JP5672033B2 - COMMUNICATION CONTROL DEVICE, COMMUNICATION CONTROL METHOD, AND COMMUNICATION SYSTEM - Google Patents

Description

  The present invention relates to a communication control device, a communication control method, and a communication system.

  Field devices are sensor devices such as flow meters and temperature sensors, valve devices such as flow control valves and on-off valves, actuator devices such as fans and motors, and other devices installed in plants and factories. In recent years, field devices (wireless field devices) that transmit and receive various signals wirelessly in accordance with ISA100.11a, a wireless communication standard for industrial automation established by the International Society of Automation (ISA). ) Is realized.

  The device management system for managing the above wireless field devices is constructed based on a communication system including a plurality of wireless field devices, a gateway, a management device, and the like. Here, the gateway connects the wired network to which the management device is connected and the wireless network to which the wireless field device is connected, and also secures a wireless band in the wireless network to establish a connection between the wireless field device and the management device. It is a device that controls the communication performed in. The management device is a device that is operated by an administrator of the device management system, for example, and collects measurement data measured by the wireless field device, sets parameters for the wireless field device, and the like in accordance with an instruction from the administrator.

  Communication between the management device and the field wireless device in the device management system described above is performed in a state where both the wireless bandwidth of the upstream wireless route and the wireless bandwidth of the downstream wireless route in the wireless network are secured by the gateway. Here, the downlink radio path is a radio path from the management apparatus (gateway) to the field wireless device, and the uplink radio path is a wireless path from the field wireless device to the management apparatus (gateway). Note that the radio band once secured is not released unless a process for intentionally disconnecting the radio path is performed.

  Patent Document 1 below discloses a communication system in which a communication repeater capable of wireless communication is connected to a field device to enable access to the field device from any place where wireless communication is possible. Patent Document 2 below discloses a communication system that enables long-distance data communication with a field device by providing a mobile phone communication function in a signal converter included in the field device. .

JP 2003-134030 A JP 2003-134261 A

  By the way, the gateway forming a part of the communication system described above secures the radio band of the uplink radio path according to the value of the parameter (Comitted Burst) indicating the transfer rate instructed by the field wireless device, and instructed by the management apparatus The radio band of the downlink radio path is secured according to the value of the same parameter. The value of the parameter instructed by the management apparatus is appropriately changed by the management apparatus according to the type of data to be communicated. On the other hand, the value of the parameter indicated by the wireless field device is fixed and cannot be changed according to the type of data to be communicated.

  As described above, the parameter indicated by the management device has a variable value, and the parameter indicated by the wireless field device has a fixed value because a battery is used as the power source of the wireless field device. It is thought that. The details are as follows.

  Field wireless devices use a battery as a power source. In order to reduce battery consumption and extend operating time, wireless communication is performed only at the minimum necessary timing, and most of the rest is wireless communication. It is set to a dormant state in which no is performed If the transfer rate is increased by simply securing a wide radio band for the upstream radio path, the hibernation state is reduced, battery consumption is increased, and the battery must be frequently replaced.

  As described above, regarding the wireless route, if the transfer rate is constantly increased by securing a wide wireless band in the dark clouds, the above-mentioned problem occurs. However, it is desirable for the management to increase the transfer rate temporarily. There is. For example, it is a case where a large amount of parameters are set for a plurality of field wireless devices or a firmware provided in the field wireless devices is upgraded. In such a case, since not only the amount of data transmitted via the downlink radio path but also the amount of data transmitted via the uplink radio path increases, the uplink radio path and the downlink radio A higher transfer rate on both paths is preferable in terms of management because the processing can be completed in a short time.

  The present invention has been made in view of the above circumstances, and is capable of freely setting a transfer rate not only for a downlink radio path but also for an uplink radio path between the management apparatus and the field wireless device. It is an object to provide a control device, a communication control method, and a communication system.

In order to solve the above-described problem, the communication control device of the present invention includes a wireless network (N1) performed between a wireless field device (1a to 1e) and a management device (4) that manages the wireless field device. In the communication control device (32) that controls communication via the network, the transfer rate information that is output from the management device and indicates a radio band to be secured in a downstream radio path from the management device to the wireless field device is stored. Based on the storage unit (32a) and the transfer rate information stored in the storage unit, a radio band in the downlink radio path is secured and an uplink radio path from the radio field device to the management device A wireless bandwidth securing unit (32b) that secures a wireless bandwidth is provided.
According to the present invention, the transfer rate information indicating the radio band to be secured in the downlink radio path output from the management device is stored in the storage unit, and the downlink radio is based on the transfer rate information stored in the storage unit. A radio band in the route is secured, and a radio band in the upstream radio route is secured.
Further, in the communication control device of the present invention, the storage unit stores information indicating a transmission source and a transmission destination in the downlink radio path in association with the transfer rate information, and the radio band securing unit Of the information stored in the storage unit, based on the transfer rate information corresponding to the information in which the transmission source and the transmission destination in the uplink radio path respectively match the transmission destination and the transmission source stored in the storage unit, A radio band in the uplink radio path is secured.
In the communication control device of the present invention, the wireless bandwidth securing unit may receive a new transfer rate from the management device in a state where both the upstream wireless route and the downstream wireless route are already secured. When the information is output, the radio band of both the uplink radio path and the downlink radio path is changed based on the new transfer rate information.
In the communication control device of the present invention, the wireless bandwidth securing unit may receive a new transfer rate from the management device in a state where both the upstream wireless route and the downstream wireless route are already secured. When the information is output, after releasing the radio band already secured in both the uplink radio path and the downlink radio path, the uplink radio is based on the new transfer rate information. It is characterized by newly securing radio bands for both the route and the downlink radio route.
The communication control method of the present invention is a communication control for controlling communication through a wireless network (N1) between a wireless field device (1a to 1e) and a management device (4) that manages the wireless field device. In the method, a first step of storing transfer rate information indicating a radio band to be secured in a downlink radio path from the management device to the wireless field device, which is output from the management device, and stored in the first step A second step of securing a radio band in the downlink radio path based on the transferred transfer rate information, and the management device from the radio field device based on the transfer rate information stored in the first step And a third step of securing a radio band in an upstream radio path toward the network.
The communication system of the present invention is a communication system (CS) comprising wireless field devices (1a to 1e) connected to a wireless network (N1) and a management device (4) for managing the wireless field devices. The communication control device according to any one of the above, which controls communication via the wireless network performed between the wireless field device and the management device.

  According to the present invention, the transfer rate information indicating the radio band to be secured in the downlink radio path output from the management device is stored in the storage unit, and the downlink radio is based on the transfer rate information stored in the storage unit. Since the radio band in the route is secured and the radio band in the uplink radio route is secured, the transfer rate can be freely set not only for the downlink radio route between the management apparatus and the field wireless device but also for the uplink radio route. There is an effect that it can be set to.

1 is a block diagram illustrating an overall configuration of a communication system according to an embodiment of the present invention. It is a figure which shows an example of the contract table used in one Embodiment of this invention. 5 is a timing chart for explaining the operation of the communication system according to the embodiment of the present invention. It is a timing chart for demonstrating other operation | movement of the communication system by one Embodiment of this invention. It is a timing chart for demonstrating other operation | movement of the communication system by one Embodiment of this invention.

  Hereinafter, a communication control device, a communication control method, and a communication system according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of a communication system according to an embodiment of the present invention. As shown in FIG. 1, the communication system CS of this embodiment includes I / O devices 1 a to 1 e (wireless field devices), routing devices 2 a and 2 b, a gateway 3, and a management device 4. Therefore, communication between the I / O devices 1a to 1e and the management apparatus 4 via the wireless network N1 is possible. The number of I / O devices 1a to 1e and routing devices 2a and 2b shown in FIG. 1 is arbitrary.

  The I / O devices 1a to 1e are wireless field devices installed in plants and factories such as sensor devices such as flow meters and temperature sensors, valve devices such as flow control valves and on-off valves, and actuator devices such as fans and motors. And performs wireless communication conforming to ISA100.11a which is a wireless communication standard for industrial automation. The operations of these I / O devices 1a to 1e are controlled by the management apparatus 4 setting various parameters for the I / O devices 1a to 1e. In addition, measurement data obtained by the I / O devices 1 a to 1 e are collected by the management device 4 via the gateway 3.

  The routing devices 2a and 2b perform wireless communication conforming to ISA100.11a between the I / O devices 1a to 1e and the gateway 3, and are transmitted and received between the I / O devices 1a to 1e and the gateway 3. Relay. The I / O devices 1a to 1e, the routing devices 2a and 2b, and the gateway 3 are wirelessly connected to each other, thereby forming a star-mesh wireless network N1. Instead of the routing devices 2a and 2b, an I / O device having the functions (relay function) of the routing devices 2a and 2b may be provided.

  The gateway 3 includes a gateway unit 31, a system manager unit 32 (communication control device), and a security manager unit 33, and controls communication performed in the communication system CS. The gateway unit 31 connects the wireless network N1 formed by the I / O devices 1a to 1e and the wired plant network N2 to which the management device 4 is connected, and the I / O devices 1a to 1e and the management device. 4 relays various data transmitted to and received from 4. The gateway unit 31 performs wireless communication conforming to the above-described wireless communication standard ISA100.11a.

  The system manager unit 32 controls communication between the I / O devices 1a to 1e and the management apparatus 4 via the wireless network N1. Specifically, before the data transmission from the management apparatus 4 to the I / O devices 1a to 1e is performed, the system manager unit 32 transmits a wireless path (hereinafter referred to as “the I / O devices 1a to 1e” from the management apparatus 4). A radio band of “downlink radio path” is secured. Conversely, before data transmission from the I / O devices 1a to 1e to the management apparatus 4 is performed, a radio path (hereinafter referred to as "uplink radio path") from the I / O devices 1a to 1e to the management apparatus 4 is performed. ) Radio band.

  The system manager unit 32 includes a memory 32a (storage unit) and a radio band securing unit 32b, and the radio band securing unit 32b refers to a contract table stored in the memory 32a as necessary. The radio band is secured so that the radio band of the downlink radio path and the uplink radio path where the transmission source and the transmission destination are opposite to each other are the same. As a result, for example, when a large number of parameters are set for a plurality of I / O devices 1a to 1e, or when upgrading firmware provided in the I / O devices 1a to 1e, etc. In addition to this, it is possible to freely set the transfer rate of the uplink radio path.

  The contract table stored in the memory 32a includes information indicating a transmission source and a transmission destination of data transmitted via a wireless path, and a transfer rate parameter (Comitted) indicating a transfer rate indicating a wireless band to be secured in the wireless path. Burst: transfer rate information). FIG. 2 is a diagram illustrating an example of a contract table used in an embodiment of the present invention. The contract table illustrated in FIG. 2 includes a route number, information indicating a communication direction, a transmission source address, a transmission destination address, a transmission source port number, a transmission destination port number, and a transfer for each wireless route secured in the wireless network N1. A rate parameter is associated.

  Here, the devices (I / O devices 1a to 1e, routing devices 2a and 2b, gateway 3 and management device 4) constituting the communication system CS of the present embodiment have an IPv6 (Internet Protocol Version 6) address or the like. Uniquely determined addresses are assigned, and these devices can simultaneously operate a plurality of functions (applications). The above-mentioned transmission source address and transmission destination address are addresses that specify a data transmission source device and a transmission destination device, respectively. The transmission source port number and the transmission destination port number are numbers (TLPort numbers) that operate on the transmission source device and the transmission destination device and identify functions related to data transmission (transmission / reception).

  The transfer rate parameter can take a positive value and a negative value. If the value is a positive value, the value of an APDU (Application Protocol Data Unit) that can be transmitted in one second is defined. If the value is a negative value, the period in which one APDU is transmitted is defined. For example, when the value of this parameter is set to “−15”, the radio band securing unit 32b secures a radio band necessary for transmitting an APDU once every 15 seconds. .

  The security manager unit 33 is a device that manages security under the system manager unit 32. For example, the security manager unit 33 includes a white list indicating I / O devices allowed to enter the wireless network N1, a black list indicating I / O devices denied entry to the wireless network N1, and the like. Is registered. With reference to the contents of these lists, the system manager unit 32 performs an entry process as to whether or not to make an I / O device enter the wireless network N1.

  The management device 4 is connected to the wired plant network N2, is operated by, for example, an administrator of the communication system CS, and collects measurement data measured by the I / O devices 1a to 1e according to the instructions of the administrator. And setting parameters for the I / O devices 1a to 1e. The management apparatus 4 can also upgrade firmware provided in the I / O devices 1a to 1e. The management device 4 is realized by, for example, a notebook or desktop personal computer.

  Next, the operation of the communication system having the above configuration will be described. FIG. 3 is a timing chart for explaining the operation of the communication system according to the embodiment of the present invention. In the following, in order to facilitate understanding, an operation when the management apparatus 4 acquires the parameters of the I / O device 1a will be described. In the following, in the initial state, both the wireless bandwidth of the downstream wireless path from the management apparatus 4 to the I / O device 1a and the upstream wireless path from the I / O device 1a to the management apparatus 4 are secured. It shall not be.

  First, a client request (Client.Request) indicating that a parameter read request of the I / O device 1a is requested is sent from the management apparatus 4 to the I / O device 1a (step S10). This client request includes a transfer rate parameter indicating a radio band to be secured in a downstream radio path from the management apparatus 4 to the I / O device 1a.

  When a client request from the management apparatus 4 is received by the gateway 3, the gateway unit 31 provided in the gateway 3 has secured a radio band for a downstream radio path from the management apparatus 4 to the I / O device 1a. Judge whether or not. If it is determined that it is not secured, the gateway unit 31 outputs an execution request (Execute.Request) for securing the radio band to the system manager unit 32 (step S11). The execution request includes an address (transmission source address) and a transmission source port number assigned to the management apparatus 4, an address (transmission destination address) and a transmission destination port number assigned to the I / O device 1a, and a client. The transfer rate parameter included in the request is included.

  When receiving the execution request from the gateway unit 31, the system manager unit 32 stores the address, port number, and transfer rate parameter included in the execution request in the contract table of the memory 32a (step S12: first) Step). Thereby, for example, corresponding to the route number “1” shown in FIG. 2, information indicating “downlink”, transmission source address, transmission destination address, transmission source port number, transmission destination port number, and transfer rate parameter “−1” Is stored in the contract table.

  Next, the radio band securing unit 32b of the system manager unit 32 can obtain the transfer rate indicated by the transfer rate parameter (transfer rate parameter stored in the contract table of the memory 32a) included in the execution request from the gateway unit 31. A wireless band is set by notifying the wireless band information to all devices existing in the downstream wireless path from the management apparatus 4 to the I / O device 1a. Specifically, the radio band securing unit 32b sequentially performs radio band setting (SetContract) on the routing device 2a and the I / O device 1a (steps S13 and S14: second step), and executes them on the gateway unit 31. A response (Execute. Response) is made (step S15: second step).

  When the execution response is received from the radio band securing unit 32b, the gateway unit 31 sends a client request from the management apparatus 4 to the I / O device 1a using the radio band secured by the radio band securing unit 32b of the system manager unit 32. Send to. This client request is first transmitted to the routing device 2a existing in the downstream radio path (step S16), and then transmitted from the routing device 2a to the I / O device 1a (step S17).

  When receiving the client request from the management apparatus 4, the I / O device 1 a reads the parameter instructed by the client request and transmits a client response (Client.Response) including the read parameter to the management apparatus 4. To do. Here, when transmitting the client response, the I / O device 1a determines whether or not the radio band of the upstream radio path from the I / O device 1a to the management apparatus 4 is secured.

  If it is determined that it is not secured, the I / O device 1a outputs an execution request (Execute.Request) for securing the wireless bandwidth to the system manager 32 of the gateway 3 (step S18). The execution request includes an address (source address) and source port number assigned to the I / O device 1a, an address (destination address) and destination port number assigned to the management device 4, and a value. Contains a fixed transfer rate parameter. Note that the value of the transfer rate parameter is fixed to, for example, “−15” in order to suppress the battery consumption of the I / O device 1a.

  When the execution request from the I / O device 1a is received, the radio band securing unit 32b of the system manager unit 32 determines from the contract table stored in the memory 32a that the transmission source and transmission destination in the uplink radio route are in the downlink route. A search is made for a match with the transmission destination and the transmission source (step S19). Specifically, the transmission source address and the transmission source port number included in the execution request from the I / O device 1a are respectively the transmission destination address and the transmission destination port number, and the execution from the I / O device 1a is performed. A downlink wireless path in which the transmission destination address and transmission destination port number included in the request are the transmission source address and transmission source port number is searched from the contract table.

  For example, an execution request including a transmission source address, a transmission destination address, a transmission source port number, a transmission destination port number, and a transfer rate parameter “−15” corresponding to the route number “3” illustrated in FIG. It is assumed that the system manager unit 32 has received from the I / O device 1a. The transmission source address and the transmission destination address included in the execution request coincide with the transmission destination address and the transmission source address corresponding to the route number “1”, respectively, and the transmission source port number and the transmission destination port number are The destination port number and the source port number corresponding to the route number “1” respectively match. The radio band securing unit 32b of the system manager unit 32 searches for a downlink radio path having such a relationship.

  When the downlink radio path having the above relationship is searched, the radio band securing unit 32b of the system manager unit 32 can obtain the transfer rate indicated by the transfer rate parameter in the searched downlink radio path. A radio band is also secured for the upstream radio path. That is, regardless of the transfer rate parameter (parameter whose value is fixed to “−15”) included in the execution request received from the I / O device 1a, the radio bandwidth securing unit 32b performs the path number “1” shown in FIG. The wireless bandwidth of the upstream wireless path is secured based on the value “−1” of the transfer rate parameter corresponding to “”. If no downlink radio path having the above relationship is retrieved from the contract table, the radio bandwidth securing unit 32b transfers the transfer rate with a fixed value included in the execution request received from the I / O device 1a. Based on the parameters, the radio band of the uplink radio path is secured.

  When the radio band is secured, the radio band securing unit 32b notifies the radio band information to all devices existing on the upstream radio path from the I / O device 1a to the management apparatus 4 to set the radio band. Do. Specifically, the radio band securing unit 32b sequentially performs radio band setting (SetContract) for the routing device 2a and the gateway unit 31 (steps S20 and S21: third step) and executes the I / O device 1a. A response (Execute.Response) is made (step S22: third step).

  Upon receiving the execution response from the radio band securing unit 32b, the I / O device 1a transmits a client response to the management apparatus 4 using the radio band secured by the radio band securing unit 32b of the system manager unit 32. . This client response is first transmitted to the routing device 2a existing in the upstream radio path (step S23), then transmitted from the routing device 2a to the gateway unit 31 (step S24), and finally from the gateway unit 31 to the management device 4 (Step S25).

  As described above, in this embodiment, the transfer rate parameter (a parameter indicating the radio bandwidth to be secured in the downlink radio path) included in the client request output from the management device 4 is stored in the memory 32a of the system manager unit 32 of the gateway 3. And a radio band in the downlink radio path is secured based on the transfer rate parameter, and a radio band in the uplink radio path is secured. For this reason, it becomes possible to freely set the transfer rate not only for the downlink radio path between the management apparatus 4 and the field wireless devices 1a to 1e but also for the uplink radio path.

  As a result, a flexible operation is possible in which the management apparatus 4 temporarily performs high-speed communication with the I / O devices 1a to 1e. For example, when the firmware of the I / O devices 1a to 1e is upgraded, the transfer rate indicated by the transfer rate parameter value “−1” is obtained for both the downlink radio path and the uplink radio path. By securing such a radio band, the time required for the upgrade can be reduced to 1/10 or less of the conventional time.

  As described above, in the initial state, the wireless bands of both the downstream wireless path from the management apparatus 4 to the I / O device 1a and the upstream wireless path from the I / O device 1a to the management apparatus 4 are not secured. The operation has been described. Next, an operation when a client request indicating that the radio band should be changed is transmitted from the management apparatus 4 in a state where the radio band of the downlink radio path and the uplink radio path has already been secured will be described. .

  4 and 5 are timing charts for explaining other operations of the communication system according to the embodiment of the present invention. The timing chart shown in FIG. 4 shows an operation of changing the radio band without releasing the radio band when a client request indicating that the radio band should be changed is transmitted from the management device 4. The timing chart shown in FIG. 5 shows an operation of newly securing a radio band after releasing the radio band. 4 and 5, the same steps as those shown in FIG. 3 are denoted by the same reference numerals.

  First, in the timing chart shown in FIG. 4, similarly to step S10 shown in FIG. 3, a client request (Client.Request) indicating that a parameter read of the I / O device 1a is requested is sent from the management device 4 to the I / O device. It is assumed that the message is sent to the device 1a (step S30). However, it is assumed that the value of the transfer rate parameter included in the client request has been changed and an instruction to change the already secured radio band is given.

  When a client request from the management apparatus 4 is received by the gateway 3, the gateway unit 31 provided in the gateway 3 has secured a radio band for a downstream radio path from the management apparatus 4 to the I / O device 1a. Judge whether or not. Further, it is determined whether or not the transfer rate parameter included in the client request from the management apparatus 4 is to change the already secured radio band.

  Here, the gateway unit 31 outputs an execution request (Execute.Request) for changing the wireless band to the system manager unit 32 since the wireless band in which the transfer rate parameter is already secured is changed. (Step S31). It should be noted that this execution request also includes the address (transmission source address) and transmission source port number assigned to the management apparatus 4, the address (transmission destination address) and transmission destination port number assigned to the I / O device 1a, and the client. The transfer rate parameter included in the request is included.

  When receiving the execution request from the gateway unit 31, the system manager unit 32 stores the address, port number, and new transfer rate parameter included in the execution request in the contract table of the memory 32a (step S32). . Next, the radio band securing unit 32b of the system manager unit 32 secures a radio band so that the transfer rate indicated by the new transfer rate parameter can be obtained, and the downlink radio path from the management device 4 toward the I / O device 1a. The wireless band is set by notifying all the devices existing in the wireless band information.

  Specifically, the radio bandwidth securing unit 32b sequentially changes the radio bandwidth (ModifyContract) to the routing device 2a and the I / O device 1a (steps S33 and S34), and executes an execution response (Execute. Response) is performed (step S35). As a result, both the upstream wireless path and the downstream wireless path between the management apparatus 4 and the I / O device 1a are changed.

  When the above processing is completed, a client request from the management apparatus 4 is transmitted from the gateway unit 31 to the I / O device 1a (steps S16 and S17). When receiving the client request from the management apparatus 4, the I / O device 1 a reads the parameter instructed by the client request and transmits a client response (Client.Response) including the read parameter to the management apparatus 4. (Steps S23 to S25).

  Next, in the timing chart shown in FIG. 5, a client request (Client.Request) indicating that the parameter reading of the I / O device 1 a is requested and instructing the change of the already secured radio band is the management device 4. Is sent to the I / O device 1a (step S30). When a client request from the management apparatus 4 is received by the gateway 3, the gateway unit 31 provided in the gateway 3 has secured a radio band for a downstream radio path from the management apparatus 4 to the I / O device 1a. Judge whether or not. Further, it is determined whether or not the transfer rate parameter included in the client request from the management apparatus 4 is to change the already secured radio band.

  Here, the gateway unit 31 outputs an execution request (Execute.Request) for releasing the radio band to the system manager unit 32 because the above-described transfer rate parameter is for changing the already reserved radio band. (Step S41). Thereby, the radio band securing unit 32b of the system manager unit 32 releases the radio band secured in each of the uplink radio path and the downlink radio path between the management apparatus 4 and the I / O device 1a. I do. Specifically, the radio band securing unit 32b sequentially performs radio band release (DeleteContract) on the routing device 2a and the I / O device 1a (Steps S42 and S43), and executes an execution response (Execute. Response) is performed (step S44).

  When receiving the execution response from the radio band securing unit 32b, the gateway unit 31 outputs a new radio band securing execution request (Execute.Request) to the system manager unit 32 (step S11). Then, the address, port number, and transfer rate parameter included in the execution request are stored in the contract table of the memory 32a (step S12), and the processing of steps S13 to S25 shown in FIG. . As a result, a wireless bandwidth is obtained so that a transfer rate indicated by the new transfer rate parameter can be obtained for both the downlink radio path and the uplink radio path, and then the client request from the management apparatus 4 is transmitted to the I / O. The client response from the I / O device 1a is transmitted to the management apparatus 4 while being transmitted to the device 1a.

  The communication control device, the communication control method, and the communication system according to the embodiment of the present invention have been described above. However, the present invention is not limited to the above-described embodiment, and can be freely changed within the scope of the present invention. It is. For example, in the above-described embodiment, the aspect in which the gateway unit 31, the system manager unit 32, and the security manager unit 33 are provided in the gateway 3 has been described. However, the functions of the gateway unit 31, the system manager unit 32, and the security manager unit 33 may be realized as separate devices. Furthermore, the function of performing wireless communication with the I / O devices 1a to 1e and the routing devices 2a and 2b may be separated from the gateway unit 31 and realized as a wireless access point device.

1a to 1e I / O device 4 management apparatus 32 system manager unit 32a memory 32b radio band securing unit CS communication system N1 radio network

Claims (5)

In a communication control device that controls communication via a wireless network performed between a wireless field device and a management device that manages the wireless field device,
The first transfer rate information, which is output from the management apparatus and indicates a radio band to be secured in the downlink radio path from the management apparatus to the field wireless device, indicates the transmission source and the transmission destination in the downlink radio path A storage unit for storing information in association with the information ;
Based on the first transfer rate information stored in the storage unit, a radio band in the downlink radio path is secured and output from the radio field device to the management device from the radio field device A radio band securing unit that secures a radio band in the uplink radio path based on second transfer rate information in which a value indicating a radio band to be secured in the radio path is fixed ;
The wireless band securing unit includes information in which the transmission source and the transmission destination in the uplink wireless path match the transmission destination and the transmission source stored in the storage unit, among the information stored in the storage unit. In this case, regardless of the second transfer rate information, a radio band in the uplink radio path is secured based on the first transfer rate information corresponding to the information.
A communication control device, characterized in that. The radio band securing unit, when new first transfer rate information is output from the management apparatus in a state where the radio bands of both the uplink radio path and the downlink radio path are already secured. 2. The communication control apparatus according to claim 1 , wherein the radio bandwidth of both the uplink radio path and the downlink radio path is changed based on the new first transfer rate information. The radio band securing unit, when new first transfer rate information is output from the management apparatus in a state where the radio bands of both the uplink radio path and the downlink radio path are already secured. After releasing the radio band already secured in both the uplink radio path and the downlink radio path, based on the new first transfer rate information, the uplink radio path and the downlink radio The communication control apparatus according to claim 1 , wherein new radio bands for both paths are secured. In a communication control method for controlling communication via a wireless network performed between a wireless field device and a management device that manages the wireless field device,
The first transfer rate information indicating the radio band to be secured in the downlink radio path from the management apparatus to the wireless field device, output from the management apparatus, indicates the transmission source and destination in the downlink radio path A first step of storing in correspondence with the information ;
A second step of securing a radio band in the downlink radio path based on the first transfer rate information stored in the first step;
Among the information stored in the first step, whether there is information that matches the transmission destination and the transmission source in which the transmission source and the transmission destination in the uplink wireless path from the wireless field device to the management device are stored. A step to check whether or not,
When the information does not exist, the uplink wireless path is based on the second transfer rate information that is output from the wireless field device and has a fixed value indicating the radio band to be secured in the uplink radio path. If a radio band is secured and the information is present, the radio band in the uplink radio path is secured based on the first transfer rate information corresponding to the information regardless of the second transfer rate information. A communication control method comprising: a third step. In a communication system comprising a field wireless device connected to a wireless network and a management device for managing the field wireless device,
The communication comprising the communication control device according to any one of claims 1 to 3 , which controls communication between the wireless field device and the management device via the wireless network. system.

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