JP6880611B2 - Processing equipment, systems, processing methods and processing programs - Google Patents

Description

The present invention relates to processing devices, systems, processing methods and processing programs.

Conventionally, various methods using the NTP protocol have been proposed in order to synchronize the time between a plurality of devices (see, for example, Patent Document 1).
Patent Document 1 JP-A-2005-106696

However, it is desired to further improve the accuracy of calculating the time difference.

In the first aspect of the present invention, it is a processing device that detects a time error with the other device, and the acquisition unit that acquires the internal time in the processing device and the other device via a network. The difference between the communication unit that sends the time inquiry and receives the response of the other party's time in the other device and the other party's time for each of the first multiple time inquiries and the internal time that sent the time inquiry is smaller. Of the difference between the internal time and the other party's time that received the answers for each of the second multiple time queries, the first decision unit that determines the time difference for the time query by preferentially using the difference. Based on the time difference between the second decision unit, which determines the time difference for the answer by preferentially using the small difference, and the time difference for the time inquiry and the time difference for the answer, the time difference between the other device and the processing device is determined. A processing device including an error calculation unit for calculation is provided.

In the second aspect of the present invention, it is a processing method performed by a processing device that detects a time error with the other device, and is an acquisition step of acquiring the internal time in the processing device and the other party via a network. The difference between the communication stage in which the time inquiry is sent to the device and the response of the other party's time in the other device is received, and the other party's time for each of the first multiple time inquiries and the internal time in which the time inquiry is sent. Of these, the difference between the internal time and the other party's time, which is the first decision stage in which the time difference for the time query is determined by preferentially using the smaller difference, and the internal time for which the answers for each of the second multiple time queries are received. Between the second decision stage, which preferentially uses the smaller difference to determine the time difference for the answer, and the other device and the processing device based on the time difference for the time inquiry and the time difference for the answer. A processing method including an error calculation step for calculating the time difference of the above is provided.

In the third aspect of the present invention, the computer of the processing device that detects the time error with the other device is attached to the other device via the acquisition unit that acquires the internal time in the processing device and the other device. The difference between the communication unit that sends the time inquiry and receives the response of the other party's time in the other device and the other party's time for each of the first multiple time inquiries and the internal time that sent the time inquiry is smaller. Of the difference between the internal time and the other party's time that received the answers for each of the second multiple time queries, the first decision unit that determines the time difference for the time query by preferentially using the difference. Based on the time difference between the second decision unit, which determines the time difference for the answer by preferentially using the small difference, and the time difference for the time inquiry and the time difference for the answer, the time difference between the other device and the processing device is determined. A processing program that functions as an error calculation unit for calculation is provided.

The above outline of the invention does not list all the features of the present invention. A subcombination of these feature groups can also be an invention.

The system according to the first embodiment is shown. The operation of the system according to the first embodiment is shown. The method of calculating the time difference according to the first embodiment is shown. An example of calculating the time difference is shown. The system according to the second embodiment is shown. The operation of the system according to the second embodiment is shown. An example of system installation is shown. An example of the configuration of the computer according to this embodiment is shown.

Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the inventions that fall within the scope of the claims. Also, not all combinations of features described in the embodiments are essential to the means of solving the invention.

[1. First Embodiment]
[1-1. System 1 configuration]
FIG. 1 shows the system 1 according to the first embodiment. The system 1 includes a server device 11 connected via the network 100 and one or more client devices 12, and synchronizes the internal time of the client device 12 with the server device 11. The network 100 connects the server device 11 and the client device 12 by wire or wirelessly. For example, network 100 may be Ethernet®.

[1-1-1. Server device 11]
The server device 11 is an example of the other device, and holds a reference time for adjusting the time of the client device 12. For example, the server device 11 may be an NTP server. The server device 11 includes a timekeeping unit 110, an acquisition unit 111, a communication unit 113, and a control unit 114.

The timekeeping unit 110 measures the time. For example, the timekeeping unit 110 is a circuit having a clock function and may hold a reference time. The timekeeping unit 110 may output the current reference time to the acquisition unit 111 or the like.

The acquisition unit 111 acquires the reference time in the server device 11. For example, the acquisition unit 111 may acquire the reference time from the timekeeping unit 110. The acquisition unit 111 may supply the acquired reference time to the communication unit 113 and the like.

The communication unit 113 receives the time inquiry from the client device 12 and transmits the response of the reference time in the server device 11. The answer of the reference time indicates the reference time at the timing when the server device 11 receives the time inquiry or the timing when the answer is transmitted, and is processed as the answer of the other party time as seen from the client device 12. The communication unit 113 may communicate with the client device 12 using the NTP protocol or the SNMP protocol.

The control unit 114 controls each unit in the server device 11. For example, the control unit 114 may synchronize the timekeeping unit 110 with the time held by another device (as an example, the time in Japan Standard Time). As an example, the control unit 114 causes a GPS receiving unit (not shown) to receive radio waves from GPS satellites and supplies the time information included in the radio waves to the time measuring unit 110, so that the time information in the time measuring unit 110 is used. You may match the information. Instead, the control unit 114 may cause a radio-controlled clock (not shown) to receive a standard radio wave from a transmitting station and use it for synchronization.

[1-1-2. Client device 12]
The client device 12 is an example of a processing device, and detects a time error with the server device 11. The client device 12 includes a timekeeping unit 120, an acquisition unit 121, a communication unit 123, a storage unit 124, a first determination unit 125, a second determination unit 126, and an error calculation unit 127. The client device 12 may further have a synchronization unit 129.

The timekeeping unit 120 measures the time. For example, the timekeeping unit 120 is a circuit having a clock function, and may hold the internal time in the client device 12. This internal time is a local time with respect to the reference time held by the server device 11. The timekeeping unit 120 may output the current internal time to the acquisition unit 121 or the like.

The acquisition unit 121 acquires the internal time in the client device 12. For example, the acquisition unit 121 may acquire the internal time from the timekeeping unit 120. The acquisition unit 121 may supply the acquired internal time to the communication unit 123 and the like.

The communication unit 123 transmits a time inquiry to the server device 11 and receives a response of the other party's time in the server device 11. The communication unit 123 may perform the time inquiry and the exchange of answers a plurality of times.

The communication unit 123 may acquire the internal times of the time inquiry transmission timing and the response reception timing from the acquisition unit 121 and supply them to the storage unit 124. Further, the communication unit 123 may supply the received response to the storage unit 124.

The storage unit 124 stores and stores the internal time at the transmission timing of the time inquiry and the reception timing of the answer, and the other party time included in the answer for each of the plurality of exchanges of the time inquiry and the answer.

The first determination unit 125 preferentially uses the smaller difference between the other party time included in the answer and the internal time when the time inquiry is sent for each of the plurality of time inquiries for the time inquiry. Determine the time difference of. The first determination unit 125 may read each time from the storage unit 124 and use it for determining the time difference. The first determination unit 125 may supply the determined time difference to the error calculation unit 127. The operation of the first determination unit 125 will be described in detail later.

The second determination unit 126 preferentially uses the smaller difference between the internal time when the answer is received and the other party's time included in the answer for each of the plurality of time queries, and the time for the answer. Determine the difference. The second determination unit 126 may read each time from the storage unit 124 and use it for determining the time difference. The second determination unit 126 may supply the determined time difference to the error calculation unit 127. The operation of the second determination unit 126 will be described in detail later.

The error calculation unit 127 sets the server device 11 and the client device 12 based on the time difference for the time inquiry calculated by the first decision unit 125 and the time difference for the answer calculated by the second decision unit 126. Calculate the time difference between. The error calculation unit 127 may supply the calculated time difference to the synchronization unit 129. The operation of the error calculation unit 127 will be described in detail later with reference to FIG.

The synchronization unit 129 synchronizes the internal time of the client device 12 with the reference time of the server device 11 based on the time difference calculated by the error calculation unit 127.

According to the client device 12 in the above system 1, the smaller difference between the other party time of the answer for each of the plurality of time inquiries and the internal time of sending the time inquiry is preferentially used for the time. The time difference for the query is determined. Further, among the differences between the internal time when the answer for each of the plurality of time inquiries is received and the time of the other party of the answer, the smaller difference is preferentially used to determine the time difference for the answer. Then, based on these time differences, the time difference between the server device 11 and the client device 12 is calculated. Therefore, the time difference between the devices can be calculated by using the time difference between the devices with a small error due to the delay for each of the time difference for the time inquiry and the time difference for the answer, so that the calculation accuracy of the time difference between the devices can be calculated. Can be improved.

[1-2. System 1 operation]
FIG. 2 shows the operation of the system 1. This operation may be performed periodically between the server device 11 and each client device 12.

First, the server device 11 and the client device 12 perform time inquiry and response communication a plurality of times while acquiring the time from the timekeeping units 110 and 120 (steps S101 and S201). For example, the client device 12 may send a time inquiry to the server device 11, and the server device 11 may return an answer. The server device 11 and the client device 12 perform the first plurality of exchanges for determining the time difference by the first determination unit 125, and the second plurality of times for determining the time difference by the second determination unit 126 described later. May be exchanged.

The first plurality of time queries used by the first determination unit 125 and the second plurality of time queries used by the first determination unit 125 may be the same. Instead, at least a part of the first plurality of time queries and the second plurality of time queries may be different.

When the server device 11 communicates with a plurality of client devices 12, the server device 11 may communicate with one client device 12 a plurality of times and then with another client device 12 a plurality of times. By changing the client device 12 of the communication partner each time the communication is performed, the communication with the plurality of client devices 12 may be performed a plurality of times in parallel.

Next, the first determination unit 125 of the client device 12 determines the difference between the response partner time and the internal time when the time inquiry is transmitted for each of the first plurality of (5 times as an example) time inquiry. , The smaller difference is preferentially used to determine the time difference for the time query (step S203). Further, the second determination unit 126 gives priority to a smaller difference among the differences between the internal time when the answer is received and the time of the other party of the answer for each of the second plurality of (5 times as an example) time inquiry. To determine the time difference for the answer (step S205).

For example, the first determination unit 125 calculates the difference obtained by subtracting the internal time when the time inquiry is sent from the time of the other party of the answer for each time inquiry, and calculates the smallest difference among the obtained plurality of differences for the inquiry. It may be determined as the time difference of. Similarly, the second determination unit 126 calculates the difference obtained by subtracting the other party's time of the answer from the internal time when the answer is received for each time inquiry, and determines the smallest difference among the obtained plurality of differences for the answer. It may be determined as the time difference of.

When the minimum difference is smaller than the threshold value among the plurality of differences obtained by subtracting the internal time when the time inquiry is sent from the other party's time of the answer, the first determination unit 125 replaces the minimum difference with the second. A small difference may be determined as the time difference for the time query. Similarly, the second determination unit 126 replaces the minimum difference with the minimum difference when the minimum difference is smaller than the threshold value among the plurality of differences obtained by subtracting the response partner time from the internal time when the response is received. The second smallest difference may be determined as the time difference for the response. This makes it possible to determine the time difference without using this difference when the error contains an unusually small difference.

The first determination unit 125 may determine the time difference by preferentially using a plurality of smaller differences among the plurality of differences obtained by subtracting the internal time at which the time inquiry is transmitted from the other party's time of the answer. For example, the first determination unit 125 may determine the average of the smallest plurality of differences as the time difference. Further, the first determination unit 125 may calculate a weighted average by weighting each of the plurality of differences as the smaller the value, and determine the difference as a time difference. Similarly, the second determination unit 126 may also determine the time difference by preferentially using a plurality of smaller differences among the plurality of differences obtained by subtracting the response partner time from the internal time when the response is received.

Next, the error calculation unit 127 determines the server device 11 and the client based on the time difference for the time inquiry calculated by the first determination unit 125 and the time difference for the answer calculated by the second determination unit 126. The time difference with the device 12 is calculated (step S207). The method of calculating the time difference by the error calculation unit 127 will be described in detail later with reference to FIG.

Then, the synchronization unit 129 synchronizes the internal time of the client device 12 with the reference time of the server device 11 based on the time difference calculated by the error calculation unit 127 (step S209). For example, the synchronization unit 129 may synchronize the time by advancing / delaying the internal time in the time measuring unit 120 by the calculated time difference.

The synchronization unit 129 may adjust the time before the estimated timing in which the time difference between the server device 11 and the client device 12 exceeds the reference value (for example, the maximum allowable time difference, 1 ms as an example). For example, the processing cycle of steps S101 and S201 may be set every 2 seconds so that the timing of time adjustment by the synchronization unit 129 does not exceed the estimation timing. Instead of / in addition, the first plurality of times in step S203 described above and the second plurality of times in step S205 described above are used as reference so that the timing of time adjustment by the synchronization unit 129 does not exceed the estimated timing. It may be set to a number or less.

Here, the estimated timing may be held in advance in the synchronization unit 129 as a fixed value. In this case, the estimated timing may be calculated using the clock accuracy of the product specifications of the timekeeping unit 120. When the clock accuracy fluctuates depending on the temperature, the estimation timing may be held in the synchronization unit 129 in association with each temperature.

Instead of this, the estimation timing may be periodically calculated and set by the synchronization unit 129. For example, the estimation timing may be calculated from the history of the time difference calculated by the error calculation unit 127 so far, or may be calculated from the time difference calculated last time. The estimated timing may be further calculated in consideration of temperature.

[1-3. Calculation method of time difference in system 1]
[1-3-1. Comparative example calculation method]
First, as a comparative example, a conventional method for calculating an error value will be described.
FIG. 3 shows a method for calculating the time difference.

In the time inquiry and response communication, the client device 12 first transmits the time inquiry to the server device 11 at the internal time Tcs of the client device 12. Time query is transmitted over a transmission time t _ps, it is received by the server device 11 at the reference time Tm of the server device 11. Next, the server device 11 transmits a reply indicating the reference time Tm (the other party time Tm as seen from the client device 12 side). Answer is transmitted over a transmission time t _pr, it is received by the client device 12 within the time Tcr of the client device 12.

Transmission time _t ps round trip time inquiry and _answer, assuming equal _{t pr,} and the internal time Tcs when originated the time query, just an intermediate time of the internal time Tsr when receiving a reply (= (Tcs + Tcr ) / 2), it is estimated that the server device 11 received the time inquiry and transmitted the answer. Therefore, time difference Delta] t between the server device 11 and client device 12, and the mating time Tm responses may be estimated as a time difference Delta] t _e of the intermediate time. Note that Δt becomes a positive value when the client device 12 is ahead of the server device 11.

More specifically, the other party time Tm when the time inquiry is received and the internal time Tcr when the answer is received are represented by the following equations (1) and (2). Here, for the client device 12, Tcs, Tm and Tcr it is _{known, t ps} and _{t pr} is unknown.

Tm = Tcs + t _ps −Δt… (1)
Tcr = Tm + t _pr + Δt… (2)

A transmission time Tcs and answer reception time Tcr of intermediate time between time query (= (Tcs + Tcr) / 2), time difference Delta] t _e with the mating time Tm answer is expressed by the following equation (3).
_{Δt e ≡ (Tcs + Tcr)} ÷ 2-Tm ... (3)

By substituting the equations (1) and (2) into the equation (3), the following equation (4) is obtained.
_{Δt e = (Tcs + Tm +} t pr + Δt) ÷ 2-Tm
= (Tcs + Tcs + t _{ps −Δt + t pr} + Δt) ÷ 2- (Tcs + t _ps −Δt)
= (T _pr −t _ps ) ÷ 2 + Δt… (4)

Assuming that the round-trip transmission times t _ps and t _pr are equal, t _pr = t _ps, so the equation (4) becomes the following equation (5).
Δt _e = Δt ... (5)

Therefore, it can be seen that use a Delta] t _e represented by the above formula (3) as an estimate of the time difference Delta] t.

Here, the above method presupposes the following (i) to (iii).
(i) Round-trip transmission times t _ps and t _pr are equal.
(ii) The time required for the server device 11 to send a response after receiving the time inquiry is sufficiently shorter than the required accuracy of the time correction.
(iii) The advance / lag of each clock of the server device 11 and the client device 12 during a series of transmission / reception is negligibly small compared to the required accuracy of time correction.

Of these, with regard to (ii), the time required from receiving the time inquiry to transmitting the answer is about 1 ms even for a general device, and is almost constant if the server device 11 is the same device. .. Therefore, it can be sufficiently ignored, especially when the purpose is to synchronize between a plurality of client devices 12.

Further, regarding (iii), even a general inexpensive crystal clock has an accuracy of about 50 ppm, which is smaller than the round-trip transmission time, and therefore can be ignored.

On the other hand, regarding (i), when the network 100 is an Ethernet (registered trademark) line, the transmission timing of each device is random, and when the transmission timings are close to each other and packets collide, each device detects this and mutually. After arbitration, re-transmission is performed without updating the transmission time. Therefore, since the transmission time is affected by the transmission timing, the degree of line congestion, the number of connected devices, and the like, the transmission times _tps and _tpr are not always the same. The transmission time _{t ps,} the difference between _{t pr} is the transmission time _{t ps,} it may be greater in proportion to the magnitude of _{t pr} itself.

Therefore, in the comparative example, the time inquiry and the answer are transmitted and received a plurality of times, and the equation (3) is used using the result when the _{round-trip transmission time (= t ps} + t _{pr = Tcr-Tcs) is minimized.} ) to calculate the time difference Delta] t _e by.

[1-3-2. Calculation method of this embodiment]
Subsequently, the calculation method of this embodiment will be described.

In the calculation method of the comparative example described above, the transmission time of the round trip is calculated the time difference Delta] t _e using the result in the case of the minimum, the minimum value of the transmission time of the round trip and the minimum value of the necessarily forward transmission time It is not always the sum of the minimum value of the transmission time on the return route. Therefore, in this embodiment, calculates a time difference Delta] t _e is used as an example, the minimum transmission time for each forward path and the backward path.

More specifically, by rewriting the above equation (3), the following equation (6) can be obtained. The first term on the right side changes according to the transmission time of the return path, and the second term changes according to the transmission time of the outward path.
_{Δt e = (Tcr-Tm)} ÷ 2- (Tm-Tcs) ÷ 2 ... (6)

Here, the above equations (1) and (2) can be converted as the following equations (7) and (8).
Tm −Tcs = t _ps −Δt… (7)
Tcr-Tm = t _pr + Δt ... (8)

According to these equations (6) to (8), assuming that the time difference Δt is constant in a short period of time, the transmission time when the first term (Tcr-Tm) of the equation (6) becomes the minimum. It can be seen that t _{pr is also minimized, and the transmission time t ps} is also minimized when the second term (Tm-Tcs) is minimized.

Therefore, the numerical values of each time in a plurality of transmissions and receptions are distinguished by suffixes (i), (ii), ... Is expressed as the following equation (9).
_{Δt e (k, j) =} (Tcr (k) -Tm (k)) ÷ 2
-(Tm (j) -Tcs (j)) ÷ 2 ... (9)

In this embodiment, to calculate the time difference Delta] t _e using the equation (9) instead of equation (3) above. In other words, the time difference for time query (first term on the right side), to calculate a time difference Delta] t _e Based on the difference between the time difference for answers (second term on the right side).

In this embodiment, it is assumed that the time difference Δt is constant in a short time. For example, when transmitting and receiving 5 times at 1-second intervals, it takes about 4 seconds to complete the exchange. If the accuracy of the crystal clock is 50 ppm, the advance / delay in these 4 seconds is about 0.2 ms, so that there is no problem even if the time difference Δt is regarded as constant.

[1-3-3. Calculation example of time difference]
FIG. 4 shows an example of calculating the time difference. More specifically, when the client device 12 sends the time inquiry to the server device 11 a total of 5 times at 1-second intervals, the time difference of the time inquiry (transmission time of the outward route) and the time difference of the response (the time difference of the return route). Transmission time) etc. are shown. The internal clock of the client device 12 is behind the server device 11 by 2 seconds. In addition, transmission takes a few ms, and the time varies. Further, the processing time from the reception of the time inquiry to the transmission of the response by the server device 11 is so short that it can be ignored.

In this calculation example, the round-trip transmission time (= t _ps + t _pr = Tcr-Tcs) was the smallest among the five transmissions and receptions in the fifth transmission and reception (third column from the left in the figure). , See column 7). Therefore, according to the calculation method of the comparative example, the time difference Delta] t _e is calculated to -1.9996 seconds from the following equation, the actual time difference Δt (= - 2 seconds) the absolute value of the correction error for | Delta] t _e - Δt | is 0.0004 seconds. The time in brackets in the formula is expressed in hours: minutes: seconds (4 decimal places).

_{Δt e (5) = (Tcs} (5) + Tcr (5)) ÷ 2-Tm (5)
= ("15: 00: 04.0000" + "15: 00: 04.0026") / 2- "15: 00: 06.0009"
=-1.9996 (seconds)

On the other hand, of the five transmissions and receptions, the time difference (Tm-Tcs) of the time inquiry was the smallest in the third transmission and reception, and Tm (3) -Tcs (3) = 20008 seconds. .. The time difference (Tcr-Tm) of the answers was minimized in the fourth transmission / reception, where Tcr (4) -Tm (4) = 1.9994 seconds. Therefore, according to the calculation method of the embodiment, the time difference Delta] t _e is calculated to -2.0001 seconds from the following equation, the actual time difference Δt (= - 2 seconds) the absolute value of the correction error for | Delta] t _e - Δt | is 0.0001 seconds, which is smaller than that of the comparative example.

_{Δt e (4,3) = (Tcr} (4) -Tm (4)) ÷ 2
-(Tm (3) -Tcs (3)) / 2
= 1.9994 ÷ 2-2.0008 ÷ 2
= -2.001 (seconds)

[2. Second Embodiment]
[2-1. System 2 configuration]
FIG. 5 shows the system 2 according to the second embodiment. The system 2 includes a plurality of client devices 21 and a server device 22 connected via the network 100, and synchronizes the internal times of the plurality of client devices 21 with the server device 22.

[2-1-1. Client device 21]
The client device 21 is an example of the other device, and holds a local time set by the server device 22. The client device 21 has a timekeeping unit 210, an acquisition unit 211, a communication unit 213, and a control unit 214.

The timing unit 210 and the acquisition unit 211 may have the same configuration as the timing unit 110 and the acquisition unit 111 described above. However, the timekeeping unit 210 holds the local time in the client device 21.

The communication unit 213 receives the time inquiry from the server device 22, and transmits the response of the local time in the client device 21. The answer at the local time indicates the local time at the timing when the client device 21 receives the time inquiry or the timing when the answer is transmitted, and is processed as the answer at the other party's time as seen from the server device 22. The communication unit 213 may communicate with the server device 22 using the NTP protocol or the SNMP protocol.

The control unit 214 controls each unit in the client device 21. For example, the control unit 214 may manage the operation mode of the client device 21 so that the client device 21 can process the intermittent time inquiry from the server device 22. As an example, the control unit 214 may return the client device 21 from the power saving state to the normal state at an intermittent timing when the time inquiry is transmitted, and set the time inquiry standby state.

[2-1-2. Server device 22]
The server device 22 is an example of a processing device, and detects a time error with the client device 21. The server device 22 includes a timekeeping unit 220, an acquisition unit 221, a communication unit 223, a storage unit 224, a first determination unit 225, a second determination unit 226, and an error calculation unit 227. The server device 22 may further have a synchronization unit 229.

The timing unit 220 and the acquisition unit 221 may have the same configuration as the timing unit 120 and the acquisition unit 121 described above. However, the timekeeping unit 220 may hold the internal time in the server device 22. This internal time is a reference time for adjusting the time of the client device 21. The internal time of the server device 22 may be synchronized with the time held by another device (as an example, the time in Japan Standard Time), as in the first embodiment described above.

The communication unit 223 may have the same configuration as the communication unit 123 described above. However, the communication unit 223 transmits a time inquiry to the client device 21 and receives a response of the other party's time in the client device 21.

The storage unit 224 stores and stores the internal time at the transmission timing of the time inquiry and the reception timing of the response and the other party time included in the response for each of the plurality of exchanges of the time inquiry and the response for each client device 21. ..

The first determination unit 225, the second determination unit 226, and the error calculation unit 227 may have the same configuration as the first determination unit 125, the second determination unit 126, and the error calculation unit 127 described above.

The synchronization unit 229 transmits the time difference calculated by the error calculation unit 227 from the communication unit 223 to the client device 21 to synchronize the client device 21 with the internal time (reference time).

According to the server device 22 in the system 2 described above, in addition to being able to obtain the same effect as the client device 12 in the system 1, the client device 21 does not calculate the time difference, so that the client device 21 Power consumption can be suppressed.

The server device 22 may have a data processing unit that processes data received from the client device 21 (measurement data as an example) instead of the synchronization unit 229. Based on the time difference calculated by the error calculation unit 227, the data processing unit corrects the time included in the received data to the time at the internal time (reference time) of the server device 22. In this case, it is possible to eliminate the time lag between the data received from the plurality of client devices 21. Further, since the time is not adjusted by the client device 21, the power consumption of the client device 21 can be further suppressed.

[2-2. System 2 operation]
FIG. 6 shows the operation of the system. This operation may be performed periodically between the server device 22 and each client device 21, and may be performed, for example, at the timing when the client device 21 is in the standby state for time inquiry.

First, similarly to the processing of steps S101 and S201 described above, the server device 22 and the client device 21 perform time inquiry and response communication a plurality of times while acquiring the time from the timekeeping units 110 and 120 (steps S301 and S401). However, in this process, the server device 22 may send a time inquiry to the client device 21, and the client device 21 may return an answer.

Next, as in the process of step S203 described above, the first determination unit 225 of the server device 22 determines the other party time of the answer and the internal time when the time inquiry is transmitted for each of the first plurality of time inquiries. Of the differences, the smaller difference is preferentially used to determine the time difference for the time query (step S303). Further, similarly to the process of step S205 described above, the second determination unit 226 determines the difference between the internal time when the answer is received and the other party time of the answer for each of the second plurality of time inquiries. The time difference for the answer is determined by preferentially using the small difference (step S305).

Next, in the same manner as in the process of step S207 described above, the error calculation unit 227 has a time difference between the time inquiry calculated by the first determination unit 225 and the answer calculated by the second determination unit 226. Based on the above, the time difference between the server device 22 and the client device 21 is calculated (step S307).

Then, the synchronization unit 229 transmits the time difference calculated by the error calculation unit 227 from the communication unit 223 to the client device 21 (step S309), and the control unit 214 sends the client device 21 to the server device based on the received time difference. Synchronize with the internal time (reference time) of 22 (step S409). Similar to the process of step S209 described above, the synchronization unit 229 transmits the time difference calculated by the error calculation unit 227 before the estimated timing when the time difference between the server device 11 and the client device 12 exceeds the reference value. You may let me.

[3. Application example]
FIG. 7 shows an application example of the systems 1 and 2.

Systems 1 and 2 are so-called monitoring systems 3 that diagnose the structural performance of a plurality of structures 300. The monitoring system 3 includes a plurality of seismic sensors 31, one or more collection devices 33, and a data processing device 35, and the one or more collection devices 33 and the data processing device 35 are connected via the network 100. To.

At least one seismic sensor 31 is installed for each of the structure 300 as an object, and measures a physical quantity (acceleration as an example) when the structure 300 vibrates due to an earthquake or the like. Each seismic sensor 31 has, for example, a timekeeping unit 310, a sensor unit 311, a control unit 313, and a communication unit 315.

The timekeeping unit 310 is a circuit having a clock function, and holds time information inside. The timekeeping unit 310 may output the current time to the sensor unit 311 or the like.

The sensor unit 311 measures the physical quantity (acceleration as an example) of the structure 300. The sensor unit 311 may supply the measurement data to the control unit 313 together with the measurement time.

The control unit 313 controls each unit of the seismic sensor 31. For example, the control unit 313 may synchronize the time measuring unit 310 with respect to the internal time of the collecting device 33 in order to keep the plurality of seismic sensors 31 in a state of being synchronized with each other.

The communication unit 315 wirelessly communicates with the corresponding collection device 33. For example, the communication unit 315 may receive the measurement data from the control unit 313 and transmit it to the collection device 33. Further, the communication unit 315 may receive the time information from the collection device 33 and supply the time information to the control unit 313.

The one or more collection devices 33 wirelessly collect measurement data from the plurality of seismic sensors 31 and transmit the measurement data to the data processing device 35 via the network 100. The collecting device 33 may be the client device 12 in the system 1 or the client device 21 in the system 2.

The data processing device 35 receives the measurement data collected by one or a plurality of collecting devices 33 and performs various processes. For example, the data processing device 35 diagnoses the structural performance of the structure 300 by distributing and analyzing the received measurement data for each structure 300 and for each seismic sensor 31. The data processing device 35 may be the server device 11 in the system 1 or the server device 22 in the system 2.

According to the above monitoring system 3, since the plurality of collecting devices 33 and the plurality of seismic sensors 31 can be brought into a state of being synchronized with each other with high accuracy, the diagnostic accuracy of the structure 300 can be improved. For example, if the synchronization accuracy between the plurality of collecting devices 33 is low, the time information of the seismic sensor 31 will be different for each collecting device 33. In this case, for example, when an earthquake occurs, the structure 300 may be distorted to be larger / smaller than it actually is, and it may be diagnosed that a bend has occurred. By increasing the synchronization accuracy between the plurality of seismic sensors 31, such misdiagnosis can be prevented.

In the above installation example, the client devices 12 and 21 have been described as the collecting device 33 of the monitoring system 3, but a plurality of inverter devices that should be synchronized with each other may be used.

FIG. 8 shows an example of the configuration of the computer according to the present embodiment. The computer 1900 according to the present embodiment functions as an element of the client device 12, the server device 22, or a part thereof.

The computer 1900 according to the present embodiment is connected to the host controller 2082 by the input / output controller 2084 and the CPU peripheral portion having the CPU 2000, the RAM 2020, the graphic controller 2075, and the display device 2080 which are interconnected by the host controller 2082. It includes an input / output unit having a communication interface 2030, a hard disk drive 2040, and a DVD drive 2060, and a legacy input / output unit having a ROM 2010, a flash memory drive 2050, and an input / output chip 2070 connected to the input / output controller 2084. ..

The host controller 2082 connects the RAM 2020 to the CPU 2000 and the graphic controller 2075 that access the RAM 2020 at a high transfer rate. The CPU 2000 operates based on the programs stored in the ROM 2010 and the RAM 2020, and controls each part. The graphic controller 2075 acquires image data generated on a frame buffer provided in the RAM 2020 by the CPU 2000 or the like, and displays the image data on the display device 2080. Instead, the graphic controller 2075 may internally include a frame buffer for storing image data generated by the CPU 2000 or the like.

The input / output controller 2084 connects the host controller 2082 to the communication interface 2030, the hard disk drive 2040, and the DVD drive 2060, which are relatively high-speed input / output devices. The communication interface 2030 communicates with other devices via a network by wire or wirelessly. In addition, the communication interface functions as hardware for communication. The hard disk drive 2040 stores programs and data used by the CPU 2000 in the computer 1900. The DVD drive 2060 reads a program or data from the DVD 2095 and provides it to the hard disk drive 2040 via the RAM 2020.

Further, the ROM 2010, the flash memory drive 2050, and the relatively low-speed input / output device of the input / output chip 2070 are connected to the input / output controller 2084. The ROM 2010 stores a boot program executed by the computer 1900 at startup and / or a program depending on the hardware of the computer 1900. The flash memory drive 2050 reads a program or data from the flash memory 2090 and provides it to the hard disk drive 2040 via the RAM 2020. The input / output chip 2070 connects the flash memory drive 2050 to the input / output controller 2084, and inputs / outputs various input / output devices via, for example, a parallel port, a serial port, a keyboard port, a mouse port, and the like. Connect to controller 2084.

The program provided to the hard disk drive 2040 via the RAM 2020 is stored in a recording medium such as a flash memory 2090, a DVD 2095, or an IC card and provided by the user. The program is read from the recording medium, installed on the hard disk drive 2040 in the computer 1900 via the RAM 2020, and executed in the CPU 2000.

Programs installed on the computer 1900 that cause the computer 1900 to function as at least part of the client device 12 or the server device 22 include acquisition modules, communication modules, first decision modules, second decision modules, error calculation modules, and synchronization modules. It has at least one of them. These programs or modules act on the CPU 2000 or the like to transfer the computer 1900 to the acquisition unit 121, the communication unit 123, the first determination unit 125, the second determination unit 126, the error calculation unit 127, the synchronization unit 129, the acquisition unit 221 and the like. It may function as a communication unit 223, a first determination unit 225, a second determination unit 226, an error calculation unit 227, and a synchronization unit 229, respectively.

The information processing described in these programs is read into the computer 1900 to work on the CPU 2000 or the like, which is a concrete means in which the software and the various hardware resources described above cooperate with each other, to acquire the computer 1900. Unit 121, communication unit 123, first determination unit 125, second determination unit 126, error calculation unit 127, synchronization unit 129, acquisition unit 221, communication unit 223, first determination unit 225, second determination unit 226, error calculation. It functions as a unit 227 and a synchronization unit 229. Then, by realizing the calculation or processing of information according to the purpose of use of the computer 1900 in the present embodiment by these specific means, a unique equipment management system 1 according to the purpose of use is constructed.

As an example, when communicating between the computer 1900 and an external device or the like, the CPU 2000 executes a communication program loaded on the RAM 2020, and based on the processing content described in the communication program, a communication interface. Instruct 2030 to perform communication processing. Under the control of the CPU 2000, the communication interface 2030 reads the transmission data stored in the transmission buffer area or the like provided on the storage device such as the RAM 2020, the hard disk drive 2040, the flash memory 2090, or the DVD 2095, and transmits the transmission data to the network. Alternatively, the received data received from the network is written to a receive buffer area or the like provided on the storage device. As described above, the communication interface 2030 may transfer the transmitted / received data to / from the storage device by the DMA (direct memory access) method, and instead, the CPU 2000 may transfer the transfer source storage device or the communication interface 2030. The transmitted / received data may be transferred by reading the data from the data and writing the data to the communication interface 2030 or the storage device of the transfer destination.

Further, the CPU 2000 performs DMA all or necessary parts from files or databases stored in an external storage device such as a hard disk drive 2040, a DVD drive 2060 (DVD2095), and a flash memory drive 2050 (flash memory 2090). It is read into the RAM 2020 by transfer or the like, and various processes are performed on the data on the RAM 2020. Then, the CPU 2000 writes the processed data back to the external storage device by DMA transfer or the like. In such processing, the RAM 2020 can be regarded as temporarily holding the contents of the external storage device. Therefore, in the present embodiment, the RAM 2020 and the external storage device are collectively referred to as a memory, a storage unit, a storage device, or the like. For example, the client device 12 and the server device 22 may appropriately include a storage device that stores the data before, during, and after the processing of the present embodiment.

Various information such as various programs, data, tables, and databases in the present embodiment are stored in such a storage device and are subject to information processing. The CPU 2000 can also hold a part of the RAM 2020 in the cache memory and read / write on the cache memory. Even in such a form, the cache memory plays a part of the function of the RAM 2020. Therefore, in the present embodiment, the cache memory is also included in the RAM 2020, the memory, and / or the storage device, unless otherwise indicated. To do.

In addition, the CPU 2000 includes various operations, information processing, condition determination, information retrieval / replacement, and the like specified in the instruction sequence of the program for the data read from the RAM 2020. Is performed, and the data is written back to the RAM 2020. For example, when the CPU 2000 determines the condition, whether or not the various variables shown in the present embodiment satisfy the conditions such as large, small, above, below, and equal to other variables or constants. If the condition is satisfied (or if it is not satisfied), it branches to a different instruction sequence or calls a subroutine.

In addition, the CPU 2000 can search for information stored in a file in the storage device, a database, or the like. For example, when a plurality of entries in which the attribute value of the second attribute is associated with the attribute value of the first attribute are stored in the storage device, the CPU 2000 describes the plurality of entries stored in the storage device. By searching for an entry in which the attribute value of the first attribute matches the specified condition and reading the attribute value of the second attribute stored in that entry, it is associated with the first attribute that satisfies the predetermined condition. The attribute value of the second attribute obtained can be obtained.

Further, when a plurality of elements are listed in the description of the embodiment, elements other than the listed elements may be used. For example, when it is described that "X executes Y using A, B and C", X may execute Y using D in addition to A, B and C.

Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various changes or improvements can be made to the above embodiments. It is clear from the description of the claims that such modified or improved forms may also be included in the technical scope of the present invention.

For example, in the first and second embodiments described above, one of the processing device and the other device is described as the server devices 11 and 22, and the other is described as the client devices 12 and 21, but the first device and the first device of the same type are used. It may be the device of 2. Also in this case, the accuracy of calculating the time difference between the devices can be improved.

Further, although it has been described that the timing units 110 and 220 of the server devices 11 and 22 are synchronized with the time of another device by using GPS radio waves or standard radio waves, the client devices 12 and 21 have the same with respect to the server devices 11 and 22. It may be synchronized in the same way that it is synchronized. For example, the server devices 11 and 22 may be connected to another device via the network 100 and may be synchronized with the other device by the same processing as in FIGS. 2 and 6.

The order of execution of operations, procedures, steps, steps, etc. in the devices, systems, programs, and methods shown in the claims, specification, and drawings is particularly "before" and "prior to". It should be noted that it can be realized in any order unless the output of the previous process is used in the subsequent process. Even if the scope of claims, the specification, and the operation flow in the drawings are explained using "first", "next", etc. for convenience, it means that it is essential to carry out in this order. It's not a thing.

1 system, 2 systems, 3 monitoring system, 11 server equipment, 12 client equipment, 21 client equipment, 22 server equipment, 31 seismic sensor, 33 collection equipment, 35 data processing equipment, 100 networks, 110 timekeeping unit, 111 acquisition unit , 113 communication unit, 114 control unit, 120 timing unit, 121 acquisition unit, 123 communication unit, 124 storage unit, 125 first determination unit, 126 second determination unit, 127 error calculation unit, 129 synchronization unit, 210 timing unit, 211 Acquisition unit, 213 Communication unit, 214 Control unit, 220 Timekeeping unit, 221 Acquisition unit, 223 Communication unit, 224 Storage unit, 225 First determination unit, 226 Second determination unit, 227 Error calculation unit, 229 Synchronization unit, 300 Structure, 310 Timekeeping, 311 Sensor, 313 Control, 315 Communication, 1900 Computer, 2000 CPU, 2010 ROM, 2020 RAM, 2030 Communication Interface, 2040 Hard Disk Drive, 2050 Flash Memory Drive, 2060 DVD Drive, 2070 I / O Chip, 2075 Graphic Controller, 2080 Display, 2082 Host Controller, 2084 I / O Controller, 2090 Flash Memory, 2095 DVD

Claims (15)

A processing device that detects a time error with the other device.
An acquisition unit that acquires the internal time of the processing device,
A communication unit that sends a time inquiry to the other device via the network and receives an answer of the other time in the other device.
The first determination to determine the time difference for the time query by preferentially using the smaller difference among the differences between the other party time and the internal time for which the time query was sent for each of the first plurality of time queries. Department and
With the second determination unit that determines the time difference for the answer by preferentially using the smaller difference among the differences between the internal time that received the answer for each of the second multiple time inquiries and the other party's time. ,
An error calculation unit that calculates the time difference between the partner device and the processing device based on the time difference for the time inquiry and the time difference for the answer.
A synchronization unit that synchronizes the internal time with the other device based on the time difference calculated by the error calculation unit, and
Equipped with a,
The synchronization unit is a processing device that adjusts the time before the estimated timing at which the time difference between the partner device and the processing device exceeds the reference value . A processing device that detects a time error with the other device.
An acquisition unit that acquires the internal time of the processing device,
A communication unit that sends a time inquiry to the other device via the network and receives an answer of the other time in the other device.
The first determination to determine the time difference for the time query by preferentially using the smaller difference among the differences between the other party time and the internal time for which the time query was sent for each of the first plurality of time queries. Department and
With the second determination unit that determines the time difference for the answer by preferentially using the smaller difference among the differences between the internal time that received the answer for each of the second multiple time inquiries and the other party's time. ,
An error calculation unit that calculates the time difference between the partner device and the processing device based on the time difference for the time inquiry and the time difference for the answer.
A synchronization unit that transmits the time difference calculated by the error calculation unit from the communication unit to the other device to synchronize the other device with the internal time.
Equipped with a,
The synchronization unit causes the communication unit to transmit the time difference calculated by the error calculation unit to the other device before the estimated timing at which the time difference between the other device and the processing device exceeds the reference value. apparatus. The other device can process intermittent time queries and can handle intermittent time queries.
The processing device according to claim 2 , wherein the communication unit communicates with the other device at a timing when the other device enters a standby state for time inquiry. The error calculation unit calculates the time difference between the other device and the processing device based on the difference between the time difference for the time inquiry and the time difference for the answer, according to claims 1 to 3. The processing apparatus according to any one item. The first determination unit determines the smallest difference among a plurality of differences obtained by subtracting the internal time at which the time inquiry is transmitted from the other party time as the time difference for the time inquiry.
Any of claims 1 to 4, wherein the second determination unit determines the smallest difference among a plurality of differences obtained by subtracting the other party's time from the internal time at which the answer is received as the time difference for the answer. The processing apparatus according to one item. The processing apparatus according to any one of claims 1 to 5 , wherein the first plurality of time queries and the second plurality of time queries are the same. The processing apparatus according to any one of claims 1 to 5 , wherein at least a part of the first plurality of time queries and the second plurality of time queries are different. A data processing unit that processes data received from the other device is further provided.
The data processing unit
The processing apparatus according to any one of claims 1 to 7 , wherein the time included in the data is corrected to the time at the internal time based on the time difference calculated by the error calculation unit. One or more client devices as the processing device according to claim 1.
A system including a server device as the partner device. The server device as the processing device according to claim 2 and
A system including one or more client devices as the other device. The system according to claim 9 or 10 , wherein the one or more client devices are collection devices that collect measurement data from a plurality of seismic sensors. It is a processing method performed by a processing device that detects a time error with the other device.
The acquisition stage for acquiring the internal time in the processing device, and
A communication stage in which a time inquiry is sent to the other device via the network and a response of the other time in the other device is received.
The first determination to determine the time difference for the time query by preferentially using the smaller difference among the differences between the other party time and the internal time for which the time query was sent for each of the first plurality of time queries. Stages and
With the second determination step of determining the time difference for the answer by preferentially using the smaller difference among the differences between the internal time when the answer for each of the second multiple time inquiries is received and the other party's time. ,
An error calculation step for calculating the time difference between the partner device and the processing device based on the time difference for the time inquiry and the time difference for the answer.
A synchronization step of synchronizing the internal time with the partner device based on the time difference calculated by the error calculation step, and
Equipped with a,
In the synchronization stage, a processing method in which the time is adjusted before the estimated timing at which the time difference between the partner device and the processing device exceeds the reference value. It is a processing method performed by a processing device that detects a time error with the other device.
The acquisition stage for acquiring the internal time in the processing device, and
A communication stage in which a time inquiry is sent to the other device via the network and a response of the other time in the other device is received.
The first determination to determine the time difference for the time query by preferentially using the smaller difference among the differences between the other party time and the internal time for which the time query was sent for each of the first plurality of time queries. Stages and
With the second determination step of determining the time difference for the answer by preferentially using the smaller difference among the differences between the internal time when the answer for each of the second multiple time inquiries is received and the other party's time. ,
An error calculation step for calculating the time difference between the partner device and the processing device based on the time difference for the time inquiry and the time difference for the answer.
A synchronization step in which the time difference calculated by the error calculation step is transmitted to the other device to synchronize the other device with the internal time.
Equipped with a,
In the synchronization stage, a processing method in which the time difference calculated by the error calculation step is transmitted to the partner device before the estimated timing at which the time difference between the partner device and the processing device exceeds the reference value. The computer of the processing device that detects the time error with the other device,
An acquisition unit that acquires the internal time of the processing device,
A communication unit that sends a time inquiry to the other device via the network and receives an answer of the other time in the other device.
The first determination to determine the time difference for the time query by preferentially using the smaller difference among the differences between the other party time and the internal time for which the time query was sent for each of the first plurality of time queries. Department and
With the second determination unit that determines the time difference for the answer by preferentially using the smaller difference among the differences between the internal time that received the answer for each of the second multiple time inquiries and the other party's time. ,
An error calculation unit that calculates the time difference between the partner device and the processing device based on the time difference for the time inquiry and the time difference for the answer .
It is made to function as a synchronization unit that synchronizes the internal time with the partner device based on the time difference calculated by the error calculation unit .
The synchronization unit is a processing program that adjusts the time before the estimated timing when the time difference between the partner device and the processing device exceeds the reference value. The computer of the processing device that detects the time error with the other device,
An acquisition unit that acquires the internal time of the processing device,
A communication unit that sends a time inquiry to the other device via the network and receives an answer of the other time in the other device.
The first determination to determine the time difference for the time query by preferentially using the smaller difference among the differences between the other party time and the internal time for which the time query was sent for each of the first plurality of time queries. Department and
With the second determination unit that determines the time difference for the answer by preferentially using the smaller difference among the differences between the internal time that received the answer for each of the second multiple time inquiries and the other party's time. ,
An error calculation unit that calculates the time difference between the partner device and the processing device based on the time difference for the time inquiry and the time difference for the answer .
The time difference calculated by the error calculation unit is transmitted from the communication unit to the other device to cause the other device to function as a synchronization unit that synchronizes with the internal time.
The synchronization unit causes the communication unit to transmit the time difference calculated by the error calculation unit to the other device before the estimated timing at which the time difference between the other device and the processing device exceeds the reference value. program.

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