JPH11282812A - Distributed time matching device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a distributed time matching device which can reduce the load to be applied on a network and can assure the time synchronization accuracy as required. SOLUTION: A time notifying cycle management part 14 decides a transmitting cycle based on a maximum allowable error range set for a time error that is requested in a relevant distributed system which is managed by a maximum allowable error management part 12 and also on the maximum and minimum velocity ratios set between the speeds of clock devices of the slave stations 31 , 32 ...3n which are managed by a clock speed ratio management part 13 and the speed of a reference clock 11 of a master station. Based on the transmitting cycle decided at the part 14, a reference time transmitting part 15 transmits the value of the clock 11 as a reference time. Thus, the time errors occurring among the slave stations can be kept within a requested range with reduced load applied to a network 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distributed time adjusting apparatus for automatically adjusting the time of a plurality of stations, such as computers connected via a network, within a predetermined range in a distributed system. is there.

[0002]

2. Description of the Related Art FIG. 8 is a system configuration diagram for explaining an outline of time adjustment in a conventional distributed system. In the figure, 1 is a parent station, 2 is a network, 3 ₁ , 3 ₂ ,..., 3 _n are child stations. Reference numeral 11 denotes a reference clock in the parent station 1, and reference numeral 31 denotes each child station 3 ₁ , 3 ₂ ,.
The clock device in _n .

Next, the operation will be described. In the time adjustment in the conventional distributed system, the parent station 1 having the reference clock 11 is controlled at regular intervals (for example, every hour) based on a constant cycle at the reference time by the reference clock 11.
Time information is stored in child stations 3 ₁ , 3 ₂ ,..., 3 _n
Broadcast to. Each of the slave stations 3 ₁ , 3 ₂ ,..., 3 _n receiving the time information synchronizes the time of the entire distributed system by adjusting the time of the built-in clock device 31 to the time information. ing.

In general, the purpose of time adjustment between stations in such a distributed system is to use a network 2
Connected to the child station 3 _1, 3 _2, ...,
The main purpose is to clarify the temporal order of events that each of the 3 _n independently collected. In this case, the times managed by the child stations 3 ₁ , 3 ₂ ,..., 3 _n do not need to be equal to the standard time as much as possible, and the child stations 3 ₁ , 3 ₂ ,. The error of the time managed by _n is a specific time width required by the distributed system,
For example, the error may be within one minute or one millisecond.

[0005] For example, the child station with a clock unit 31 which travels faster at a rate of 1 millisecond to 1 second, and Tatoebako station 3 _1, children with a clock unit 31 which proceeds slowly at a rate of 1 millisecond to 1 second When the time of the clock device 31 is adjusted within a 1 ms error range between a station, for example, the child station 3 _n, it is necessary to broadcast the reference time at least once every 0.5 seconds. . in this case,
When broadcasting at the reference time is performed once every 0.1 second,
Time synchronization communication and time synchronization processing are performed more than necessary. If the broadcast communication of the reference time is performed once every two seconds, the required time error range will be exceeded.

The causes of such time errors are mainly caused by the child stations 3 ₁ , 3 ₂ ,.
.., 3 _n , the internal clock speed shift is almost constant at time intervals such as several hours or several days.

[0007] As a document describing a time setting device in such a conventional distributed system,
For example, there is JP-A-3-271959.

[0008]

[Problems that the Invention is to Solve Since conventional dispersion time adjustment device is constructed as described above, the speed of travel of the clock unit 31 of the child station 3 _1, 3 _2, ..., a 3 _n There from different respectively, it too becomes longer transmission period to broadcast the reference time from the master station 1, each child station 3 _1, 3 _2, ..., the shift of time between 3 _n greater Become each child station 3
₁ , 3 ₂ ,..., 3 _n will cause the temporal order of each other to be out of order, and if it is too short, not only will the load on the network 2 increase unnecessarily, but also each child station There were problems such as unnecessary time correction processing occurring at 3 ₁ , 3 ₂ ,..., 3 _n .

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and considers an error range required for the distributed system and a maximum variation width of clock speeds of stations connected to a network. Accordingly, it is an object of the present invention to obtain a distributed time adjustment device which can reduce a load on a network and guarantee required time synchronization accuracy.

In addition, the present invention dynamically responds to a change in the clock speed due to aging by dynamically measuring a change in the clock speed of each slave station and reflecting the value in the transmission cycle of the reference time. It is another object of the present invention to obtain a time setting device capable of performing the above-mentioned operations.

[0011]

According to the present invention, there is provided a distributed time adjusting apparatus, comprising: a maximum allowable error range of a time error required by the distributed system; Based on the maximum value and the minimum value of the speed ratio of the clock device of the child station to the speed of the reference clock managed by the slave station, the value of the reference clock is used as a reference in accordance with the transmission cycle determined by the time notification cycle management unit. By transmitting the time from the reference time transmission unit, the time difference between the child stations is suppressed within a required range with a small load on the network.

In the distributed time setting device according to the present invention, the clock speed ratio management unit of the parent station inputs the clock of the child station connected to the distributed system, which is input from the maximum speed ratio input means and the minimum speed ratio input means. The difference between the maximum speed ratio and the minimum speed ratio of the speed of the device with respect to the speed of the reference clock is calculated by the maximum speed ratio difference obtaining means, and is stored in the maximum speed ratio difference holding means as the maximum speed ratio difference. ,
The transmission cycle for transmitting the reference time is determined from the maximum speed ratio difference and the maximum allowable error range managed by the maximum allowable error management unit.

[0013] In the distributed time setting apparatus according to the present invention, the clock speed ratio management unit of the parent station holds the speeds of the clock devices of all the child stations connected to the distributed system, which are held by the speed ratio management means. For the speed ratio with respect to the speed of the reference clock, the difference between the maximum value and the minimum value of the speed ratio is obtained by the maximum speed ratio difference acquisition means, and the difference is stored in the maximum speed ratio difference holding means as the maximum speed ratio difference. The transmission cycle for transmitting the reference time is determined from the maximum speed ratio difference and the maximum allowable error range managed by the maximum allowable error management unit.

In the distributed time setting apparatus according to the present invention, the speed ratio acquisition management unit provided in the slave station uses the clock speed ratio acquisition means to determine the speed of the reference clock of the speed of the clock device of the slave station. By notifying the master station of the clock speed ratio, which is the speed ratio with respect to the master station, from the clock speed ratio notification means, the maximum value and the minimum value of the clock speed ratio can be determined without setting the clock speed ratio of each child station in advance. It is what is required.

[0015] In the distributed time setting device according to the present invention, the speed ratio change notification management unit provided in the child station may include:
The clock speed ratio of the slave station acquired by the clock speed ratio acquisition means is equal to the speed of the clock device of all slave stations connected to the distributed system and held by the maximum speed ratio holding means and the minimum speed ratio holding means. If the speed ratio is not between the maximum value and the minimum value of the speed ratio with respect to the speed of the reference clock, the clock speed ratio change notification means notifies the clock speed ratio management unit of the parent station of the change in the clock speed ratio, The speed change of the clock device of the child station can be detected by the parent station.

In the distributed time adjusting apparatus according to the present invention, the clock speed ratio management unit of the parent station uses the maximum speed ratio holding unit and the minimum speed ratio holding unit to control the clocks of all the child stations connected to the distributed system. The maximum value and the minimum value of the speed ratio of the speed of the device with respect to the speed of the reference clock are held, and the change in the clock speed ratio of the clock device of the child station is detected by the clock speed ratio change detection means, and the detected clock speed ratio is detected. If the changed speed ratio is larger than the maximum value of the held speed ratio, it is sent to the maximum high speed ratio holding means.If the changed speed ratio is smaller than the minimum value of the speed ratio, it is sent to the minimum high speed ratio holding means. And the difference between them is obtained by the maximum speed ratio difference acquiring means and stored in the maximum speed ratio difference holding means, whereby the notification cycle of the reference clock at the parent station can be recalculated. Those were Unishi.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a block diagram showing a configuration example of the distributed time setting device according to the first embodiment of the present invention. In the figure, reference numeral 1 denotes a parent station, such as a computer, that totally controls the processing in the distributed system.
Reference numeral 2 denotes a network of the distributed system to which the parent station 1 is connected. 3 ₁ , 3 ₂ , ..., 3 _n
Are a plurality of child stations such as computers connected to the network 2 respectively.

In the parent station 1,
Reference numeral 11 denotes a reference clock which is arranged in the parent station 1 and generates a reference time. Reference numeral 12 denotes each of the child stations 3 ₁ , 3 ₂ ,.
A maximum allowable error management unit that manages a maximum allowable error range that is the maximum value of the time error of the clock device during 3 _n ;
Is a maximum allowable error holding means in which the maximum allowable error range is stored. Reference numeral 13 denotes a clock speed ratio management for managing a difference between the maximum speed ratio and the minimum speed ratio of the speeds of the clock devices of the slave stations 3 ₁ , 3 ₂ ,..., 3 _n with respect to the speed of the reference clock 11. Numeral 131 denotes a maximum speed ratio difference holding means for storing a maximum speed ratio difference which is a maximum value of a difference between the maximum speed ratio and the minimum speed ratio.

Reference numeral 14 denotes a maximum allowable error range held by the maximum allowable difference holding means 121 of the maximum allowable error management section 12 and a maximum speed ratio difference held by the maximum speed ratio difference holding means 131 of the clock speed ratio management section 13. Thus, a time notification cycle management unit that determines a transmission cycle when the parent station 1 transmits the reference time, and 141 is a transmission cycle holding unit that stores the transmission cycle. Reference numeral 15 denotes a reference time transmission unit that broadcasts a reference time to each of the slave stations 3 ₁ , 3 ₂ ,..., 3 _n in accordance with the transmission cycle held by the transmission cycle holding unit 141 of the time notification cycle management unit 14. is there.

Next, the operation will be described. The clock speed ratio management unit 13 controls the speed of the clock device of each of the slave stations 3 ₁ , 3 ₂ ,..., 3 _n connected to the network 2 of the distributed system with respect to the speed of the reference clock 11. The difference between the maximum value and the minimum value of the ratio is held in the maximum speed ratio difference holding means 131 in advance as the maximum speed ratio difference. On the other hand, the maximum permissible error management unit 12, all the child stations 3 _1, 3 _2, ..., at the time difference between 3 _n, the maximum value allowed in the distributed system, in advance as the maximum permissible error range It is stored in the maximum allowable error storage unit 121.

When the distributed system is started, the time notification cycle management unit 14 first determines the value of the maximum speed ratio difference held in the maximum speed ratio difference holding unit 131 of the clock speed ratio management unit 13 and the maximum allowable error management unit. 12 maximum allowable error holding means 1
Then, the value of the maximum allowable error range held at 21 is read. Next, the reference clock 11 is obtained from the read values.
The maximum period for transmitting the reference time at which the error occurs is calculated and stored in the transmission period holding unit 141 as the transmission period.
The reference time transmitting unit 15 is activated at intervals of the transmission cycle stored in the transmission cycle holding unit 141, and reads the value of the reference clock 11 every time it is activated, and transmits the value to the network 2 as the reference time.

Next, the processing of the time notification cycle management unit 14 will be described. Here, FIG. 2 is a conceptual diagram for explaining the processing by the time notification cycle management unit 14. The horizontal axis t1 in the figure represents the elapsed time on the reference clock 11, and the vertical axis t1
Reference numeral 2 denotes a time difference between the time of the clock device having the maximum speed ratio difference and the time of the reference clock 11. Also, T is the time of the clock device having the speed of the maximum speed ratio difference α, the reference clock 1
1 is a graph showing the transition of the deviation from the time of 1, where Tm is the maximum allowable error range allowed for the distributed system;
Tc is the time from the moment when the clock having the maximum speed ratio difference α occurs to the time difference within the maximum allowable error range Tm.

Therefore, a relationship expressed by the following equation (1) is established between the time Tc and the maximum allowable error range Tm. Tm = α · Tc (1)

The value α of the maximum speed ratio difference stored in the maximum speed ratio difference holding means 131 of FIG.
The time notification cycle management unit 14 reads the value Tm in the range of the maximum permissible error stored in 21 and performs the operation of the above equation (1) to obtain the time Tc. Time notification cycle management unit 14
Stores the calculated time Tc in the transmission cycle holding means 141 as the transmission cycle of the reference time. The reference time transmission unit 15 is activated according to the transmission time Tc of the reference time stored in the transmission period holding means 141,
Is transmitted to the network 2.

As described above, according to the first embodiment,
The maximum allowable error range required for the distributed system held in the maximum allowable error management unit 12 and the child stations 3 ₁ , 3 ₂ connected to the distributed system held in the clock speed ratio management unit 13 , ..., 3 from the maximum value of the difference between the maximum value and the minimum value of the speed ratio of the clock unit of _n, each child station 3 ₁ than the parent station 1, 3 _2,..
.., 3 _n It is possible to obtain the maximum value of the transmission cycle of the reference time for transmission, and each child station 3 ₁ , 3 ₂ ,.
, 3 _n can be suppressed to a required value or less with a small load on the network 2.

Embodiment 2 FIG. FIG. 3 is a block diagram showing a configuration example of a main part of a distributed time setting apparatus according to Embodiment 2 of the present invention. In the figure, 12 is a maximum allowable error management unit, 121 is a maximum allowable error holding unit, 13 is a clock speed ratio management unit, 131 is a maximum speed ratio difference holding unit, 14 is a time notification cycle management unit, and 141 is a transmission cycle holding unit. These are the same parts as those of the first embodiment, which are indicated by the same reference numerals in FIG. 1, and thus detailed description is omitted.

The reference numeral 132 designates the maximum speed ratio, which is the maximum value of the speed ratio of the speed of the fastest traveling speed among the clock devices of all the slave stations connected to the distributed system, to the speed of the reference clock. The maximum speed ratio input means 133 is input from the terminal. 133 is a minimum speed ratio which is the minimum value of the speed ratio of the speed of the clock device of each slave station to the speed of the reference clock. Is a minimum speed ratio input means for inputting from the.
134, a maximum speed ratio difference is obtained from the difference between the maximum speed ratio input by the maximum speed ratio input means 132 and the minimum speed ratio input by the minimum speed ratio input means 133, and the difference is obtained. This is a maximum speed ratio difference acquisition unit stored in the difference holding unit 131.

Next, the operation will be described. The maximum speed ratio input means 132 of the clock speed ratio management unit 13 uses an external terminal in advance to determine the speed of the clock that advances the fastest among the clock devices of all the child stations connected to the distributed system. Enter the speed ratio to speed,
It is held as the maximum speed ratio. Similarly, the minimum speed ratio input means 133 also inputs in advance the speed ratio of the slowest clock speed of the clock device of each child station to the speed of the reference clock from the external terminal, and inputs the minimum speed ratio. As hold. The maximum speed ratio difference acquisition unit 134 reads the values of the maximum speed ratio held by the maximum speed ratio input unit 132 and the minimum speed ratio held by the minimum speed ratio input unit 133 when the distributed system is started, The difference between the maximum speed ratio and the minimum speed ratio is calculated and stored in the maximum speed ratio difference holding means 131 as the maximum speed ratio difference.

Next, the time notification cycle management unit 14 compares the value of the maximum allowable error range stored in the maximum allowable error holding unit 121 of the maximum allowable error management unit 12 with the maximum speed ratio of the clock speed ratio management unit 13. From the value of the maximum speed ratio difference stored in the difference holding means 131, a cycle for transmitting the reference time is calculated, and the calculated cycle is stored in the transmission cycle holding means 141 as a transmission cycle.

As described above, according to the second embodiment,
The maximum speed ratio and the minimum speed ratio among the speed ratios of the clock devices of all the slave stations connected to the distributed system with respect to the reference clock are input, and the maximum speed ratio of the clock device of the slave station obtained from the difference is input. From the difference and the maximum allowable error range allowed for the distributed system, it is possible to determine the period for transmitting the reference time, and to reduce the time difference between the child stations with a small load on the network 2,
The effect of being able to be suppressed below the required value is obtained.

Embodiment 3 FIG. 4 is a block diagram showing a configuration example of a main part of a distributed time adjustment device according to a third embodiment of the present invention. The corresponding parts are denoted by the same reference numerals as in FIG. 3 and description thereof is omitted. In the figure, reference numeral 135 denotes a speed ratio of the speed of each clock device to the speed of the reference clock, which is measured in advance for the clock devices of all the slave stations connected to the distributed system, is input from an external terminal and is stored. It is a speed ratio management means for managing.

Next, the operation will be described. The speed ratio management means 135 of the clock speed ratio management unit 13 inputs, from an external terminal, the speed ratio of the speeds of the clock devices of all the slave stations connected to the distributed system to the speed of the reference clock, and inputs them. Maintained and managed for each child station. That is, the speed ratio management means 135 stores the speed ratio of each slave station as a measurement result measured in advance. When the distributed system is started, the maximum speed ratio difference acquisition unit 134 starts the speed ratio management unit 1.
With reference to 35, the maximum value and the minimum value of the speed ratios stored therein are detected, and the difference is stored in the maximum speed ratio difference holding means 131 as the maximum speed ratio difference.

Next, the time notification cycle management unit 14 compares the value of the maximum allowable error range stored in the maximum allowable error holding unit 121 of the maximum allowable error management unit 12 with the maximum speed ratio of the clock speed ratio management unit 13. From the value of the maximum speed ratio difference stored in the difference holding means 131, a cycle for transmitting the reference time is calculated, and the calculated cycle is stored in the transmission cycle holding means 141 as a transmission cycle.

As described above, according to the third embodiment,
The maximum speed ratio difference of the clock device of the child station, obtained from the difference between the maximum value and the minimum value of the speed ratio of the clock device to the reference clock of all the child stations connected to the distributed system that is being maintained and managed. The period for transmitting the reference time can be determined from the maximum allowable error range allowed for the distributed system, and the time difference between the child stations is required with a small load on the network 2. The effect of being able to be suppressed below the value is obtained.

Embodiment 4 FIG. FIG. 5 is a block diagram showing a configuration example of a main part of a distributed time setting apparatus according to Embodiment 4 of the present invention. In the figure, 1 is a parent station, 2
Is a network, and 13 is a clock speed ratio management unit in the parent station 1. These units are the same as those shown in FIG. 3 is the symbol 3 ₁ , 3 ₂ ,
.., 3 _n are representatively displayed of a plurality of child stations indicated by 3 _n , and 31 is arranged in the child station 3 and generates a time used in the child station 3. It is a clock device.

Reference numeral 321 denotes a reference time acquisition and holding means for acquiring the reference time of the reference clock of the parent station 1 at a fixed cycle by the clock device 31 of the child station 3 and holding the reference time. 322 is a child station 3
The clock device 31 of the child station 3 with respect to the speed at which the reference clock of the parent station 1 advances, based on the fixed period of the clock device 31 and the elapsed time based on the reference time acquired from the parent station 1 by the reference time acquisition holding means 321 Clock speed ratio acquiring means for acquiring a clock speed ratio which is a speed ratio of a moving speed of the vehicle. 323 is the clock speed ratio acquisition means 3
This is a clock speed ratio notifying unit that notifies the clock speed ratio management unit 13 of the parent station 1 of the clock speed ratio acquired at 22. Reference numeral 32 denotes a reference time acquisition and holding unit 321, a clock speed ratio acquisition unit 322, and a clock speed ratio notification unit 323.
It is a speed ratio acquisition management unit provided with:

Next, the operation will be described. The speed ratio acquisition management unit 32 of the slave station 3 firstly operates the clock device 3 of the slave station 3 by the reference time acquisition and holding unit 321.
1 at a fixed cycle, the master station 1 sends a request for transmission of the standard time to the parent station 1 and holds the acquired reference time of the parent station 1. The reference time acquisition and holding means 3
The communication for obtaining the reference time by 21 is performed a plurality of times. The speed ratio acquisition management unit 32 then uses the clock speed ratio acquisition unit 322 to determine the clock device of the child station 3 based on the difference between the reference time last acquired by the reference time acquisition and holding unit 321 and the previously acquired reference time. The elapsed time of the reference time at the parent station 1 in the period of the fixed cycle at 31 is determined. Thereby, the clock device 31 of the child station 3 with respect to the speed of the reference clock of the parent station 1
To get the clock speed ratio with the speed of. Next, the speed ratio acquisition management unit 32 notifies the clock speed ratio management unit 13 of the parent station 1 via the network 2 of the clock speed ratio acquired by the clock speed ratio acquisition unit 322 by the clock speed ratio notification unit 323. I do.

According to the above procedure, the clock speed ratios of the clock devices 31 of all the slave stations 3 are transmitted to the clock speed ratio management unit 13 of the parent station 1.

As described above, according to the fourth embodiment,
By measuring the clock speed ratio of the clock device 31 of the child station 3 and notifying the parent station 1, the maximum value and the minimum value of the clock speed ratio can be set without setting the speed ratio of the clock device 31 of each child station 3 in advance. And the time difference between the slave stations 3 can be suppressed to a required value or less with a small load on the network 2.

Embodiment 5 FIG. 6 is a block diagram showing a configuration example of a main part of a distributed time adjustment device according to a fifth embodiment of the present invention. The corresponding parts are denoted by the same reference numerals as in FIG. In the figure, reference numeral 331 denotes a transmission cycle holding unit for holding a transmission cycle at which the parent station 1 transmits the reference time. Reference numeral 332 holds, as the maximum speed ratio, the maximum value of the speed ratio of the clock device 31 of the child station 3 to the reference clock speed of the parent station 1 used by the parent station 1 to determine its transmission cycle. A maximum speed ratio holding unit 333 is a minimum speed ratio holding unit that holds the minimum value of the speed ratio as a minimum speed ratio.

334 is the clock device 31 of the child station 3
Clock speed ratio acquiring means for acquiring a clock speed ratio which is a speed ratio of the speed of the parent station 1 with respect to the reference clock. Reference numeral 335 denotes the clock speed ratio acquired by the clock speed ratio acquiring means 334, and the maximum speed ratio is held. The clock speed for notifying the change of the clock speed ratio to the clock speed ratio management unit 13 of the parent station 1 when the speed ratio becomes equal to or higher than the maximum speed ratio held by the means 332 or lower than the minimum speed ratio held by the minimum speed ratio holding means 333. This is a ratio change notification unit. Reference numeral 33 denotes a speed ratio change management unit (speed ratio change notification unit) including the transmission cycle holding unit 331, the maximum speed ratio holding unit 332, the minimum speed ratio holding unit 333, the clock speed ratio acquisition unit 334, and the clock speed ratio change notification unit 335. Management section).

Next, the operation will be described. The speed ratio change management unit 33 of the child station 3 stores the transmission cycle at which the parent station 1 transmits the reference time in the transmission cycle holding unit 33.
Hold at 1. At that time, the maximum speed ratio of the speed of the clock device 31 of the child station 3 to the speed of the reference clock of the parent station 1 used by the parent station 1 to determine the transmission cycle is stored in the maximum speed ratio holding means 332.
The minimum speed ratio is held in the minimum speed ratio holding means 333, respectively.

Next, the speed ratio change manager 33 activates the internal clock speed ratio acquisition means 334 every time the reference time is received from the parent station 1. The clock speed ratio acquisition unit 334 that has been activated measures the speed of the clock device 31 of the slave station 3 in a fixed period of the reference time by acquiring the time at the clock device 31 and determines the speed of the reference clock with respect to the advance speed of the reference clock. A clock speed ratio, which is a speed ratio of the speed at which the clock device 31 of the slave station 3 advances, is determined.

Next, the speed ratio change management unit 33 uses the clock speed ratio change notification unit 335 to store the clock speed ratio obtained by the clock speed ratio acquisition unit 334 into the maximum speed ratio holding unit 3.
32 and the minimum speed ratio held by the minimum speed ratio holding means 333. As a result, if the clock speed ratio is larger than the maximum speed ratio or smaller than the minimum speed ratio, the clock speed ratio change notification unit 335 determines that the clock speed ratio of the distributed system has changed, and The clock speed ratio is notified to the clock speed ratio management unit 13 of the parent station 1 via the network 2.

As described above, according to the fifth embodiment,
When the speed ratio of the clock device 31 of the child station 3 is equal to or more than the maximum speed ratio or equal to or less than the minimum speed ratio, the change of the clock speed ratio is notified to the parent station 1 to change the speed of the clock device 31 of the child station 3. Can be dynamically detected by the parent station 1, and an effect of being able to cope with a change in clock speed due to aging is obtained.

Embodiment 6 FIG. FIG. 7 is a block diagram showing a configuration example of a main part of a distributed time setting apparatus according to a sixth embodiment of the present invention. The corresponding parts are denoted by the same reference numerals as in FIG. 3 and description thereof is omitted. In the figure, reference numeral 136 denotes maximum speed ratio holding means for holding the maximum value of the speed ratio of the clock devices of all the slave stations connected to the distributed system to the speed of the reference clock of the parent station as the maximum speed ratio. Reference numeral 137 denotes a minimum speed ratio holding unit that holds the minimum value of the speed ratio of the upper standard child station clock device to the reference clock speed of the parent station as the minimum speed ratio. 138 detects a change in the clock speed ratio of the clock device of the child station, and if the detected changed speed ratio is larger than the maximum speed ratio, the maximum speed ratio holding means 136
Is rewritten with the value of the changed speed ratio. If the changed speed ratio is smaller than the minimum speed ratio, the minimum speed ratio holding means 137
Is a clock speed ratio change detecting means for rewriting the contents of the above with the value of the change speed ratio.

Next, the operation will be described. Clock speed ratio change detecting means 138 provided in clock speed ratio management unit 13
Monitors the notification of the change in the clock speed ratio from the child station. The clock speed ratio change detecting means 138 that has detected the change in the clock speed ratio of the slave station is stored in the detected changed speed ratio and the maximum speed ratio and the minimum speed ratio holding means 137 held by the maximum speed ratio holding means 136. Comparison with the minimum speed ratio. As a result, if the detected change speed ratio is larger than the maximum speed ratio held by the maximum speed ratio holding means 136, the content of the maximum speed ratio holding means 136 is updated with the value of the change speed ratio. If the detected change speed ratio is smaller than the minimum speed ratio held by the minimum speed ratio holding unit 137, the content of the minimum speed ratio holding unit 137 is updated with the value of the changed speed ratio.

Next, the maximum speed ratio difference acquisition unit 134 provided in the clock speed ratio management unit 13 sets the maximum speed ratio newly set in the maximum speed ratio holding unit 136 and the minimum speed ratio holding unit 137 in the minimum speed ratio holding unit 137. The difference from the obtained minimum speed ratio is obtained, and the difference is stored in the maximum speed ratio difference holding means 131 as the maximum speed ratio difference. From the maximum speed ratio difference newly set in the maximum speed ratio difference holding unit 131 and the maximum allowable error range held in the maximum allowable error holding unit 121 by the maximum allowable error management unit 12, the time notification cycle management unit 14 The transmission cycle of the reference time is calculated and stored in the transmission cycle holding means 141.

As described above, according to the sixth embodiment,
The change in the speed ratio of the clock device of the slave station can be dynamically detected at the master station, and the value is reflected in the recalculation of the notification cycle of the reference clock, thereby changing the clock speed due to aging. Is obtained.

[0050]

As described above, according to the present invention, the maximum allowable error range required for the distributed system, the maximum value and the minimum value of the speed ratio of the clock device of the child station connected to the distributed system. Values, and based on them, based on the error range allowed for the distributed system and the maximum variation width of the speed, the transmission cycle of the reference time for transmission is considered. The maximum value can be obtained, the load on the network is small, and there is an effect that a distributed time adjustment device that can guarantee required time synchronization accuracy is obtained.

According to the present invention, the maximum speed ratio and the minimum speed ratio of the speed ratios of the clock devices of all the stations connected to the distributed system with respect to the speed of the reference clock are input and those speed ratios are input. Since the difference is obtained and held as the maximum speed ratio difference, the reference time is transmitted from the maximum speed ratio difference of the clock device of the child station and the maximum allowable error range allowed for the distributed system. The period can be determined, and the time difference between the child stations can be kept within a required range with a small load on the network.

According to the present invention, the speeds of the clock devices of all the child stations connected to the distributed system are
The speed ratio to the speed of the reference clock is held, the difference between the maximum value and the minimum value is obtained, and the difference is held as the maximum speed ratio difference. It is possible to determine the cycle of transmitting the reference time from the maximum allowable error range allowed for the distributed system, and the time difference between the child stations is required with a small load on the network. There is an effect that can be kept within the range.

According to the present invention, at the child station,
Since the clock speed ratio, which is the speed ratio of the speed of the clock device to the speed of the reference clock, is measured and notified to the parent station, without setting the speed ratio of the clock of each child station in advance, The maximum value and the minimum value of the clock speed ratio can be obtained, and there is an effect that the time difference between the child stations can be kept within a required range with a small load on the network.

According to the present invention, the clock speed ratio of the speed of the clock device of the child station to the speed of the reference clock is:
If the change in the clock speed ratio is notified to the parent station when it is higher than or equal to the held maximum speed ratio or lower than the minimum speed ratio, the change in the speed of the clock device of the child station is transmitted to the parent station. Can be dynamically detected, and there is an effect of being able to cope with a change in clock speed due to aging.

According to this invention, the clock device of all the slave stations connected to the distributed system, wherein the change speed ratio of the clock speed ratio detected by the clock speed ratio change detection means is held by the maximum speed ratio holding means. If the speed is larger than the maximum value of the speed ratio with respect to the speed of the reference clock, the maximum speed ratio holding means is updated with that value, and if the speed is smaller than the minimum value held by the minimum speed ratio holding means, the minimum speed ratio holding means is updated. By updating with that value and holding the difference as the maximum speed ratio difference, a change in the speed ratio of the clock device of the child station can be dynamically detected by the parent station, and the By reflecting the value in the recalculation of the notification cycle of the reference clock, there is an effect that it is possible to cope with a change in clock speed due to aging.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of a distributed time setting device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing processing of a time notification cycle management unit according to the first embodiment.

FIG. 3 is a block diagram showing a configuration example of a main part of a distributed time setting device according to a second embodiment of the present invention;

FIG. 4 is a block diagram showing a configuration example of a main part of a distributed time setting device according to a third embodiment of the present invention;

FIG. 5 is a block diagram showing a configuration example of a main part of a distributed time setting device according to a fourth embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration example of a main part of a distributed time setting device according to a fifth embodiment of the present invention.

FIG. 7 is a block diagram showing a configuration example of a main part of a distributed time setting device according to a sixth embodiment of the present invention.

FIG. 8 is a system configuration diagram for explaining an outline of time adjustment in a conventional distributed system.

[Explanation of symbols]

1 parent station, 2 networks, 3, 3 ₁ , 3
₂ , ..., 3 _n child stations, 11 reference clocks,
12 maximum allowable error management unit, 13 clock speed ratio management unit,
14 time notification cycle management unit, 15 reference time transmission unit, 3
1 clock device, 32 speed ratio acquisition management unit, 33 speed ratio change management unit (speed ratio change notification management unit), 131 maximum speed ratio difference holding unit, 132 maximum speed ratio input unit, 133
Minimum speed ratio input means, 134 maximum speed ratio difference acquisition means, 135 speed ratio management means, 136,332 maximum speed ratio holding means, 137,333 minimum speed ratio holding means,
138 Clock speed ratio change detection means, 321 Reference time acquisition holding means, 322, 334 Clock speed ratio acquisition means, 3
23 Clock speed ratio notification means, 335 Clock speed ratio change notification means.

Claims (6)

[Claims] 1. A distributed system connected to a parent station having a reference clock for providing a reference time via a network, wherein a plurality of child stations each having a clock device are connected to the master station at the time of the reference clock. In a distributed time adjustment device that adjusts the time of the clock device of each slave station within a predetermined range, a maximum allowable error management unit that manages a maximum allowable error range of a time error allowed in the distributed system; A clock speed ratio management unit that manages a maximum speed ratio difference that is a maximum value of a difference between a maximum speed ratio and a minimum speed ratio of a speed of the clock device included in each of the slave stations with respect to a speed, and the maximum allowable error management unit. The parent station transmits the reference time from the maximum allowable error range managed by the master station and the maximum speed ratio difference managed by the clock speed ratio management unit. A time notification cycle management unit that determines a cycle to be performed, according to the cycle determined by the time notification cycle management unit,
A reference time transmitting unit for broadcasting to each slave station the value of the reference clock as a reference time. 2. A clock speed ratio management unit of a parent station, wherein a maximum speed which is a speed ratio of a speed of a clock device of a child station connected to the distributed system which is advancing fastest to a speed of a reference clock. A maximum speed ratio input means for inputting a speed ratio; and a minimum speed ratio input means for inputting a minimum speed ratio which is a speed ratio of a speed of a slowest moving speed of the timepiece device to a speed of the reference clock. A maximum speed ratio difference obtaining unit that obtains a maximum speed ratio difference by obtaining a difference between the maximum speed ratio and the minimum speed ratio, and a maximum speed ratio difference holding unit that holds the maximum speed ratio difference. The distributed time adjustment device according to claim 1, wherein 3. The clock speed ratio management unit of the parent station, for the clock devices of all the child stations connected to the distributed system, maintains the speed ratio of the speed of each clock device to the speed of the reference clock. Ratio management means, the speed ratio held by the speed ratio management means, a maximum speed ratio difference obtaining means for obtaining a maximum speed ratio difference by obtaining a difference between a maximum value and a minimum value, the maximum speed ratio difference 2. The distributed time setting device according to claim 1, further comprising a maximum speed ratio difference holding unit that holds the difference. 4. A reference time acquisition and holding means for acquiring a reference time of a parent station at a fixed cycle in a clock device of the child station, and holding the reference time in each child station; The clock speed ratio, which is the speed ratio of the speed of the clock device of the child station to the speed of the reference clock of the parent station, based on the constant period of the clock and the elapsed time based on the reference time acquired by the reference time acquisition and holding means. And a clock speed ratio notifying unit that notifies the clock speed ratio managing unit of the parent station of the clock speed ratio obtained by the clock speed ratio obtaining unit. The distributed time setting device according to claim 1, further comprising: 5. A maximum speed ratio holding means for holding, as a maximum speed ratio, a maximum speed ratio in each slave station as a maximum speed ratio of a speed of the clock device of the slave station to a speed of a reference clock of the parent station; A minimum speed ratio holding unit that holds a minimum value of the clock speed as a minimum speed ratio; a clock speed ratio obtaining unit that obtains a clock speed ratio of a speed of the clock device of the child station to a speed of a reference clock of the parent station; When the clock speed ratio acquired by the clock speed ratio acquisition means is equal to or greater than the maximum speed ratio or equal to or less than the minimum speed ratio, a clock speed ratio that notifies a change in the clock speed ratio to a clock speed ratio management unit of the parent station. 2. The distributed time setting device according to claim 1, further comprising a speed ratio change notification management unit including a change notification unit. 6. A clock speed ratio management unit of a parent station, wherein a maximum value which is a maximum value of a speed ratio of clock devices of all child stations connected to the distributed system with respect to a speed of a reference clock of the parent station is provided. A maximum speed ratio holding unit that holds a speed ratio; a minimum speed ratio holding unit that holds a minimum speed ratio that is a minimum value of the speed ratio; anda change in the speed ratio of the clock device of the slave station is detected and detected. If the changed speed ratio is larger than the maximum speed ratio, the value of the maximum speed ratio holding means is rewritten with the value, and if the changed speed ratio is smaller than the minimum speed ratio, the value is used as the minimum speed ratio. Clock speed ratio change detecting means for rewriting the contents of the holding means; and a difference between a maximum speed ratio held by the maximum speed ratio holding means and a minimum speed ratio held by the minimum speed ratio holding means. And a maximum speed ratio difference acquiring means for acquiring a Umate maximum speed ratio difference, dispersion time adjustment device according to claim 1, characterized in that it comprises a maximum speed ratio value holding means for holding the maximum speed ratio difference.