JP2834895B2 - Network system time adjustment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
Area network),
In a system including a plurality of stations each having a clock (a unit or device having an information processing function), the present invention relates to a time adjusting device for synchronizing the clocks of the stations. In the drawings, the same reference numerals indicate the same or corresponding parts.

[0002]

2. Description of the Related Art FIG. 5 shows a main structure of a conventional system of this kind. In FIG. 1, reference numeral 3 denotes a network such as a LAN (local area network), and reference numerals 1 and 2 denote stations (that is, units or devices having an information processing function) connected by the network 3; A station (referred to as a station with a master clock for convenience) and 2 is a station having a slave clock 21 (referred to as a station with a slave clock for convenience). Reference numeral 13 denotes a time information transmitting unit in the master clock station 1 and reference numeral 24 denotes a time information receiving unit in the slave clock station 2. In such a system, a time adjustment method for synchronizing the clocks of the stations 1 and 2 is as follows. The time information is transmitted from the master clock 11 to the slave clock 21 via the time information transmitting unit 13, the network 3, and the time information receiving unit 24. And the time is adjusted.

[0003]

However, in the conventional method, time information is transmitted from a master clock to a slave clock via a network system such as a LAN (local area network) to perform time adjustment. Transmission time delay and dispersion of transmission time on the system,
Alternatively, there is a problem in that the accuracy of time synchronization is poor and a time error between clocks is large due to a transmission time delay due to a retry operation at an abnormal time. Therefore, an object of the present invention is to provide a time setting device for a network system that can solve this problem.

[0004]

According to a first aspect of the present invention, there is provided a time setting apparatus comprising: a plurality of first stations (1 and the like) having a master clock (11 and the like); 21) and a plurality of second stations (2
In a system where each of the stations can communicate data via a common network (3 or the like) such as a LAN, a time synchronization pulse (TP) is provided between the first and second stations. The first station is provided with a dedicated signal line for transmission (such as 4), and the first station is provided with synchronous pulse transmitting means (time synchronous pulse) for transmitting a time synchronous pulse to the dedicated signal line at a predetermined cycle based on the master clock. Signal output unit 12) and time information transmitting means (time information transmitting unit 13 and the like) for transmitting time information (TD and the like) at the time of transmission of the time synchronization pulse obtained from the master clock to the network each time the pulse is transmitted. And the connection between the synchronization pulse transmitting means and the dedicated signal line and the connection between the time information transmitting means and the network are collectively opened. Switching means (output gate section 14,
15), wherein the second station synchronizes with the time synchronization pulse received from the dedicated signal line, and obtains the time of its own slave clock from the time information received from the network. Time setting means (time synchronization pulse input unit 23, time information receiving unit 24, time setting unit 22, etc.) to match the time of the master clock at the time of reception
Opening / closing control means (gate control unit 5) for selecting one of the first stations and closing only the opening / closing means of the selected first station.
Etc.)

According to the time adjusting device of the second aspect, the first aspect
In the time setting device according to the above, "the first station shares one master clock",

According to a third aspect of the invention, there is provided a time adjusting apparatus comprising: a plurality of first stations having a master clock or a slave clock (stations 1A with master / slave clock, etc.), at least one of which has a master clock. The first one that is
And a plurality of second stations having slave clocks, wherein each of the stations can exchange data via a common network such as a LAN. A first synchronization signal transmitting means for transmitting a time synchronization pulse to the dedicated signal line at a predetermined cycle based on a master clock which the first station can have. A time information transmitting means for transmitting time information of the time synchronization pulse transmission time obtained from the master clock which the own clock can have to the network every time the pulse is transmitted, and a time synchronization pulse received from the dedicated signal line. The time of the master clock or slave clock of the time synchronization clock obtained from the time information received from the network. Time setting means for adjusting to the time of the synchronization master clock of the system outside of the reception time point, connection of the synchronization pulse transmission means to the dedicated signal line, and connection of the time information transmission means to the network First opening / closing means (output gate units 14, 1) for opening and closing all at once
5) and second opening / closing means (such as input gates 16 and 17) for simultaneously opening and closing the connection between the time setting means and the dedicated signal line and the network.
Is provided with the time setting means, further selects one of the first stations having a master clock, closes the first opening / closing means of the selected first station, and sets the Opening the second opening / closing means, and closing the second opening / closing means of the first station and the first opening of the station;
Opening / closing control means (gate control unit 5 etc.) for opening the opening / closing means of the

According to a fourth aspect of the present invention, there is provided a time adjusting apparatus comprising: a plurality of first stations having a common master clock and individual slave clocks (stations 1A with a master / slave clock) and a plurality of second stations having slave clocks. A system in which each of the stations can exchange data via a common network such as a LAN. In the system, a dedicated signal line for transmitting a time synchronization pulse is provided between the first station and the second station. The first station comprises: a synchronization pulse transmitting means for transmitting a time synchronization pulse to the dedicated signal line at a predetermined cycle based on the master clock; and A time information transmitting means for transmitting time information at the time of transmitting the time synchronous pulse; and a time information transmitting means for synchronizing with the time synchronous pulse received from the dedicated signal line. Time setting means for adjusting the time of the slave clock having the time to the time of the master clock at the time of receiving the time synchronization pulse obtained from the time information received from the network, and connecting the synchronization pulse transmitting means to the dedicated signal line; A first opening / closing means (such as output gates 14 and 15) for simultaneously opening and closing the connection between the time information transmitting means and the network; and a simultaneous connection between the time setting means and the dedicated signal line and the network. And second opening / closing means (such as input gates 16 and 17) for opening and closing, and the second station includes the time setting means, and further selects one of the first stations. Closing of the first opening / closing means of the selected first station, opening of the second opening / closing means of the selected station, and other first stations And those with an opening and closing control means for causing the open circuit of the first opening and closing means closed and said station of said second switching means of emissions (such as gate control unit 5). "

[0009]

A station having a dedicated line for a time synchronization pulse signal in addition to a network such as a LAN, and having a master clock,
A time synchronization pulse signal from the master clock is output to a dedicated line, and time information is transmitted to the network in synchronization with the signal. The station having the slave clock receives the time information from the network and sets the time on the slave clock in synchronization with the time synchronization pulse signal input from the dedicated line.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing a main part of an embodiment according to the first aspect of the present invention. In FIG. 1, the output gate unit 1 is connected to the network 3 and the time synchronization pulse signal line 4 respectively.
A plurality (two in this example) of stations 1 with a master clock connected via the master clocks 5 and 14 are provided, and any one of the output gates 14 and 15 of the stations 1 with a master clock is provided.
Are selectively turned on by the gate control unit 5. Then, during an arbitrary period, the output of the time synchronization pulse signal TP and the time information (year, month, date, hour, minute, second, m second, etc.) from the selected station 1 with master clock.
The transmission of the TD is performed. This makes it possible to multiplex master clocks.

FIG. 2 is a block diagram showing a main part of an embodiment according to the second aspect of the present invention. In FIG. 2, the master clock 11 of FIG. 1 is commonly used as one.

FIG. 3 is a block diagram of a main part as an embodiment of the invention according to claim 2. In FIG. 3, there are a plurality (two in this example) of stations 1A having a master clock or a slave clock (referred to as a station with a master / slave clock for convenience). The station 1A with a master / slave clock switches between a master clock and a slave clock in response to a command from the gate control unit 5. In the station 1A, the master clock is replaced with a clock 11 that is a master clock or a slave clock, and a time setting unit 22, a time synchronization pulse signal input unit 23, and time information reception The section 24 and the input gate sections 16 and 17 are newly provided.

The parent / child clock station 1A
If the clock 11 of the master is a master clock, the output gates 14 and 1
5 is ON, the input gates 16 and 17 are OFF, and if the clock 11 is a slave clock, the output gates 14 and 15 are OF
F. The gate control unit 5 controls the input gate units 16 and 17 to turn on. That is, the gate control unit 5
One of an arbitrary number of parent / child clock stations 1A is selected, and the selected parent / child clock station 1A is set as a parent clock station for another period and the other parent / child clock stations 1A are selected. Is a station with a slave clock, and the master / slave clock station 1A having the master clock outputs a time synchronization pulse signal and transmits time information. This makes it possible to multiplex the master clock and always synchronize the time of all the clocks.

In FIG. 3, a dedicated time synchronization pulse signal line 4 is provided between an arbitrary number of stations 1A with a parent / child clock and a plurality of stations 2 with a child clock, in addition to a network 3 such as a LAN. I have. When the station 1A has a master clock, the clock 11 becomes the master clock, and a time synchronization pulse signal of an arbitrary cycle from the master clock is output from the time synchronization pulse signal output unit 12 to the time synchronization pulse signal line 4 to the output gate unit 14. , And the time information (year, month,
The date, hour, minute, second, m second, etc.) are transmitted from the time information transmitting unit 13 to the parent / child clock station 1A having the child clock and the plurality of child clock stations 2 via the network 3 via the output gate unit 15. And send.

When the station 1A has a slave clock, the time synchronization pulse signal from the time synchronization pulse signal line 4 is input to the time synchronization pulse signal input unit 23 via the input gate unit 16.
The time information (year, month, day, hour, minute, second, m second, etc.) transmitted from the parent / child clock station 1A having the parent clock via the network 3 is input to the input gate unit 17. Received by the time information receiving unit 24 via the
Synchronizes the time synchronization pulse signal with the time information, and sets the time on the clock 11 which is a slave clock. The slave clocked station 2 inputs the time synchronization pulse signal from the time synchronization pulse signal line 4 at the time synchronization pulse signal input unit 23, and transmits the time information (from the station 1A having the master clock via the network 3). Year / month / day / hour / minute / second / m-second, etc.) is received by the time information receiving unit 24, and the time setting unit 22 synchronizes the time synchronization pulse signal with the time information and sets the slave clock 21.
Set the time.

FIG. 4 is a block diagram of the main part of the invention according to claim 3. In FIG. 4, the clock 11 in the station 1A shown in FIG.
Is a slave clock and the master clock is commonly one.

[0020]

According to the present invention, as a time adjusting method for synchronizing clocks of a plurality of stations each having a clock and connected by a network such as a LAN, a dedicated time synchronizing pulse signal for a time synchronizing pulse signal is provided in addition to the network. A conventional method of transmitting time information to the network and synchronizing time by transmitting time information to the network in synchronization with a time synchronization pulse signal of the dedicated line and providing time information by only the network is used. In comparison, the accuracy of time synchronization can be improved and the time error between clocks can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a main part of a system as an embodiment of the invention according to claim 1;

FIG. 2 is a configuration diagram of a main part of a system as an embodiment of the invention according to claim 2;

FIG. 3 is a configuration diagram of a main part of a system as an embodiment of the invention according to claim 3;

FIG. 4 is a configuration diagram of a main part of a system as an embodiment of the invention according to claim 4;

FIG. 5 is a configuration diagram of a main part of a conventional system.

[Explanation of symbols]

 Reference Signs List 1 station with master clock 1A station with master / child clock 2 station with slave clock 3 network 4 time synchronization pulse signal line 5 gate control unit TP time synchronization pulse signal TD time information 11 master clock 12 time synchronization pulse signal output unit 13 time information Transmitters 14 and 15 Output gates 16 and 17 Input gates 21 Child clock 22 Time setting unit 23 Time synchronization pulse signal input unit 24 Time information receiving unit

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H04L 12/40 H04Q 9/00 321F H04Q 9/00 321 H04L 11/00 321

Claims (4)

(57) [Claims] A plurality of first stations having a master clock; and a plurality of second stations having a slave clock.
A system in which each of the stations can exchange data via a common network such as a LAN, comprising a dedicated signal line for transmitting a time synchronization pulse between the first station and the second station; A station for transmitting a time synchronization pulse to the dedicated signal line at a predetermined period based on the master clock; and a time synchronization pulse transmission time point obtained from the master clock to the network for each pulse transmission. Time information transmitting means for transmitting the time information, a connection between the synchronization pulse transmitting means and the dedicated signal line, and an opening / closing means for opening and closing the connection between the time information transmitting means and the network collectively. The second station synchronizes with the time synchronization pulse received from the dedicated signal line, To the time of the master clock at the time of receiving the time synchronization pulse obtained from the time information received from the network, further comprising: selecting one of the first stations; A time adjustment device for a network system, comprising: an opening / closing control unit for closing only the opening / closing unit of the first station. 2. The time adjustment device according to claim 1, wherein the first station shares one master clock. 3. A plurality of first stations having a master clock or a slave clock, wherein at least one of the stations has a master clock and a plurality of first stations having a slave clock. A second station,
A system in which each of the stations can exchange data via a common network such as a LAN, comprising a dedicated signal line for transmitting a time synchronization pulse between the first station and the second station; Means for transmitting a time synchronization pulse to the dedicated signal line at a predetermined cycle based on the master clock that the station can have; and Time information transmitting means for transmitting the time information at the time of sending the time synchronization pulse, and receiving the time of the master clock or the slave clock of its own from the network in synchronization with the time synchronization pulse received from the dedicated signal line. The time of the master clock for synchronization of this system outside of the time synchronization pulse reception time obtained from the obtained time information. Time setting means, first opening / closing means for simultaneously opening / closing a connection between the synchronization pulse transmitting means and the dedicated signal line, and a connection between the time information transmitting means and the network; and Second opening / closing means for simultaneously opening / closing the connection with the dedicated signal line and the network, the second station includes the time setting means, and the first station has a master clock. Selecting one to close the first open / close means of the selected first station, open the second open / close means of the selected station, and the second open / close means of the other first station A time adjusting device for a network system, comprising: an opening / closing control unit for performing a closing operation of the station and an opening operation of the first opening / closing unit of the station. 4. A system comprising a plurality of first stations having a common master clock and individual slave clocks and a plurality of second stations having a slave clock, each of which is connected via a common network such as a LAN. In a system capable of exchanging data, a dedicated signal line for transmitting a time synchronization pulse is provided between the first station and the second station, and the first station has a predetermined period based on the master clock. A synchronization pulse transmitting means for transmitting a time synchronization pulse to the dedicated signal line, and a time information transmitting means for transmitting time information of the time synchronization pulse transmission time obtained from the master clock to the network for each pulse transmission; In synchronization with the time synchronization pulse received from the dedicated signal line, the time of the slave clock possessed by itself, the time information received from the network The time setting unit that adjusts the time of the master clock at the time of receiving the time synchronization pulse, the connection between the synchronization pulse transmission unit and the dedicated signal line, and the connection between the time information transmission unit and the network. First opening / closing means for opening / closing the time setting means, and second opening / closing means for simultaneously opening / closing the connection between the time setting means and the dedicated signal line and the network, wherein the second station includes the time setting means. Further comprising selecting one of the first stations, closing the first opening / closing means of the selected first station, opening the second opening / closing means of the selected station, and the like. Opening / closing control means for closing the second opening / closing means of the first station and opening the first opening / closing means of the station. Time alignment apparatus of the network system.