JPH11103300A - Time stamp system for time synchronizing system observation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain improvement in the reliability of monitoring/measuring time by receiving a radio wave, which contains time synchronizing information, from a satellite and transmitting it while adding the time synchronizing information to data received from a sensor. SOLUTION: A GPS reception antenna 17 receives a time signal from a GPS satellite 100, and that time information signal is generated on a data line 24 by a time signal generator 15 and applied to a phase comparison control part 16 and a time information converting part 18. The phase comparison control part 16 sends a phase synchronizing control signal to a control line 25, and the phase synchronism of a system clock signal and the time information signal is established. The system clock signal is distributed through a clock signal line 20 to a data processing part 11 of transmission equipment 4 and respective sensors 2 of sensors #1-#n. The respective sensors 2 measure an installed environment state and transmit sensor data through a connecting line 21 to the data processing part 11. The direct time information from the satellite is added to the data from the sensors 2 and out-of-synchronism in time is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method of adding a time stamp for guaranteeing an absolute time of data measured by a sensor in a monitoring system and an observation system.

[0002]

2. Description of the Related Art In a conventional general monitoring system and observation system, data obtained by a sensor is
Finding the absolute accuracy of the obtained time was not common due to its difficulty.

As a conventional method, as shown in FIG. 2, first, sensor data from a sensor 52 is transmitted to a data processing unit 56 in a transmission device 51 via a connection line 61. The data processing unit 56 that has received the sensor data transmits the sensor data to the receiving device 53 via the transmission line 62. The receiving device 53 converts the received sensor data into a format used on the connection line 63 and transmits the converted data to the terminal 54 that performs data processing via the connection line 63. When receiving the sensor data, the terminal 54 fetches the time information from the reference clock 55,
A system that confirms the relative relationship between data and time was common.

[0004]

In the conventional method, since the sensor 52 has no time information, the terminal 52 measures the environment of the installation place and outputs the sensor data before the terminal 56.
The transmission delay occurs during the reception of the sensor data, and there is a drawback that the reliability of the obtained data with respect to the absolute time (referred to as time synchronization information at the reference time; hereinafter, referred to as absolute time) cannot be obtained. Was.

[0005] It is an object of the present invention to add accurate time information to data from a sensor so that the time monitored and measured by the sensor has high reliability.

[0006]

In order to solve the above-mentioned problems, a time stamp system in a time synchronous observation system according to the present invention uses a transmitting device in which a satellite for transmitting a radio wave including time synchronous information and a plurality of sensors are connected. And a plurality of receiving stations that require the information of the sensor, and a transmission line that interconnects the transmitting device and the receiving station, the transmitting device transmits radio waves including the time synchronization information from the satellite. It is characterized by comprising receiving means for receiving, adding means for adding the time synchronization information to data received from the sensor, and transmitting means for transmitting the additional data added by the adding means to the receiving station.

[0007] In addition to the above, the transmission device has a delivery means for delivering a clock synchronized with the time synchronization information signal to the sensor.

[0008]

Next, embodiments of the present invention will be described with reference to the drawings.

Referring to FIG. 1, an embodiment of the present invention employs a GPS (Global Positioning System) transmitting a radio wave including an absolute time.
bal Positioning System) satellite 100, transmitting apparatus 1, and sensors # 1 to 1 for measuring the environment.
It includes n sensors 3 of #n, m receiving stations 3 of receiving stations # 1 to #m, a connection line 21, a transmission line 22, and a clock signal line 20.

The transmitting device 1 includes a transmitting unit 4, a time unit 5,
It comprises a clock signal line 20 and a data line 26.

The time section 5 includes a reference clock generator 13 for generating a stable clock for a long time, a system clock generator 14 for outputting a system clock required for operation to a clock signal line 20, and radio waves from the GPS satellite 100. , A time signal generator 15 for receiving time information from the GPS antenna 17 and outputting the time information as a time information signal to the data line 24 in units of 0.1 s, and a time information signal (data line 24). ) And a system clock signal (clock signal line 20) to compare phases and control system clock generator 14.
6 and a control line 2 for controlling the system clock generator 14
5 and a time information converter 18 that receives a time information signal (data line 24) and outputs a time information data signal suitable for data processing to a data line 26.

The transmission unit 4 receives sensor data from each of the sensors 2 of the sensors # 1 to #n via the connection line 21 and adds time data to the sensor data.
1 and data with a time synchronization signal suitable for the transmission line interface, and any receiving station # 1 via the transmission line 22.
And an interface unit 12 for distributing to each of the receiving stations 3 of #m.

The data processing unit 11 has a CPU and a storage unit, though not explicitly shown in FIG. 1, and performs data processing by a program.

The receiving station 3 comprises a receiving device 31 and a terminal 32
And a connection line 23.

Next, the operation of this embodiment will be described in detail with reference to FIG.

A time signal is received from the GPS satellite 100 by the GPS receiving antenna 17. The received time signal is generated by the time signal generator 15 as a time information signal on the data line 24 at intervals of 0.1 s, and transmitted to the phase comparison control unit 16 and the time information conversion unit 18.

The time information converter 18 that has received the time information signal (data line 24) stores the time information signal in a timer register (not shown) at every 0.1 s. The time information converter 18 transmits the data via the data line 26 in response to a read request from the data processor 11.

On the other hand, the system clock generator 14 receiving the basic clock from the reference clock oscillator 13
A system clock signal necessary for operating the system is generated on the clock signal line 20 and the phase comparison control unit 16
Send to

The phase comparison controller 16 compares the phase of the time information signal received from the time signal generator 15 with the phase of the system clock signal received from the system clock generator 14, and generates a phase synchronization control signal on the control line 25. I do. The output phase of the system clock signal of the system clock generator 14 is controlled by the phase synchronization control signal,
Phase synchronization between the system clock signal and the time information signal is established.

The system clock signal whose phase synchronization has been established is transmitted to the data processing unit 11 of the transmitting unit 4 and the sensors # 1 to #.
n are distributed to each of the n sensors 2 via a clock signal line 20.

Each of the sensors # 1 to #n operates on the basis of the system clock signal, measures the installed environmental condition, and transmits the sensor data to the data processing unit 11 via the connection line 21.

When the sensor data is transmitted to the data processing unit 11, the CPU in the data processing unit is interrupted,
Performs an interrupt process for adding time data to sensor data by a program.

That is, the data processing unit 11 includes a sensor data (connection line 21) received from each sensor 2, a time data signal (data line 26) received by reading of the time information conversion unit 18, and a system clock generator. Using the system clock (clock signal line 20) received from 14, data with a time synchronization signal is generated and transmitted to the interface unit 12.

The interface unit 12 converts the received data with the time synchronization signal into a signal format (for example, a frame format) suitable for the interface conditions of the transmission line 22, and receives the receiving stations # 1 to # 1 which need the sensor data.
It transmits to each receiving station 3 of #m.

At the receiving station 3, the received data with the time synchronization signal is converted by the receiving device 31 into a signal form suitable for the interface condition with the terminal 32 which performs data processing, and transmitted to the terminal 32 via the connection line 23. Is done. Data processing is performed by the terminal 32, and display, recording, and the like are performed.

Although the time processing of the receiving station 3 is not specified in the above description, the receiving station 3 receives the absolute time from the GPS satellite, and receives the absolute time from the sensor data transmitted from the transmitting apparatus 1. The general usage is to adjust the time (match data) so that the time does not shift.

As described above, in the transmitting device 1, since the reference time is directly taken from the satellite, the time information generated by the time unit 5 is added to obtain data whose absolute time is guaranteed. be able to. As a result, the error in the absolute time due to the transmission delay is eliminated, and time-synchronized data can be simultaneously transmitted to an arbitrary place. Furthermore, it is effective for various observation systems and monitoring systems that require a time stamp.

Further, by transmitting a system clock synchronized with the absolute time to the sensor, the sensor 2 can always obtain high-quality observation data synchronized with the time without causing time synchronization.

That is, in the transmitting device, the radio wave including the absolute time from the satellite is received and the time information is directly added to the data transmitted from the sensor, so that the receiving station far from the transmitting device receives the data. In this case, data to which the absolute time is added can be received.

[0030]

According to the present invention, the reliability of the data with respect to time is improved by synchronizing the sensor with the absolute time and by attaching accurate time information to the observation data from the sensor to perform the operation with a clock synchronized with the absolute time. There is an effect of improving. Further, by directly receiving information from a device having a GPS receiving function in a transmitting / receiving device that receives data from a sensor and transmits the data to another location, it is not necessary to consider a time loss when transmitting data to a remote location. Was.

[Brief description of the drawings]

FIG. 1 shows a block diagram of an observation system of the present invention.

FIG. 2 is a block diagram of a conventional general observation system.

[Explanation of symbols]

 Reference Signs List 1,51 transmitting device 2,52 sensor 3 receiving station 4 transmitting unit 5 time unit 11,56 data processing unit 12 interface unit 13 reference clock oscillator 14 system clock generator 15 time signal generator 16 phase comparison control unit 17 GPS antenna 18 Time information converter 20 Clock signal line 21, 23, 61, 63 Connection line 22, 62 Transmission line 24, 26 Data line 25 Control line 31, 53 Receiver 32, 54 Terminal 55 Reference clock 100 GPS satellite

Claims (2)

[Claims] 1. A satellite transmitting a radio wave including time synchronization information, a transmitting device to which a plurality of sensors are connected, a plurality of receiving stations requiring information of the sensors, and A transmission path connected to the transmitting device, the transmitting device receives a radio wave including the time synchronization information from the satellite, an addition unit that adds the time synchronization information to data received from the sensor, A transmitting means for transmitting the additional data added by the adding means to the receiving station. 2. The time stamp method in the time synchronization observation system according to claim 1, wherein the transmission device has a delivery unit that delivers a clock synchronized with the time synchronization information signal to the sensor.