JP3820807B2 - Process control system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a process control system.
[0002]
[Prior art]
For example, laying a network with dedicated lines on the premises of factories, etc., connecting equipment machines / sensors, etc. installed in various places in the factory to the above network, and operating information of each equipment machine, data such as alarms, For example, a process control system that collects / receives and processes by a computer such as a personal computer via the network is constructed.
[0003]
Also, not limited to factories, for example, theme parks, amusement parks, event venues, parks, parking lots, construction sites, office buildings, agricultural facilities, golf courses, sports facilities, airport facilities, port facilities, water treatment facilities, garbage treatment facilities Etc., for various purposes such as guidance display data distribution, environmental measurement, failure alarm transmission, security alarm transmission, on-site logistics information collection distribution, entrance / exit data management, monitoring, etc. A process control system is conceivable.
[0004]
[Problems to be solved by the invention]
Process control systems that are constructed by laying networks in specific areas such as the above factories and various facilities have conventionally been wired, but in the case of wired, labor / costs such as laying communication lines In addition, there is a problem that it is not easy to add or relocate, and it takes time and cost. In particular, in a factory or the like, equipment machines are often added / changed / moved in accordance with a change in a product to be manufactured.
[0005]
In addition, so-called “wireless LAN” is known as a method that uses wireless rather than wired communication. This is also the case between each wireless LAN access point and a wireless device connected to each equipment machine, sensor, etc. However, it is also necessary to install a wired LAN. Further, when it becomes necessary to provide a new wireless LAN access point due to the addition / change / movement, the labor / cost of laying a wired communication line is required. Furthermore, if the movement of a large facility / material, etc., blocks the wireless communication path between each wireless LAN access point and the wireless device, and communication becomes impossible, it may not function at all.
[0006]
In addition, it is conceivable to use a PHS, a mobile phone or the like as a wireless device, but this does not require labor / cost at the time of installation, but the subsequent communication cost becomes high. Also in this case, there is a possibility that the wireless communication path with the nearest PHS base station (within the communicable range) is blocked and communication becomes impossible.
[0007]
Alternatively, for example, in JP-A-10-227400, a communication device connected to each monitoring device relays sensor detection information and commands from the monitoring device to the host side or from the host side to the monitoring device. A remote monitoring system for sending data has been proposed. This remote monitoring system is simple in construction and can easily install many monitoring devices. However, once installed, each wireless device (communication device) is capable of autonomously and flexibly changing the relay destination for changes in the surrounding environment, addition / movement / failure of monitoring devices, etc. There wasn't.
[0008]
An object of the present invention is to provide a highly reliable process that can be easily constructed at a low cost in an arbitrary area and can automatically cope with a change or failure of a network configuration due to addition / movement of a wireless device or an environmental change. To provide a control system.
[0009]
[Means for Solving the Problems]
The process control system according to the present invention is configured by a plurality of wireless terminals having a relay function for autonomously selecting a relay destination being distributed in a specific area, and each of the wireless terminals is directly or one or more other A wireless network capable of communicating with all other wireless terminals by being relayed by the relay function of the wireless terminal; and one of the wireless terminals, and connected to an object of measurement, detection, display, or control. One or more PIO stations that perform output control, and a host that includes one of the wireless terminals and performs measurement, detection, display, or control commands to the PIO stations via the wireless network.
Further, each of the plurality of wireless terminals associates the wireless terminal that is the destination of data transmitted by itself with the minimum number of communications required until the data arrives at the destination wireless terminal. The first storage means for storing the first system configuration information shown, the destination wireless terminal of the data transmitted by itself, and the adjacent wireless terminal capable of direct communication with itself to the destination wireless terminal Second storage means for storing second system configuration information indicating the minimum number of communication times required until an incoming call is associated with each other; Send yourself For transferring data to the target wireless terminal Next destination As a result, the number of communications to the target wireless terminal is minimized. Forwarding destination Based on the first or second system configuration information Choice Communication channel Choice Means.
[0010]
According to the above process control system, since a network is constructed by a plurality of wireless devices, work / costs such as laying a wired cable as in the case of constructing a wired network are not required. Simply work to place the radios in various places. Furthermore, even after a network is once constructed, the system can be easily expanded / changed by simply placing a new wireless device (PIO station) or moving a wireless device that has already been placed. Furthermore, even if a communication failure, communication channel interruption, or radio failure occurs, and a previously available communication channel becomes unusable, a relay route is automatically selected flexibly in response to this (detour) Therefore, the possibility of communication failure or system failure is extremely low, and a highly reliable system can be provided.
[0011]
In the process control system, for example, the wireless network is a distributed network, and one or more relay-dedicated wireless terminals are further arranged as necessary. In other words, if the wireless network can be constructed only by the PIO station and the host including the wireless terminal, it may be. However, if it is not possible, a relay-dedicated wireless terminal having a configuration of only the wireless terminal is arranged.
[0012]
For example, in the process control system, when the wireless network is built in a premises, one or more of the PIO stations are connected to a current sensor, and when a measurement command is received from the host, measurement data obtained by the current sensor is transmitted to the process control system. This is an electric energy measurement system that transmits to a host via a wireless network, and collects / stores, analyzes or displays measurement data sent from a PIO station. .
[0013]
Further, for example, in the process control system, the wireless network is constructed in a chemical factory or chemical plant, one or more of the PIO stations are connected to a gas sensor, and when a gas detection command is received from the host, the gas sensor The obtained detection data is transmitted to the host via the wireless network, one or more of the PIO stations are connected to an alarm device or a display device, and the host is sent from a PIO station connected to the gas sensor. The presence or absence of an abnormality is determined based on the detected data, and if it is determined that there is an abnormality, an alarm instruction instruction is transmitted to the PIO station connected to the alarm device and an alarm is issued by the alarm device, or the display device A warning message is sent to the PIO station connected to the Shows a gas detection / alarm system for displaying the warning message to the device.
[0014]
Alternatively, for example, in the process control system, when the wireless network is constructed in a water treatment-related facility, one or more of the PIO stations are connected to a water quality sensor, and when a command from the host is received, the water quality sensor The detected water quality data is transmitted to the host via the wireless network, and the host is a water quality management system for collecting / accumulating, analyzing or displaying the detected data sent from the PIO station.
[0015]
Alternatively, in the process control system, for example, when the wireless network is built in a radiation-related facility, one or more of the PIO stations are connected to the radiation sensor, and the command from the host is received, the radiation sensor Is transmitted to the host via the wireless network, and the host collects / stores, analyzes or displays the radiation dose data sent from the PIO station, or the radiation dose data is predetermined. When the value exceeds the value, the system issues a warning instruction instruction to the PIO station connected to the warning device and issues a warning by the warning device.
[0016]
In addition, for example, the wireless network is constructed in an arbitrary facility, and one or more of the PIO stations are connected to an intruder detection switch or a security switch, and when the intruder detection switch or the security switch is turned on, Notifying the host via a wireless network, and when the host receives the notification, a crime prevention system that sends an alarm instruction instruction to the PIO station connected to the alarm device and issues an alarm by the alarm device, etc. Various systems are possible.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a process control system according to an embodiment of the present invention.
[0018]
In the figure, for example, the display device 4, the sensor 5, the contact 6, the SW (switch) 7, the alarm device 8, the valve 9 and the like are present at each installation location in a specific area. It is assumed that the information processing apparatus 10 such as a personal computer is installed. This figure does not mean that the process control system is a system in which all of the display 4 to valve 9 are connected. In the figure, it can be said that many application examples of the process control system of the present invention are mixed.
[0019]
A PIO (process I / O) station 1 is connected to each of the display device 4, sensor 5, contact 6, SW (switch) 7, alarm device 8, and valve 9. In addition, the wireless device 2 is connected to the information processing apparatus 10. Further, a relay radio device 3 is installed as necessary. The PIO station 1, the wireless device 2, and the wireless device 3 form a wireless network to be described later. As a whole, the information processing apparatus 10 measures / displays / controls each PIO station 1 via the wireless network. A process control system that operates by instructing the above is configured. Details will be described later.
[0020]
Above In “The relay wireless device 3 is installed accordingly” means that only the PIO station 1 and the wireless device 2 cannot sufficiently establish a wireless network described later. For example, when there is a PIO station 1 in a position where wireless communication with another PIO station 1 (or radio device 2) is not possible, it is used as a relay, reinforcement of a portion where a high-quality communication path cannot be formed, or in a wireless network A relay radio device 3 is installed to form a detour in a portion where traffic is concentrated (in other words, when a radio network can be sufficiently constructed with only the PIO station 1 and the radio device 2) Therefore, the relay radio device 3 is not necessary).
[0021]
FIG. 2 is a diagram illustrating an example of the configuration of the PIO station 1.
The PIO station 1 shown in FIG. 1 includes a wireless device 11, a microcomputer 12, an input / output device 13, and the like. The wireless device 11 will be described later. The input / output device 13 is a process input / output I / O interface, and includes DI (digital input), DO (digital output), AI (analog input), AO (analog output), and the like. A process is an input / output control target device such as a measuring device, a display device, a control device, and the like such as the display device 4, the sensor 5, the contact 6, the SW (switch) 7, the alarm device 8, and the valve 9.
[0022]
1 radio 2 ,transceiver 3 2 and the radio equipment 11 in the PIO station 1 shown in FIG. 2 are basically the same, and have at least a flexible relay function.
[0023]
Here, the applicant of the present invention distributes a plurality of wireless devices (having at least a flexible relay function) in a specific area in a prior application (Japanese Patent Application No. 10-185866, etc.), and A wireless communication network (hereinafter referred to as a wireless network) in which another wireless device existing between a wireless device and a destination wireless device transfers data packets while repeating relaying has been proposed. In this wireless network, the wireless communication path is not fixed, but has a function of autonomously changing the relay destination in each wireless device, so that it is automatically and flexibly changed. Even if a failure or a wireless device failure occurs, the relay route can be automatically changed and dealt with.
[0024]
Each wireless device in this wireless network is assigned a unique identification code so that they can be distinguished from each other. For example, in the process control system shown in FIG. 1, identification codes A to J are assigned to the wireless device 2, the wireless device 3, and the wireless device 11 of the PIO station 1 as shown in FIG. And
[0025]
A wireless network constructed by these wireless devices A to J is shown in FIG.
In the figure, a straight line (solid line) connecting the wireless devices A to J indicates a communication path through which each of the wireless devices A to J can directly communicate. The distance that each wireless device in the wireless network can communicate directly is finite (short distance). For example, when the wireless devices A to J are dispersedly installed in a facility such as a factory or a park, each wireless device A ~ J cannot communicate directly with all other radios. On the other hand, in the case of constructing the wireless network, all wireless devices can directly communicate with at least one other wireless device and all of the wireless networks constituting the wireless network via the other wireless devices are configured. It is possible to communicate with other wireless devices and to have a plurality of relay routes. For example, as an order, first, each PIO station 1 and the wireless device 2 connected to the information processing apparatus 10 are installed. If a wireless network cannot be established with only these wireless devices 11 and 2, a relay wireless device 3 is installed. In the example illustrated in FIG. 1, radio devices B, E, and F are installed as relay radio devices 3. In the example shown in the figure, each of the wireless devices can communicate directly with at least one other wireless device even if only the wireless devices A, D, G, H, J, I, and C are used. Although it is possible to communicate with all the wireless devices constituting the wireless network via the wireless device, there is one relay route between the wireless devices AI and the wireless devices HD, for example, the wireless device G When any failure occurs in the communication path between -D, another relay route cannot be selected. Therefore, the wireless devices 3 (B, E, F) for relay are installed.
[0026]
Each wireless device constituting the wireless network needs to be aware of which other wireless device is connected to itself through which wireless device has a direct communication path, for example, not shown. The system configuration information is stored in the memory (EEPROM, RAM, flash memory) built in each radio.
[0027]
4 and 5 are diagrams showing an example of the system configuration information. Here, the system configuration information 20 and 30 stored / managed by the wireless device A are shown.
FIG. 4 shows the system configuration information 20 of the wireless device A itself.
[0028]
In the system configuration information 20 shown in the figure, the number of communications 21 indicates the number of communications that are performed before the packet transmitted by the radio A reaches the destination radio. The wireless terminal 22 indicates a destination wireless device that reaches the communication frequency as the minimum communication frequency. By referring to the system configuration information 20 shown in the figure, for example, it can be seen that there are B, C, E, and F in the radio that can transfer the packet by the radio A in one communication. It can be seen that there are D, G, H, and I in wireless devices that require at least two communications, including relay communication by the wireless device. Similarly, it can be seen that there is J in a radio that requires at least three communications.
[0029]
FIG. 5 shows the configuration information 30 of the radios B, C, E, and F that can communicate directly with the radio A. That is, the wireless device A stores / manages configuration information 30 shown in FIG. 5 in addition to its own configuration information 20 shown in FIG. Then, referring to these pieces of configuration information, a wireless device to be directly communicated with in order to send a packet to the receiving wireless device is determined.
[0030]
For example, when the destination wireless device is any one of B, C, E, and F, it can be seen from the configuration information 20 that it is a wireless device that can directly communicate with it. Wireless communication with the machine is sufficient. Further, for example, when the destination wireless device is I, referring to the configuration information 30, it can be seen that the wireless device B can transfer data by three communications. Similarly, the wireless device C can be transferred by one communication. From the wireless device E, it can be seen that the data can be transferred by two communications. From the wireless device F, it can be seen that the data can be transferred by one communication. Thus, since the wireless device A basically selects the one that requires fewer transfer times, a packet whose destination is the wireless device I is transmitted to either of the wireless devices C and F. .
[0031]
The configuration information is not fixed. When there is a change in the system configuration (for example, a new communication channel is set in the system, a new radio is added, a communication channel that was valid until then becomes invalid, or vice versa) When the communication channel is valid), the configuration information stored / managed by each wireless device is updated. This is related to the presence notification packet described in the earlier application.
[0032]
FIG. 6 shows a state in which the wireless device E and the wireless device I transmit the presence notification packet in the wireless network of FIG. The presence notification packet stores a unique code (identification code of A to J) for identifying a wireless device that transmits the presence notification packet. This is a special packet to notify the machine.
[0033]
In FIG. 6, the wireless devices A, B, D, F, G, and H receive the presence notification packet transmitted by the wireless device E at regular intervals in the same manner (indicated by solid arrows in the figure). Recognize the possibility of direct communication with the machine E. Radios C, F, H, and J have the possibility of communicating directly with radio I by receiving presence notification packets transmitted by radio I at regular intervals (indicated by dotted arrows in the figure). Recognize that Similarly, although not shown in FIG. 6, all the radio devices A, B, C, D, F, G, H, and J transmit presence notification packets.
[0034]
As described above, each of the wireless devices A to J transmits the presence notification packet at a constant period, so that the possibility of direct communication according to the radio wave propagation state at that time can be mutually recognized. Furthermore, each wireless device transmits a communication channel diagnosis packet to diagnose the reliability of the communication channel between the wireless devices having the possibility of direct communication recognized by the presence notification packet, and achieves reliability exceeding the standard. Set what you have as an effective channel. Further, each wireless device transmits a presence notification packet storing the configuration information 20 of the transmission source communication device, and recognizes the system configuration at that time. For example, in the above example, the wireless devices A, B, D, F, G, and H receive the configuration information 20 of the wireless device E. If the configuration information 20 of the wireless device E is different from the previously received configuration information 20 of the wireless device E due to some reason (communication path interruption, addition / movement / failure of the wireless device, etc.). In this case, each of the wireless devices A, B, D, F, G, and H reflects this change in the configuration information 20 and 30 stored therein. In this way, the configuration information stored / managed by each wireless device is automatically updated in response to a change in the system configuration.
[0035]
In addition, as described in the above-mentioned prior application, the wireless network has a communication path reliability diagnosis, a packet transmission timing setting, a reply that a packet has been received, and an incoming communication packet. It has various functions such as history maintenance, introduction of broadcast communication packets, detection of missing wireless terminals, selection of detour transfer routes, and the like. However, the wireless network used in the process control system of the present invention does not necessarily have all the functions described in the previous application. It is necessary to have at least a function for realizing flexible relay and communication path search.
[0036]
The process control system of the present invention employing such a wireless network can automatically cope with changes in the network configuration due to changes in the environment, movement / addition / reduction of wireless devices, etc., which requires effort / cost. Therefore, a highly reliable system can be provided. For example, in factories and the like, the surrounding environment (radio wave environment) changes as equipment machines are added / changed / moved along with changes in the product to be manufactured, etc. In some cases, the communication path may be interrupted, or conversely, the communication path that was previously interrupted may be restored, and cannot be handled by a conventional wired network or a fixed communication path wireless network (or However, in the process control system of the present invention, the optimum relay route is automatically determined each time as described above, so even in an environment such as a factory. Keep high reliability. Furthermore, the wireless device can secure higher reliability by using SS wireless (radio by a spread spectrum communication system). In addition, it can be installed without problems even in places where the radio wave environment is inferior, such as in a distribution board (distribution board).
[0037]
As described above, the process control system of the present invention has the following advantages.
(1) Since a network is constructed by a plurality of wireless devices, the labor / cost of construction such as laying a wired cable as in the case of constructing a wired network is not required. Simply work to place the radios in various places. Furthermore, even after a network is once constructed, the system can be easily expanded / changed by simply placing a new wireless device (PIO station) or moving a wireless device that has already been placed. Furthermore, even if a failure occurs, it is difficult for repairs unless it is a maintenance person with specialized knowledge in the case of a wired connection. Therefore, the operation cost can be reduced.
(2) Generally, a wireless communication path is susceptible to the surrounding environment where it is installed. On the other hand, the surrounding environment in factories, plants, buildings, etc. where process control systems are mainly constructed often changes gradually after installation. Further, there may be a case where it is a bad environment for the wireless communication path. For this reason, in a conventional system using a fixed communication path, if one of the fixed communication paths is interrupted due to the influence of the environment, communication becomes impossible and the system does not function, or the system goes down in the worst case. . Furthermore, the system cannot be easily changed / expanded and cannot cope with a change in communication topology due to a failure of the radio.
[0038]
On the other hand, in the process control system of the present invention, the network configuration (communication connection between the radios) is automatically searched periodically by the presence notification packet described above, and the network configuration is established by newly installing, malfunctioning, moving, etc. Even if changes occur, this change can be handled automatically and flexibly, and even if one of the communication routes of the relay route becomes unusable due to environmental changes, other relay routes are automatically used. Therefore, the possibility of communication failure or system failure is extremely low, and a highly reliable system can be provided.
[0039]
Hereinafter, various specific proposals are made for the process control system using the wireless network described above.
First, an electric energy measurement system will be described as an example of a process control system.
[0040]
The electric energy measurement system shown in FIG. 7 is constructed in a premises such as a factory or a building, for example.
Each PIO station 1 shown in the figure is installed in the vicinity of a distribution board existing in, for example, a factory or a building. And it connects to the current sensor 5a attached in the distribution board. The current sensor 5a is a split-type current sensor proposed by the applicant of the present invention as a current sensor that replaces a conventional CT, and is clamped to a power line (power circuit) in a distribution board as shown in FIG. (Attach the circuit without cutting it without disconnecting it) and measure the current value. The number of current sensors 5 a that can be connected to one PIO station 1 is determined by the number of input / output points of the input / output device 13. For example, 32 current sensors 5a can be connected. In this example, the input / output device 13 is AI (analog input). For example, when the microcomputer 12 receives a packet including a current value read command (described later) from the information processing device 40 from the wireless device 11, the microcomputer 12 inputs the detection value by each current sensor 5 a via the input / output device 13 and uses it. The power amount and instantaneous power are measured, and processing such as returning this to the information processing apparatus 40 by the wireless device 11 is performed. Alternatively, the electric energy used and the instantaneous electric power are measured from each current sensor 5a at regular intervals and stored, and the electric energy integrated value is calculated, and a current value read command (described later) from the information processing device 40 is issued. When the included packet is received, the stored electric energy and its integrated value may be returned.
[0041]
On the other hand, the information processing apparatus 40 accumulates / manages / analyzes the power amount measured by each PIO station 1. Here, the information processing apparatus 40 has, for example, the configuration illustrated in FIG. 9 and includes a CPU 41, an input unit 42, a display unit 43, a memory 44, a storage unit 45, an input / output interface 46, and the like.
[0042]
The CPU 41 is a central processing unit that controls the entire information processing apparatus 40.
The input unit 42 is, for example, a keyboard or a mouse.
The display unit 43 is a display.
[0043]
The memory 44 is, for example, a RAM or a flash memory.
The storage unit 45 is an HD (hard disk), an FDD (floppy disk drive), or the like, and stores a program that realizes a function of accumulating / managing / analyzing the electric energy.
[0044]
The input / output interface 46 is a connection interface with the wireless device 2.
FIG. 10 is a flowchart for explaining an example of processing by the information processing apparatus 40. The process shown in the figure is performed at regular intervals, for example.
[0045]
In the figure, the information processing apparatus 40 transmits the above current value read command to a specific wireless device (step S1). The specific wireless device is a wireless device of each PIO station 1 connected to the current sensor 5a. In the example illustrated in FIG. 7, the specific wireless devices are wireless devices C, D, G, H, I, and J. In the information processing apparatus 40, for example, the identification codes (C, D, G, H, I, J) of these specific wireless devices are registered in the memory (or the memory 44 or the storage unit 45) built in the CPU 41, For example, the processes in steps S1 to S3 are sequentially performed on the C to J wireless devices. That is, for example, first, a current value read command is transmitted from the wireless device A to the wireless device C in the process of step S1, and the used power amount, instantaneous power, and the like are transmitted from the PIO station 1 having the wireless device C. Wait until the measurement data is returned (step S2). When all the requested measurement data is received (step S3, YES), the received measurement data is accumulated or displayed (step S4). Then, it is determined whether or not measurement data has been received from all the PIO stations 1 (step S5). In the above example, the processes of steps S1 to S4 are repeated in sequence until the measurement data is received from all the PIO stations 1 of the wireless devices C, D, G, H, I, and J.
[0046]
In the data transmission / reception between the information processing device 40 and each PIO station 1, a packet is transmitted from the wireless device 2 of the information processing device 40, which is directly or relayed by another wireless device, and wirelessly transmitted from the destination PIO station 1. Get to the machine. For example, if the measurement data request destination is the PIO station 1 of the wireless device J, communication between the information processing apparatus 40 and the PIO station 1 (wireless device J) is performed by, for example, packet relay shown in FIG.
[0047]
In FIG. 11, when the information processing apparatus 40 sends the current value read command in step S <b> 1 to the PIO station 1 (wireless device J), a packet is sent from the wireless device A to the wireless device J. This packet is composed of, for example, a destination wireless device identification code (J), a transmission source wireless device identification code (A), a current value read command, and the like. For example, as shown in FIG. 11, this packet is relayed by a PIO station 1 (wireless device C, wireless device I) on the way and arrives at the wireless device J. Of course, this relay path is flexible and may change depending on the environment in the factory at that time.
[0048]
The PIO station 1 of the wireless device J that has received this packet returns the measurement value of the current sensor 5a connected thereto to the information processing apparatus 40. The packet in this case is composed of a destination wireless device identification code (A), a transmission source wireless device identification code (J), measurement data, and the like.
[0049]
The information processing apparatus 40 may have functions such as classification (for example, totaling for each department), measurement data table / graphing, and the like in addition to the above-described storage / display of the measurement data.
As described above, by collecting / analyzing the electric energy for each circuit of the distribution board, it becomes possible to grasp the actual power usage, and it can be expected to save energy based on this. In the present invention, such a system can be easily constructed at low cost, and the system can be easily expanded / changed even after the system has been constructed once. Thus, it is also suitable when it is desired to change the measurement location at any time or when it is desired to measure temporarily (only for a short period).
[0050]
Next, a gas detection / alarm system will be described as another example of the process control system.
For example, in chemical factories or chemical plants that handle or may generate toxic or flammable gases, sensors (referred to as gas sensors) that detect the presence or concentration of the gas are installed at various locations in the factory. These sensors are connected to the PIO station.
[0051]
For example, as shown in FIG. 12, the PIO stations 1 (PIO stations of radio devices C, G, H, and J) are connected to gas sensors 5b installed at various locations in the factory. Further, the PIO station 1 (wireless device I) is connected to the alarm device.
[0052]
And the gas detection information of each gas sensor 5b is collected with a fixed period by information processing apparatus. The information processing apparatus includes an identification code (C, G, H, J) of the radio of the PIO station 1 connected to each gas sensor 5b and an identification code of the radio of the PIO station 1 connected to the alarm ( I) is registered, and by using these, packets having the identification codes (C, G, H, J) as destinations are sequentially transmitted from the radio A. This packet includes the identification code (A) of the transmission source radio and the gas detection request command in addition to the identification code of the destination radio. In response to this, each PIO station 1 obtains gas detection information of the gas sensor 5b connected to itself, and transmits a packet including this information to the wireless device A as the transmission source. The information processing apparatus performs, for example, a process of determining whether or not it is in a dangerous state based on the detection information of the gas sensor sent from the wireless device of each PIO station 1 in this way. When it is determined that the state is dangerous, an alarm is issued. For example, the alarm device 8 is sounded. In this case, the wireless device A to which the information processing apparatus is connected transmits a packet whose destination is the wireless device I to which the alarm device 8 is connected. This packet is relayed by, for example, the wireless device F or the wireless device C and reaches the wireless device I. For example, an alarm instruction command is stored in this packet, and the microcomputer 12 of the PIO station 1 provided with the wireless device I decodes the alarm instruction command and sends it to the alarm device 8 connected to the input / output device 13. Outputs an alarm signal. Thus, an alarm is issued by the alarm device 8. Examples of the alarm device 8 include a sound generated by a buzzer, a siren and the like, a lighting display using a patrol light, and the like. In addition, as a warning, you may make it display a warning content on the display of information processing apparatus. In addition, the information processing apparatus causes the wireless device A to transmit a packet including message information such as “gas leak! Dangerous! Evacuation of all members!” To the wireless device D and display the message on the display device 4. You may do it. Further, the gas main stopper may be tightened. For example, a packet containing a valve control instruction command is transmitted to the PIO station 1 (radio device C) connected to the valve 9 (in this case, the valve of the gas main valve). The microcomputer 12 of the PIO station 1 that has received this packet by the wireless device C decodes the valve control instruction command and controls the valve 9 to close, for example.
[0053]
The above electric energy measurement system and gas detection / alarm system are not limited to those constructed in one factory or building. For example, when there are a plurality of factories in a site, the factories are also connected by a wireless network. Thus, a system that collectively manages the processes of all factories on the site may be adopted.
[0054]
As described above, as an example of the process control system, the electric energy measurement system and the gas detection / alarm system have been described in detail, but the present invention is not limited to this.
[0055]
For example, not limited to factories, for example, the above-mentioned theme parks, amusement parks, event venues, parks, parking lots, construction sites, office buildings, agricultural facilities, golf courses, sports facilities, airport facilities, port facilities, water treatment facilities, garbage The process control system of the present invention can be constructed in various areas such as processing facilities. For example, process control systems for various purposes such as guidance display data distribution, environmental measurement, failure alarm transmission, security alarm transmission, on-site logistics information collection and distribution, attendee data management, and monitoring are constructed. This is particularly optimal when real-time characteristics are not required so much (for example, the measurement of the gas amount is sufficient in the order of seconds).
[0056]
For example, a system for managing water quality in a water treatment facility can be considered. In this case, the sensor 5 connected to the PIO station 1 may be a water quality sensor that detects the water quality of water sources and water purification facilities, water quality of the water storage tank, and the like, and the detection data by the water quality sensor is transmitted via a wireless network. Then, the system is transferred to the information processing apparatus and performs data collection / analysis or the like, or controls the valve 9 according to the analysis result to open and close the sluice gate.
[0057]
Alternatively, a nuclear power plant, a radioactive material processing apparatus, a monitoring system in other radiation-related facilities, and the like can be considered. In this case, the sensor 5 connected to the PIO station 1 is a radiation sensor or the like that measures the radiation dose.
[0058]
Alternatively, a switch (SW) 7 that is automatically turned on upon detection of an intruder or a switch (SW) 7 such as an alarm / emergency button is connected to the PIO station 1 so that the microcomputer 12 of the PIO station 1 When it is detected that the connected switch (SW) 7 is turned on, a security system that transmits abnormality occurrence information to the information processing apparatus can be considered.
[0059]
Alternatively, when the information processing device detects a leakage based on the measurement data sent from the PIO station 1 connected to the current sensor or the like, the information processing device is connected to the PIO station 1 connected to the contact (breaker). A security system that transmits a control signal for dropping a breaker can be considered.
[0060]
Or, for example, display devices 4 are installed in various places in the park, information processing devices are installed in park management offices, etc., and these are connected via a wireless network. For example, a system that transmits information, general entertainment information, lost child information, etc.) from the information processing apparatus and displays the information on the display device 4 can be considered.
[0061]
Or the system etc. which install the display machine 4 in a factory etc., and display the manufacture instruction | indication in a manufacturing line, the quantity instruction | indication, etc. can be considered.
In this way, various systems can be constructed easily, inexpensively, and with high reliability, and demand for new system construction can be expected in fields that have not been considered so far.
[0062]
【The invention's effect】
As described above in detail, according to the process control system of the present invention, for example, in a factory, a building, a specific site, or a facility, it can be easily constructed at low cost, and a radio can be added / moved. It is possible to realize a highly reliable process control system that can automatically cope with a change in network configuration or a failure due to an environmental change or the like.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a process control system according to an embodiment.
FIG. 2 is a diagram illustrating an example of a configuration of a PIO station.
FIG. 3 is a diagram showing a wireless network constructed by each wireless device in FIG. 1;
FIG. 4 is a diagram showing system configuration information of the wireless device A itself.
5 is a diagram showing configuration information of radios B, C, E, and F that can directly communicate with radio A. FIG.
6 is a diagram illustrating a state in which a wireless device E and a wireless device I transmit a presence notification packet in the wireless network system of FIG. 3. FIG.
FIG. 7 is a configuration diagram of an electric energy measurement system which is an example of a process control system according to the present embodiment.
FIG. 8 is a diagram showing in detail a PIO station connected to a current sensor.
FIG. 9 is a diagram illustrating an example of a configuration of an information processing device.
FIG. 10 is a flowchart for explaining an example of processing by the information processing apparatus.
FIG. 11 is a diagram illustrating an example of power amount data collection by the information processing apparatus.
FIG. 12 is a configuration diagram of a gas detection / alarm system which is an example of a process control system according to the present embodiment.
[Explanation of symbols]
1 PIO station
2 radio
3 radio equipment (for relay)
4 display
5 Sensor
5a Current sensor
5b Gas sensor
6 contacts
7 SW (switch)
8 Alarm
9 Valve
10 Information processing equipment
11 Radio
12 Microcomputer
13 Input / output devices
20 System configuration information
21 Number of communications
22 Wireless terminal
30 System configuration information
40 Information processing equipment
41 CPU
42 Input section
43 Display
44 memory
45 storage unit
46 I / O interface
50 Gas sensor

Claims (7)

A plurality of wireless terminals having a relay function for autonomously selecting a relay destination are distributed and arranged in a specific area, and any of the wireless terminals is relayed directly or by the relay function of one or more other wireless terminals. A wireless network capable of communicating with all other wireless terminals,
One or more PIO stations comprising one of the wireless terminals, connected to an object of measurement, detection, display or control and performing input / output control;
A host that includes one of the wireless terminals, and performs a measurement, detection, display, or control command to the PIO station via the wireless network;
Each of the plurality of wireless terminals is
First system configuration information is stored that indicates the wireless terminal that is the destination of data transmitted by itself and the minimum number of communications required until the data arrives at the destination wireless terminal. 1 storage means;
Associating a wireless terminal that is the destination of data transmitted by itself with a minimum number of communications required until the data arrives at the destination wireless terminal from an adjacent wireless terminal that can directly communicate with itself Second storage means for storing second system configuration information shown;
As the next transfer destination for transferring the data transmitted by itself to the target wireless terminal, the transfer destination that minimizes the number of times of communication to the target wireless terminal is the first or second system configuration information. A channel selection means for selecting based on
A process control system comprising:   The process control system according to claim 1, wherein the wireless network is a distributed network, and further includes one or more wireless terminals dedicated for relay as necessary. The wireless network is built on campus;
When one or more of the PIO stations are connected to a current sensor and receive a measurement command from the host, the measurement data obtained by the current sensor is transmitted to the host via the wireless network;
2. The process control system according to claim 1, wherein the host collects / accumulates, analyzes or displays measurement data sent from the PIO station. The wireless network is built in a chemical factory or chemical plant,
When one or more of the PIO stations are connected to a gas sensor and receive a gas detection command from the host, the detection data obtained by the gas sensor is transmitted to the host via the wireless network;
One or more of the PIO stations are connected to an alarm device or a display device;
The host determines whether there is an abnormality based on detection data sent from the PIO station connected to the gas sensor. The alarm message is transmitted by the alarm device, or a warning message is transmitted to the PIO station connected to the display device to display the warning message on the display device. Process control system. The wireless network is built in a water treatment facility,
One or more of the PIO stations connect to a water quality sensor, and upon receiving a command from the host, send water quality data detected by the water quality sensor to the host via the wireless network;
2. The process control system according to claim 1, wherein the host collects / stores, analyzes or displays detection data sent from the PIO station. The wireless network is built in a radiation-related facility;
When one or more of the PIO stations are connected to a radiation sensor and receive a command from the host, the radiation dose data detected by the radiation sensor is transmitted to the host via the wireless network;
The host collects / accumulates, analyzes or displays the radiation dose data sent from the PIO station, or issues a warning instruction instruction to the PIO station connected to the alarm device when the radiation dose data exceeds a predetermined value. The process control system according to claim 1, wherein the alarm is issued by the alarm device. The wireless network is built in any facility,
One or more of the PIO stations are connected to an intruder detection switch or a security switch, and when the intruder detection switch or the security switch is turned on, the host is notified via the wireless network;
2. The process control system according to claim 1, wherein, upon receiving the notification, the host transmits a warning issuing instruction to a PIO station connected to the warning device, and causes the warning device to issue a warning.

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