JPH02137436A - Remote monitor and control equipment - Google Patents

Abstract

PURPOSE:To detach a terminal equipment concerned from a transmission line by monitoring the present or absent state of a carrier from the terminal equipment at the time of calling the terminal, sequentially transmitting the power 'off' control signal of the terminal equipment and detecting the terminal equipment of unauthorized carrier transmission when the carrier is present. CONSTITUTION:The terminal supervisory part 22 of a central unit 1 checks the presence or absence of the carrier in a reception circuit 12 through a transmission line coupling part 14 after a supervisory returning action for a terminal equipment R1 terminates and before call for a subsequent terminal equipment R2 is performed. When the carrier is present at that time, a power disconnection time limit command R1X is transmitted to the transmission line (l) from the terminal equipment R1 through the transmission circuit 13 and the transmission line coupling part 14 and the presence or absence of a transmission carrier f1 is checked in the middle of the power disconnection time limit operation of the terminal equipment R1. When the carrier is present, a power disconnection time limit command R2X for the terminal equipment R2 is transmitted to the transmission line (l). When the carrier is absent, it is judged to be the fault of the terminal equipment, and a power disconnection continuous command R2Y is transmitted on the transmission line (l).

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention enables a central device to cyclically monitor a plurality of terminals, easily detects a failure in a terminal device equipped with remote monitoring control, and This is designed so as not to interfere with normal data transfer of the terminal device.

[Prior Art] FIG. 3 is a block diagram showing a configuration example of a conventional remote monitoring and control device disclosed in, for example, Japanese Patent Application Laid-Open No. 59-28743. In the figure, (1) is a central device, and a simple Multiple terminal bags @ (R1) via one transmission line (1).

(R2), ...... (Rn) are connected.

Here, the central device (1) is the terminal device (R1).

(R2), . . . (Rn), and a transmitting/receiving circuit Ill that sends a supervisory control signal to (Rn) and receives a supervisory return signal from the same device in response to the signal, and the terminal devices ft(R1), (R2). ), ・・・−・・・ (Rn)
and a sequential monitoring circuit (21) that controls the transmitting/receiving circuit 0υ to sequentially call and cyclically monitor the terminal device. Also, each terminal device (R1).

(R2)... (Rn) is assigned a unique address.

Next, the operation will be explained. FIG. 4(a) shows the case where each terminal device is constantly cyclically called and monitored, as shown in FIG. 4(b).
1 and 2 respectively show how a specific terminal device is controlled.

In FIG. 4(a), the central device (1) first sends a monitoring request signal to the terminal device (R1), and in response, the terminal device (R1) sends back a monitoring return signal, which is then received. Then, a monitoring request signal is sent to the terminal device (R1), and the monitoring return signal is similarly received. Thereafter, the monitoring operation up to the terminal device (Rn) is performed in the same way,
Next, iterative terminal devices (R1), (R2), ...
. . . (Rn) Monitoring operation is performed, and this operation is repeated. These repeated operations are sequentially controlled by the supervisory control circuit (2).

Next, a case will be described in which a specific terminal device is controlled.

In FIG. 4(b), in a state where cyclic call monitoring is being performed at all times as shown in FIG. 4(a),
The operator selects a specific terminal device (here, the terminal device (R)
1), the sequential monitoring control circuit Qυ interrupts the above-described cyclic call monitoring operation and continuously monitors only the selected terminal bag @(R1). However, the sequential monitoring control circuit 121) waits for the operation currently in progress, that is, in FIG. 4(b), to wait for the completion of reception of the monitoring return signal of the terminal bag fit (R2), and only controls the selected terminal device (R1). control to continuously monitor. Thereafter, the operator selects and controls the controlled equipment, and deselects the terminal device (R1), and the supervisory control circuit (2B) similarly controls the operation of the central device (1).

Here, the control operation from the central device (1) is based on three behavior operations: terminal selection and controlled device selection signal control.

Next, the operator selects the controlled device.

The central device (1) sends a controlled device selection signal to the terminal bag M (R1). When the terminal device R1) receives this signal, it selects the controlled device and returns a monitoring return signal.

Next, when the operator issues a control command, the central device (1)
sends a control signal to the terminal bag ff1 (R1).

When the terminal device (R1) receives this signal, it controls the device and returns a monitoring return signal. When the operator confirms that the device is controlled, the operator connects the terminal device (R
Deselect 1).

As a result, the sequential monitoring control circuit (21) resumes the cyclic call monitoring operation. Normally, the cyclic call monitoring operation is restarted from the terminal device where it was interrupted first, which is the terminal device (R2) in the example of FIG. 4(b).

As mentioned above, since this remote monitoring and control device uses a polling method, only one set of transmitting/receiving circuits (111) of the central device (1) is required, and the transmission path (1) also connects multiple terminal devices (R1).
), (R2), ... (Rn), making it possible to configure the device at relatively low cost. Also, all terminal devices (R1) at all times.

Since (R2), ..., (Rn) are monitored sequentially,
Even if there is a status change in a monitoring item of a specific terminal device (such as when a monitored and controlled device is abnormal), it can be immediately transmitted to the central device (1) and displayed.

Furthermore, all terminal devices (R1), (R2)...(R
n) is sequentially monitored, it becomes possible to immediately detect abnormalities (for example, disconnection, etc.) in the transmission line (1).

[Problems to be Solved by the Invention] Since the conventional remote monitoring and control device is configured as described above, it is difficult to prevent terminal devices connected to a single line transmission path from receiving data that would affect data transfer on the transmission path. When a failure occurs, in order to isolate the faulty processing device, it is necessary to carry out failure diagnosis while manually pulling out the printed cards on which the transmitting and receiving circuits of each terminal device are mounted one by one from the terminal device. However, there was a problem in that it required a considerable amount of time to repair the failure.

This invention was made in order to solve the above-mentioned problems, and provides a remote monitoring and control device that can automatically detect a faulty terminal device using a central device and can also disconnect the terminal device from the transmission path. The purpose is to obtain.

[Means to solve the problem]

In the remote monitoring and control device according to the present invention, each terminal device is provided with a part that controls the power supply of the transmitting circuit, and when a terminal is called, the central device monitors the presence or absence of a carrier from the terminal device on the transmission path, and In this case, a control signal to turn off the power of the transmission circuit of the terminal device is sent to each terminal device in sequence to detect the terminal device transmitting on an unauthorized carrier and disconnect the terminal device from the transmission path. It is.

[Effect]

In this invention, the inter-carrier wave number for calling from the central device to each terminal device is different from the carrier frequency for monitoring return from the terminal device, so that even if the terminal device sends an illegal carrier to the transmission path, the central device can It functions to be able to send out a power-off control signal for the transmitting circuit to the terminal device.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, (1) is a central device that connects multiple terminals @(R1) via a single line transmission path <1>.

(R2), ... (Rn) are connected. Here, the central device (1) is the terminal device (R1), (R2).

... The monitoring control signal for (Rn) is sent to the transmitting circuit f+
3) and the transmission carrier (
fo), and a receiving circuit (12) that sequentially receives a monitoring return signal from the same device in response to the signal via a transmission line coupling unit Q41, and the terminal bag [(R1), (R2), ..., (R
The transmitting circuit (13) and an all-terminal monitoring section 4 that controls the receiving circuit f12 sequentially call the terminals f12 and cyclically monitor the terminal devices.

In addition, each terminal device (R1), (R2), ... (Rn)
A terminal address (41) is assigned to the terminal address (41), and the call receiving carrier (cfo) from the central device (1) is input to the receiving circuit (1) via the transmission path coupling unit (14), and the receiving circuit 15) passes the contents of the call from the central device (1) to the terminal control section (2), and the terminal control section ■ checks its own terminal address + 41) with the terminal address called from the central device (1). After that, depending on the content of the call,
A command is given to the power supply control unit (1η) or the transmission circuit +161, and if the call content from the central device is a return command, the transmission circuit (1■) sends a return signal in response to the call signal to the transmission carrier (fl) to the transmission line coupling unit q41. via the central device (1
) to each terminal device (R1''), (R2).

... (Rn) is configured.

Next, the operation will be explained.

FIG. 2 shows how terminal control signals from each terminal device are cyclically monitored.

In FIG. 2, when the central device (1) recognizes that there is no receiving carrier (fl) on the transmission path, it sends a monitoring request signal to the terminal device (R1) from the transmitting circuit (13) to the transmitting carrier (fl). fo), the transmission line connecting unit 0 station via transmission line (
1). Each terminal device (R1), (R2>).

... (Rn) takes in the received carrier (fo) to the receiving circuit 05) via the transmission line coupling unit (14), and passes the monitoring request signal from the central device (1) to the terminal control unit (2). The terminal control unit ■ has its own terminal address (41) and the central device (
Verify the terminal address called from 1). Here, the terminal address verification process can be avoided because the terminal device (R1
), and the terminal bag Ml (R1) sends out the transmission carrier (fl) from the transmission circuit (1ω) and connects it to the transmission line coupling unit 1.
14) to the central device (1) via the transmission path (I).The central device (1) sends the monitoring return signal to the terminal device (
The received carrier (fl) from R1) is transferred to the transmission path coupling unit (1
4) Take it into the receiving circuit t13 via the terminal device (R1)
Pass the monitoring return contents from to the All Terminal Monitoring Department @. Thereafter, similar operations are repeated from the terminal devices (R2) to (Rn). These series of repeated operations are controlled by the all-terminal monitoring unit (No.).The Chuo Fukuro@(1) is configured to call the next terminal device after a certain period of time if there is no response from the terminal device. ing.

Next, a case will be described in which the transmission circuit (161) of a specific terminal device fails and continues to send out fraudulent carriers.

Here, a case will be explained taking as an example a case where the terminal bag @ (R2) breaks down after sending the monitoring return signal from the terminal device (R1).

After the central device (1) completes the monitoring return operation for one terminal device (R1) and before calling the next terminal device @ (R2), the central device (1) transmits the transmission carrier (f) from the terminal device on the transmission path (j).
In order to check whether or not 1) is being sent illegally, the all terminal monitoring unit q checks whether there is a carrier in the receiving circuit 113 via the transmission line coupling unit (141).At this time, if there is a carrier, all terminals are Since the terminal monitoring unit does not know which terminal device is transmitting the illegal carrier, it sequentially sends a power cut-off command (RIX) from the terminal device R (R1) to the transmitting circuit (13) and the transmission line coupling unit (141). The terminal device (R1) sends the data to the central device (
1) When receiving the power cut-off time limit command (RIX) from
The terminal control section 1 (branch) gives a command to the power supply control section αη to cut off the power supply route to the transmitting circuit fllli) for a certain period of time.

When the power supply control unit (1η receives this command, it starts the transmission circuit (
It operates to cut off the power supply route to the 1 mark for a certain period of time.

The central unit @ (1) checks the presence or absence of a transmission carrier (fl) from the terminal equipment on the transmission path <1> using all terminal monitoring units, while the terminal equipment @ (R1) is in the power-off time limit operation. do.

At this time, if there is a carrier, it is assumed that the failure is not in the terminal device (R1) but in another terminal device, and a power cut-off time limit command (R2X) for the next terminal device (R2) is issued on the transmission line (1). )) send out on. When the terminal device (R2) receives the power cut-off time limit command (R2X') from the central device (1), the terminal control section (■) instructs the power supply control section (17) to set the power supply route to the transmitting circuit eel in a fixed manner. Give it a time limit. When the power supply control unit (1?) receives this command, it operates to cut off the power supply route to the transmission circuit 116) for a certain period of time.

The central device (1) checks the presence or absence of a transmission carrier (fx, +) from the terminal device on the transmission path (j) using the all terminal monitoring unit ■, while the terminal device (R2) is in the power-off time limit operation. .

At this time, if the carrier is gone, the terminal device (R2
) is determined to be a failure.

The central unit @(1) sends a power-off continuation command (R2Y) to the terminal device (R2) onto the transmission line (1).

Terminal device! (R2) receives the power supply continuation command (R2Y) from the central unit (1), and the terminal control unit (branch) instructs the power supply control unit 07) to continue the power supply route to the transmitting circuit (1■). The power control unit (1η, upon receiving this command, self-retains the command until a manual recovery operation is performed (not shown)), the transmission circuit (power supply route to te+) It works to continuously cut off.

When the central unit @ (1) completes the operation of the power-off continuation command to the terminal device (R2), it confirms that there is no transmission carrier (fl) from the terminal device on the transmission path (1>), and
The state of calling the original terminals fl(R1), (R2), . . . (Rn) is returned.

Note that even if the transmitting circuit uQ of the terminal equipment flu (R2) remains powered off, the terminal equipment (R
2) The terminal device (
This is to enable the terminal device (R2) to automatically participate in the transmission path (1) without performing any special operations on the central device (1) after the failure recovery work of R2) is completed.

In the above embodiment, the case where a failure occurs in the terminal device fil (R2) is explained, but it goes without saying that the same operation as in the above embodiment is performed even if a failure occurs in another terminal device. do not have.

In the above embodiment, the power of the terminal device in which the fraudulent carrier has been generated is cut off, but other means for stopping the transmission of this terminal device may be used. For example, a transmission gate may be provided in the transmission circuit to open and close it, or the transmission coupling path I may be bypassed and disconnected.

〔Effect of the invention〕

As described above, according to the present invention, since the presence/absence of a transmitting carrier from a terminal device is monitored, a terminal transmitting an illegal carrier can be easily detected, and power supply to the transmitting circuit of the terminal device can be easily detected. Since it is configured to be separated from the transmission path by cutting off the route, a highly reliable remote monitoring and control device can be obtained without interfering with data transfer of other terminal devices.

[Brief explanation of the drawing]

Figure 1- is a block diagram showing the configuration of a remote monitoring control device according to an embodiment of the present invention, Figure 2 is a time chart for explaining the operation of the present invention, and Figures 3 and @4 are conventional remote monitoring systems. 2 is a block diagram and a time chart of a control device. (12 and (13 are the receiving circuit and transmitting circuit of the central unit, Oa
is the transmission line coupling section, (1 and +16) are the receiving circuit and transmitting circuit of the terminal device, +1 is the power supply control section, @ is the all terminal monitoring section, (branch) is the terminal control section, (41) is the terminal address ,(
fO) is the transmit carrier frequency from the central unit, (fl)
is the transmission carrier frequency from the terminal @(fl). In addition, the same symbols in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) In a polling-type remote monitoring and control device that monitors and controls the terminal devices of each station in response to a call from a central device, the above-mentioned terminal devices are called all at once on a predetermined carrier frequency, and each of the above-mentioned terminal devices is sequentially sends a monitoring return signal having a carrier frequency different from the predetermined carrier frequency to the central device during the time period assigned to its own station, and performs cyclic monitoring by the central device, and Before calling the terminal device, the device monitors the presence or absence of a carrier in the monitor return signal from each terminal device, and when the carrier is present, sends a stop control signal to each terminal device to stop transmission from the terminal device. What is claimed is: 1. A remote monitoring device characterized in that it detects a terminal device transmitting an illegal carrier transmission by sequentially transmitting data to a terminal device, disconnects the terminal device from the transmission path, and performs cyclic monitoring.