JP2001325003A - Plant controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a plant controller for reducing inter-control board cable installation costs and for improving the production efficiency. SOLUTION: A job site control board 1 set outdoor is provided with an internal temperature adjusting means, and electrical equipment can be mounted inside, and all control boards constituting the plant controller are constituted as electrical equipment, and inside wiring is integrated into a printed circuit board and, the production efficiency of the control boards can be improved, and wrong connections can be prevented. Also, information communication between respective control boards is realized as radio communication by a laser beam 21, and when the laser beam becomes abnormal, information communication is continued by wire communication by a core cable 22 so that the production efficiency can be improved, and that cable installation cost can be reduced by dispersing with a multi-core cable used in the conventional manner. Also, when any abnormal situation is generated, the contents of the abnormality are announced to external communications equipment 47 such as an outside PHS or portable radio telephone in detail by radio communication, and each control board is controlled from the outside part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plant control device, and more particularly to a plant control device used in a small-scale sewage plant control system having a processing capacity of 10,000 m ³ / day or less.

[0002]

2. Description of the Related Art FIG. 21 is a system configuration diagram of a conventional small-scale sewerage plant control device. Conventionally, a control panel 58 for supplying power to a motor 59, a field operation panel 1 for operating mechanical equipment on site, a field An auxiliary relay panel 38 for processing an operation command from the operation panel 1 and transmitting the control command to the control center 58;
The monitoring instrumentation panel 46 for monitoring the operation status of the plant equipment and performing instrumentation and control commands is all 1.25 for each signal line.
mm ² was done by (cross-sectional area, hereinafter the same) or more multi-core cable 81.

[0003] The reason for this is that, for the humid underground and pipe gallery laying the cable in the vicinity of the sludge pipes and sewage pipes, and not laying experience on 1.25mm ² or more cables, the cable during use for many years Cracks and abrasion occur on the exterior due to moisture and organic gas, and the cable wires are corroded and rusted.
This is because there is a possibility that a trouble that the signal cannot be transmitted between the control panel and the control panel without fail may occur.

Further, in the vicinity where the cable is laid, many machines operated by a large-capacity motor are installed.
When these large-capacity motors start or stop, very large pulse noise is generated, guided to nearby cable wires, and generates erroneous signals, which cause the auxiliary relay panel 38 and the monitoring instrument panel 46 to erroneously generate signals. There is a possibility that the auxiliary relay panel 38 and the monitoring instrument panel 46 may malfunction due to the transmission of the information. In order to prevent this, from experience, multi-core cables 81 of 1.25 mm ² or more are bundled into 10 to 30 bundles, and the bundled cables are stored in a metal cable rack.
Conventionally, laying work for grounding a metal cable rack was performed.

The internal wiring of each of the control center 58, the on-site operation panel 1, the auxiliary relay panel 38, and the monitoring and instrumentation panel 46 has been connected by electric wires for each individual signal.

In FIG. 21, reference numeral 61 denotes an electrode rod;
2 is a water level detector, 63 is a relay, 76 is a contactor (M
C) and 77 are breakers (MCCB), 79 is a machine equipment signal, and 80 is a control center unit. In addition,
The water level detector 62 is a continuous analog water level detection circuit for a water level indicator. The mechanical equipment signal 79 is a signal input from the mechanical equipment, for example, “flooding”, “temperature rise”
When a signal such as "over torque" occurs, power supply to the power is stopped.

FIG. 22 is a diagram showing the internal arrangement of a conventional auxiliary relay panel 38, in which 63 is a relay, 69 is an electric wire, 71 is a cable duct, 83 is a signal terminal block, and 84 is a cable support.

The relays 63 are all wired by 1.25 mm ² electric wires 69 passing through the cable duct 71. The reason is that there are many types of treatment systems for small-scale sewage plant control systems, and the equipment and equipment to be controlled by the treatment systems, and the water levels, flow rates, and pressures for monitoring and instrumentation are different. Due to the small number of units produced, it was common to manufacture each item individually.

FIG. 23 shows an example of a water level detection circuit connected to the electrode rod 61 and provided inside the auxiliary relay panel 38. Here, a circuit for detecting four water levels is shown. In this case, four floatless circuits are provided. A relay 67 and a relay 63 are required, and a wire 69 connecting them crosses the terminals of each relay 63 and the floatless relay 67, so that a total of 28 wires 6
9 was needed. The water level detection circuit in FIG. 23 is a circuit that catches only a predetermined water level, and is mainly used for controlling mechanical equipment.

FIG. 24 shows a circuit of a control center unit 80 constituting the control center 58.
Is a forward rotation display circuit, 52 is a reverse rotation display circuit, 63 is a relay,
70 is a relay contact, 76 is a contactor (MC), 78 is a power terminal, and 87 is an indicator light.

The control center 58 is provided for each control center unit 80 for supplying power to each motor 59, and each control center unit 80 supplies power to a large-capacity motor.
Power wires to be wired to the at generally 3.5 mm ² or more wires, also other control wire were wire at the 1.25 mm ² wires.

The control electric wire is 1.25 m in length due to the inherently weak current.
wire m ² but need, had a wire from all wire convention.

As a control method of the motor 59, there are cases where only forward rotation is required and cases where both forward rotation and reverse rotation are required.
Since all the control center units 80 were manufactured using electric wires, two types of control center units 80 were manufactured.

[0014] Further, when an abnormality or a failure occurs in the plant equipment, a limited number of words are issued only to a predetermined person in charge of maintenance through a general telephone line.

The reason is that, in the case of a small-scale sewage treatment plant, the control is an ON-OFF operation of a relay contact, so that only a specific word can be issued when a certain relay contact is ON. there were.

An apparatus using communication for a plant control apparatus includes "plant control equipment and method for updating plant control equipment" described in Japanese Patent Publication No. 6-225364.

This means that when the new and old control panels are updated, the wireless means is used temporarily. The reason is the humidity,
Using a communication device with built-in electronic equipment for a long time in an extremely bad environment such as organic gas and high temperature outdoors may cause the electronic equipment to break down due to corrosion, rust, dew condensation, etc. from these bad environments. Met. Tokuhei 7-646
The “plant control transmission device” described in Japanese Patent Application Publication No. 07-2007 and the “plant monitoring and warning device” described in Japanese Patent Publication No. 1-253496 mainly focus on emergency transmission when a plant facility is abnormal.

The "portable on-site operation panel" described in Japanese Patent Publication No. Hei 8-234834 controls a plant facility using a dedicated on-site operation console.

Regarding the standardization of units in the auxiliary relay panel, there is a "plant control device" described in Japanese Patent Publication No. 5-292612. However, this is because each unit is connected by a dedicated connector. there were.

[0020]

In the above-mentioned conventional plant control apparatus, the control center 58, the on-site operation panel 1,
Since the auxiliary relay panel 38 and the monitoring instrument panel 46 are all connected by a multi-core cable 81 of 1.25 mm ² or more for each individual signal line, the production efficiency is poor, and a large amount of cable A malfunction occurred due to incorrect connection at the time of cable connection.

Further, since the internal wiring of each of the control center 58, the on-site operation panel 1, the auxiliary relay panel 38, and the monitoring and instrumentation panel 46 is an electric wire 69, an operator needs to wire each electric wire for each control panel. As a result, the production efficiency was poor, and a malfunction occurred due to incorrect connection.

Further, in the control center 58, two types of control center units 80, that is, a control circuit for normal rotation and reverse rotation of the motor, a control circuit for normal rotation, and two types of control center units 80 have to be manufactured because of wiring by electric wires, and the production efficiency is poor. .

Further, in the conventional plant control device, when an abnormality or a failure of the plant device monitored by the
Only a limited number of words were issued to the maintenance personnel set in advance by a general telephone line, so the maintenance personnel could always use the plant control device at any time, anywhere, day and night. I had to rush to the site where there was.

Conventionally, in each control panel of a small-scale sewage plant control device, various signals such as control, monitoring, failure, and instrumentation are composed of several signal lines, and address lines and control lines supporting the signal lines. "Common bus line", "Wireless communication" to transmit information between control panel and control panel and portable radio telephone by laser beam or electromagnetic wave communication, analog signal of water level, flow rate, pressure measurement, mechanical failure contact and operation command It has been difficult to provide a plant control device that constantly controls mechanical equipment by using a “digital signal” that treats contact signals as signal information of several bits ON / OFF and a “signal conversion” method of modulating and demodulating those digital signals.

The reason for this is that all of them use electronic equipment. Generally, the “operating temperature range” specified by the electronic device manufacturer is −5 to 60 ° C. Therefore, in the case of the on-site operation panel 1 installed outdoors, the temperature in the panel becomes 70 ° C. or more due to direct sunlight of the sun in summer, and the electronic device becomes inoperable. Further, in the case of the on-site operation panel 1 installed underground or in a corridor, there is a possibility that equipment malfunction due to poor contact of electronic equipment due to gas generated from moisture, sludge, or the like.

An object of the present invention is to solve the above-mentioned problems and to provide a plant control device capable of improving production efficiency.

It is still another object of the present invention to provide a plant control device which does not need to go to a site where the plant control device is located when an abnormality or a failure occurs.

[0028]

According to a first aspect of the present invention, there is provided a plant control apparatus for detecting a temperature inside a local operation panel, and outputting a detection signal when the detected temperature is equal to or higher than a set temperature; Temperature control means for lowering the temperature inside the operation panel in response to a detection signal from the means.

Thus, since the temperature in the operation panel at the site can always be maintained at or below the set temperature, it is possible to mount the electronic device inside the operation panel installed at a place where the temperature becomes high.

According to a second aspect of the present invention, there is provided a plant control device for detecting humidity inside a field operation panel, and outputting a detection signal when the detected humidity is equal to or higher than a set humidity. A humidity adjusting means for lowering the humidity inside the operation panel in response thereto is provided.

Thus, since the humidity in the operation panel at the site can always be kept below the set humidity, it is possible to mount the electronic device inside the operation panel installed in a place where the humidity is high.

According to a third aspect of the present invention, there is provided the plant control apparatus according to the first or second aspect, wherein each control panel includes a control center, an auxiliary relay panel, a monitoring instrument panel, and an on-site operation panel. A laser beam communication means for performing information communication between the boards using a laser beam is provided.

This eliminates the need for cables for connecting the control panels for information communication, which leads to a significant reduction in cable materials and omission of cable laying work.

According to a fourth aspect of the present invention, there is provided the plant control apparatus according to the first or second aspect, wherein each control panel includes a control center, an auxiliary relay panel, a monitoring instrument panel, and a field operation panel. A laser beam communication unit for performing information communication by a laser beam between the panels, a laser beam communication abnormality detection unit for detecting communication abnormality by the laser beam communication unit, and a laser beam communication abnormality detection unit for detecting an abnormality. A wired communication unit for performing information communication by wired communication between the control panels is provided.

This eliminates the need for a cable for connecting each control panel for performing normal information communication.
Significant reduction in cable materials and omission of cable laying work. Further, when the communication by the laser beam communication means is abnormal, the communication is automatically switched to the wired communication, so that the plant apparatus can be continuously operated.

A plant control device according to a fifth aspect of the present invention is the plant control device according to the first, second, third or fourth aspect, wherein the control center, the auxiliary relay panel, the monitoring instrumentation panel, and the on-site operation panel have respective internal parts. In addition, a power supply circuit is provided which converts a commercial AC voltage into a DC, converts it into an AC with a constant voltage circuit, further shapes the waveform, and supplies power to the internal circuit of each control panel.

Thus, even if the impulse noise from the mechanical equipment enters the commercial AC voltage, the impulse noise can be removed, and the malfunction of the internal circuit of each control panel can be prevented.

According to a sixth aspect of the present invention, in the plant control apparatus according to the third or fourth aspect, the information communication by the laser beam communication means is performed by a laser beam of a digital pulse signal modulation system. I do.

Since information communication is performed using such a laser beam, it is possible to prevent noise generated in the air or space from interfering with the communication signal.

According to a seventh aspect of the present invention, in the plant control apparatus according to the fourth aspect, the information communication by the wired communication means is performed by connecting each control panel with a 20-core cable. .

As a result, the cables connecting the control panels are all 20-core cables only, which leads to a significant reduction in cable materials and omission of cable laying work.

The plant control device according to the eighth aspect is the plant control device according to the first, second, third or fourth aspect, wherein the control center, the auxiliary relay panel, the monitoring instrumentation panel, and the on-site operation panel have respective internal parts. A common bus line for passing control signals and address signals, etc., and internal circuits in which necessary information is input and output from the common bus line and addresses are set, from one internal circuit to another internal circuit. When outputting information, the address of another internal circuit and the transmission information are output to a common bus line, the transmission information is input only to the other internal circuit specified by the address, and the other internal circuit to which the transmission information is input is input. Outputs the address of one internal circuit and reply information to a common bus line.

As a result, the electric wiring in each control panel is greatly reduced, and the control panel manufacturing cost can be reduced.

According to a ninth aspect of the present invention, in the plant control apparatus of the eighth aspect, each internal circuit for inputting and outputting information from a common bus line in each control panel is formed on a printed circuit board. A printed circuit board and a terminal block into which the printed circuit board is inserted.

Thus, when a printed circuit board of a certain internal circuit breaks down, the printed circuit board is pulled out from the terminal block and a substitute printed circuit board is inserted, so that the plant can be restarted immediately.

According to a tenth aspect of the present invention, in the plant control apparatus according to the third or fourth aspect, the information in the monitoring instrumentation panel is transmitted to an external communication device such as a PHS or a portable radio telephone in the monitoring instrumentation panel. A communication device that transmits control signals from an external communication device to the control center, an auxiliary relay panel, a monitoring instrument panel, and a control signal from the external communication device received by the communication device in the monitoring instrument panel. It is characterized in that the on-site operation panel can be controlled.

Thus, even if an abnormality or failure occurs in the plant equipment, the person in charge does not immediately rush to the site,
Necessary treatment can be controlled on the spot using the external communication device.

The plant control device according to claim 11 is the plant control device according to claim 1 or 2, wherein all the power units of the control center are one type of print having a forward rotation control circuit and a reverse rotation control circuit of a motor. It is characterized by comprising a substrate and a short-circuit pin for short-circuiting the reverse rotation control circuit.

As a result, the power unit of the control center can be covered by one type, so that the cost of the power unit can be reduced.

[0050]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment of the present invention, it is possible to mount electronic devices inside all on-site operation panels which are installed under severe environmental conditions, and all control panels constituting a plant control device are provided. The information communication between each control panel shall be wireless communication by laser beam.If laser beam abnormality occurs, information communication will be continued by wire communication.If an abnormal situation occurs, external communication will be performed by wireless communication. It can report the details of the abnormality to the PHS or the portable radio telephone in detail, and can control each control panel from the outside by the PHS or the portable radio telephone. Hereinafter, this will be described in detail with reference to the drawings.

FIG. 20 is a system configuration diagram showing an outline of a plant control apparatus according to an embodiment of the present invention. A mechanical equipment signal 79 from a mechanical equipment and a signal from an electrode rod 61 are sent to a terminal block 60 of an auxiliary relay 38. The signal from the water level detector 62 is connected to the terminal block 60 of the monitoring instrument panel 46, and each signal is mounted on a common bus line inside each control panel and transmitted to each control circuit. The common bus line passes control signals, failure signals (abnormal signals), address signals, and measurement state signals. The measurement state signal is a water level measurement signal, and is a continuous analog signal such as a pump well water level, a floor drainage pit water level, and a drainage tank water level at that time.

Hereinafter, each feature of the present embodiment will be described. First, FIG. 1 shows a configuration of a field operation panel 1 when installed outdoors in an embodiment of the present invention.
FIG. 1A is an external view from the front, and FIG. 1B is a block diagram of a main part thereof.

In the construction, a heat exchanger 3 is attached to the front door surface of the on-site operation panel 1, and the heat exchanger 3 opens and closes together with the door when the door 1 is opened and closed by the handle 1a. On-site operation panel 1
A temperature sensor 4 is mounted inside. Heat exchanger 3,
The temperature sensors 4 are mounted one by one on the left and right, and if one fails, the other performs alternative operation. The power supply to the temperature sensor 4 and the heat exchanger 3 is performed by AC1 of the power supply in the general panel of the on-site operation panel 1.
It is performed at 00V or 200V AC.

In this operation, power is always supplied to the temperature sensor 4 so that the temperature sensor 4 is operated. Here, when the outside air temperature of the on-site operation panel 1 rises, the in-panel temperature of the on-site operation panel 1 indirectly increases. If the set temperature of the temperature sensor 4 is set to 40 ° C., and the temperature in the panel becomes 40 ° C. or more, the temperature sensor 4 emits a detection signal 5a, and power is supplied to the heat exchanger 3 in response to the detection signal 5a. Be started. The heat exchanger 3 takes in the outside air, further cools the outside air by the heat exchanger 4 itself, sends cool air into the on-site operation panel 1, and discharges warm air inside the panel to the outside of the panel. When the temperature inside the panel falls below 40 ° C., the temperature sensor 4 stops supplying power to the heat exchanger 3.

The effect is that the electronic device can be used without any problem even if the electronic device having the “operating temperature range” of −5 to 60 ° C. is mounted in the operation panel 1 in the above operation. Further, in the example of FIG.
, The cooling effect of the heat exchanger 3 is prevented from lowering.

Next, FIG. 2 shows the configuration of the on-site operation panel 1 when installed in a basement or a corridor in the present embodiment.
2A is an external view from the front, and FIG. 2B is a block diagram of a main part thereof.

In this configuration, a heater 7 and a humidity sensor 6 are mounted inside the on-site operation panel 1.

In this operation, power is always supplied to the humidity sensor 6 to keep it operating. Here, when the humidity outside the operation panel 1 increases, the humidity inside the operation panel 1 increases indirectly. If the set humidity of the humidity sensor 6 is set to 60% and the humidity in the panel becomes 60% or more, the humidity sensor 6 emits a detection signal 5b, and power supply to the heater 7 is started in response to the detection signal 5b. You. The heater 7 generates heat to lower the humidity in the panel. When the humidity inside the panel falls below 60%, the humidity sensor 6 stops supplying power to the heater 7.

The effect of the above is that the electronic device can be operated without any trouble even if the electronic device is installed in the operation panel 1 installed in a humid underground or in a corridor.

It is sufficient that one or both of the features of FIG. 1 and the features of FIG. 2 are provided in the on-site operation panel 1 as required. The control center 58, the auxiliary relay panel 38, and the monitoring instrument panel 46 may be provided as necessary.

Next, FIG. 3 is a configuration diagram of a wired facility and a radio facility in the present embodiment, and FIG. 4 is a configuration diagram of an abnormality detection circuit.

The wired equipment 19 and the wireless equipment 18 shown in FIG.
Are provided in each of the auxiliary relay panel 38, the monitoring and instrumentation panel 46, the control center 58, and the on-site operation panel 1 (hereinafter, also referred to as each control panel) in FIG. However,
The wireless transmitting and receiving circuit 17 is a wireless device 18 in the monitoring instrument panel 46.
, And is not provided in the radio equipment 18 in the other control panels (1, 38, 58).

Signals from each control circuit in the control panel are collected from the common bus line 10 to the wired equipment 19 and further collected from the signal bus line 14 to the wireless equipment 18. Here, the wired equipment 19 and the wireless equipment 18 always share the same information. The information transmission between the control panels is normally performed by the laser beam 21 by the wireless equipment 18.
Information is transmitted through the zero-core cable 22.

Further, information transmission with other communication equipment such as an external PHS and a portable radio telephone is performed by a radio wave 20 by the radio equipment 18.

The power supply for supplying power to the radio equipment 18 and the wired equipment 19 is a power supply for generating a clean sine wave voltage with no distortion in the power supply waveform by the impulse noise elimination power supply 8 in order to protect the equipment from surge voltage and impulse noise. Shall be. Therefore, in this example, it is assumed that each control panel includes the impulse noise removal power supply device 8.

The cable facility 19 includes a common bus line signal conversion circuit 11 for converting a signal on the common bus line 10 into wired and wireless information, a data communication circuit 12 for transmitting the signal wirelessly and wired, and a wired It comprises a wired transmission / reception circuit 13 for creating a communication protocol for communication and performing wired communication, and a communication system switching circuit 23 for switching to wired communication when laser beam communication is abnormal.

The radio equipment 18 is provided with the data communication circuit 1.
2, a laser beam transmission / reception circuit 15 for creating a communication protocol for laser beam communication and performing laser beam communication, and a response (reply) of a result of transmitting control information with the laser beam 21 by the laser beam transmission / reception circuit 15 for a predetermined time. If it does not return within (several seconds), the communication congestion signal 26 (FIG. 4)
And a signal congestion detection circuit 29 that outputs an error, and detects whether or not the same numerical value is returned by sending a laser beam communication to each control panel based on a random number at each time, and if it does not match, treats it as abnormal (communication failure) Abnormality detection circuit 16
S, and a wireless transmission / reception circuit 17 (only in the case of the monitoring instrument panel 46) for communicating with external wireless equipment such as a portable wireless telephone. In the communication between the control panels by the laser beam transmitting / receiving circuit 15, a response to the transmission is made from the receiving side to the transmitting side within a predetermined time.

FIG. 4 is a signal input / output diagram connected to the abnormality detection circuit 16. Machine failure / plant failure signal 2
4 is transmitted from the control circuit in each control panel to the common bus line 10 in FIG. 3, input to the wired facility 19, and output from the common bus line signal conversion circuit 11 to the data communication circuit 12. After being processed by the data communication circuit 12 of the wireless equipment 18 from the data communication circuit 12 of the wired equipment 19 via the signal bus line 14, the data is input to the abnormality detection circuit 16. The mechanical equipment failure / plant abnormality signal 24 input to the abnormality detection circuit 16 is processed as a plant equipment abnormality signal 27 in FIG. The plant equipment abnormality signal 27 processed by the auxiliary relay panel 38, the control center 58, and the abnormality detection circuit 16 of the on-site operation panel 1 is output to the laser beam transmitting / receiving circuit 15 in FIG. . Further, the monitoring instrumentation panel 46 receives the plant equipment abnormality signal 27 transmitted from another control panel and the plant equipment abnormality signal 2 of the abnormality detection circuit 16 of the monitoring instrumentation panel 46 itself.
7, the content of the abnormality is transmitted to the outside by the radio transmission / reception circuit 17 by the radio wave 20.

The communication failure signal 25 is transmitted from the wireless transmission / reception circuit 17.
Is input to the abnormality detection circuit 16, the abnormality detection circuit 16
Then, it is processed as a communication equipment abnormality signal 28 and output to the communication system switching circuit 23. In each control panel, the communication system switching circuit 23 switches the laser beam communication between the control panels to wired communication when the communication equipment abnormality signal 28 is input. Further, the abnormality detection circuit 16 of the monitoring instrument panel 46 transmits the contents of the abnormality to the outside by the wireless transmission / reception circuit 17 by the radio wave 20 based on the communication equipment abnormality signal 28.

If the result of transmission by the laser beam transmission / reception circuit 15 of FIG. 3 using the laser beam 21 does not return within a few seconds, the signal congestion detection circuit 29 sends the communication congestion signal 26 to the abnormality detection circuit 16. Output. When the communication congestion signal 26 is input, the abnormality detection circuit 16 processes the communication congestion signal 26 as a communication equipment abnormality signal 28 as in the case of the communication failure signal 25.

The effect is that information communication between the control panels is usually performed by laser beam communication, so that even if the plant machine equipment generates electric noise in the air, the communication information is completely affected by the laser beam. And that there is no need to connect each control panel with a conventional multi-core cable. Further, when the laser beam communication equipment of any of the control panels is out of order, it is possible to immediately switch to the wired equipment and continue the communication work. Further, the abnormality information is to be reported to the outside from the monitoring instrument panel 46 by radio, and this will be described in detail later.

Next, the present embodiment is characterized in that a noise removing power supply device 8 is provided in each control panel as shown in FIG. In FIG. 3, the noise removing power supply 8 is shown to supply power to the wireless equipment 18 and the wired equipment 19, but is not limited thereto, and is a power supply for an internal circuit of each control panel. FIG. 5 is a configuration diagram of the noise removal power supply device according to the present embodiment.

The configuration is such that a band-pass filter 31 that allows an electric signal having a frequency of 40 Hz to 70 Hz to pass through is provided.
A rectifier circuit 32 for converting an AC voltage to a DC voltage; a switching power supply circuit 34 for converting the DC voltage to an AC voltage having a switching waveform; and removing a distorted waveform of the output voltage of the switching power supply circuit 34 to obtain an accurate sine wave voltage. And a waveform shaping circuit 36.

The operation is similar to that of the band-pass filter circuit 31.
Removes impulse noise from the commercial power supply voltage 30 to 40 Hz or less and 70 Hz or more. After that, the rectifier circuit 32
Is changed to DC to remove impulse noise that cannot be removed by the band-pass filter circuit 31. Further, the DC voltage 33 is changed to the switching power supply voltage 35 by the switching power supply circuit 34, and the sine wave power supply voltage 9 is changed to the sine wave power supply voltage 9 by the waveform shaping circuit 36, and supplied to the internal circuit (control circuit) of each control panel.

The effect is that the above operation eliminates impulse noise and surge voltage jumping into the power supply from the mechanical equipment, and enables accurate sinusoidal voltage without distortion to be supplied to the control circuit of each control panel. The malfunction of the circuit can be prevented.

Next, FIG. 6A is a configuration diagram showing communication between control panels by the aforementioned laser beam, and FIG. 6B is a pulse configuration diagram of the communication system.

In the configuration, a laser beam transmitting / receiving section 37 is provided for each control panel, and communication using the laser beam 21 is performed. The bit configuration of one control information for each control panel is such that a pulse width 1 (100 ms) start signal is followed by a pulse width 1 (100 ms).
0-ms 9-bit address information (address 777 (8
In the case of (base number), all are turned ON), the subsequent 4-bit control information, the 7-bit spare information, and the end signal of the subsequent pulse width t2 (200 ms). An address according to the communication protocol for each control information communication,
Control information is created.

In the case of transmission, the operation first transmits a control circuit address, control contents, and preliminary information to be transmitted after a pulse width of t1, and ends with a signal output of a pulse width of t2.

On the other hand, the received control circuit transmits a reply of the control result in the same format as described above, and ends one information communication operation.

The effect is that the control information is input only when each control panel receives the relevant address signal by the above operation, so that the necessary information can be transmitted only to the required address.

Next, FIG. 7 is a configuration diagram of a 20-core cable 22 used in a wired facility 19 connecting each control panel in the present embodiment.

The configuration is such that a cable 5 of 0.25 mm ² is used.
After the outer periphery of the cable is protected by a material such as polyethylene 54, a cable having an outer periphery protected by a metal shield 55 is bundled into a bundle of 20 pieces, and the cable is passed through a conduit tube 57 to be constructed on site. The signal configuration is such that 9 cores are for control circuit designation address, 4 cores are for control information, and 7 cores are for spare information.

As described above, the communication by the wired facility 19
It is used when the laser beam communication is abnormal, and the communication contents and the like are the same as those of the laser beam communication.

The effect is that all the cables connecting the control panels are only the 20-core cable 22, which leads to a significant reduction in cable material, a reduction in cable laying cost, and a reduction in cable laying work. Production efficiency also improves.

As shown in FIG. 20, the connection between the mechanical equipment (mechanical equipment signal 79), the electrode rod 61, the water level detector 62, and the auxiliary relay 38 and the terminal block 60 of the monitoring instrument panel 46 are the same as in the prior art. And the multi-core cable 81.

FIG. 8 is a signal exchange diagram in the case where information communication with a specific control circuit is performed between control panels.

In the configuration, the on-site operation panel 1 and the auxiliary relay panel 38 are related by the laser beam transmitting / receiving circuit 15 and the laser beam 21.

The inside of each control panel includes a laser beam transmitting / receiving circuit 15, a common bus line 10 through which signals of the respective control circuits pass through a common signal line, and address information received and decoded from the common bus line 10 to be self-contained. In the case of the control information, the address converter 39 outputs the information to its own control circuit 40.
And a control circuit 40 for controlling mechanical equipment.

The operation is performed by the control circuit 40 in the local operation panel 1 and the specific control circuit 40 in the auxiliary relay panel 38.
When the control signal is output to the common bus line 10 after the address information specified from the local operation panel 1,
Output from the common bus line 10 to the laser beam transmission / reception circuit 15, the laser beam 21, the laser beam transmission / reception circuit 15 in the auxiliary relay panel 38, and the address converter 39 via the common bus line 10. Control circuit 40
To the command.

The control circuit 40 outputs a reply after the execution of the control from the specified control circuit 40 to the common bus line 10, and returns the control circuit 40 of the local operation panel 1 again via the reverse route.

The effect is that the operation signal (control signal) from the on-site operation panel 1 is transmitted to only the specified control circuit 40, and accurate control can be performed.

The monitoring instrument panel 46 and the control center 58 can be shown in the same manner as the internal configuration of the on-site operation panel 1 and the auxiliary relay panel 38 shown in FIG.

FIG. 9 shows an example of the control circuit 40. Each control circuit 40 inputs and outputs necessary information from the common bus line 10 in the address converter 39. In FIG. 9, 63 is a relay, and 70 is a relay contact.

FIG. 10 is a configuration diagram in which each control circuit 40 and the common bus line 10 are formed on a printed circuit board. FIG. 11 is a mounting drawing in which the relay control circuit is formed on a printed circuit board. FIG. FIG. 13 is a mounting diagram in which the water level detection circuit is formed on a printed board, and FIG.
14 is a diagram showing a state in which the auxiliary relay board 38 is inserted into a printed circuit board insertion terminal 42, and FIG. FIG.
(A) is an internal configuration view from the side of the auxiliary relay panel 38,
FIG. 14B shows the front of the auxiliary relay panel 38 (the same applies to the back).
FIG.

The configuration is such that the control circuits 40 divided for each purpose in FIG. 9 are connected to the common bus line 10 via the address converter 39, and the state is printed on a printed circuit board. It is 10.

The control circuit 41 formed on a printed board is inserted and installed on the printed board insertion terminal 42. The common bus line 43 formed as a printed board is inserted and installed on the opposite side of the printed board insertion terminal 42.

The control circuit 41 formed on a printed board shown in FIG. 11 includes a copper foil 65 in which the resist in contact with the printed board insertion terminal 42 has been removed, a back copper foil 64, a copper foil 44, and a through hole 45. And a relay 63.

A water level detection circuit 66 formed on a printed circuit board shown in FIG. 12 includes a copper foil 65 in which the resist is removed at a portion in contact with the printed circuit board insertion terminal 42, and a back side copper foil 64.
, Copper foil 44, through hole 45, relay 63,
And a floatless relay 67.

The auxiliary relay panel 38 shown in FIG.
To the components shown in FIG. Also,
In FIG. 14, reference numeral 71 denotes a cable duct, 83 denotes a signal terminal block, and 84 denotes a cable support.

The printed circuit board control circuit 41 is normally operated by being inserted at the printed circuit board insertion terminal 42. Where the common bus line 10 is not compatible with a printed circuit board, an electric wire 69 is attached to the screw terminal 68 as shown in FIG. 13, and the connection between the printed circuit board control circuit 41 and the printed circuit board insertion terminal 42 is connected. 11 and 12 show a portion of the copper foil 65 from which the resist has been removed.

The control circuit 4 on a printed circuit board
In the event that 1 is out of order, the control circuit 41 is replaced with a control circuit 41 on a printed circuit board.

The effect is that even if a certain control circuit breaks down, the operation can be restarted immediately because an alternative printed circuit board is used, and if the configuration shown in FIG. 14 is used, anyone can easily replace the printed circuit board. It can be exchanged.

It is to be noted that the monitoring instrument panel 46, the control center 58, and the on-site operation panel 1 may be similarly formed on a printed circuit board with internal circuits such as a control circuit.

FIG. 15 is a configuration diagram of the monitoring instrument panel 46 and an external communication device 47 such as a PHS and a portable radio telephone in this embodiment, and FIG. 16 is similar to FIG. It is a control circuit block diagram.

As described earlier, as shown in FIG. 15, the monitoring instrument panel 46 includes a radio transmitting / receiving circuit 17 for transmitting / receiving data to / from the external communication device 47, and a memory 82 for recording details of the alarm. And In addition, 85 is an indicator, and 86 is a recorder.

The operation is as follows. When a failure or abnormality occurs in the plant control device, a signal of the content of the failure or abnormality is transmitted from another control panel to the monitoring instrumentation panel 46 by a laser beam signal or a wired signal. Monitoring instrument panel 4 based on the content of the abnormality
The alarm information is extracted from the memory 82 in the device 6, and the information is transmitted from the wireless transmission / reception circuit 17 to the external communication device 47 such as a PHS or a portable wireless telephone by the radio wave 20.

On the other hand, the received maintenance staff takes necessary measures to the external communication device 47 such as a PHS or a portable radio telephone.
Then, the address number and the control information number of the control circuit set in advance are transmitted to the radio transmission / reception circuit 17 by the radio wave 20.

The radio transmission / reception circuit 17 having received the address and the control content transmits the address and the control content via the laser beam 21 of the radio equipment 18 of the monitoring instrument panel 46 or the 20-core cable of the wired equipment 19. The control circuit that matches the address number executes the control content.

The effect is that, when an abnormality occurs in the plant equipment, the maintenance staff can receive information anytime and from any place, and can operate appropriate measures on the spot.

The internal circuit of the monitoring instrument panel 46 shown in FIG. 16 includes an A / D converter 72, an alarm setter 73, a water level converter 7
4, relay 63, relay contact 70, address converter 3
9, a common bus line 10. The detection value of the water level detector 62 in FIG. 20 is a continuous analog amount,
The water level converter 74 of FIG. 16 integrates the amount and performs pulse rate (for example, if the water level of 1 m is held for 1 minute, 1
Pulse output).

In FIG. 16, all analog signals are converted into digital signals by the A / D converter 72 and then input to each control circuit, and information of each control circuit is input from the common bus line 10 by the address converter 39. Perform output.

As for the effect, since all analog signals are controlled by digital signals, there is no influence from mechanical equipment and high voltage.

FIG. 17 is a control circuit diagram for forward / reverse rotation of the motor of the control center unit (power unit) according to the present embodiment. FIG. 18 shows a control center unit printed circuit board in which the circuit of FIG. FIG. 19 is a configuration diagram of a control center 58 formed using the control center unit printed circuit board 48 of FIG.

In FIG. 17, reference numeral 39 denotes an address converter,
49 is a normal rotation control circuit, 50 is a reverse rotation control circuit, 51 is a normal rotation display circuit, 52 is a reverse rotation display circuit, 53 is a short-circuit pin, 63
Is a relay. The short-circuit pin 53 short-circuits the reverse rotation control circuit 50 when the motor is used only for normal rotation.

As shown in FIG. 18, the control center unit printed circuit board 48 includes a forward rotation control circuit 4 for the motor.
9 is a printed circuit board, the reverse rotation control circuit 50 is a printed circuit board, the normal rotation display circuit 51 is a printed circuit board, and the reverse rotation display circuit 52 is a printed circuit board. When the motor is used only for normal rotation, the short-circuit pin 53 is used.

As shown in FIG. 19, the control center 58 comprises a common bus line 10, a printed board insertion terminal 42, a control center unit printed board 4
8, breaker (MCCB) 77, contactor (MC) 7
6 and so on. The copper foil 44 (FIG. 18) of the control center unit printed board 48 is inserted into the printed board insertion terminal 42.

In this configuration, the motor 59 that does not require reverse rotation is used.
The control center unit printed circuit board 48 used in FIG.
N "circuit. Then, the relay “53PN” is operated, and the contact of the relay “53PN” inserted in the reverse rotation control circuit 50 and the reverse rotation display circuit 52 is opened because it is the b contact. Therefore, the contactor “88” of the reverse rotation control circuit 50
R "and the relay" 88R "of the reverse rotation display circuit 52 do not operate, and the reverse rotation is not possible.

The effect is that the circuit for controlling the motor is formed into a printed circuit board, and the printed circuit board 4 having only the forward / reverse control circuit is provided.
8 and only the forward rotation can be controlled by setting a part of the forward / reverse rotation circuit with the short-circuit pin 53. Therefore, only one type of control center unit printed circuit board 48 needs to be manufactured. The efficiency can be improved, and the cost of the control center unit can be reduced.

As shown in FIG. 19, both ends of the control center unit printed circuit board 48 are connected to the printed circuit board insertion terminals 42, and the breaker 77 for supplying power and the contactor 76 are wired with electric wires. In the control center 58, the size of the breaker 77 and the contactor 76 is changed depending on the load capacity of the motor, but the control center unit printed circuit boards 48 are all the same, and standardization is achieved. The power terminal 78 in FIG. 19 is connected to the motor 59 (FIG. 20).

As described above, according to the embodiment of the present invention, by adopting the configuration shown in FIGS. 1 and 2, it is possible to mount electronic devices inside the field operation panel 1 installed under severe environmental conditions. As an example, all the control panels constituting the plant control apparatus are configured as electronic devices, and the internal wiring is formed on a printed circuit board, thereby increasing the production efficiency of the control panel and preventing erroneous connection. In addition, information communication between each control panel is performed by wireless communication using a laser beam, and when laser beam abnormality occurs, information communication is continued by wired communication, so that a 20-core cable 22 is used instead of a conventional multi-core cable. It can improve production efficiency, reduce cable laying costs, and prevent incorrect connection when connecting cables. As described above, the cost of each control panel and the entire plant control device can be reduced. If an abnormal situation occurs, report the details of the abnormality to an external PHS or portable wireless telephone by wireless communication, and
Each control panel can be controlled by an HS or a portable radio telephone.

[0121]

According to a first aspect of the present invention, there is provided a plant control device for detecting a temperature inside a local operation panel, and outputting a detection signal when the detected temperature is higher than a set temperature, and detecting the temperature from the temperature detecting device. Temperature control means for lowering the temperature inside the operation panel in response to a signal is provided, so that the temperature inside the operation panel can always be kept below the set temperature. Electronic devices can be mounted inside the operation panel.

According to a second aspect of the present invention, there is provided a plant control device for detecting humidity inside a field operation panel, and outputting a detection signal when the detected humidity is equal to or higher than a set humidity. By providing a humidity adjusting means that reduces the humidity inside the operation panel in response, the humidity inside the operation panel can always be kept below the set humidity, so the operation panel installed in a humid place The electronic device can be mounted inside the device.

According to a third aspect of the present invention, there is provided a plant control apparatus including a control center, an auxiliary relay panel, a monitoring instrumentation panel, and a field control panel. The provision of the communication means eliminates the need for a cable for connecting each control panel for performing information communication, which leads to a significant reduction in cable material and elimination of cable laying work.

According to a fourth aspect of the present invention, there is provided a plant control apparatus comprising: a control center, an auxiliary relay panel, a monitoring instrumentation panel, and an on-site operation panel. Communication means, laser beam communication abnormality detecting means for detecting communication abnormality by the laser beam communication means, and information communication by wire communication between each control panel when the laser beam communication abnormality detecting means detects the abnormality. By providing the wired communication means, the cable connecting between each control panel for performing normal information communication,
Since it becomes unnecessary, it leads to significant reduction of cable material and omission of cable laying work. Further, when the communication by the laser beam communication means is abnormal, the communication is automatically switched to the wired communication, so that the plant apparatus can be continuously operated.

According to a fifth aspect of the present invention, in the plant control device, the commercial AC voltage is converted into DC in each control panel of the control center, the auxiliary relay panel, the monitoring instrument panel, and the on-site operation panel, and a constant voltage circuit is used. After converting to AC and further shaping the waveform,
By providing a power supply circuit that supplies power to the internal circuit of each control panel, it is possible to remove impulse noise even if impulse noise from mechanical equipment enters the commercial AC voltage.
Malfunction of the internal circuit of each control panel can be prevented.

According to a sixth aspect of the present invention, the information communication by the laser beam communication means is carried out by a laser beam of a digital pulse signal modulation system, so that the plant control device can be used in the air.
It is possible to prevent the noise generated in the space from interfering with the communication signal.

According to the plant control device of the present invention, the information communication by the wired communication means is performed by connecting each control panel with a 20-core cable, which leads to a significant reduction in cable material and omission of cable laying work. .

The plant control device according to the eighth aspect of the present invention includes a common bus line for passing control signals, address signals, and the like inside control panels such as a control center, an auxiliary relay panel, a monitoring instrumentation panel, and a field operation panel. Each of the internal circuits to which necessary information is input and output from a common bus line and whose address is set is provided, and when information is output from one internal circuit to another internal circuit, the address and transmission information of another internal circuit are transmitted. Output to the common bus line, input the transmission information only to the other internal circuit specified by the address, and input the transmission information to the other internal circuit, and then send the address and reply information of one internal circuit to the common bus line. By adopting the output configuration, the electric wiring in each control panel is significantly reduced, and the control panel manufacturing cost can be reduced.

According to a ninth aspect of the present invention, each internal circuit for inputting and outputting information from a common bus line in each control panel is formed on a printed circuit board, and the printed circuit board and the printed circuit board are inserted into each control panel. By having a terminal block, if a printed circuit board of a certain internal circuit breaks down,
By pulling out the printed circuit board from the terminal block and inserting a substitute printed circuit board, the plant apparatus can be restarted immediately.

According to a tenth aspect of the present invention, the plant control device transmits information in the monitoring instrumentation panel to an external communication device such as a PHS or a portable radio telephone, and transmits a control signal from the external communication device in the monitoring instrumentation panel. The plant has a communication device for receiving, and the control center, auxiliary relay panel, monitoring instrument panel, and on-site operation panel can be controlled by control signals from an external communication device received by the communication device inside the monitoring instrument panel. Even if an abnormality or failure occurs in the device, a person in charge can control necessary treatment on the spot using an external communication device without immediately rushing to the site.

In the plant control device according to the present invention, all the power units of the control center include one type of printed circuit board having a forward rotation control circuit and a reverse rotation control circuit of the motor, and a short-circuit pin for short-circuiting the reverse rotation control circuit. As a result, the power unit of the control center
Since all types can be covered, the cost of the power unit can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an outdoor operation panel in an embodiment of the present invention.

FIG. 2 is a configuration diagram of a field operation panel according to the embodiment of the present invention.

FIG. 3 is a configuration diagram of wired and wireless equipment according to the embodiment of the present invention.

FIG. 4 is a configuration diagram of an abnormality detection circuit according to the embodiment of the present invention.

FIG. 5 is a configuration diagram of a power supply device according to an embodiment of the present invention.

FIG. 6 is a configuration diagram of a laser beam transmission pulse in the embodiment of the present invention.

FIG. 7 is a configuration diagram of a cable according to the embodiment of the present invention.

FIG. 8 is a configuration diagram of a control signal connection according to the embodiment of the present invention.

FIG. 9 is a diagram illustrating an example of a control circuit according to an embodiment of the present invention.

FIG. 10 is a configuration diagram in which the circuit of FIG. 9 is formed on a printed circuit board.

FIG. 11 is a mounting diagram in which the relay control circuit according to the embodiment of the present invention is formed on a printed circuit board.

FIG. 12 is a mounting diagram in which a water level detection circuit according to the embodiment of the present invention is formed on a printed circuit board.

FIG. 13 is a diagram illustrating insertion into a printed circuit board insertion terminal according to the embodiment of the present invention.

FIG. 14 is a configuration diagram of an auxiliary relay board by forming a printed circuit board in the embodiment of the present invention.

FIG. 15 is a configuration diagram of a monitoring instrument panel and an external communication device according to an embodiment of the present invention.

FIG. 16 is a configuration diagram of a control circuit inside a monitoring instrument panel according to the embodiment of the present invention.

FIG. 17 is a control circuit diagram for normal rotation and reverse rotation of the motor of the control center unit in the present embodiment.

FIG. 18 is a diagram in which a control circuit for normal rotation and reverse rotation of a motor of the control center unit in the embodiment of the present invention is formed on a printed circuit board.

FIG. 19 is a configuration diagram of a control center using a printed circuit board according to an embodiment of the present invention.

FIG. 20 is a schematic system configuration diagram of a plant control device according to an embodiment of the present invention.

FIG. 21 is a system configuration diagram of a conventional plant control device.

FIG. 22 is a configuration diagram of an auxiliary relay panel in a conventional example.

FIG. 23 is a diagram showing a water level detection circuit in a conventional example.

FIG. 24 is a circuit diagram of a control center unit in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 On-site operation panel 2 Heat shield plate 3 Heat exchanger 4 Temperature sensor 6 Humidity sensor 7 Heater 8 Impulse noise removal power supply device 9 Sine wave power supply voltage 10 Common bus line 11 Common bus line signal conversion circuit 12 Data communication circuit 13 Wired transmission / reception circuit Reference Signs List 14 signal bus line 15 laser beam transmission / reception circuit 16 abnormality detection circuit 17 wireless transmission / reception circuit 18 radio equipment 19 wired equipment 20 radio wave 21 laser beam 22 20-core cable 23 communication method switching circuit 24 machine equipment failure / plant abnormality signal 25 communication failure signal 26 Communication congestion signal 27 Plant equipment abnormality signal 28 Communication equipment abnormality signal 29 Signal congestion detection circuit 30 Commercial power supply voltage 31 Bandpass filter 32 Rectifier circuit 33 DC voltage 34 Switching power supply circuit 35 Switching power supply voltage 36 Waveform shaping circuit 37 Laser light transmitting / receiving section 38 Auxiliary relay panel 39 Address converter 40 Control circuit 41 Control circuit formed on printed circuit board 42 Insert terminal for printed circuit board 43 Common bus line formed on printed circuit board 44 Copper foil 45 Through hole 46 Monitoring instrument panel 47 External communication Device 48 Control center unit printed circuit board 49 Forward rotation control circuit 50 Reverse rotation control circuit 51 Forward rotation display circuit 52 Reverse rotation display circuit 53 Short-circuit pin 54 Exterior 55 Metal shield 56 Cable 57 Conduit tube 58 Control center 59 Motor 60 Terminal block 61 Electrode rod 62 Water level detector 63 Relay 64 Copper foil (back side) 65 Copper foil without resist 66 Printed circuit board level detection circuit 67 Floatless relay 68 Screw terminal 69 Electric wire 70 Relay contact 71 Cable duct 72 A / D converter 73 Alarm setting unit 74 Water level converter 75 Antenna 76 Contactor (MC) 77 Breaker (MCCB) 78 Power terminal 79 Machine equipment signal 80 Control center unit 81 Multi-core cable 82 Memory 83 Signal terminal block 84 Cable support

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5G016 AA04 CG00 5H004 GA27 GA28 GA29 GA32 GA35 GB08 HA01 HA16 HB01 HB05 KA80 LB02 LB03 MA29 MA30 MA51 MA52 MA55 MA56 MA58 5H209 AA01 CC09 CC13 DD11 EE05 EE20 GG11 HH13 SS08 SS11 5K048 AA06 BA23 DB01 DB02 DC01 DC03 DC04 DC07 EB01 EB02 EB06 EB08 GA02 GA14 GB05 HA01 HA02 HA11 HA20

Claims (11)

[Claims] 1. A control center having a power unit for driving a plurality of motors, an auxiliary relay panel for controlling a plurality of electric devices, a monitoring instrument panel for monitoring the status of the electric devices, A temperature control means for detecting a temperature inside the field control panel, and outputting a detection signal when the detected temperature is equal to or higher than a set temperature; and And a temperature control means for reducing the temperature inside the operation panel in response to a detection signal from the means. 2. A control center having a power unit for driving a plurality of motors, an auxiliary relay panel for controlling a plurality of electric devices, a monitoring instrument panel for monitoring the status of the electric devices, A plant control device comprising a field operation panel that controls the humidity, a humidity detection unit that detects humidity inside the field operation panel, and outputs a detection signal when the detected humidity is equal to or higher than a set humidity,
A plant control device, further comprising: humidity adjusting means for reducing the humidity inside the on-site operation panel in response to a detection signal from the humidity detecting means. 3. A laser beam communication means for communicating information between each control panel using a laser beam is provided inside each control panel of the control center, the auxiliary relay panel, the monitoring instrumentation panel, and the on-site operation panel. The plant control device according to claim 1 or 2, wherein 4. A laser beam communication means for performing information communication between each control panel using a laser beam inside each control panel of a control center, an auxiliary relay panel, a monitoring instrumentation panel, and a field operation panel; A laser beam communication abnormality detecting means for detecting an abnormality of communication by the means, and a wired communication means for performing information communication by wired communication between the control panels when an abnormality is detected by the laser beam communication abnormality detecting means. The plant control device according to claim 1, wherein the plant control device is provided. 5. A commercial AC voltage is converted to DC and converted to AC by a constant voltage circuit in each control panel of a control center, an auxiliary relay panel, a monitoring instrument panel, and an on-site operation panel.
5. The plant control device according to claim 1, further comprising a power supply circuit for supplying power to an internal circuit of each control panel after waveform shaping. 6. The information communication by the laser beam communication means,
The plant control device according to claim 3, wherein the control is performed using a laser beam of a digital pulse signal modulation method. 7. The plant control apparatus according to claim 4, wherein the information communication by the wired communication means is performed by connecting each control panel with a 20-core cable. 8. A common bus line for passing control signals, address signals, and the like inside control panels such as a control center, an auxiliary relay panel, a monitoring instrument panel, and a field operation panel, and necessary information from the common bus line. Input and output, and each internal circuit to which an address is set, when outputting information from one internal circuit to another internal circuit, outputs the address and transmission information of the other internal circuit to the common bus line. Then, the transmission information is input only to the other internal circuit designated by the address, and the other internal circuit that has input the transmission information transmits the address of the one internal circuit and reply information to a common bus line. 5. The plant control device according to claim 1, wherein the output is performed. 9. An internal circuit for inputting and outputting information from a common bus line in each control panel is formed on a printed circuit board.
9. The plant control device according to claim 8, wherein each control panel includes the printed circuit board and a terminal block into which the printed circuit board is inserted. 9. When a printed circuit board of a certain internal circuit breaks down, the printed circuit board circuit is pulled out from the plug-in terminal block, and an alternative printed circuit board is inserted, whereby restarting is possible immediately.
The plant control device as described in the above. 10. A monitoring instrument panel includes a communication device that transmits information in the monitoring instrument panel to an external communication device such as a PHS or a portable radio telephone and receives a control signal from the external communication device. 4. The control center, the auxiliary relay panel, the monitoring instrument panel, and the on-site operation panel can be controlled by a control signal from the external communication device received by a communication device in the monitoring instrument panel. Or the plant control device according to 4. 11. All the power units of the control center are provided with one kind of printed circuit board having a forward rotation control circuit and a reverse rotation control circuit of a motor, and a short-circuit pin for short-circuiting the reverse rotation control circuit. The plant control device according to claim 1.