JPS643386B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a data collection method that efficiently uses public communication lines.

The first step is to collect data measured by sensors on conditions in remote areas, such as groundwater levels, ground subsidence, and air pollution levels, via public communication lines.
It is known as shown in the figure. Although the terminal device TM has a plurality of sensors SNS and measures a predetermined state, the data is not normally stored. Therefore, a data collection center CS, for example a monitoring center, has a computer CPU and a telemeter master station.
TMR, calls the terminal device TM via the network control unit NCU and public communication exchange EXC at every predetermined time, and when connected to the terminal device TM, the sensor at that time
SNS measurement values are transmitted. The computer CPU displays, stores, processes, etc. the data at that time. Note that MODEM of the terminal device is a modem,
I/O-C indicates an input/output control device. Therefore, conventional data collection is carried out from the collection center to the terminal deviceTM.
In the same way as when making a phone call, a public communication line is set up each time to call the terminal device at predetermined times and have data transmitted, which has the drawback of high communication charges. Furthermore, it was necessary to transmit the terminal device number and sensor number along with the data each time each report was made, resulting in low line usage efficiency.

SUMMARY OF THE INVENTION An object of the present invention is to improve the above-mentioned drawbacks and provide a collection method that efficiently uses public communication lines when collecting data at a predetermined time.

Embodiments of the present invention shown in the drawings will be described below. FIG. 2 is a diagram showing details of the terminal device TM in FIG. 1. In FIG. 2, MPU is a microprocessor, TMC is a clock circuit, and MF is a data storage memory file (random access memory is suitable). This embodiment is applied when the collected data does not need to be processed in real time. The clock circuit TMC interrupts the microprocessor MPU at the data collection time that was conventionally performed by the collection center CS, the microprocessor MPU starts operating, and transfers the data measured by the sensor SNS to the input/output control device I/O. It is stored in memory file MF via O-C. At this time, the time indicated by the clock circuit TMC is added to the data.
After a predetermined period of time has elapsed, for example one hour, the clock circuit TMC again issues an interrupt signal, and the microprocessor MPU operates in the same manner and stores data. The above steps are repeated, for example, every hour to accumulate one day's worth of data. When the data collection center CS collects data from the terminal device TM, for example at midnight, it accesses the terminal TM via the public communication exchange system EXC. The terminal TM converts one day's worth of data in the memory file MF into a serial/parallel converter PS/SP and a modulation/demodulation circuit according to a predetermined format.
It is sent all at once to the data collection center CS via the MODEM and NCU control circuits.

When investigating changes over time as data, for example in the case of air pollution status and weather observation values, time data from the clock circuit TM is required as mentioned above.
If it is necessary to accumulate data, increase the memory file MF capacity of the terminal TM,
Accumulate data including the amount of change.

Note that it is preferable that the terminal device TM is configured so that when the measured value of the sensor SNS at a predetermined time greatly deviates from the normally expected range, the microprocessor MPU can call the collection center CS and notify an alarm.

In this way, according to the present invention, instead of transmitting data to the center each time data is collected from the sensor, for example, one day's worth of data is transmitted all at once, thereby improving line usage efficiency.
Therefore, it has the effect that the line usage cost can be reduced.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the conventional data collection method, Figure 2
The figure is a diagram showing the configuration of an embodiment of the present invention. CS...Data collection center, EXC...Public communication switching system, TM...Terminal device, SNS...Sensor,
MPU: microprocessor, TMC: clock circuit, MF: memory file, I/O-C: input/output control device, CPU: computer.

Claims (1)

[Claims] 1. In a system having a plurality of terminal devices that can be automatically called from a data collection center via a public communication switching system, the terminal device is located at a remote location and collects data measured by a plurality of sensors. The terminal device includes a timer, a processor that collects the data by being interrupted by the timer output, and stores data collected by the processor at each predetermined time and the data collection time. the terminal is called from a collection center at a cycle longer than the storage time cycle in the memory, and the data stored in the memory and the data collection time are collected via a public communication line. collection method.