JPS6119191B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a terminal device calling method for collecting data from a plurality of terminal devices.

When attempting to centrally monitor water levels, flow rates, or water quality at multiple points on a river, calls are made to terminal devices installed in advance at each point on the river, and each point is sent to a central device that centrally manages data. data will be collected. The collection and management of data from multiple locations is carried out in a variety of ways, such as calculating the amount of electricity, water, gas, etc. used by each household in an apartment complex, or measuring the temperature at each measuring point of mechanical equipment. It is being said.

There are various methods for collecting data. The most fundamental system is one in which each terminal device and the central device are connected by separate lines, and the central device calls each terminal device as necessary to send data. However, according to this method, as the number of terminal devices increases, the number of lines increases proportionally.
Large cable installations may be required. Furthermore, on the side of the central device that collects data, the number of terminals connected to each terminal device increases, making the device larger and making the selection circuit for selecting a specific terminal more complex.

For this reason, a system has been adopted in which a common line is used to connect the central device and each terminal device. In this method, a plurality of terminal devices are connected to a common line, so it is necessary to sequentially transmit data from these terminal devices to avoid duplication.

Therefore, conventionally, each terminal device is provided with a different address, and the central device sequentially polls the address of each terminal device.
A method is used in which data is sent out sequentially.

However, according to such a paging system, it is necessary to sequentially send out paging signals with different addresses from the central device. This not only complicates the central device in this respect, but also has the drawback of requiring time for data collection.

The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a calling method for terminal devices that can sequentially send data from one line to a central device without setting an address for each terminal device. With the goal.

In the present invention, a plurality of terminal devices are connected in parallel to a pair of lines connected to a central device. Furthermore, each terminal device is equipped with a decoder that detects a specific code, and an encoder that sends out the data content indicated by the data source when a counter that counts the output signal of this decoder counts a set value. Then, by sequentially changing the setting value of the counter for each terminal device and including the above-mentioned specific code in the data sent from the encoder, the central device initially outputs a predetermined signal, and each terminal The above purpose is achieved by calling devices in a chain.

The present invention will be explained in detail with reference to Examples below.

FIG. 1 shows a data collection system according to an embodiment of the present invention, in which a plurality of terminal devices 2A, 2B, . . . are connected to a central device 1. The central device 1 is installed, for example, in an instrument central control room of an apartment complex, and each terminal device 2A, 2B, . . . is installed in each household of the apartment complex. Each of the terminal devices 2A, 2B, . Further, each terminal device is connected to data sources 7A, 7B, etc., such as water meters, respectively.

In the data collection system having such a configuration, it is assumed that the central device 1 starts data collection at time to shown in FIG. The central device 1 is shown in Figure a.
As shown in FIG. 2, a predetermined signal 8 is sent to the line 6 at time to. This predetermined signal 8 is composed of a predetermined DC voltage.

When the specific code 8 sent from the central device 1 is decoded by the decoder 3 in each terminal device, the counter 4 in each terminal device becomes operational. As a result, the first terminal device 2A whose count number is set to zero
The counted value of the counter 4 in the second match matches the set value, and the counter 4 starts the encoder 5. As a result, the encoder 5 encodes the data content indicated by the data source 7A and sends it to the line 6 as "data 1".
At this time, the encoder 5 adds another specific code 9 at the end of data transmission. This specific code 9 is common to each terminal device, and in this embodiment, it is used as ETX as a transmission control character to indicate the end of data.
(end of text) Substitute a sign.

The data sent to the line 6 is read by the central device 1 and processed as data for the first terminal device 2A. On the other hand, the specific code 9 sent to the track 6
is input not only to the first terminal device 2A itself but also to the decoders 3 of all other terminal devices 2B, 2C, . . . . As a result, each decoder 3 outputs a pulse 10a as shown in FIG. 2b, causing the counter 4 in each terminal device to increment. As a result, the second terminal device 2B whose count number is set to 1
When the counted value of the counter 4 matches the set value, the encoder 5 is activated. The encoder 5 sends out the data content indicated by the data source 7B as "data 2", and then sends out the specific code 9. railroad track 6
The second data "data 2" sent to the central device is read by the central device and processed as data for the second terminal device 2B. Further, the specific code 9 sent to the line 6 causes the decoder 3 in each terminal device to output a pulse 10b as shown in FIG. 2b, causing the counter 4 in each terminal device to increment.

The counter 4 in each terminal device has a set number of 0, 1,
2, 3, and so on, so that when the first terminal device is activated in this way, data is sequentially sent from each terminal device without duplication.

By the way, when the count value of the counter 4 in the third terminal device matches the set number due to the pulse 10b shown in FIG. 2b, for example, the counter 4 outputs an output waveform as shown in FIG. This output waveform is input to the encoder 5, and a margin time t is set as shown in FIG. This is provided so that the device 1 can separate and recognize each data sent to the line 6, and may be omitted depending on the configuration of the central device.

As described above, according to the present invention, data is sequentially transmitted without duplication by a single activation from the central device, thereby simplifying the terminal device calling function of the central device.

Moreover, since there is no need for the central device to sequentially send out paging signals including addresses or to collate and confirm the response signals sent from each terminal device in response, the data collection time is reduced by this amount. .

Note that the central device of the present invention is not limited to collecting and displaying data as shown in the embodiments, but can also provide a function of transmitting data to a central information management center by connecting to a telephone line.

In other words, for example, a central device installed in each apartment complex, factory, or individual residence sends water meter data, etc. to a central information management center, which centrally manages this data and calculates individual water charges. The present invention can also be used as part of a system that charges users, etc.

In such a case, according to the present invention, when a data call is made from the central information management center to each central device through the subscriber telephone line, the central device can quickly access the data without specifying an address for each terminal device. A call can be made and the data immediately sent to a central information management center. That is, the present invention has important significance in such an automatic meter reading system as well in terms of reducing telephone charges and the like.

Furthermore, in this embodiment, the code forming the predetermined signal sent from the central device 1 and the specific code sent by each terminal device are different, but these may be the same specific code. In this case, the set value of the counter in the first terminal device 2A will be set according to the specific code sent from the central device 1.

[Brief explanation of the drawing]

The drawings are for explaining one embodiment of the present invention. Fig. 1 is a block diagram of a system for collecting data, and Fig. 2 is a signal waveform for explaining the operation of each part shown in Fig. 1. It is a diagram. 1...Central device, 2...Terminal device, 3...Decoder, 4...Counter, 5...Encoder, 7...
...Data source.

Claims (1)

[Claims] 1 Connect multiple terminal devices via a common line,
Each terminal device is called by a predetermined signal sent to this line from the central device that collects data,
In a data collection system that sends data from a data source connected to each terminal device to a central device,
A decoder that detects a specific code in each terminal device, a counter that is set to a predetermined value that is different for each terminal device and counts each time the decoder detects a specific code, and data indicated by the data source when the counter counts the set value. and an encoder that sends the content and a specific code to the line, and one of the terminal devices is called by a predetermined signal sent from the central device, and the terminal device is called by the specific code sequentially output from each terminal device. A terminal device calling method characterized by calling sequentially.