JPH0658646U - Telemeter terminal device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a telemeter terminal device capable of determining disconnection of an analog signal line from a sensor to an A / V converter. An analog signal line disconnection determination circuit 5 for determining disconnection of an analog signal line 4 from a sensor 3 to an A / V conversion unit 2 based on an output voltage from an A / V conversion unit 2 provided inside a telemeter terminal 1. At the time of disconnection determination, the disconnection determination signals of the four analog signal line disconnection determination circuits 5 are interrupted to the central processing circuit (CPU) 7 through the OR circuit 6, and the analog data before the disconnection is generated is saved to the center. It is transmitted to the device 8.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a telemeter terminal device for A / D converting an analog output of a sensor that detects a state of a monitored object into a digital value and then transmitting the digital value to a central monitoring device.

[0002]

[Prior art]

 Conventionally, for example, as a monitoring device for this type of monitored object, a gas sensor is used to monitor the filling state of gas in a gas cylinder with an analog value larger than "0", and a public telephone line is used. A monitoring system that sends data to a central monitoring device has been put to practical use.

The conventional telemeter terminal device does not have an analog signal line disconnection judging circuit as shown in FIG. 4, and therefore, the lower limit value of the input current from the analog signal line is set and the input current value is normally set. Was used as a security alert.

On the other hand, in the remote monitoring and control system, in order to reduce the load on the central monitoring device, analog limit value data is given to the terminal device, a threshold is applied by the analog value to detect an abnormality, and the terminal device is detected. Japanese Patent Laid-Open No. 63-208393 proposes a method of sending an alarm to a central monitoring device. Here, only the means for detecting an abnormality in the terminal device is shown by using the analog value as it is.

[0005]

[Problems to be solved by the device]

 However, according to the above-mentioned conventional telemeter terminal device, since there is no analog signal line disconnection judgment circuit, the analog input data value is stored as "0", and the data value or the alarm value which is urgently required is kept correct in the normal operation. However, there was a drawback in that it could not be sent to the central monitoring device. Also, if you set the lower limit value of the input current from the analog signal line and substitute the input current value as a normal security alarm, it is not possible to determine whether it is a normal security alarm or an alarm due to a wire break when an alarm occurs. There was a drawback that the response was delayed.

Therefore, the present invention is to provide a telemeter terminal device capable of determining disconnection of an analog signal line from a sensor to an A / V converter.

[0007]

[Means for Solving the Problems]

 In order to solve the above-mentioned problem, an analog signal line disconnection determination circuit for determining disconnection of the analog signal line from the sensor to the A / V conversion unit based on the output voltage from the A / V conversion unit is provided, and the analog signal when the disconnection is determined. The central processing circuit (CPU) is interrupted by a disconnection determination signal from the disconnection determination circuit, and the analog data before the disconnection is saved and transmitted to the center unit.

[0008]

[Action]

 The analog signal from the sensor is converted from current to voltage by the A / V converter, and the analog signal line from the sensor to the A / V converter is converted by the analog signal line disconnection judgment circuit according to the output voltage from the A / V converter. Of the analog signal line at the time of the disconnection determination, interrupt the central processing circuit (CPU) with the disconnection determination signal from the disconnection determination circuit, save the analog data before the determination of the disconnection, and send it to the center device. .

[0009]

【Example】

 An embodiment of a telemeter terminal device according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 is an explanatory diagram of a configuration of a telemeter terminal device according to the present invention, and FIG. 2 is an explanatory diagram of an embodiment of an analog signal line disconnection judging circuit according to the present invention, which is provided inside the telemeter terminal 1. An analog signal line disconnection determination circuit 5 that determines disconnection of the analog signal line 4 from the sensor 3 to the A / V conversion unit 2 based on the output voltage from the A / V conversion unit 2 is provided. The disconnection determination signal of the disconnection determination circuit 5 is interrupted to the central processing circuit (CPU) 7 via the OR circuit 6, and the analog data before the disconnection is saved and transmitted to the center device 8.

The analog signal line disconnection determination circuit 5 monitors the output voltage 1V to 5V from the A / V conversion unit 2 after converting the analog signal from the sensor 3 from current to voltage in the A / V conversion unit 2. When the output voltage is 1 V or less, the analog signal line disconnection determination circuit 5 determines that the analog signal line 4 from the sensor 3 to the A / V converter 2 is disconnected, and when the disconnection determination is made, the analog signal line disconnection determination circuit 5 The disconnection determination signal outputs "H".

FIG. 3 is an explanatory view of a flow chart of an interrupt processing routine of the central processing circuit (CPU) at the time of judgment of disconnection, and after interrupting the central processing circuit (CPU) 7 of FIG. Which circuit is disconnected, read the disconnection status, save the analog data for each minute before the disconnection of the relevant circuit, and save the disconnection information and the saved analog data to the center device 8 in FIG. To terminate the interrupt.

Although the telemeter terminal device is composed of four circuits in the above embodiment, this is an example, and the number of circuits may be two or three, and also in other circuit configurations. Modifications can be made as appropriate without departing from the purpose of the present invention.

[0014]

[Effect of device]

 As described above, the telemeter terminal device according to the present invention is an analog device that determines the disconnection of the analog signal line from the sensor to the A / V conversion unit based on the output voltage from the A / V conversion unit provided inside the telemeter terminal. A signal line disconnection determination circuit is provided, and when a disconnection determination is made, the central processing circuit (CPU) is interrupted by the disconnection determination signal from the analog signal line disconnection determination circuit and the analog data before the disconnection is saved and sent to the center unit. Therefore, it has an excellent effect that the disconnection can be dealt with quickly, the analog data before the disconnection can be accurately transmitted to the center device, and the sensor power-off can be monitored. .

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a configuration of a telemeter terminal device according to the present invention.

FIG. 2 is an explanatory diagram of an embodiment of an analog signal line disconnection determination circuit according to the present invention.

FIG. 3 is an explanatory diagram of a flowchart of an interrupt processing routine of a central processing circuit (CPU) at the time of determination of disconnection.

FIG. 4 is an explanatory diagram of a conventional telemeter terminal device.

[Explanation of symbols]

1 ... Telemeter terminal, 2 ... A / V converter, 3 ...
..Sensor, 4 ... Analog signal line, 5 ... Analog signal line disconnection determination circuit, 6 ... OR circuit, 7 ... Central processing circuit (CPU), 8 ... Center device.

Claims (1)

[Scope of utility model registration request] 1. An A / V converter for converting a current of an analog signal from a sensor for measuring a state of a monitored object into a voltage,
A telemeter terminal device having an A / D converter for converting an analog signal into a digital signal, and a digital transmitting means for transmitting the A / D converted digital signal to a central monitoring device through a public telephone line network. An analog signal line disconnection determination circuit for determining disconnection of an analog signal line from the sensor to the A / V conversion unit based on an output voltage from the A / V conversion unit provided inside the telemeter terminal is provided. A telemeter terminal device characterized in that a central processing circuit (CPU) is interrupted by a disconnection determination signal from an analog signal line disconnection determination circuit, and analog data before disconnection is saved and transmitted to a center device.