JPH0528015B2 - - 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. . However, in such a conventional example, the annunciator 9 is the main part of the central monitoring and control device 3.
Since the annunciator 9 is operated by the CPU 5, there is a problem in that the installation location of the annunciator 9 is limited to a location very close to the central monitoring and control device 3.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned points, and it is an object of the present invention to provide a remote monitoring and control system in which the location where a sub-monitoring and control device is installed can be freely set.

[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. Connected to signal transmission line 1 in a remote monitoring and control system in which a transmission signal in which a return standby signal indicating the reception period of the return signal from device 2 is arranged in a time-division manner is cyclically transmitted sequentially for each address. a display unit 10 and an abnormality output unit 11 which are monitoring output units that read a control signal following the address signal when the address signal on the signal transmission line 1 matches its own address and output an output according to the control signal; An annunciator 9 is provided as a sub-monitoring control device having an individual operation switch unit 12 for setting a return signal for individual control of the terminal device 2 that is returned during the return standby signal period following the control signal, and the central monitoring and control device 3 Following the address signal that calls the annunciator 9, the monitoring content returned from the terminal device 2 is sent as a control signal, and the control signal is sent to the terminal device 2 according to the content of the return signal during the return signal period following the control signal. The content of the signal is changed. Annunciator 9 has a transmission interface 13 connected to signal transmission line 1 . This transmission interface 13 performs the same receiving and replying operations as other terminal devices 2 connected to the signal transmission line 1. That is, the transmission interface 13 of the annunciator 9 compares the address signal on the signal transmission line 1 with its own address,
When they match, the control signal following the address signal is read, and a preset return signal is sent back to the central supervisory control device 3 in a current mode or the like during a return standby signal period following the control signal. In this way, the transmission interface 13 of the annunciator 9 has its own address and can receive the control signal on the signal transmission line 1 and send back a return signal.
The annunciator 9 of this embodiment can be connected to any position on the signal transmission line 1 like the other terminals 2. Also, the annunciator 9 is the CPU
14 and a program that memorizes the operations of the CPU 14.
It has a ROM 15, a data RAM 16 for storing data required during the operation of the CPU 14, and the like. The display unit 10 is made up of a plurality of LEDs, etc., and is used to display the on/off state of the terminal device 2 or to indicate an abnormality. Further, the abnormality output section 11 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 .

The operation of this embodiment will be explained below. First, the case where on-off monitoring display and abnormality monitoring display of the terminal device 2 are performed will be explained. For example, when a certain air conditioner is turned on, the monitoring input of the terminal device 2 connected to the air conditioner changes, and the central monitoring and control device 3 detects the change in the monitoring input as a reply signal. This causes the central monitoring and control device 3 to display changes in the monitoring input, but at the same time the annunciator 9
The content of the monitoring input and the address of the terminal device 2 that sent back the monitoring input are transmitted to the address as a control signal. The annunciator 9 decodes the received control signal according to the conversion table on the data RAM 16, and changes the display content on the display section 10. Note that if the content of the monitoring input indicates some abnormality, the LED corresponding to the abnormality is lit on the display unit 10, and the abnormality output unit 1 is turned on.
1 provides relay contact output etc. to external equipment. Next, the annunciator 9 sends the terminal 2
When performing individual control of the annunciator 9
1. Operate the individual operation switch section 12. At this time, the CPU 14 of the annunciator 9 determines what kind of switch operation has been performed, and sends the result from the transmission interface 13 via the signal transmission line 1 to the central supervisory control unit 3 as a return signal. The central monitoring and control device 3 is an annunciator 9
Using a data conversion table or the like, an address signal and a control signal for the terminal 2 corresponding to the above-mentioned switch operation are created from the return signal sent back from the terminal 2, and are transmitted to the signal transmission line 1. This allows the annunciator 9 to individually control the terminals 2.

FIG. 4 is a block diagram showing the configuration of the transmission unit 4 in the central supervisory control device 3. In the same figure, the logic operation unit 17 stores the control data memory 20 based on the operation input from the main CPU 5 or the operation input unit 18, or the information on the terminal monitoring input from the reception determining unit 19, especially the information on the monitoring input from the annunciator 9. Calculate and change the contents. In addition to outputting a display signal to the display section 21, the logic operation section 17 calculates the terminal address to be transmitted and its control data in synchronization with the transmission clock in the transmission signal generation section 22, and outputs a display signal to the display section 21. 2
2. Transmission signal generator 22
converts the address signal and control signal sent from the logic operation unit 17 into transmission waveforms and sends them to the transmission unit 23, and also sends out a synchronization signal to the logic operation unit 17 as described above. The transmitter 23 converts the signal sent from the transmit signal generator 22 into a transmit signal and sends it to the terminal 2. The received signal detection section 24 detects the return signal sent from the terminal device 2 and sends it to the reception determination section 19. The reception determining section 19 determines whether the returned signal is correct data or not, and if the data is correct, sends the data to the logical operation section 17.

FIG. 5 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. 5, the input voltage from the signal transmission line 1 serves as a power source for driving a terminal logic circuit section 26 and a control relay 27 by a terminal power converter section 25. In FIG. On the other hand, the signal input is subjected to half-wave rectification by the input protection section 28 to reduce the voltage, and becomes an input signal to the terminal logic circuit section 26 (FIG. 6a). This input signal causes the oscillation section 30 to oscillate with a time constant determined by the oscillation element section 29, the oscillation output is counted by the counter section 31, and the output is sent to the logic control section 32.
It is used as a timing signal. As a result, the logic control section 32 controls the address discrimination section 33 and the control signal discrimination section 34 to read the address and control signal in the input signal. Address discrimination section 33
Then, whether the address signal is normal data or not.
It also checks whether the address matches the address setting section 35, and if they match, sends a control gate signal (FIG. 6b) to the return output section 36, and also sends a similar signal to the logic control section 32. send. on the other hand,
The control signal discriminator 34 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 32 to obtain a signal with matching addresses. , and sets the control data to the relay drive latch output section 37. When the signals from the address discrimination section 33 and the control signal discrimination section 34 are complete, the logic control section 32 outputs the return gate output (FIG. 6 f) at the timing of the return signal (FIG. 6 c) to the return output section 36. Then, the monitor input reply section 38 is operated. The monitoring input reply section 38 converts the state of the monitoring input from the monitoring section 39 into a signal based on the timing from the counter section 31, and sends it to the return output section 36. The return output unit 36 sends the return signal (FIG. 6c) from the monitoring input reply unit 38 to the signal transmission line 1 as a current mode signal.
Further, in the logic control section 32, an address discriminating section 33
When the signals from the control signal discriminator 34 and the control signal discriminator 34 are complete,
The relay drive pulse signal (Fig. 6c) for creating the timing to drive the relay drive unit 4
Send to 0. This causes the relay drive unit 40 to output the latch output (sixth output) of the relay drive latch output unit 37.
d) and drives the control relay 27 according to the load 4
1.

〔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. a monitoring output unit that is connected to the signal transmission line and reads a control signal following the address signal when the address signal on the signal transmission line matches its own address and outputs an output according to the control signal; and a return standby signal that follows the control signal. A sub-monitoring and controlling device is provided, which has an individual operation switch unit that sets a return signal for individual control of the terminal device that is returned during the period, and the central monitoring and controlling device sends a message to the terminal following the address signal that calls the sub-monitoring and controlling device. The monitoring content returned from the device is sent as a control signal, and the content of the control signal sent to the terminal is changed according to the content of the return signal during the return signal period following the control signal. The installation location of the sub-monitoring and control equipment is not limited to the vicinity of the central monitoring and control equipment as in the past, but the sub-monitoring and control equipment can be connected to any position on the signal transmission line. Therefore, there is an advantage that the installation location of the sub-monitoring control device can be set relatively freely.

[Brief explanation of the drawing]

Figure 1 is a block diagram of a conventional example, Figure 2 is a block diagram of a remote monitoring and control system according to an embodiment of the present invention, Figure 3 is a block diagram of an annunciator used in the same system, and Figure 4 is a block diagram of the same system. FIG. 5 is a block diagram of a central monitoring and control device used in the system, FIG. 5 is a block diagram of a terminal device used in the above system, and FIG. 6 is an explanatory diagram of the operation of the terminal device. 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 display unit, 1
1 is an abnormality output section, 12 is an individual operation switch section, 1
3 is a transmission interface.

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 device is connected to a signal transmission line, and when the address signal on the signal transmission line matches its own address, it reads the control signal following the address signal and outputs an output according to the control signal. A sub-monitoring and controlling device is provided, which has a monitoring output section for controlling the control signal, and an individual operation switch section for setting a return signal for individual control of the terminal device, which is returned during the return standby signal period following the control signal, and a central monitoring and control device is provided. The device sends the monitoring content returned from the terminal device as a control signal following the address signal that calls the sub-monitoring control device, and sends it to the terminal device according to the content of the return signal during the return signal period following the control signal. A remote monitoring and control system characterized by changing the content of a control signal.