JPS6236435B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a data collection method for centrally monitoring measurement data from a large number of objects to be measured.

In general, the measurement data is monitored by connecting several sensors grouped in a certain area as a method of measuring the amount of change in objects to be measured that are scattered in many locations and transmitting the data to an information center that centrally monitors the data. There is a boring method in which a central device makes a request to a terminal measuring device to transfer data and asks whether there is any data to be sent.

This method connects the center device 1 and multiple terminal measuring devices 2 at various locations with a data transfer line 3 such as a telephone line, as shown in Figure 1a, or
It is connected by a data transfer line 3 via a line scanning device 4 as shown in FIG.
The line switching circuit 5 or line scanning device 4 in the main unit switches lines at appropriate times, connects one line and asks if there is data to be sent, and when a reply is received that there is no data, sends an end signal and switches to the next line. This is a method of sequentially switching over while scanning in this manner.

In this case, for example, a general speed FS modulation signal system that uses voice band frequencies as a signal system for data transfer, or a combination of signals of two frequencies from six frequency types of voice band AC signals, can be used to express numerical values. When data is transferred using the MF signaling method,
Just checking whether there is data to be transmitted to one line, that is, one terminal measuring device, takes nearly one second. Therefore, in a system where one center device 1 has many terminal devices 2, boring only scans all the terminal measuring devices 2 once, that is, in only one cycle.
For example, in a system having 100 terminal measuring devices 2, it takes nearly 100 seconds. Therefore, in a system that must measure and send data to the center device once every 100 seconds, if it takes 10 seconds for one data transfer, the terminal measurement device that can hold one center device 1 The number 2 means 10 stations. Therefore, 100 stations terminal measurement device 2
If you want to monitor at one location, you will need 10 systems, each consisting of 10 terminal measuring devices for one central device.

In general, the properties of the object to be measured 6, which is the object of telemetering, may change over a sufficiently long period. The problem can be solved by reducing the number of terminal measurement devices and increasing the scanning speed. However, for some systems, the amount of change is rapid; for example, under normal conditions, there is no change in the object to be measured, so much so that there is no need to measure it, but when a foreign object occurs on the object, the measured value suddenly changes. Therefore, it is necessary to measure at very short intervals and transfer the data to the center device 1 for display and recording. In such a system, the scanning speed or the number of terminal measuring devices that can be connected must be determined so that the measured values that change rapidly when an abnormality occurs can be sufficiently transferred. Even in the case of an alarm monitoring system, where the normal time is extremely long and the time during which the values to be measured are not changing rapidly, the proportion of time during which the values to be measured are changing rapidly is extremely small. This is extremely uneconomical as it requires a large number of units.

The present invention solves the above-mentioned uneconomical problems, and unlike an alarm monitoring system, each terminal device rarely synchronizes and generates emergency alarm information, but each terminal device randomly and simultaneously generates emergency alarm information. Focusing on the fact that the total number of transmitted data is extremely smaller than the number of terminal devices accommodated, instead of checking the presence of transmitted data by scanning from the center device every time as in the boring method, the center device By setting the device in a state where it can receive data transferred from the terminal measuring device, the terminal measuring device immediately sends the data as soon as it obtains the data to be sent.Even when monitoring objects to be measured from a distance that change quickly, one center device can be used in many cases. The purpose is to provide a data collection method that can accommodate terminal measurement devices.

Hereinafter, the data collection method of the present invention will be explained based on FIG.

In FIG. 2, 11 is a center device, 12 is a line switching device, and 13 is a second data transfer line connecting the center device 11 and the line switching device 12.

In this line switching device 12, a plurality of terminal measuring devices 14 ₁ , 14 ₂ , . . . , 14 _o are connected to first data transfer lines 15 ₁ , 15 ₂ , .
15 _o , and each terminal measuring device 14 has a plurality of objects to be measured 17 ₁ , 17 ₂ , ......,
17 _o and a plurality of sensors 16 ₁ , 16 ₂ ,...
..., 16 _o are connected.

Here, the object to be measured 17 is, for example, sealed gas in a gas section in a communication cable, and the sensor 16
is a pressure transmitting device that outputs an analog signal such as a current value corresponding to the pressure of the sealed gas.

The terminal measuring device 14 converts an analog signal, which is a measurement value signal of the sensor 16, into a digital quantity.
The digital values from the -D converter 20 and this A-D converter 20 are compared with a preset setting value, and if the measured value exceeds or falls below the set value, an abnormality is determined, and this measured value, Data such as the location of the object to be measured where an abnormality has occurred are created according to a predetermined format, a predetermined number of the terminal measuring device 14 is added, and the data is transferred to the first data transfer line 1.
5, and also includes a data transmission/reception control circuit 21 that receives a reception confirmation signal from the center device 11 and completes data transfer.

The line switching device 12 includes signal detection circuits 22 ₁ , 22 ₂ , ..., 22 _{o that detect the presence or absence of a data transfer signal corresponding to one terminal measurement device, and a signal detection circuit 22 1 , 22 2 , ......, 22 o} that detects the presence or absence of a data transfer signal corresponding to one terminal measurement device, and Switching relays T ₁ , T ₂ , . . . which switch the data transfer line 15 from 14 to the data transfer line 13 on the center device 11 side.
..., T _o , and a priority circuit 2 that gives priority to the one line with the lowest number when signals arrive from two or more lines at the same time.
It is composed of 3 etc. When the data transmission/reception on the lower numbered line is completed, the switching relay of the lower numbered line is restored and the line is immediately switched to the line that was in the standby state until then.

The center device 11 includes a data transmission/reception control circuit 24 that receives transfer data arriving from the second data transfer line 13 and transmits a reception confirmation signal for completion of data processing, a display section 25, and a printer 26.
and a control section 27 that translates the transfer data, displays it on the display section 25, and causes the printer 26 to print.

Next, the method of data collection will be explained.

Normally, when there is no abnormality in the object to be measured 17, the terminal measuring device 14 does not output any signal to the first data transfer line 15, but when an abnormality is detected, it sends out data containing the above-mentioned contents. The signal detection circuit 22 of the line switching device 12 checks the start code provided at the beginning of this data and operates the switching relay T. As a result, the relay contact t operates to transfer the first data transfer line 15 from the terminal measuring device 14 to the second data transfer line 1 on the center device 11 side.
Switch to 3. At this time, in order to allow time for the line switching device 12 to detect the incoming signal and switch the line, a dummy code is sent for a short time, and then valid data is sent successively. 1
When the transmission of the frame is completed, the transmission of the one-way signal is stopped and the reception confirmation signal from the center device 11 is waited for. The center device 11 receives one frame of data, checks various self-check bits included in this frame, determines that the reception is normal if there is no error, and sends a reception confirmation signal to the terminal measurement device 14. If a mistake is made, the reception confirmation signal is not sent and the next signal is waited for. When the terminal measuring device 14 receives the reception confirmation signal, it confirms that the data has been transferred correctly to the center device 11, and the data transfer ends. If the terminal measuring device 14 does not receive the reception confirmation signal even after waiting for a certain period of time, the terminal measuring device 14 determines whether the data was not correctly transferred to the center device 11 and a check error occurred, causing the center device 11 to wait for the next retransmitted signal. Alternatively, the data signal from another line has already been connected with priority and is in a waiting state in front of the line switching device 12, so the signal with the same content is repeatedly sent. If the reception confirmation signal still does not arrive even after several attempts, it is assumed that there is a problem with the data transfer line and an alarm is issued on another system.

When signals are sent from multiple terminal measurement devices 14 at the same time, the priority circuit 23 of the line switching device 12 switches only the one line with the lowest number, and the other lines are placed in a queue, and when data transmission/reception on the lower number line is completed. The switching relay of the lower numbered line is restored, the line that has been used as a waiting line is switched, and the transfer data of that line is sent to the center device 11.

As explained above, in the present invention, instead of checking the presence or absence of transmitted data by scanning from the center device every time as in the boring method, the center device is kept in a state where it can normally receive transferred data from the terminal measurement device. When the terminal measurement device obtains the data to be sent, it immediately sends it to the center device,
Since the center equipment receives the data in the order of transmission from each terminal measuring device with the minimum waiting time, there is no wasted scanning time like in the polling method, and the number of terminal measuring devices that can be accommodated by one center device is reduced compared to the conventional polling method. There is a significant economic effect in introducing the system.

[Brief explanation of the drawing]

1A and 1B are block diagrams showing a conventional data collection method, and FIG. 2 is a block diagram showing an embodiment of the data collection method of the present invention. 11... Center device, 12... Line switching device, 13... Second data transfer line, 14...
Terminal measurement device, 15... First data transfer line, 16... Sensor, 17... Measured object, 22
...Signal detection circuit, 23...Priority circuit.

Claims (1)

[Claims] 1 Analog signals from multiple sensors that measure the object to be measured are converted into digital by a terminal measuring device, and this digital signal is compared with a predetermined setting value to determine an abnormality in the object to be measured. The data about the object to be measured is sent to the first data transfer line, and the line switching device receives the transferred data from the terminal measurement device by the corresponding signal detection circuit provided corresponding to the plurality of data transfer lines. Connect to the second data transfer line on the center device side, and if transfer data is received from multiple terminal measurement devices at the same time, connect only one line to the second data transfer line with priority. When the center device normally receives the transferred data, it sends a reception confirmation signal to the terminal measuring device to complete the data transfer from each terminal measuring device, and puts the other device in a waiting state. A data collection method that is characterized by being able to process lines.