JP2003157223A - Monitor and control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make receivable a response message for a request message between a controller and an electronic mail (e-mail) remote monitor and control device, and to make returnable a response message for a request message even when a plurality of controllers and a plurality of remote monitor and control devices exist in a remote monitor and control system using e-mail. SOLUTION: A request message and its response message are communicable even between a controller and an e-mail monitor and control device by installing an e-mail gateway to make a message itself communicated between controllers also reachable to the e-mail remote monitor and control devices. By mounting an Invoke- ID (message identifier) management table for managing request messages, the request message and the response message can be communicated between the plurality of controllers and the plurality of e-mail remote monitor and control devices.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supervisory control system which enables remote supervisory control via the Internet.

[0002]

2. Description of the Related Art FIG. 14 is a block diagram of a conventional example_1 of a remote monitoring control system. Reference numerals 1 and 2 are control devices, and 3 is a local monitoring control device having a monitoring screen. Reference numeral 16 is an electronic mail sending device for sending abnormal information by electronic mail, and 18 is an electronic mail remote receiving device installed in a remote place. Reference numeral 7 is an SMTP server (L) for sending electronic mail. Reference numeral 9 denotes an SMTP server (R) for the electronic mail remote receiving device to send and receive electronic mail.
Reference numeral 10 denotes a POP3 server (R) for the electronic mail remote receiving device to receive an electronic mail. Reference numeral 17 is a Web server for publishing information of the control device on the Internet. Reference numeral 19 is a Web browser for accessing this server. When an abnormality occurs, the abnormality information is converted into a text data format that can be communicated by e-mail and sent from the e-mail transmission device to the SMTP server (R) via the SMTP server (L). The e-mail remote receiving device obtains e-mail by polling the POP3 server (R) at regular intervals to know occurrence of an abnormality. W
The eb server stores information in the control device in HTML (HiperText).
Markup Language) is a device published. This is installed on the global network because it is accessed from a Web browser via the Internet. By accessing the Web server from the Web browser, detailed information of the control device can be obtained in real time and remote monitoring can be executed. Moreover, real-time remote control can be performed by sending a command such as start / stop to a point managed by the control device.

However, the conventional example_1 has the following problems. (1) The abnormal information could be sent by e-mail, but the arrival could not be confirmed. Therefore, a separate means was needed to know whether the abnormal information really arrived. (2)
From the perspective of Internet security, it is safer to install the monitoring control system (control device, local monitoring control device, Web server, etc.) in a private network. However, the Web server needs to be installed on the global network in order to enable access via the Internet. The control device and the local monitoring control device could not be installed in the private network with a simple configuration using a NAT router (a router that connects the private network and the global network). In order to install these on a private network and enable Web access from the Internet, special hardware and software were required, such as making the Web server itself a gateway. (3)
In order to perform remote monitoring control from the Web browser, it is necessary to create a dynamic HLML page in the Web server, and therefore, dedicated software for the Web server for remote monitoring control is required in addition to the local monitoring control device.

FIG. 15 shows a conventional example of a remote monitoring control system--
2 shows a configuration diagram of No. 2. Reference numerals 1 and 2 are control devices, and 3 is a local monitoring control device having a monitoring screen. Reference numeral 22 is an electronic mail receiving device, 23 is an electronic mail remote transmitting device, and 8 is a POP3 server (L) for receiving electronic mail.
The operation of reporting abnormal information from the control device to the electronic mail remote receiving device is the same as in the case of Conventional Example_1. Conventional example_2
Then, remote control using e-mail as follows. A control document is created by describing commands for executing control according to predetermined description rules.
This is sent to the electronic mail receiving device. The electronic mail receiving device obtains the control document by polling the POP3 server (L) at regular intervals. The control document is decrypted and a start / stop command is sent to a point managed by the control device to execute control. Since the Web access is not used and only the communication of the electronic mail is used, there is an advantage that the control devices can be installed in the private network by using the NAT router.

However, the conventional example_2 has the following problems. (1) The abnormal information could be sent by e-mail, but the arrival could not be confirmed. This is the same as the conventional example_1.
(2) E-mail The control document could be sent from the remote sending device by e-mail, but no response was received as to whether it arrived and the command execution result. A separate means was needed to know the results. (3) Dedicated software is required in order to create a control document in the electronic mail remote transmission device and to decode and execute the control document in the electronic mail reception device.

[0006]

The problems to be solved are: (1) In a system for remote monitoring and control via the Internet, (1) a response to a request is realized between the control device and the remote monitoring control device. There is no point, that is, information is being sent in one direction, (2) In order to perform remote monitoring via the Internet, the supervisory control system cannot be installed in the private network and must be installed in the global network. Point, (3)
The point is that special software is required for remote monitoring control.

[0007]

SUMMARY OF THE INVENTION The present invention enables a message communicated between control devices to reach a remote monitoring control device via e-mail, and the remote monitoring control device also operates in a monitoring control system. An electronic mail gateway having a function of operating as a part of the device is installed. Further, it is characterized in that an Invoke_ID management table is provided so that the request message and the response message can be correctly communicated between the plurality of control devices and the plurality of remote monitoring control devices. Invok
The e_ID is an identifier issued to the request message by the device in order to uniquely identify the request message. The response message has the same I as the request message.
It is returned with the nvoke_ID. This Invoke
The request message and the response message can be matched by using the _ID.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In a supervisory control system, mutual devices are connected to a network, and supervisory control is executed by exchanging messages between the mutual devices. Messages exchanged and their communication protocols are defined by the supervisory control system. In many cases, it is not possible to directly communicate via the Internet using the communication protocol used between control devices due to differences in the protocol with the Internet or reliability. In many cases, supervisory control systems are installed in private networks. Therefore, the control device cannot be directly accessed via the Internet. This time, by installing an e-mail gateway in the network of the control device, the message itself exchanged between the control devices is placed in the SMTP and POP3 protocols, which are the e-mail protocols, and the e-mail remote installed in the remote place. Allow access to the supervisory controller. On the contrary, a message can be reached from the electronic mail remote monitoring control device to the control device by using this electronic mail protocol. By installing this e-mail gateway, the e-mail remote monitoring control device installed at a remote place also operates as a part of the monitoring control system.

【Example】

An example of a building supervisory control system, which is one field of the supervisory control system, will be described. In building monitoring and control systems, communication messages and communication protocols are standardized by ASHRAE (American Society of Heating, Air Conditioning and Air Conditioning). The message is "BACnet message"
(See below for the structure of the BACnet message). This message itself is encoded as binary data in order to improve transmission efficiency. The "BACnet / IP" protocol is defined as a protocol for carrying this BACnet message. This is carried as a UDP packet.

FIG. 1 is a block diagram of a remote monitoring control system using electronic mail according to the present invention. Reference numerals 1 and 2 are control devices, and 3 is a local monitoring control device having a monitoring screen. 4 is an e-mail gateway device newly installed this time. Reference numerals 5 and 6 are electronic mail remote monitoring and control devices installed at remote locations via the Internet. Reference numeral 7 is an SMTP server (L) for the control device to send and receive electronic mail. Reference numeral 8 is a POP3 server (L) for the control device to receive an electronic mail. Reference numeral 9 is an SMTP server (R) for the remote electronic mail monitoring device to send and receive electronic mail. Reference numeral 10 denotes a POP3 server (R) for the remote electronic mail monitoring device to receive an electronic mail. In order to send and receive e-mail via the Internet, these 7, 8, 9, and 10 e-mail servers must all be installed on the global network. These e-mail servers are installed in the Internet connection service provider or the user who has obtained the global address. Reference numerals 12 and 13 are routers that connect the Internet and the electronic mail server. Each of the devices 1, 2, 3, 4 is installed in the private network. 11 is a NAT for connecting a private network and a global network
(Network Address Translation) Router. It has the function of replacing multiple private addresses with one global address by converting the port number. Only a single global address of the NAT router can be referenced from the Internet. In this way, by being connected to the Internet via the NAT router, the building monitoring control device is not directly accessed from the Internet side, which is safe for security. 5 is also installed on the private network, and 14 is a NAT router for address conversion and connection with the global network. Similarly, 6 is also installed on the private network, and 15 is an NA that translates and connects to the global network.
It is a T router. Therefore, the e-mail remote monitoring control devices 5 and 6 are not directly accessed from the Internet, and are safe for security. Addresses 1, 2, 3, 4, 5, 6 are 192.168.1.11, 192.168.1.12, 192.168.1.90, 19 for use in later explanation.
2.168.1.50, 172.16.1.5, 172.16.2.5.

FIG. 2 shows the software configuration of the control devices 1 and 2. The request from the control application is BA
It is converted into a BACnet message by the Cnet protocol stack, converted into message data in a format carried by the BACnet / IP protocol via the BACnet / IP interface, and transmitted via the socket interface, the TCP / IP protocol stack, the Ethernet (trademark) driver, and the Ethernet ( Trademark) on U
It is transmitted as a DP packet. In the case of packet reception, the reverse process is followed. FIG. 3 shows a software configuration of the local monitoring control device 3 of FIG. Compared to FIG. 2, only the application portion of the top layer is different, and the layers below it are the same as in FIG. FIG. 4 shows the software configuration of the electronic mail gateway device 4 of FIG. This email gateway is based on BACnet / I
Portion to interface with P protocol (left side)
And the SMTP (Simple
Mail Transfer Protocol) and POP3 (Post Offi)
ce Protocol Ver3) It has two sides, the part that interfaces with the protocol (right side). The left part is the same as FIG. 2 and FIG. 3 except that the application layer is different. The right part interfaces with the email protocol. BAC received from BACnet / IP
The net message is once captured by the email gateway application. Since the message is transmitted to the e-mail remote monitoring controller by the SMTP protocol, the transmission / reception address and Invoke_ID in the message are converted. BA on the BACnet protocol stack
It is re-converted into a Cnet message, converted into a data format carried by the SMTP protocol via the SMTP client interface, and transmitted over the Ethernet (trademark) via the socket interface, the TCP / IP protocol stack, and the Ethernet (trademark) driver.
It is transmitted as CP data. On the other hand, the e-mail gateway receives e-mail data (BACnet message) transmitted from the e-mail remote monitoring control devices 5 and 6 via the POP3 client interface by polling the POP3 server (L) at regular intervals. The received BACnet message is once captured by the email gateway application. Since it is sent to the control device by the BACnet / IP protocol, the send / receive address in the message, Invo
The ke_ID and the like are converted. It is converted into message data in the format carried by the BACnet / IP protocol via the BACnet / IP interface, and is transmitted as a UDP packet on the Ethernet (trademark) via the socket interface, the TCP / IP protocol stack, and the Ethernet (trademark) driver. It Figure 5
Shows the software configuration of the electronic mail remote control monitoring devices 5 and 6. The software of the highest application layer is almost the same as that of the local supervisory controller of FIG. Subsequent layers are the same as the part on the right side of the e-mail gateway in FIG. 4 (the part that interfaces with e-mail).

The e-mail gateway and the e-mail remote monitoring control device have a conversion function between binary data and text data. This conversion rule is MIME (Multip
urpose Internet Mail Extension). BAC carried by BACnet / IP protocol
The net message is binary data to improve transmission efficiency. On the other hand, SMT used in email
The messages carried in the P and POP3 protocols are textual data. Therefore BACnet / IP
The BACnet message from is converted to MIME by the e-mail gateway and sent as text data to the e-mail remote monitoring controller. The e-mail remote monitoring device obtains BACnet message data, which is the original binary data, by performing the MIME reverse conversion on the received data. The e-mail remote monitoring control device converts the BACnet message into MIME and sends it as text data to the e-mail gateway. The e-mail gateway obtains BACnet message data, which is the original binary data, by performing the MIME reverse conversion on the received data.

FIG. 6 shows the structure of a BACnet message (hereinafter simply referred to as a message) exchanged between the building monitoring and control devices. Parts related to message routing are shown separately from data. The request / response flag is a flag indicating whether this message is a request message or a response message. A 0 indicates a request message and a 1 indicates a response message. The reception address indicates the address of the device that receives the message. The device address is represented by an IP address in the TCP / IP network. The transmission address indicates the device address that transmits the message. Invoke_ID is an identifier for uniquely identifying the request message. Response messages are not always returned in the order of request message issuance. Therefore, it is used to match the request message and the response message. The Invoke_ID is managed for each device. Every time the device issues a new request message, the device generates an Invoke_ID as a unique identifier and adds it to the request message. The response message is returned with the same Invoke_ID as the request message. Therefore, when a response message is returned, this I
It is possible to know which request message is supported by referring to the nvoke_ID.

FIGS. 7 and 8 show the object structure inside the control device, the object structure inside the e-mail gateway, the object structure inside the e-mail remote monitoring and control device, and the messages between these objects. Show the flow. FIG. 7 shows the case where the request message is issued from the control device. FIG. 8 shows a case where a request message is issued from the electronic mail remote monitoring control device.
The request message is shown by a solid line and the response message is shown by a dotted line. Physical entry / exit point information such as a temperature sensor and an ON / OFF switch is modeled as an entry / exit point object in software inside the control device. 25, 26, 2
Reference numerals 7 and 28 denote these input / output point objects. The electronic mail gateway is a device having a function of communicating as BACnet / IP and a function of transmitting and receiving electronic mail. Of these, the function of sending an electronic mail is modeled as an SMTP object in software. Two
Reference numerals 9 and 30 denote SMTP objects. The SMTP object and the electronic mail remote monitoring controller have a 1: 1 relationship. Therefore, there are as many SMTP objects as there are electronic mail remote monitoring control devices. The SMTP object is identified by the SMTP object_ID in the email gateway device. The message sent to the SMTP object is sent via the SMTP client interface inside the SMTP object to the configured e-mail remote monitoring controller. On the other hand, the function of receiving an electronic mail is modeled as a POP3 object in software. There is only one POP3 object in the email gateway. The POP3 object is an internal POP
The POP3 server (L) is polled at regular intervals via the 3-client interface to receive the electronic mail (BACnet message) sent to the electronic mail gateway. Next, the BACnet / IP message is transmitted to the control device via the BACnet / IP interface with reference to the reception address described in the message. The electronic mail remote monitoring control device is a device having a function of transmitting and receiving electronic mail. Of these, the function of sending an electronic mail is modeled as an SMTP object in software. 32 and 34 are SMTP
Indicates an object. The SMTP object in the electronic mail remote monitoring controller sends the message to the set electronic mail gateway regardless of the destination of the message. The final message destination is described as a receiving address inside the message. The email gateway forwards the message to this final destination. on the other hand,
The function to receive e-mail is POP on software.
It is modeled as a three object. 33 and 35 are P
Indicates an OP3 object. The POP3 object polls the POP3 server (R) via the internal POP3 client interface at regular intervals and sends an electronic mail (BACnet) to the electronic mail remote monitoring device.
Message).

The message routing operation will be described. Message routing is executed by using the tables shown in FIGS. 9, 10, and 11 created inside the electronic mail gateway as constituent elements. FIG. 9 shows an SMTP object / e-mail remote monitoring control device correspondence table. It defines the relationship between the SMTP object inside the email gateway and the corresponding email remote monitoring and control device. The SMTP object holds the SMTP object_ID as the object attribute value and the address information of the electronic mail remote control device. Therefore, the table of FIG. 9 is created when the email gateway is activated with reference to this information.

The Invoke_ID management table_1 of FIG. 10 is a table for managing the request message sent from the control device to the electronic mail remote monitoring device. B
ACnet_Invoke_ID is a message identifier issued by the control device. The email gateway is a request message (that is, an SM message sent from the BACnet / IP interface to the email remote monitoring controller).
When a message addressed to a TP object) is received, a new record is created. From the received message information etc., the e-mail gateway device address,
SMTP object_ID, BACnet_Invo
The ke_ID and controller address are filled. The email gateway has a new unique message identifier SMTP_In for the SMTP interface.
Issue the voke_ID and send the message. At this time, the receiving address of the message is converted into the address of the e-mail remote monitoring control device, and the Invoke_ID is changed to SM.
Convert to TP_Invoke_ID. At the same time, this information (email remote monitoring controller address and SMTP_I
(nvoke_ID) in the record. When a response message is returned from the electronic mail remote monitoring controller, this table is searched to obtain a record of the corresponding request message. Original BACn from this record
Know the et_Invoke_ID. Also, from this record information, the transmission address of the response message, Invoke
The ID part is processed and transmitted to the control device as a BACnet / IP message. Response messages may be returned as multiple messages. Information indicating that it is the last message is added to the response message. Therefore, when the processing of the last response message is completed, the record corresponding to this is deleted from the table.

FIG. 12 shows a protocol for carrying a message and a message content at each stage regarding a request message and a response message from the control device_1 to the electronic mail remote monitoring control device_1. (B)
The field value of the message indicates the request / response flag, the reception address, the transmission address, the Invoke_ID, and the request / response data. This corresponds to the BACnet message structure diagram of FIG.

The Invoke_ID management table_2 in FIG. 11 is a table for managing the request message sent from the electronic mail remote monitoring device to the control device. S
MTP_Invoke_ID is a message identifier issued from the electronic mail remote monitoring control device. The e-mail gateway creates a new record when it receives a request message addressed to the controller from the POP3 interface. From the received message information etc.,
The controller address, SMTP_Invoke_ID, email remote controller address are filled. By searching the table of FIG. 9 using the e-mail remote control device address as a key, the e-mail gateway address and SMTP object_ID are filled. BAC
A new unique message identifier BACnet_Invoke_I for the net / IP interface
Issue D to send the message. At this time, the transmission address of the message is converted into the address of the electronic mail gateway device, and the Invoke_ID is changed to BACnet_I.
Convert to nvoke_ID. At the same time this information (email dateway device address and BACnet_Inv
ake_ID) in the record. When a response message is returned from the control device, this table is searched to obtain the record of the corresponding request message. Original SMTP_Invoke_ID, S from this record
Know MTP object_ID, email remote controller address. This record information is used to process the reception address and Invoke_ID part of the response message and SMT
Ask the P object to send a message. SMTP
The object sends a message to the email remote monitoring controller via the SMTP client interface. Response messages may be returned as multiple messages. Information indicating that it is the last message is added to the response message. Therefore, when the processing of the last response message is completed, the record corresponding to this is deleted from the table.

FIG. 13 shows an electronic mail remote monitoring controller_.
1 is a diagram showing a protocol for carrying a message and a message content at each stage for a request message and a response message from 1 to the controller_1. (B)
The field value of the message indicates the request / response flag, the reception address, the transmission address, the Invoke_ID, and the request / response data. This corresponds to the BACnet message structure diagram of FIG.

It will be explained that by using the Invoke_ID management table_1 of FIG. 10, a response message can be correctly returned even when request messages are sent from a plurality of control devices to the same electronic mail remote monitoring control device. . Since the Invoke_ID is managed for each device that issues the request message, the same Invoke_ID may be accidentally issued from different devices. In FIG. 10, separate control devices (192.168.1.
11 and 192.168.1.12) to the same electronic mail remote control device (= 172.16.1.5),
Coincidentally the same BACnet_Invoke_ID (=
An example when the request message is issued in 1) is shown. The email gateway responds to these messages by
Separate unique identifiers, SMTP_Invoke_
Issue IDs (101 and 102). This new SMT
Issuance of P_Invoke_ID and Invoke of FIG.
By using the _ID management table_1, the response message can be correctly transmitted with the original control device address and the original BACn.
It can be restored to et_Invoke_ID and returned. Further, by using FIG. 10, when a plurality of request messages are sent from the same control device to the same e-mail remote monitoring control device, a plurality of request messages are sent from the same control device to different e-mail remote monitoring control devices. In the same manner, the response message can be returned correctly to the original request message.

By using the Invoke_ID management table_2 in FIG. 11, even when a request message is sent from a plurality of electronic mail remote monitoring control devices to the same control device and the same input / output point object, a correct response message is sent. Explain that you can return. Invoke
Since the _ID is managed for each device that issues the request message, the same Invoke_I is accidentally sent from different devices.
The case where D is issued occurs. FIG. 11 shows separate e-mail remote monitoring control devices (172.16.1.5 and 1).
72.16.2.5) from the same controller (= 19
2.16.1.11) accidentally the same SMTP_
An example in which a request message is issued with Invoke_ID (= 2) is shown. The email gateway has a unique identifier, B, for these messages.
Issue ACnet_Invoke_ID (102 and 103). This new BACnet_Invoke_I
Issue D and Invoke_ID management table in FIG.
2 is used to correctly send the response message to the original e-mail remote controller address and the original BACnet
It can be restored to _Invoke_ID and returned. Further, by using FIG. 11, when a plurality of request messages are sent from the same e-mail remote monitoring control device to the same control device, a plurality of request messages are sent from the same e-mail remote monitoring control device to different control devices. In the same manner, the response message can be returned correctly to the original request message.

Items related to mounting will be described. The device sets a timeout period when issuing a request message. If the response message is not returned within this time, the request message is retransmitted a predetermined number of times. Since message communication via e-mail takes time, a request message from the control device to the e-mail remote monitoring control device (S in the e-mail gateway)
When issuing a request message to the MTP object), this timeout time is set to be longer (about twice) than the average e-mail round trip time. SM from e-mail gateway to e-mail remote monitoring controller
Similarly, when issuing a TP request message, when issuing an SMTP request message from the e-mail remote monitoring controller to the e-mail gateway, the timeout time is set longer than the average e-mail round trip time (about twice). To do so. Invoke of FIGS. 10 and 11
Add the time stamp information for issuing the request message to the record of the _ID management table, compare the time stamp information with the current time, and delete the record of the request message for which a response has not been returned for some reason. .
This prevents an unlimited increase of invalid records on the Invoke_ID management table.

Next, application examples will be described. In order to secure the Internet communication, the electronic mail between the electronic mail gateway and the electronic mail remote monitoring control device is encrypted by the public key encryption method for communication.
Each of the above devices has its own private and public key. When sending a message, encrypt it with your private key before sending. The receiving side determines the transmitting device from the address of the transmitting side and decrypts it using the public key of the transmitting device. Only mail encrypted with the private key, that is, mail from a reliable sender can be decrypted with the public key. If the decryption fails, it is determined that the email is not authorized by a third party and is discarded. As a result, it is possible to prevent an email sent from a third party who is “spoofing”. Moreover, since the information in the e-mail is encrypted, it is possible to prevent eavesdropping on the Internet.

The email gateway has been described as a separate device from the controller. However, the email gateway can also be implemented in the controller or local supervisory controller. With this configuration, it becomes possible to support a small-scale system with a small number of hardware.

[0025]

By providing the electronic mail gateway so that the control message itself can reach the electronic mail remote monitoring control device, the control device and the electronic mail remote monitoring control device respond to each request message. You will be able to receive reply messages. That is, the point that the information is continuously sent in one direction is improved. I
By having the nvoke_ID management table as a constituent element, it becomes possible to correctly return a response message to request messages from a plurality of control devices and request messages from a plurality of electronic mail remote control devices. The Internet is an email protocol SM
Since the TP and the POP3 protocol are used for communication, the control device, the private monitoring control system, the e-mail gateway, and the e-mail remote monitoring control device can be installed in the private network, which makes the internet security more secure. Since the electronic mail remote monitoring control device operates by using the message itself communicated between the control devices, the software of the local monitoring control device can be diverted and the man-hours for creating software for remote monitoring control can be reduced. By performing communication using the public key encryption method between the e-mail gateway and the e-mail remote monitoring and control device, it is possible to prevent "eavesdropping" and "spoofing" that may occur in Internet communication.

[Brief description of drawings]

FIG. 1 is a configuration diagram of the present invention.

FIG. 2 is a software configuration diagram of a control device.

FIG. 3 is a software configuration diagram of a local monitoring control device.

FIG. 4 is a software configuration diagram of an electronic mail gateway device.

FIG. 5 is a software configuration diagram of an electronic mail remote monitoring control device.

FIG. 6 is a diagram showing the structure of a BACnet message.

FIG. 7 is a diagram showing a control device, an electronic mail gateway, objects in an electronic mail remote monitoring control device, and their relations. It also shows the flow of request and response messages from the controller.

FIG. 8 is a diagram showing a control device, an electronic mail gateway, objects in an electronic mail remote monitoring control device, and their relations. It also shows the flow of the request message and its response message from the electronic mail remote monitoring control.

FIG. 9 is an SMTP object / e-mail remote monitoring control device correspondence table.

FIG. 10 is an Invoke_ID management table_1 for managing a request message from the control device to the e-mail remote monitoring control device.

FIG. 11 is an Invoke_ID management table_2 that manages a request message from the electronic mail remote monitoring controller to the controller.

FIG. 12 shows a request message and its response message from the control device_1 to the electronic mail remote monitoring control device_1.

FIG. 13 shows a request message and its response message from the electronic mail remote monitoring controller_1 to the controller_1.

FIG. 14 is a configuration diagram of a conventional example_1.

FIG. 15 is a configuration diagram of a conventional example_2.

[Explanation of symbols]

1 control device_1 2 control device_2 3 local monitoring control device 4 e-mail gateway device 5 e-mail remote monitoring control device_1 6 e-mail remote monitoring control device_2 7 SMTP server (L) 8 POP3 server (L) 9 SMTP server ( R) 10 POP3 server (R) 11 NAT router 12 Router 13 Router 14 NAT router 15 NAT router 16 E-mail sending device 17 Web server 18 E-mail remote receiving device 19 Web browser 20 Router 21 NAT router 22 E-mail receiving device 23 E Remote mail sending device 24 NAT router 25 I / O point object _1 in control device_1 26 I / O point object_2 in control device_1 27 I / O point object_1 in control device_2 I / O point object in control device_2 To — 2 29 SMTP object in email gateway — 1 30 SMTP object in email gateway — 2 31 POP3 object in email gateway 32 SMTP object in email remote monitoring controller — 33 In email remote monitoring controller — 1 POP3 object 34 SMTP object in e-mail remote monitoring controller_2 POP3 object in e-mail remote monitoring controller_2

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04Q 9/00 321 H04Q 9/00 321E F term (reference) 5B089 GA31 HA10 JA35 KA17 KC15 KC57 KH30 LA01 LA11 5H223 AA20 DD07 EE06 EE11 5K030 HA06 HC14 HD03 HD06 JA10 MB18 5K048 AA02 BA51 CA08 DA05 EA11 EB12 EB13 FB08 FC01 HA01 HA02

Claims (3)

[Claims] 1. A monitoring control system including a control device for communicating a message to perform control and a monitor control device having an electronic mail transmission / reception function as a component, between the control device and the email monitor control device. A monitoring control system, wherein an electronic mail gateway is installed as described above, and the electronic mail gateway enables communication of a request message and a response message between the control device and the electronic mail monitoring control device. 2. A request message and a response message are associated between a plurality of control devices and a plurality of electronic mail remote monitoring control devices by using an Invoke_ID (request message identifier) management table. The monitoring control system according to claim 1. 3. The monitoring control system according to claim 1, wherein communication is performed between the electronic mail gateway and the electronic mail remote monitoring control device by using a public key encryption method.