JP2006197402A - Wireless lan explosion-proof relay and communication system in dangerous area - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless LAN explosion-proof relay and a communication system in a dangerous area which can safely and efficiently communicate bulky data between a wide dangerous area like an oil factory or a petrochemical factory and a non-dangerous area by passing a wireless LAN. <P>SOLUTION: The wireless LAN explosion-proof relay has a configuration including a wireless LAN access point 2 connecting a transmitter and a receiver by the wireless LAN, a plane antenna 3 connected to the wireless LAN access point, and a closed vessel 4 which has at least a part made of an electric wave transmission material transmitting an electric wave transmitted/received by the plane antenna 3 and has the wireless LAN access point 2 and the plane antenna 3 stored therein and has an explosion-proof structure. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wireless LAN (local area network) explosion-proof repeater and a communication system in a hazardous area. Wireless LAN explosion-proof relay that enables a large amount of data related to operation data of manufacturing equipment to be communicated safely and efficiently between the manufacturing equipment and non-hazardous area management equipment via the wireless LAN. And communication systems in hazardous areas.

Refineries, petrochemical plants, etc. have many production facilities installed. In order to operate these plants safely and efficiently, these production facilities are in a certain period (for example, until the next periodic inspection). It needs to work properly.
For this reason, it is necessary not only to properly operate the manufacturing facility, but also to confirm that the manufacturing facility is operating normally, and to detect an abnormality at an early stage and deal with it promptly when an abnormality occurs.

  In particular, in refineries and petrochemical factories, a production electrometer is located in a place (hazardous area in the present invention) where there is a possibility that a vapor of flammable gas or flammable liquid (abbreviated as explosive gas as appropriate) exists. Electric equipment such as equipment and motors are installed. These facilities and equipment generally have an explosion-proof structure that does not generate an electric spark that has an ignition capability for explosive gas or does not ignite surrounding explosive gas even if it occurs. is there.

By the way, the risk areas of refineries and petrochemical plants are usually very large, so measurement equipment installed in multiple manufacturing facilities and computers in measurement rooms installed in non-hazardous areas are used for measurement. Connecting the cables and collecting the operation data of the manufacturing equipment has a drawback that it is economically expensive considering the cost of the measurement cable and the cost of installing it.
For this reason, the technique which solves the said fault has been proposed.

For example, in an explosion-proof antenna installed in a hazardous area, a container made of a hollow cylinder having a pressure-proof explosion-proof structure made of a material that transmits radio waves transmitted and received by the antenna body, having one end side closed and the other end side open. The antenna body is housed in the hollow cylindrical body of the container, and the container housing the antenna is directly projected from the outer wall surface of the fully closed container so as to satisfy the explosion-proof structure and connected. An explosion-proof antenna technology is disclosed (see Patent Document 1).
According to this technology, in order to construct a circuit having an intrinsically safe explosion-proof structure, a circuit such as a series connection of a plurality of blocking capacitors is not required, and it is necessary to perform grounding work on the transmission line's cider line. Therefore, the entire apparatus can have a simple structure.
Japanese Patent No. 3040068

  However, in order to operate the plant safely and efficiently at a higher level, and in order to further improve the safety of the plant in the event of a disaster, the operation data of the equipment, the history data of equipment management, the field operation drawing It is necessary to communicate a large amount of data such as information, monitoring image information, and acoustic information closely between the dangerous area and the non-hazardous area, and manage it accurately based on these data. On the other hand, the technique of the explosion-proof antenna has a problem that it cannot respond to the above-mentioned extremely important request because a large amount of data cannot be efficiently communicated.

  The present invention has been proposed to solve the above problems, and a large amount of data can be obtained between a vast danger area such as a refinery or a petrochemical factory and a non-hazardous area via a wireless LAN. It is an object of the present invention to provide a wireless LAN explosion-proof repeater that enables safe and efficient communication and a communication system in a hazardous area.

In order to achieve the above object, a wireless LAN explosion-proof repeater of the present invention includes a wireless LAN access point that connects a transceiver with a wireless LAN, and one or more wireless LAN access points connected to the wireless LAN access point. A planar antenna and a sealed container that uses a radio wave transmitting material that transmits radio waves transmitted and received by the planar antenna at least partially, and that houses the wireless LAN access point and the planar antenna and has a pressure-proof explosion-proof structure. As a configuration.
In this way, a large amount of data can be communicated safely and efficiently by using the wireless LAN. In addition, since the radio wave output can be increased by using the planar antenna, the communicable area can be expanded.
The transmitter / receiver is a portable computer, an explosion-proof camera, etc. The information transmitted / received includes plant operation data, piping diagram information, operation method information, plant design data, device plot display information, operation procedure Information related to manuals, information related to piping and instrumentation diagrams, information related to board operation automation systems, information related to equipment inspection, and image information.

In the wireless LAN explosion-proof repeater of the present invention, the sealed container has a cylindrical portion made of the radio wave transmitting material, one end of which is formed in a hemispherical shape and the other end is opened, and the other end of the cylindrical portion. And a base portion connected to the cylindrical antenna, and the planar antenna is housed in the cylindrical portion.
If it does in this way, the mechanical strength of a cylindrical part can be improved and the direction of a plane antenna can be set up freely.

In addition, the wireless LAN explosion-proof repeater of the present invention is configured such that when two or more planar antennas are accommodated, the planar antennas are arranged in an L shape or a polygonal shape.
Thus, by providing the planar antenna in an L shape, it is possible to cover about twice as many areas as in the case of providing one planar antenna. Further, by arranging the planar antenna in a polygonal shape, it is possible to cover an area in almost the entire circumference, that is, communication in a wide-angle area is possible.

In addition, the wireless LAN explosion-proof repeater of the present invention has a configuration in which an optical / electrical converter that is connected to the wireless LAN access point and converts an electrical signal and an optical signal bidirectionally or in one direction is stored in the sealed container. It is as.
In this way, since communication with the outside is possible via an optical signal, a large amount of data can be communicated at high speed.

Moreover, the wireless LAN explosion-proof repeater of the present invention has a configuration in which an AC adapter is accommodated in the sealed container.
If it does in this way, generally used alternating current power supply (for example, alternating current 100V power supply) can be used.

The communication system in the hazardous area according to the present invention is a wireless LAN access point for connecting a transceiver installed in the dangerous area to the transceiver via a wireless LAN, and a wireless LAN access point connected to the wireless LAN access point. Or two or more planar antennas, an optical / electrical converter connected to the wireless LAN access point and converting an electrical signal and an optical signal in both directions or in one direction, and radio waves transmitted and received by the planar antenna at least partially A wireless LAN installed in the hazardous area, using a radio wave transmitting material that transmits light, and including a sealed container that houses the wireless LAN access point, the planar antenna and the optical / electrical converter and has a pressure-proof explosion-proof structure An explosion-proof repeater, a wireless LAN server installed in a non-hazardous area, and an electrical signal connected to this wireless LAN server It is housed in the optical / electrical converter installed in the non-hazardous area, the optical / electrical converter installed in the non-hazardous area, and the wireless LAN explosion-proof repeater, which converts the signal to bidirectional or unidirectional. And an optical cable for connecting the optical / electrical converter.
In this way, even when the wireless LAN server in the non-hazardous area and the wireless LAN explosion-proof repeater in the dangerous area are separated, a large amount of data can be communicated at high speed. Further, by wiring up to the wireless LAN explosion-proof repeater with an optical cable, it is possible to reduce transmission loss and prevent the influence of electromagnetic noise. Furthermore, when wireless communication is performed between the wireless LAN server and the wireless LAN access point, it is possible to avoid a problem that the wireless LAN server is easily affected by noise from other devices.

The communication system in the hazardous area according to the present invention is a wireless LAN access point for connecting a transceiver installed in the dangerous area to the transceiver via a wireless LAN, and a wireless LAN access point connected to the wireless LAN access point. Or, two or more planar antennas, and at least a part of which uses a radio wave transmitting material that transmits radio waves transmitted and received by the planar antenna, and accommodates the wireless LAN access point and the planar antenna, and has a flameproof structure. A wireless LAN explosion-proof repeater installed in the hazardous area, a switching HUB connected to the wireless LAN access point via a LAN cable, and an electrical signal and an optical signal connected to the switching HUB. -To-bidirectional or unidirectional optical / electrical converter, and the switching HUB An explosion-proof concentrator installed in the hazardous area, a wireless LAN server installed in a non-hazardous area, a wireless LAN server installed in the dangerous area, An optical / electrical converter installed in the non-hazardous area, and an optical / electrical converter installed in the non-hazardous area, and the explosion-proof type, which are connected to convert an electric signal and an optical signal bidirectionally or in one direction. An optical cable for connecting an optical / electrical converter housed in the concentrator is provided.
If it does in this way, a wireless LAN explosion-proof repeater can be expanded easily using an explosion-proof concentrator.

The communication system in the hazardous area according to the present invention is a wireless LAN access point for connecting a transceiver installed in the dangerous area to the transceiver via a wireless LAN, and a wireless LAN access point connected to the wireless LAN access point. Or, two or more planar antennas, and at least a part of which uses a radio wave transmitting material that transmits radio waves transmitted and received by the planar antenna, and accommodates the wireless LAN access point and the planar antenna, and has a pressure-proof explosion-proof structure. An explosion proof structure including a sealed container, housing a wireless LAN explosion-proof repeater installed in the hazardous area, a switching HUB connected to the wireless LAN access point via a LAN cable, and the switching HUB Explosion-proof type concentrator installed in the hazardous area, and a non-hazardous area A wireless LAN server installed in the network, a HUB connected to the wireless LAN server and installed in the non-hazardous area, a HUB installed in the non-hazardous area, and a switching HUB housed in the explosion-proof concentrator. And a LAN cable for connecting the two.
In this way, even if the wireless LAN server in the non-hazardous area and the wireless LAN explosion-proof repeater in the hazardous area are separated, communication can be performed using the LAN cable.

  As described above, according to the wireless LAN explosion-proof repeater of the present invention and the communication system in the hazardous area, the dangerous area is manufactured in a large hazardous area such as a refinery or a petrochemical factory that manufactures and handles the dangerous goods. A large amount of data related to the operation data of the manufacturing facility can be communicated safely and efficiently between the facility and the non-hazardous area management facility via the wireless LAN. In addition, by communicating a large amount of data safely and efficiently, the plant can be operated safely and efficiently at a higher level, and the safety of the plant in the event of a disaster can be further improved.

[Wireless LAN explosion-proof repeater]
FIG. 1 is a schematic perspective view of a wireless LAN explosion-proof repeater according to an embodiment of the present invention.
In the figure, a wireless LAN explosion-proof repeater 1 includes a wireless LAN access point 2, a planar antenna 3, a sealed container 4, an optical / electrical converter 5, and an AC adapter 6.

(Wireless LAN access point)
The wireless LAN access point 2 is a radio wave relay that connects a transceiver (not shown) by a wireless LAN (local area network), and generally has a connection function with a wired LAN. ing.
An identifier called ESSID (Extended Service Set Identifier) is normally assigned to the wireless LAN access point 2 and a transceiver (for example, a computer with a wireless LAN adapter attached or a PDA (personal information terminal) having a transmission / reception function). The wireless LAN access point 2 relays only communication with a transceiver having the same ESSID as itself. Thereby, even in an environment where a plurality of transceivers are mixed in the same area, it is possible to prevent interference and useless communication.
The wireless LAN access point 2 normally relays communication with a plurality of transceivers, but may relay communication with one transceiver.

(Flat antenna)
The planar antenna 3 is a rectangular flat antenna, and has one antenna element (not shown) in this embodiment. When an electric signal is input from the wireless LAN access point 2, the planar antenna 3 emits a radio wave corresponding to the electric signal, and when receiving the radio wave, outputs an electric signal corresponding to the received radio wave. In the present embodiment, the number of antenna elements is one, but is not limited to this number. In addition, the planar antenna 3 is configured to receive and transmit radio waves, but may be configured to perform either reception or transmission.
In general, the planar antenna 3 is molded by a resin that transmits radio waves, and a coaxial cable 74 is drawn from the center of the lower portion and connected to the wireless LAN access point 2.

  The planar antenna 3 covers a front surface and an area that spreads at a predetermined angle from the front surface, receives radio waves from the covered area direction, and transmits radio waves toward the covered area. Therefore, the planar antenna 3 is attached toward the direction of the installed transceiver. Further, since the planar antenna 3 transmits radio waves toward a predetermined area, a stable electric field strength can be obtained.

Preferably, the two planar antennas 3 are attached in a substantially L shape, and in this way, a wide-angle area that is about twice as large as that in the case where one planar antenna 3 is attached can be covered. it can.
Further, as shown in FIG. 2, the four planar antennas 3 may be mounted in a substantially rectangular ring shape when viewed from above, and in this way, an area in the direction of approximately 360 ° (ie, the entire circumference) is covered. Can do. Depending on the wide-angle characteristics of the planar antenna 3, for example, the five planar antennas 3 may be attached in a regular pentagon shape. Furthermore, when the transceiver is in the left-right direction, the two planar antennas 3 may be arranged so as to face each other with their backs facing each other.
In general, since the planar antenna 3 is fixed to the upper lid 422 with screws or the like (not shown), the mounting direction can be easily adjusted.

(Optical / electrical converter)
When an optical signal is input from the outside, the optical / electrical converter 5 converts the optical signal into an electrical signal, and outputs the converted electrical signal to the wireless LAN access point 2. When an electrical signal is input from the wireless LAN access point 2, the electrical signal is converted into an optical signal, and the converted optical signal is output to the outside. In the present embodiment, the optical signal and the electric signal are converted in both directions, but may be converted in any one direction.
The optical / electrical converter 5 is connected to the wireless LAN access point 2 via, for example, a category 5 UTP (Unshielded Twist Pair) cable 75, and an external connection terminal (not shown) Connection is made via an optical cable 72.
In this way, optical communication can be performed with, for example, a wireless LAN server provided outside, and a large amount of data can be communicated at high speed. In this embodiment, the optical / electrical converter 5 is provided. However, the optical / electrical converter 5 may not be provided, and communication with the outside by an electrical signal may be employed.

(AC adapter)
The AC adapter 6 receives an alternating current of 100 V from the outside via the power cable 71 and converts it into a low-voltage direct current. The direct current is converted into the optical / electrical converter 5 and the power via the power cable 73. The wireless LAN access point 2 is supplied.
If it does in this way, the AC power supply generally used (for example, AC 100V power supply) can be utilized, and it can install easily even when there is no DC power supply outside.

(Sealed container)
The sealed container 4 includes a cylindrical portion 41 that houses the planar antenna 3, and a base portion 42 that houses the wireless LAN access point 2, the optical / electrical converter 5, and the AC adapter 6.
The cylindrical portion 41 is formed in a substantially cylindrical shape with one end formed in a hemispherical shape and the other end opened. The material of the cylindrical portion 41 is a radio wave transmitting material that transmits radio waves transmitted and received by the planar antenna 3, such as glass or the like. Resin or the like is used. By setting it as such a shape, the mechanical strength of the cylindrical part 41 with respect to an internal pressure can be improved, and the direction of the planar antenna 3 can be set freely. In the present embodiment, heat-resistant tempered glass is used.

The cylindrical portion 41 has a structure in which the lower cylindrical portion is fitted into the upper cylindrical portion of the base portion 42 and is connected to the base portion 42 in an airtight state by an adhesive (not shown) such as an epoxy resin. The
In the present embodiment, an adhesive is used, but the present invention is not limited to this configuration. For example, a general hermetic structure, for example, a structure for sealing using an O-ring or a gasket may be used.

The base 42 is a bottomed cylindrical metal container with an upper lid 421 attached to the base 42 and houses the wireless LAN access point 2, the optical / electrical converter 5, and the AC adapter 6. In addition, the base 42 is provided with a sealing means 423 for inserting the power cable 71 and the optical cable 72 on the side surface and blocking the outside from the inside of the base 42. In general, the sealing means 423 uses a cable packing made of cylindrical rubber (not shown).
In this way, the inside of the cylindrical portion 41 and the base portion 42 is sealed with respect to the outside. For example, even if a spark occurs inside the wireless LAN access point 2, a spark is generated outside the sealed container 4. A structure that does not pop out can be obtained.

  Here, preferably, the upper lid 421 is bonded to the base 42 so that the inside of the base 42 is sealed, and the cable hole 422 through which the coaxial cable 74 passes is sealed with an epoxy resin or the like. In this way, the inside of the base portion 42 is blocked from the inside of the cylindrical portion 41, so that even if the cylindrical portion 41 is damaged, a problem such as a spark jumping out from the inside of the base portion 42 is prevented. can do.

  According to the wireless LAN explosion-proof repeater 1 configured as described above, communication can be performed safely and efficiently by using a wireless LAN. Moreover, since the radio wave output can be increased by using the planar antenna 3, the communicable area can be expanded.

[First embodiment of communication system in danger area]
FIG. 3: has shown the schematic block diagram for demonstrating 1st embodiment of the communication system in the danger zone of this invention.
In the figure, a communication system 10 in a hazardous area includes a transmitter / receiver (not shown) provided in a plurality of terminals and a plurality of the above-described wireless LAN explosion-proof repeaters 1 in the dangerous area. A wireless LAN access point 2 built in the type repeater 1 is connected to a transceiver by a wireless LAN.

An optical / electrical converter that is connected to the measurement room 80 in the non-hazardous area via the wireless LAN server 8 and the wireless LAN server 8 via the LAN cable 82, and converts an electric signal and an optical signal bidirectionally or unidirectionally. 81, and the optical / electrical converter 81 and the optical / electrical converter 5 housed in the plurality of wireless LAN explosion-proof repeaters 1 are connected via the optical multi-cable 83.
The wireless LAN server 8 is a computer connected to a terminal in a dangerous area through a wireless LAN.

Thus, according to the communication system 10 of the present embodiment, when the wireless LAN server 8 in the non-hazardous area and the wireless LAN explosion-proof repeater 1 in the dangerous area are separated (for example, several hundred meters away). Even so, a large amount of data can be communicated at high speed in both directions or in one direction. Further, by wiring up to the wireless LAN explosion-proof repeater 1 with the optical multi-cable 83, it is possible to reduce transmission loss and prevent the influence of electromagnetic noise.
In the present embodiment, the wireless LAN server 8 and the optical / electrical converter 81 are configured to be connected using the LAN cable 82. However, the present invention is not limited to this configuration, and is not illustrated, for example. Instead of the LAN cable 82, a UTP cable having a switching HUB connected therebetween may be used.

[Second Embodiment of Communication System in Dangerous Area]
FIG. 4: has shown the schematic block diagram for demonstrating 2nd embodiment of the communication system in the danger zone of this invention.
In this figure, the communication system 10a in the hazardous area uses the optical / electrical converter 5 and the removed wireless LAN explosion-proof repeater 1a as compared with the first embodiment, and the wireless LAN access point 2 and the LAN cable 82. The switching HUB (star-type concentrator) 9 connected via the optical housing 5, the optical / electrical converter 5 connected to the switching HUB 9, and the switching HUB 9 and the optical / electrical converter 5 are accommodated, The point which provided the explosion-proof type concentrator 40 provided with the airtight container 4a installed in the danger zone is different. Other components are the same as those in the first embodiment.
Therefore, in FIG. 4, the same components as those in FIG. 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

The sealed container 4a of the explosion-proof type concentrator 40 is a large metal sealed container that is not provided with a glass window or the like because it does not need to transmit radio waves.
Here, the reason why the size is large is that when the wireless LAN explosion-proof repeater 1a is added, the optical / electrical converter 5 and the switching HUB 9 can be accommodated. The optical multi-cable 83 for connecting the optical / electrical converter 81 and the optical / electrical converter 5 is preliminarily wired inside the sealed container 4a by an amount corresponding to the additional wireless LAN explosion-proof repeater 1a. . In this way, the wireless LAN explosion-proof repeater 1a can be easily added using the explosion-proof concentrator 40.

  The switching HUB 9 is a HUB equipped with a switching port that can manually change the communication speed and communication mode. In the present embodiment, the optical / electrical converter 5 and the switching HUB 9 are provided. However, the present invention is not limited to this configuration. For example, the optical / electrical converter incorporating the switching HUB may be provided. Good.

  As described above, according to the communication system 10a of the present embodiment, a plurality of (for example, five) wireless LAN explosion-proof repeaters 1a are scattered in an area of several hundreds of square meters. In the case of several kilometers away, an explosion-proof concentrator 40 is installed at substantially the center of the above area, the optical / electrical converter 81 and the optical / electrical converter 5 are connected by an optical multi-cable 83, and each switching HUB 9 The wireless LAN explosion-proof repeater 1a can be connected by a LAN cable 82. That is, since optical communication using the optical multi-cable 83 can be performed over a distance of several kilometers, it is not necessary to provide a signal amplifier or the like, and the optical multi-cable 83 can be easily laid. Further, for each wireless LAN explosion-proof repeater 1a, a LAN cable 82 may be laid between the wireless LAN explosion-proof repeater 1a and the explosion-proof concentrator 40, and the introduction cost of the communication system 10a can be reduced.

[Second Embodiment of Communication System in Dangerous Area]
FIG. 5: has shown the schematic block diagram for demonstrating 3rd embodiment of the communication system in the danger zone of this invention.
In the figure, the communication system 10b in the hazardous area is different from the second embodiment in that instead of the explosion-proof type concentrator 40, the switching HUB 9 and the sealed container 4b that houses the switching HUB 9 and has a pressure-proof explosion-proof structure The point is that an explosion-proof type concentrator 40 b provided with a wireless LAN server 8 and a switching HUB 9 are connected via a LAN cable 82, and a HUB 9 b is provided instead of the optical / electrical converter 81. Other components are substantially the same as those in the second embodiment.
Therefore, in FIG. 5, the same components as those in FIG. 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The switching HUB 9 of the present embodiment has a signal amplification function, and the relay distance by the LAN cable 82 can be about 100 m at the maximum. Therefore, when the relay distance is long, it is possible to connect to the remote wireless LAN explosion-proof repeater 1a by connecting the explosion-proof type concentrator 40b between the LAN cables 82 as much as necessary. Moreover, the communication system 10b of this embodiment is effective for a relatively small danger area.

The communication systems 10, 10a, and 10b have a plurality of manufacturing facility operation data, facility management history data, on-site operation drawing information, and monitoring image information when the dangerous area is a refinery or a petrochemical plant. Since a large amount of data such as acoustic information can be closely communicated between the dangerous area and the non-hazardous area, the plant can be managed accurately based on these data. Therefore, the plant can be operated safely and efficiently at a higher level, and the safety of the plant in the event of a disaster can be further improved.
Also, in field operations and equipment maintenance management operations in hazardous areas, a large amount of data (information) can be easily communicated between measurement rooms and offices (non-hazardous areas) and the field (hazardous areas). Therefore, the work efficiency of these operations can be greatly improved.

The preferred embodiment of the wireless LAN explosion-proof repeater and the communication system in the hazardous area has been described above, but the wireless LAN explosion-proof repeater and the communication system in the dangerous area according to the present invention have been described above. Needless to say, the present invention is not limited to the embodiments, and various modifications can be made within the scope of the present invention.
For example, although the wireless LAN explosion-proof repeater 1 is configured to be fixed in a state where it is placed on the installation table, although not shown, the wireless LAN explosion-proof repeater 1 is turned upside down and supported by the legs. It may be fixed to the lower surface of the top plate, and in this way, it is possible to effectively prevent a problem that the cylindrical portion 41 is damaged by a fallen object from above.

  For example, the wireless LAN explosion-proof repeater 1 is configured to transmit radio waves through the cylindrical portion 41, but is not limited to this configuration. Although not shown, an opening for accommodating the planar antenna 3 may be provided on the side surface of the cubic metal container, and the opening may be closed with an acrylic plate. In this way, the structure can be simplified. At the same time, since the amount of radio wave transmitting material having a low mechanical strength is reduced, the overall mechanical strength of the wireless LAN access point can be improved.

  As described above, the wireless LAN explosion-proof repeater of the present invention and the communication system in the hazardous area are not limited to plants such as refineries and petrochemical plants. For example, the equipment industry that requires explosion-proof equipment. It can be effectively applied to the whole.

1 is a schematic perspective view of a wireless LAN explosion-proof repeater according to an embodiment of the present invention. The schematic plan view for demonstrating the state which attached the four planar antenna to the wireless LAN explosion-proof repeater which concerns on embodiment of this invention is shown. 1 shows a schematic block diagram for explaining a first embodiment of a communication system in a danger zone of the present invention. FIG. The schematic block diagram for demonstrating 2nd embodiment of the communication system in the danger zone of this invention is shown. The schematic block diagram for demonstrating 3rd embodiment of the communication system in the danger zone of this invention is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wireless LAN explosion-proof repeater 2 Wireless LAN access point 3 Planar antenna 4,4a, 4b Sealed container 5 Optical / electrical converter 6 AC adapter 8 Wireless LAN server 9 Switching HUB
9b HUB
10, 10a, 10b Hazardous area communication system 40, 40b Explosion-proof concentrator 41 Cylindrical part 42 Base 71 Power cable 72 Optical cable 73 Power cable 74 Coaxial cable 75 UTP cable 80 Measurement room 81 Optical / electrical converter 82 LAN cable 83 Light Multi cable 421 Upper lid 422 Cable hole 423 Sealing means

Claims (8)

A wireless LAN access point for connection between the transceiver and the wireless LAN;
One or more planar antennas connected to the wireless LAN access point;
A sealed container having a pressure-proof explosion-proof structure that uses a radio wave transmitting material that transmits radio waves transmitted and received by the planar antenna and that houses the wireless LAN access point and the planar antenna. Wireless LAN explosion-proof repeater. The sealed container includes a cylindrical portion made of the radio wave transmitting material, one end formed in a hemispherical shape and the other end opened, and a base connected to the other end of the cylindrical portion,
The wireless LAN explosion-proof repeater according to claim 1, wherein the planar antenna is housed in the cylindrical portion.   The wireless LAN explosion-proof repeater according to claim 1 or 2, wherein when two or more planar antennas are accommodated, the planar antennas are arranged in an L shape or a polygonal shape.   4. An optical / electrical converter connected to the wireless LAN access point and converting an electric signal and an optical signal in both directions or in one direction is housed in the sealed container. The wireless LAN explosion-proof repeater described in the paragraph.   The wireless LAN explosion-proof repeater according to claim 1, wherein an AC adapter is housed in the sealed container. A transceiver installed in the hazardous area;
A wireless LAN access point that connects the transceiver with the wireless LAN, one or more planar antennas connected to the wireless LAN access point, and an electrical signal and an optical signal that are connected to the wireless LAN access point An optical / electrical converter that converts bidirectionally or unidirectionally, and a radio wave transmitting material that transmits radio waves transmitted and received by the planar antenna at least partially, and the wireless LAN access point, planar antenna, and light A wireless LAN explosion-proof repeater installed in the hazardous area, including a sealed container that houses an electrical converter and has an explosion-proof construction;
A wireless LAN server installed in a non-hazardous area;
An optical / electrical converter installed in the non-hazardous area that is connected to the wireless LAN server and converts an electric signal and an optical signal in both directions or in one direction;
A communication system in a hazardous area, comprising: an optical cable connecting the optical / electrical converter installed in the non-hazardous area and the optical / electrical converter housed in the wireless LAN explosion-proof repeater. A transceiver installed in the hazardous area;
A wireless LAN access point connecting the transceiver with the wireless LAN, one or more planar antennas connected to the wireless LAN access point, and at least a part of the radio waves transmitted and received by the planar antenna. A wireless LAN explosion-proof repeater installed in the hazardous area, using a radio wave transmitting material that passes through, and a sealed container that houses the wireless LAN access point and the planar antenna and has a pressure-proof explosion-proof structure;
A switching HUB connected to the wireless LAN access point via a LAN cable, an optical / electrical converter connected to the switching HUB and converting an electric signal and an optical signal in both directions or in one direction, and the switching HUB Explosion-proof type concentrator installed in the dangerous area, including a sealed container that houses the photoelectric converter and has a pressure-proof explosion-proof structure;
A wireless LAN server installed in a non-hazardous area;
An optical / electrical converter installed in the non-hazardous area that is connected to the wireless LAN server and converts an electric signal and an optical signal in both directions or in one direction;
A communication system in a hazardous area, comprising: an optical cable connecting the optical / electrical converter installed in the non-hazardous area and the optical / electrical converter housed in the explosion-proof concentrator. A transceiver installed in the hazardous area;
A wireless LAN access point connecting the transceiver with the wireless LAN, one or more planar antennas connected to the wireless LAN access point, and at least a part of the radio waves transmitted and received by the planar antenna. A wireless LAN explosion-proof repeater installed in the hazardous area, using a radio wave transmitting material that passes through, and a sealed container that houses the wireless LAN access point and the planar antenna and has a pressure-proof explosion-proof structure;
A switching HUB connected to the wireless LAN access point via a LAN cable, and an explosion-proof type concentrator installed in the hazardous area, including a sealed container that houses the switching HUB and has a pressure-proof explosion-proof structure;
A wireless LAN server installed in a non-hazardous area;
HUB connected to this wireless LAN server and installed in the non-hazardous area,
A communication system in a hazardous area, comprising: a LAN cable that connects a HUB installed in the non-hazardous area and a switching HUB housed in the explosion-proof concentrator.

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