _U is not included, but whether or not the condition of the above formula is included in the transmission condition is not the essence of the present invention, and the measured value D _n is transmitted as the measurement data when the condition of the above formula is satisfied. However, it is clear that the basic effect of the present invention does not change.

Further, in FIG. 3, the input device 17 is added to the measurement data transmitting device 10. However, the measurement data transmitting device 10 is provided with an input section such as an operation panel instead of the input device 17. However, the effect of the present invention does not change.

[0052]

As described above, according to the present invention,
When the measured value fluctuates beyond a certain value in the telemetry system, the measured data entered is not sent to the master station as long as the measured value changes within the allowable fluctuation range. It is possible to reduce the possibility of occurrence of overloading of the host computer, which greatly contributes to improvement of investment efficiency and improvement of operational reliability of such a telemetry system.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram (1) of the present invention.

FIG. 2 is a basic configuration diagram of the present invention (2)

FIG. 3 is a block diagram of an embodiment of the present invention.

[Figure 4] Measurement value change pattern diagram

[Explanation of symbols]

 1a, 1b Transmission condition storage means 2 Previous measurement value storage means 3 Transmission control means 4 Transmission condition calculation means

Claims (2)

[Claims] 1. A telemetry system for transferring measurement data to a master station only when a large change occurs in a measurement value measured at a terminal station, wherein the terminal station is provided with a change detection value for detecting a change in the measurement value. And a transmission condition storage means (1a) for storing an allowable upper limit value set to a larger value by a predetermined value from an average value of measured values for a certain period and an allowable lower limit value set to a smaller value by a predetermined value from the average value, The previous measurement value storage means (2) that stores the previous measurement value received from the measuring instrument, and when the measurement value is received from the measurement instrument, the received measurement value and the previous measurement value storage means (2) are stored. Calculate the difference between the previous measured values, the absolute value of the difference exceeds the change detection value,
Also, the measured value received when at least one of the received measured value and the previous measured value exceeds the allowable upper limit value or is less than the allowable lower limit value is transmitted to the master station as the measured data. A telemetry data transfer method comprising a control means (3). 2. The previous measurement value storage means in the terminal station
(2) and the transmission control means (3), receiving the measurement value from the measuring instrument, when the measurement value of a predetermined number of times is received, while calculating the average value of the measurement value, by a predetermined calculation method A transmission condition calculation means (4) for calculating an allowable upper limit value and an allowable lower limit value is provided, and the predetermined change detection value is stored in place of the control transmission condition storage means (1a), and the transmission condition is A telemetry data transfer method, comprising: transmission condition storage means (1b) for receiving and storing the allowable upper limit value and the allowable lower limit value from a calculating means (4).