JPH0528014B2 - - 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 multiplexed transmission signals based on the baseband transmission system are 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. The signal transmission line 1 includes a transmission unit 4 of the central monitoring and control device 3.
are connected, and each terminal device 2 is connected to the signal transmission line 1.
, a control signal that gives a control command to the terminal device 2 selected by the address signal, and a long pulse that indicates a waiting period for a return signal in current mode from the terminal device 2. The return standby signals 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 the main CPU 5 as an input device, and a CRT 7 and a printer 8 are connected as output devices. Reference numeral 9 denotes an annunciator, which is a sub-monitoring control device, and selects a specific number of equipment such as air conditioning and lighting from among all control points by the terminal device 2, and performs on-off control, status monitoring, and abnormality monitoring. . In this way, in the conventional example, the annunciator 9 is connected to the main CPU 5 in the central monitoring and control device 3.
Therefore, if the main CPU 5 fails, the annunciator 9 will also become inoperable, and the installation location of the annunciator 9 will be limited to a location very close to the central monitoring and control unit 3. There was a problem.

[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 continuous abnormality monitoring and the like, and also allows the user to freely set the location where a sub-monitoring and control device is installed.

[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, a transmission signal in which a transmission signal is arranged in a time-division manner and a return standby signal indicating the receiving period of the return signal from the device 2 is cyclically transmitted sequentially for each address. It is interposed in series between the central monitoring and control device 3 and each terminal device 2, and receives address signals and control signals from the central monitoring and control device 3 and sends them to each terminal device 2. A relay interface unit 10 is provided which receives a return signal from the central supervisory control unit 3 and sends it back to the central supervisory control device 3. An annunciator 9 serving as a monitoring control device is provided, and the annunciator 9
, an individual operation switch section 12 sets the content of the transmission signal sent from the relay interface section 10 to each terminal device 2 in place of the transmission signal from the central monitoring and control device 3, and a A display section 13 serving as a monitoring output section that outputs signal contents and an abnormality output section 14 are provided to display the contents of the transmission signal set by the individual operation switch section 12 and each terminal device 2 received by the relay interface section 10. The contents of the return signal from the sub-signal transmission line 11 are transmitted from the sub-signal transmission line 11. The relay interface unit 10 includes a transmission interface 15,
This transmission interface 15 has the function of monitoring the contents of the transmission signal sent from the central monitoring and control device 3, the function of sending this transmission signal to each terminal device 2, and the function of transmitting the current mode etc. from each terminal device 2. It has a function of monitoring the return signal sent back by the controller and a function of sending the return signal back to the central monitoring and control device 3. In this way, the relay interface section 10 needs to monitor the return signals sent back from each terminal device 2 in current mode, etc.
Its installation location must be on the signal transmission line 1 from the central supervisory control device 3 to the first terminal device 2. FIG. 3 is a block diagram showing the internal configuration of the relay interface section 10. In the same figure, 16 is a CPU (central processing unit), and 1
7 is a program memory for storing the operation of the CPU 16, and 18 is a data memory for storing data required during the operation of the CPU 16. Also 19
is a data conversion table memory, and from the terminal address monitored by the transmission interface 15, the terminal device 2 at that address is transferred to the annunciator 9.
Which position of the display section 13 corresponds to in
It is also a memory for determining whether monitoring is for operating conditions or abnormalities. A transmission interface 20 transmits signals to and from the annunciator 9 via the sub-signal transmission line 11. This sub-signal transmission line 11 is a multiplex transmission line. On the other hand, as shown in FIG. 4, the annunciator 9 has a transmission interface 21 connected to the sub-signal transmission line 11 so that the annunciator 9 can send and receive signals to and from the relay interface section 10. It's summery. The annunciator 9 has a CPU 22, a program ROM 23, and a data RAM 24, and transmits information input from the individual operation switch section 12 to the relay interface section 10 via the transmission interface 21 and the sub-signal transmission line 11. , or the repeater interface section 10 receives the return signal from the terminal device 2 via the sub-signal transmission line 11 and the transmission interface 21, and displays it on the display section 1.
3 and the abnormality output section 14 as appropriate. The display unit 13 is made up of a plurality of LEDs, etc., and is used to display the on/off state of the terminal device 2 or an abnormality. Further, the abnormality output section 12 includes a contact output, an open collector output, a TTL output, etc. for transmitting abnormality to external equipment. Furthermore, the individual operation switch unit 12 has a plurality of switch groups, and the switch unit 12 has a plurality of switch groups, from the annunciator 9 to the terminal device 2.
It is now possible to set the contents of the address signal and control signal when individually controlling the .

Therefore, the transmission interface 15 in the relay interface section 10 constantly monitors the transmission signal on the signal transmission line 1, and if there is a received signal,
The received signal is sent to the CPU 16. CPU16
Now, when the above data is received, the terminal address contained therein is stored in the data conversion table memory 19.
If registered in
The signal is sent to the annunciator 9 via the sub-signal transmission line 11, and the LED at the position corresponding to the terminal address is lit on the display section 13. If there is any abnormality, the display section 13 lights up an LED corresponding to the abnormality, and the abnormality output section 14 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 of the annunciator 9 is operated. At this time, annunciator 9
The CPU 22 determines what kind of switch operation has been performed, and sends the result to the relay interface section 10 via the sub-signal transmission line 11. The CPU 16 of the relay interface section 10 refers to the data conversion table memory 19 and creates an address signal and a control signal for the terminal device 2 corresponding to the above switch operation. Thereafter, the CPU 16 waits until the address signal sent from the transmission interface 15 onto the signal transmission line 1 becomes 0ch, and sends out the above-mentioned created address signal and control signal at the next access timing. be. However, in this case, the transmission of address signals from the transmission unit 4 of the central monitoring and control device 3 and the transmission interface 15 of the relay interface section 10 is 0 when terminal devices 2 with addresses 1ch to nch are connected. ,0,1,2,3,4,...,
Do it in the order like n, 0, 0, 1, 2,...
When the 0ch address signal is sent out for the second time, the above-mentioned address signal and control signal for individual control are sent out. By doing so, it becomes possible to individually control each terminal device 2 by the relay interface section 10 based on commands from 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 25 calculates and changes the contents of the control data memory 28 based on the operation input from the main CPU 5 or the operation input section 26, or the terminal monitoring input from the reception determination section 27. In addition to outputting a display signal to the display section 29, the logic operation section 25 calculates the terminal address to be transmitted and its control data in synchronization with the transmission clock in the transmission signal generation section 30, and 30. Transmission signal generator 30
converts the address signal and control signal sent from the logic operation section 25 into transmission waveforms and sends them to the transmission section 31, and also sends out a synchronization signal to the logic operation section 25 as described above. The transmitter 31 converts the signal sent from the transmit signal generator 30 into a transmit signal and sends it to the terminal 2. The received signal detection section 32 detects a return signal sent from the terminal device 2 and sends it to the reception determination section 27. The reception determining section 27 determines whether the returned signal is correct data, and if the data is correct, sends the data to the logic operation section 25.

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 34 and a control relay 35 by a terminal power supply conversion section 33. On the other hand, the signal input is subjected to half-wave rectification by the input protection section 36 to reduce the voltage, and becomes an input signal to the terminal logic circuit section 34 (FIG. 7a). This input signal causes the oscillation section 38 to oscillate with a time constant determined by the oscillation element section 37, the oscillation output is counted by the counter section 39, and the output is sent to the logic control section 40.
It is used as a timing signal. As a result, the logic control section 40 controls the address discrimination section 41 and the control signal discrimination section 42 to read the address and control signal in the input signal. Address discrimination section 41
Then, whether the address signal is normal data or not.
It also checks whether the address matches the address setting section 42, and if they match, sends a control gate signal (FIG. 7b) to the return output section 44, and also sends a similar signal to the logic control section 40. send. on the other hand,
The control signal discriminator 42 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 40 to obtain a signal with matching addresses. , and sets the control data to the relay drive latch output section 45. When the signals from the address discrimination section 41 and the control signal discrimination section 42 are complete, the logic control section 40 outputs the return gate output (FIG. 7f) at the timing of the return signal (FIG. 7c) to the return output section 44. In addition, the monitor input reply section 46 is operated. The monitoring input reply section 46 converts the state of the monitoring input from the monitoring section 47 into a signal based on the timing from the counter section 39 and sends it to the return output section 44 . The return output unit 44 sends the return signal (FIG. 7c) from the monitoring input reply unit 46 to the signal transmission line 1 as a current mode signal.
Further, in the logic control section 40, an address discrimination section 41
When the signals from the control signal discriminator 42 and the control signal discriminator 42 are complete,
The relay drive pulse signal (Fig. 7c) for creating the timing to drive the relay drive unit 4
Send to 8. This causes the relay drive unit 48 to output the latch output (seventh output) of the relay drive latch output unit 45.
d) and drives the control relay 35 according to the load 4
2.

〔Effect of the invention〕

The present invention is constructed as described above, and is used to transmit signals in a remote monitoring and control system in which a plurality of terminal devices and a central monitoring and control 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 relay interface section that receives signals and sends them back to the central monitoring control device is provided, and a sub-monitoring and control device is provided that is connected to the relay interface section via a sub-signal transmission line different from the above-mentioned signal transmission line. The control device includes an individual operation switch section that sets the content of the transmission signal sent from the relay interface section to each terminal device in place of the transmission signal from the central monitoring and control device, and an individual operation switch section that sets the content of the transmission signal sent back from each terminal device. A monitoring output section is provided to output the contents of the transmission signal set by the operation switch section and the contents of the return signal from each terminal device received by the relay interface section via the sub-signal transmission line. Because the system is designed to transmit signals, the installation location of the sub-monitoring and control equipment is not limited to the very vicinity of the central monitoring and control equipment as in the past, but rather By connecting to the relay interface provided up to the terminal device via a separate sub-signal transmission line, the installation location of the sub-monitoring and control device can be set relatively freely. This sub-monitoring control device has the advantage that it is provided with 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 sent back from each terminal device. Since it is possible to control and monitor each terminal device via the sub-signal transmission line and the relay interface section, it is not dependent on the main CPU of the central monitoring and control device as in the past, and can be used in all situations. One advantage is that even if the main CPU of the central supervisory control device fails, the subsidiary supervisory control device can continue the supervisory control operation.

[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 a relay interface section used in the above, and Fig. 4 is a block diagram of an annunciator used in the same. , 5th
FIG. 6 is a block diagram of a transmission unit used in the above, FIG. 6 is a block diagram of a terminal used in the same, and FIG. 7 is an operation explanatory diagram showing the timing of signal transmission and reception of the terminal used in the same. 1 is a signal transmission line, 2 is a terminal device, 3 is a central monitoring and control device, 9 is an annunciator, 10 is a relay interface section, 11 is a sub signal transmission line, 12 is an individual operation switch section, 13 is a display section, 14 is a This is the 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 control device on the signal transmission line and each terminal device receives the address signal and control signal from the central monitoring and control device, and each A relay interface unit is provided which transmits signals to the terminals and also receives return signals from each terminal unit and sends them back to the central supervisory control unit. A sub-monitoring and controlling device is provided which is connected to the central monitoring and controlling device, and the sub-monitoring and controlling device has an individual operation switch that sets the content of the transmission signal sent from the relay interface section to each terminal device in place of the transmission signal from the central monitoring and control device. and a monitoring output section that outputs the contents of the signals sent back from each terminal device, and outputs the contents of the transmission signal set by the operation switch section and the contents of the signal sent back from each terminal device by the relay interface section. A remote monitoring and control system characterized in that the content of the return signal is transmitted via a sub-signal transmission line.