JPH0532937B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a remote monitoring and control system using a time division multiplex transmission method.

[Background technology]

FIG. 1 is a block diagram of a conventional remote monitoring and control system using a time division multiplex transmission method. In the figure, reference numeral 1 denotes a two-wire signal transmission line, through which time-division multiplex transmission using a baseband transmission method is transmitted. A plurality of terminal devices 2 are connected in parallel to the signal transmission line 1, and each terminal device 2 is assigned a unique address. A transmission unit 4 of a central monitoring and control device 3 is connected to the signal transmission line 1, and an address signal for selecting each terminal 2 is transmitted on the signal transmission line 1, and a terminal 2 selected by the address signal is A control signal for giving a control command to the terminal 2 and a return standby signal consisting of a long pulse indicating a waiting period for a return signal in current mode from the terminal 2 are transmitted in a time-division manner. The transmission unit 4 is controlled by a main CPU 5 within the central supervisory control unit 3.
A keyboard 6 is connected to this main CPU 5 as an input device, and as an output device.
A CRT 7 and a printer 8 are connected. 9
An annunciator is a sub-monitoring control device, which selects a specific number of equipment such as air conditioning and lighting from among all control points by the terminal 2, and performs on-off control, status monitoring, and abnormality monitoring. In this way, in the conventional example, the annunciator 9
is operated by the main CPU 5 in the central supervisory control device 3, so if the main CPU 5 breaks down, the annunciator 9 will also become inoperable, and the annunciator 9 is installed in the central supervisory control device 3. There was a problem that it was limited to the very vicinity of .

[Purpose of the invention]

The present invention has been made in view of the above-mentioned points, and even if the functions of the central monitoring and control unit fail, the sub-supervisory and control unit can control the terminals, monitor the status, and
It is an object of the present invention to provide a remote monitoring and control system that allows continued abnormality monitoring and the like, and allows relatively freely setting the position where a sub-monitoring and control device is connected to a signal transmission line.

[Disclosure of the invention]

Hereinafter, the configuration of the present invention will be explained with reference to the illustrated embodiment. As shown in FIGS. are connected to each other via a signal transmission line 1, and an address signal for selecting a specific terminal device 2 from the central monitoring and control device 3 to the signal transmission line 1, a control signal for giving a control command to the terminal device 2, and a control signal for giving a control command to the terminal device 2. In a remote monitoring and control system in which a transmission signal in which a return standby signal indicating a reception period of a return signal from a device 2 is arranged in a time-division manner is cyclically transmitted sequentially for each address, the center of the signal transmission line 1 It is interposed in series between the supervisory control device 3 and each terminal device 2, and receives an address signal and a control signal from the central supervisory control device 3 and sends it to each terminal device 2, and also receives an address signal and a control signal from each terminal device 2. An annunciator 9 is provided as a sub-supervisory control device that receives a return signal from the central supervisory control device 3 and sends it back to the central supervisory control device 3.
an individual operation switch unit 10 that sets the content of the control signal for the transmission signal sent from the terminal device 2 to each terminal device 2;
A display section 11 serving as a monitoring output section and an abnormality output section 12 are provided to output the contents of signals returned from each terminal device 2. The annunciator 9 is equipped with a transmission interface section 13, and this transmission interface section has the function of monitoring the contents of the transmission signal sent from the central monitoring and control device 3, and the function of transmitting this transmission signal to each terminal device 2. It has a function of transmitting a signal, a function of monitoring a return signal sent back from each terminal device 2 in current mode, etc., and a function of sending the return signal back to the central monitoring and control device 3. In this way, the annunciator 9 needs to monitor the return signal sent back from each terminal device 2 in current mode, etc., so its installation location is from the central monitoring and control device 3 on the signal transmission line 1 to the first terminal device 2.
It must be a place up to. FIG. 3 is a block diagram showing the internal structure of the annunciator 9. As shown in FIG. In the figure, 14 is a CPU (central processing unit), 15 is a program memory that stores the operations of the CPU 14, and 16 is a data memory that stores data required during the operation of the CPU 14. Reference numeral 17 denotes a data conversion table memory, which is used to determine from the terminal address monitored by the transmission interface section 13 whether the terminal device 2 at that address is for monitoring operating conditions or for abnormality monitoring. . Reference numeral 11 denotes a display section consisting of an LED or the like, which displays whether the terminal device 2 is on/off or abnormal. Reference numeral 12 denotes an abnormality output section, which includes a contact output, an open collector output, a TTL output, etc. for transmitting an abnormality to an external device.

As described above, the transmission interface section 13 constantly monitors the transmission signal on the signal transmission line 1, and if there is a received signal, sends the received signal to the CPU 14. When the CPU 14 receives the above data, if the terminal address included therein is registered in the data conversion table memory 17,
The return data from the terminal device 2 with the terminal address is set as the operating state of the terminal side, and the LED at the position corresponding to the terminal address is turned on on the display section 11. In addition, if there is any abnormality, the LED corresponding to the abnormality is lit on the display unit 11,
The abnormality output section 12 also provides a relay contact output or the like to an external device.

Further, when performing individual control using the annunciator 9, the individual operation switch section 10 is operated. At this time, the CPU 14 determines what kind of switch operation was performed, and refers to the data conversion table memory 17 to create an address signal and a control signal for the terminal device 2 corresponding to the above switch operation. Thereafter, the CPU 14 waits until the address signal sent from the transmission interface section 13 becomes 0ch, and sends out the above-described created address signal and control signal at the timing of the next access. However, in this case, it is assumed that address signals are sent out from the transmission unit 4 of the central supervisory control device 3 and the transmission interface section 13 of the annunciator 9 in the order shown in FIG. That is, the address
When terminal devices 2 of lch to nch are connected, address signals are sent as 0, 0, 1, 2,
3, 4, ..., n, 0, 0, 1, 2, ..., the transmission signal including the second 0ch address signal is a pseudo transmission signal, and this transmission When sending out a signal, the annunciator 9 sends out a transmission signal containing the above-mentioned individual control address signal and control signal instead of a pseudo transmission signal. By doing as described above, it becomes possible to individually control each terminal device 2 by the annunciator 9.

FIG. 5 is a block diagram showing the configuration of the transmission unit 4 in the central supervisory control device 3. In the figure, the logic operation section 18 calculates and changes the contents of the control data memory 21 based on the operation input from the main CPU 5 or the operation input section 19, or the terminal monitoring input from the reception determination section 20. In addition to outputting a display signal to the display section 22, the logic operation section 18 calculates the terminal address to be transmitted and its control data in synchronization with the transmission clock in the transmission signal generation section 23, and 23. Transmission signal generator 2
3 converts the address signal and control signal sent from the logic operation unit 18 into a transmission waveform, and transmits the signal to the transmission unit 24.
At the same time, as described above, the logic operation unit 18
Sends a synchronization signal to The transmitter 24 converts the signal sent from the transmit signal generator 23 into a transmit signal and sends it to the terminal 2. The received signal detection section 25 detects a return signal sent from the terminal device 2 and sends it to the reception determination section 20. The reception determining section 20 determines whether the returned signal is correct data, and if the data is correct, sends the data to the logical operation section 18.

FIG. 6 is a block diagram showing the configuration of the terminal device 2 connected to the signal transmission line 1, and FIG.
FIG. 2 is an operation explanatory diagram showing the timing of signal transmission and reception. In FIG. 6, the input voltage from the signal transmission line 1 serves as a power source for driving a terminal logic circuit section 27 and a control relay 28 by a terminal power supply conversion section 26. On the other hand, the signal input is subjected to half-wave rectification by the input protection section 29 to reduce the voltage, and becomes an input signal to the terminal logic circuit section 27 (FIG. 7a). This input signal causes the oscillation section 31 to oscillate with a time constant determined by the oscillation element section 30, the oscillation output is counted by the counter section 32, and the output is sent to the logic control section 33.
It is used as a timing signal. As a result, the logic control section 33 controls the address discrimination section 34 and the control signal discrimination section 35 to read the address and control signal in the input signal. Address discrimination section 34
Then, whether the address signal is normal data or not.
It also checks whether the address matches the address setting section 36, and if they match, sends a control gate signal (FIG. 7b) to the return output section 37, and also sends a similar signal to the logic control section 33. send. on the other hand,
The control signal discriminator 35 checks whether the control signal is a normal signal, and if it is a normal control signal, sends the signal to the logic control section 33 to obtain a signal with matching addresses. , sets the control data to the relay drive latch output section 38. When the signals from the address discrimination section 34 and the control signal discrimination section 35 are complete, the logic control section 33 changes the timing of the return signal (FIG. 7c) to the return gate output (FIG. 7f) to the return output section 37. Then, the monitoring input return section 39 is operated. The monitoring input reply unit 39 converts the status of the monitoring input from the monitoring unit 40 into a signal based on the timing from the counter unit 32,
It is sent to the return output section 37. The return output unit 37 sends the return signal (FIG. 7c) from the monitoring input reply unit 39 to the signal transmission line 1 as a current mode signal. Furthermore, in the logic control section 33, when the signals from the address discriminating section 34 and the control signal discriminating section 35 are complete, a relay drive pulse signal (see FIG. c) is sent to the relay drive section 41. As a result, the relay drive section 4
1 drives the control relay 28 in accordance with the latch output of the relay drive latch output section 38 (FIG. 7d) to control the load 42.

〔Effect of the invention〕

The present invention is configured as described above, and is used for signal transmission in a distance control monitoring system in which a plurality of terminal devices and a central monitoring device are connected by a signal transmission line using a time division multiplex transmission method. Interposed in series between the central supervisory control unit and each terminal on the line, receives address signals and control signals from the central supervisory control unit, sends them to each terminal, and sends them back from each terminal. A sub-monitoring and control device is provided which receives signals and sends them back to the central monitoring and control device, and the sub-monitoring and controlling device has a transmission signal sent from the annunciator to each terminal in place of the pseudo transmission signal sent from the central monitoring and control device. Since it is equipped with an individual operation switch section that sets the contents of the control signal and a display output section that displays the signal contents returned from each terminal, it does not require the installation location of the sub-monitoring and control device as in the conventional case. It is said that the setting is not limited to the immediate vicinity of the central monitoring and control unit, but can be set relatively freely anywhere from the central monitoring and control unit on the signal transmission line to the first terminal device. This sub-monitoring control device has the advantage of having an individual operation switch section for setting the contents of the transmission signal sent to each terminal device, and a display output section for displaying the contents of the signal returned from each terminal device. Because of this, the main central monitoring and control equipment
The advantage is that it does not depend on the CPU, and even if the main CPU of the central supervisory control unit fails, supervisory control operations can continue as long as the signal transmission between the submonitoring control unit and each terminal device is normal. There is.

Moreover, since the sub-monitoring and control equipment is inserted in series between the central monitoring and control equipment and each terminal, all transmission signals that are bidirectionally transmitted between the central monitoring and control equipment and the terminals are It is possible to monitor the overall operation of the system, to accurately display the operating status of the system, and by using the individual operation switch section of the sub-monitoring and control device. As a result, it has become possible to control terminals not only from the central supervisory control unit but also from the sub-supervision and control units.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a conventional example, Fig. 2 is a block diagram of an embodiment of the present invention, Fig. 3 is a block diagram of an annunciator used in the above, and Fig. 4 is an operation showing the order of sending out address signals in the same. Explanatory diagram,
FIG. 5 is a block diagram of the transmission unit used in the above, and FIG. 6 is a block diagram of the terminal used in the same.
FIG. 7 is an operation explanatory diagram showing the timing of signal transmission and reception of the terminal device used in the above. 1 is a signal transmission line, 2 is a terminal device, 3 is a central monitoring device, 9 is an annunciator, 10 is an individual operation switch section, 11 is a display section, and 12 is an abnormality output section.

Claims (1)

[Claims] 1. Connect multiple terminals to which unique addresses have been assigned and the central supervisory control unit to each other via a two-wire signal transmission line, and select a specific terminal from the central supervisory control unit on the signal transmission line. A transmission signal in which an address signal, a control signal giving a control command to the terminal device, and a return standby signal indicating a reception period for a return signal from the terminal device are arranged in a time-sharing manner is sequentially cyclically transmitted for each address. In a remote monitoring and control system configured to transmit data, the terminals are interposed in series between the central monitoring and controlling device on the signal transmission line and each terminal device receives address signals and control signals from the central monitoring and controlling device, and each A sub-monitoring and controlling device is provided which transmits signals to the terminals and also receives return signals from each terminal and sends them back to the central monitoring and controlling device. An individual operation switch section is provided for setting the content of the control signal for the transmission signal sent from the sub-monitoring control device to each terminal device in place of the signal, and a monitoring output section is provided for outputting the signal content returned from each terminal device. A remote monitoring and control system characterized by: