JPH057251A - Terminal side network controller - Google Patents

Abstract

PURPOSE:To secure the reliability of a terminal side network controller at the time of power restoration. CONSTITUTION:An EEPROM 27 is provided to store its ID number and the telephone number of a center side device in it. Whether or not there is abnormality in data stored in a RAM 26 is checked. When there is abnormality in the data, the EEPROM 27 calls the telephone number of the center side device and its ID number, automatically performs communication between it and the center side device and downloads necessary data from a center side device 11 to the RAM 26.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a terminal side network control device used in a telemeter communication system for transmitting data using a telephone line.

[0002]

2. Description of the Related Art Generally, in a telemeter communication system,
The basic operating conditions of the terminal side network control device, the current time, the telephone number, etc. are stored in the main control unit (microcomputer) as R.
Accumulated in AM. Usually, this data is downloaded from the center side device by no ringing communication,
It is transmitted and stored in the terminal side network control device by the data setting device.

[0003]

However, when the watchdog circuit for detecting the operation abnormality of the terminal side network control device is operated, or when the main control unit is reset due to noise or the like, it is stored in the RAM. Data will be lost. This loss of data not only makes the operation mode of the terminal-side network control device indeterminate, but even if the main control unit detects an abnormality in the data at the time of restoration, the center-side telephone number to be dialed is lost. As a result, it does not work at all.

In view of the above, the present invention is a terminal that, even if the power is cut off for some reason, communicates with the center side device at the time of restoration and downloads necessary data again to ensure the reliability of the device. It is intended to provide a side network control device.

[0005]

The problem solving means according to the present invention is, as shown in FIGS. 1 and 2, a terminal side network control device for transmitting data to and from the center side device 11 through a telephone line to which a terminal device 14 is connected. , The CPU 24 and the CPU
ROM 25 for instructing control to 24, RAM 26 for storing data, and E ² PROM ^{2 for} storing its own ID number and center side telephone number without erasing even when the power is turned off
7, the contents of the data in the RAM 26 are checked, and when an abnormality is found in the data, the E ² PRO
Based on the center side telephone number stored in M27, the center side device 11 is dialed to output its own ID number, and necessary data is sent from the center side device 11 to the RAM.
26 is configured to be downloaded.

[0006]

In the means for solving the above problems, for example, when the power is cut off and the CPU 24 is reset and then restored,
The data stored in the RAM 26 is checked. Then, when the data is abnormal, E ² PR
The center side telephone number and own ID number are called from the OM 27 to automatically communicate with the center side device 11, and necessary data is transferred from the center side device 11 to the RAM 26.
Download to.

Therefore, communication is prevented from being disabled due to noise or some other reason, and reliability is improved.

[0008]

An embodiment of the present invention will be described below with reference to the drawings.

First, the outline of the telemeter communication system will be described with reference to FIG. In the figure, 11 is a center side device, 12 is an exchange, 13 is a terminal side network control device, 14 is a terminal device such as a gas meter, and 15 is a telephone line. When the designated date and time arrives, the terminal-side network control device 13 dials the center-side device 11, communicates with the center-side device 11, and communicates with the terminal device (gas meter).
14 meter reading values are transmitted.

Next, details of the terminal side network control device will be described with reference to FIG. In the figure, reference numeral 21 denotes a station line circuit which is a connection portion with a telephone line, and a ringer / polarity reversal detection circuit for detecting a ringer detection or a polarity reversal of a telephone line, 22
Is a modem for communication, and 23 is a main control unit for controlling the terminal side network control device 13. The main control unit 23 uses a one-chip microcomputer, and has a CPU 24 as a central control unit, a ROM 25 for instructing the CPU 24 to control, an ID number of itself, a telephone number of the center, and a designated date and time. -Has a RAM 26 for storing and accumulating time, current time, and the like. Also, 27 memory accumulates without erasing the own ID number and a center-side telephone number even when the main control unit 23 to the externally connected power-off E ²
PROM (Electrically Erasable)
e Programmable Read Only M
28) is a watchdog circuit for detecting an abnormal operation of the terminal side network control device 13.

Then, the terminal-side network control device 13 uses the R
Checking means for checking the contents of the data of the AM 26, and calling means for calling the center side telephone number and its own ID number stored in the E ² PROM 27 when an abnormality is found in the data by the checking means, Dial means for dialing the center side device 11 based on the center side telephone number called by the calling means and outputting its own ID number, and necessary for communicating with the center side device 11 by the dial means. Downloading means for downloading data from the center side device 11 to the RAM 26 is provided.

In the above structure, the main control unit 23 causes the abnormality of the data contents of the RAM 26 when the watchdog circuit 29 operates due to some abnormality in the equipment, the CPU 24 is reset due to noise or the like. When an abnormality is found in the device, such as when is detected, the operation is continued by downloading the necessary data from the center-side device 11.

That is, when the CPU 24 is reset due to the operation of the watchdog circuit 29, noise, or the like, and is restored thereafter, when the garbled data of the RAM 26 is detected, or at a fixed time, the total content of the data of the RAM 26 is calculated. It is determined, and if it is different by comparing with the initially accumulated total value, it is determined that the contents of the RAM 26 have changed somewhere.

Then, by the above-mentioned check, the RAM 26
When an abnormality is detected in the content of, the main controller 23
Based on the center-side telephone number stored in the E ² PROM 27, the center-side device 11 is automatically dialed to output its own ID number, and communication is performed with the center-side device 11 to obtain necessary data. The contents of the data are restored by downloading from the center-side device 11, and the operation of the system is continued.

In the conventional terminal-side network control device that does not have the above-mentioned function, the contents of the RAM remain changed due to noise and other causes, so that an unexpected operation is performed or a center stored in the RAM is stored. Since the telephone number on the side is changed or lost, even if the telephone number is dialed, the device on the center side cannot be connected. However, according to the present embodiment, the system can automatically continue the operation in order to automatically download and restore the data from the center side device.

Although such a thing does not often occur, in the case of a natural phenomenon such as a lightning strike having a very large amount of energy, many devices are abnormal at a time in a very wide range. The side network control device operates effectively.

The present invention is not limited to the above embodiments, and it goes without saying that many modifications and changes can be made to the above embodiments within the scope of the present invention.

[0018]

As is apparent from the above description, when the terminal side network control device is in an abnormal state, the CPU is reset and the data stored in the RAM is lost. After that, the terminal-side network control device falls into a malfunction, but according to the present invention, when it falls into an abnormality, the RAM
Error is detected, and if an error is detected, E ² PRO
The center side telephone number written in M and its own ID number can be used to call the center side device for communication, and the necessary data can be downloaded from the center side device to the RAM. There is an excellent effect that reliability can be improved without being unable to perform.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a telemeter communication system.

FIG. 2 is a block diagram of a terminal side network control device according to an embodiment of the present invention.

[Explanation of symbols]

11 center side device 12 switchboard 13 terminal side network control device 14 gas meter 15 telephone line 21 ringer / polarity reversal detection circuit 22 modem 23 main control unit 24 CPU 25 ROM 26 RAM 27 E ² PROM 28 interface circuit 29 watchdog circuit

Claims (1)

Claim: What is claimed is: 1. A terminal-side network control device to which terminal equipment is connected and which transmits data to and from a center-side device through a telephone line.
M, a RAM for storing data, and an E ² PROM for storing the ID number and center side telephone number without erasing even when the power is cut off. When found, the center side device is dialed based on the center side telephone number stored in the E ² PROM to output its own ID number, and necessary data is downloaded from the center side device to the RAM. A terminal side network control device characterized by the above.