JP2008134774A - Protocol conversion device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve monitoring of communication or data by protocol conversion without modification of the hardware or software of existing equipment. <P>SOLUTION: Conversion from a TCP/IP to an RS232C is operated by a protocol conversion part 22 from a control PC 1 through a TCP/IP communication part 21 in a protocol conversion device 2, and a control signal is transmitted through an RS232C communication part 23 to job site equipment 3. Also, a reply signal is transmitted from the job site equipment through an RS232C communication part 23, a protocol conversion part 22 and a TCP/IP communication part 21 of the protocol conversion device 2 to a control PC1. At that time, data are transmitted from the protocol conversion part 22 through a data copy processing part 24 for monitoring for executing the copy of transmitted/received data and a TCP/IP communication part 21 to external equipment 4. Also, when a switching signal is transmitted from the external equipment 4 to the protocol conversion part 22, the data of the external equipment 4 are transmitted to the job site equipment 3 as it is. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a protocol converter, and more particularly to a protocol converter for enabling serial data to be transmitted to a terminal on a communication network.

  As a conventional protocol conversion device, it converts TCP / IP (Transmission Control Protocol / Internet Protocol) so that serial data received from a serial line can be transmitted to a terminal on Ethernet (registered trademark) which is a predetermined communication network Is known (see, for example, Patent Document 1).

  In the protocol conversion device described in Patent Document 1, an ID number (the ID number is determined according to each terminal on the Ethernet (registered trademark) as a transmission destination) is added to serial data input from a plurality of serial lines. In addition, an arithmetic device that converts (protocol converts) the serial data input at the same time into one transmission packet is provided, and the transmission packet is stored in the storage device. When a line of the Ethernet (registered trademark) communication network becomes available, the transmission packet is broadcast to each terminal on the Ethernet (registered trademark).

  Also, a protocol conversion unit that performs a plurality of types of protocol conversion between the calling side protocol of the calling side terminal and the called side protocol of the called side terminal, and between the calling side terminal and the called side terminal A protocol having a signal detection unit that detects a connectivity confirmation signal to be communicated, and a control unit that specifies a calling side protocol and a called side protocol based on the connectivity confirmation signal detected by the signal detection unit A conversion device is also conventionally known (see, for example, Patent Document 2). In this protocol conversion device, the control unit selects one protocol conversion from among a plurality of types of protocol conversions performed by the protocol conversion unit based on the specification of the calling side protocol and the specification of the called side protocol. Have the part perform the protocol conversion.

  Further, the protocol conversion analysis unit analyzes the data received from the terminal device, converts the received data into a conversion protocol by the protocol conversion analysis unit based on the conversion analysis result, and causes the output device to monitor the conversion data. An apparatus is also known (see, for example, Patent Document 3).

JP 2001-67293 A (summary) Republished patent WO01 / 061963 (page 7, lines 3-14, page 9, lines 4-8, FIGS. 1 and 2) JP-A-8-102772 (page 2-3, FIG. 1)

  However, the protocol conversion device described in Patent Document 1 has a problem that data cannot be transmitted from an external device. The reason is that in the fields of FA (factory automation), instrumentation, and LA (laboratory automation), serial signals such as RS-232C and RS-422 are used for communication between field equipment and a control computer (hereinafter, control PC). There are many cases. Therefore, communication data between the field device and the control PC cannot be transmitted to the field device from an external device that is a third party.

  Further, the protocol conversion device described in Patent Document 1 has a problem that application software of the control PC needs to be modified. The reason is that, when data is monitored or protocol conversion is performed, if the function does not correspond to the control PC application itself, modification is required.

  On the other hand, in the protocol conversion device described in Patent Literature 2 and Patent Literature 3, when applied to the FA, instrumentation, and LA fields, monitoring of field equipment and the control PC is possible. There is a problem that data cannot be transmitted / received to / from field devices.

  The present invention has been made in view of the above points, and provides a protocol converter capable of performing protocol conversion and monitoring data without modifying hardware or software of existing equipment. With the goal.

  Another object of the present invention is to provide a protocol converter capable of transmitting and receiving data between an external device and a field device.

  In order to achieve the above object, a protocol conversion device according to a first aspect of the present invention is connected between a first terminal communicating with a first protocol and a second terminal communicating with a second protocol, The protocol conversion between the first terminal and the second terminal is performed, and the protocol conversion between the external apparatus and the second terminal is performed by being connected to an external apparatus by a third party communicating with the first protocol. A protocol conversion device for performing a second communication between a first communication unit communicating with a first terminal or an external device using a first protocol and a second protocol communicating with a second terminal. And a protocol that is connected to the first communication unit and the second communication unit and performs protocol conversion between the first transmission / reception signal of the first communication unit and the second transmission / reception signal of the second communication unit. The conversion unit and the protocol conversion unit convert the protocol Or after copying the second transmission and reception signals, and having a monitor for data copy processing unit for outputting to an external device via the first communication unit. In the present invention, protocol conversion can be performed without modifying the hardware and software of the existing first and second terminals.

  Here, in the second invention, based on the switching signal from the external device, the first communication unit sets communication between the first terminal and the protocol conversion unit offline, and the protocol conversion unit and the external device The protocol conversion between the two communication units is performed. In this invention, the transmission / reception signal (data) between the first and second terminals can be monitored by the external device. Further, the transmission / reception signal between the first and second terminals can be copied by the monitor data copy processing unit.

In order to achieve the above object, the third invention is connected between the first terminal and the second terminal communicating with the first protocol, and between the first terminal and the second terminal. A protocol conversion device that performs protocol conversion and performs protocol conversion between an external device and a second terminal connected to an external device by a third party that communicates with the second protocol, Between the first communication unit that communicates with each other using the first protocol, the second communication unit that communicates with the second terminal using the first protocol, and the external device using the second protocol. A third communication unit for communication;
Connected to the first communication unit, the second communication unit, and the third communication unit, transfers a transmission signal from the first communication unit to the second communication unit, and transmits from the second communication unit The signal is transferred to the first communication unit, and the protocol conversion unit converts the protocol between the transmission / reception signal of the second terminal and the transmission / reception signal of the third communication unit, and the protocol conversion unit converts the protocol. And a monitor data copy processing unit that copies a transmission / reception signal between the first and second communication units and outputs the signal to an external device via the third communication unit. In the present invention, protocol conversion can be performed without modifying the hardware and software of the existing first and second terminals. Further, the transmission / reception signal between the first and second terminals can be copied by the monitor data copy processing unit.

  Here, in the fourth invention, based on the switching signal from the external device, the third communication unit of the third invention makes communication between the first terminal and the protocol converter offline, and the protocol converter A protocol conversion between the external device and the third communication unit is performed.

  In order to achieve the above object, according to a fifth aspect of the present invention, there is provided a protocol between the first terminal and the second terminal connected between the first and second terminals communicating with the first protocol. A protocol conversion device for performing protocol conversion between an external device and a second terminal by performing conversion and being connected to an external device by a third party communicating with the second protocol, A first communication unit that communicates with the first protocol between the first communication unit and a second communication unit that communicates with the second communication unit using the first protocol and the first communication unit. A third communication unit that communicates with an external device using a second protocol, and is connected to the first communication unit, the second communication unit, and the third communication unit. The protocol conversion of the transmission / reception signal between the two communication units is performed and the external communication device is transmitted via the third communication unit. And having a protocol conversion unit for force.

  Here, in the sixth invention, the first terminal in the first to fifth inventions is a control personal computer, the second terminal is a field device, and the control personal computer starts and stops the field device. Generates control signals such as operation instructions, status inquiry signals to on-site equipment, or log information download request commands for on-site equipment, and the on-site equipment responds with a signal corresponding to the signal from the control personal computer. It is characterized by doing.

  According to the present invention, if the first and second terminals can communicate with the first protocol such as TCP / IP or the second protocol of RS232C, the protocol converter can be connected. Protocol conversion and data monitoring are possible regardless of the model type.

  In addition, according to the present invention, even when the first terminal is updated and the communication method is changed, the virtual COM that is the driver software of the general-purpose OS is installed without modifying the software installed in the first terminal. By installing in the first terminal, communication becomes possible, and transmission / reception signals (data) whose protocol is converted by the protocol conversion unit can be monitored by an external device. No hardware / software modification is required.

  Furthermore, according to the present invention, bidirectional communication can be performed between the external device and the second terminal after the communication between the first terminal and the second terminal is made offline.

(First embodiment)
Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a block diagram of a first embodiment of a protocol conversion apparatus according to the present invention. In the figure, a protocol conversion device 2a is connected to a control PC 1 that transmits a control signal, a field device 3 controlled by the control PC 1, and an external device 4 that monitors communication data between the control PC 1 and the field device 3, respectively. It includes a TCP / IP communication unit 21, a protocol conversion unit 22, an RS232C communication unit 23, and a monitor data copy processing unit 24, and performs protocol conversion between TCP / IP and RS232C to copy communication data. To do.

  The TCP / IP communication unit 21 transmits / receives data to / from the control PC 1, the protocol conversion unit 22, or the external device 4. The protocol conversion unit 22 performs protocol conversion on the data received from the TCP / IP communication unit 21 and converts the data received from the RS232C communication unit 23 to protocol and transmits the data received from the RS232C communication unit 23 to the TCP / IP communication unit 21. The RS232C communication unit 23 transmits / receives data to / from the protocol conversion unit 22 or the field device 3.

  The protocol conversion device 2a of the present embodiment is a protocol conversion device applied to the FA, instrumentation, and LA fields. In this technical field, serial signals such as RS-232C and RS-422 are often used for communication between the field device 3 and the control personal computer (control PC) 1. In recent years, with the spread of TCP / IP (Transmission Control Protocol / Internet Protocol), TCP / IP communication has become mainstream in the control PC 1. However, the field equipment 3 has a long service life of 10 to 15 years and is mostly serial communication such as RS232C, whereas the control PC 1 often uses a general PC, and the manufacturer's warranty period Due to the consumption of hard disks and hard disks, the useful life is as short as about 5 years. Also, since most of the PCs that have recently spread are TCP / IP connections, the communication method differs due to the difference in their update cycles. As a result, it is impossible to connect by TCP / IP communication which is currently mainstream. The application software of the control PC 1 is often used as it is in order to reduce the update cost and shorten the update period.

  In this case, even if the control PC 1 is updated, enhancement of functions such as acquisition of detailed alarm information and remote maintenance from a remote location cannot be realized. This is because in order to acquire the detailed alarm information, it is necessary to once stop the control PC 1 and install the analysis device, and then communicate again between the control PC and the field device via the analysis device. In addition, installing analysis software in the current control PC 1 is difficult because it may cause a load on the control PC 1 and hinder the original control function.

  Therefore, in order to acquire detailed alarm information from the field device 3 that performs serial communication using RS232C or the like, or to perform remote maintenance or monitoring of the field device 3 from the remote control PC 1, the control PC 1 Protocol conversion device 2a that can perform serial communication such as RS232C or the like with field equipment 3 is also required. Furthermore, the protocol conversion device 2a is also required for the external device 4 to monitor the communication between the control PC 1 and the field device 3 through the TCP / IP connection.

  Next, the operation of the protocol conversion device 2a of this embodiment will be described. In FIG. 1, control signals such as start / stop and operation instructions for the field device 3 generated by the control PC 1, status inquiry signal to the field device 3, log information (alarm information) siphoning request command for the field device 3, etc. After being received by the TCP / IP communication unit 21 in the protocol conversion device 2a by TCP / IP communication, the signal is supplied to the protocol conversion unit 22, where the protocol is converted from TCP / IP to RS232C. The control signal, status inquiry signal, log information siphoning request command, etc., converted by the protocol conversion unit 22 are transmitted to the field device 3 by the RS232C communication unit 23 in accordance with the RS232C communication protocol.

  On the other hand, upon receiving a control signal, a status inquiry signal, or a log information siphoning request command from the control PC 1, the field device 3 performs an operation corresponding to the received signal and transmits a response signal to the control PC1. This response signal is received by the RS232C communication unit 23 in the protocol conversion device 2a in accordance with the RS232C communication protocol, and then supplied to the protocol conversion unit 22, where the protocol is converted from RS232C to TCP / IP. The response signal from the field device 3 subjected to protocol conversion by the protocol conversion unit 22 is transmitted by the TCP / IP communication unit 21 to the control PC 1 according to the TCP / IP communication protocol.

  At that time, all data transmitted and received between the control PC 1 and the field device 3 in the protocol conversion unit 22 are copied by the monitor data copy processing unit 24, and then passed through the TCP / IP communication unit 21. To the external device 4.

  Further, when a switching signal is transmitted from the external device 4 to the protocol conversion unit 22, subsequently transmitted data of the external device 4 is directly transmitted through the TCP / IP communication unit 21, protocol conversion unit 22, and RS23C communication unit 23. It is transmitted to the device 3. Thus, for example, when the external device 4 is installed remotely from the field device 3 and it is desired to obtain detailed alarm information of the field device 3 from a distance, a log information (alarm information) siphoning request command is issued from the external device 4. Detailed information of the alarm is transmitted even if the maintenance person does not go directly to the place where the field device 3 is installed by receiving the detailed information of the alarm transmitted to the field device 3 and transmitted from the field device 3 as a response. Can see.

  Further, communication between the external device 4 and the field device 3 can be made offline, and thereafter communication between the field device 3 and the external device 4 can be made possible. In this case, the communication between the control PC 1 and the field device 3 is made offline, and the field device 3 and the external device 4 are connected. As a result, detailed alarm information from the field device 3 can be provided to the external device 4. However, during this time, communication between the field device 3 and the control PC 1 is interrupted.

  Therefore, according to the present embodiment, bidirectional communication between the control PC 1 and the field device 3 having different communication methods by protocol conversion is enabled, and the external device 4 is connected between the field device 3 and the control PC 1. In addition, the communication between the field device 3 and the control PC 1 is made offline, and then the two-way communication can be performed between the external device 4 and the field device 3. A specific example of data transmitted from the external device 4 that is a third party to the field device 3 is a log siphoning command that is transmitted from the external device 4 when it is desired to retrieve the log information of the field device 3.

(Second Embodiment)
Next, a second embodiment of the present invention will be described in detail with reference to the drawings. FIG. 2 shows a block diagram of the first embodiment of the protocol conversion apparatus according to the present invention. In the figure, the same components as in FIG. In FIG. 2, the protocol conversion device 2 b includes a control PC 1 ′ that transmits a control signal and the like, a field device 3 that is controlled by the control PC 1 ′, and an external device 4 that monitors communication data between the control PC 1 and the field device 3. Each is connected, and includes a TCP / IP communication unit 21, a protocol conversion unit 22 ′, an RS232C communication unit 23 and 23 ′, and a monitor data copy processing unit 24, and performs protocol conversion between TCP / IP and RS232C. And copy the communication data.

  This protocol conversion device 2b is characterized in that it is not connected to the control PC 1 'with the TCP / IP communication unit 21 but with a new RS232C communication unit 23'. The RS232C communication unit 23 'transmits / receives data to / from the protocol conversion unit 22' or the control PC 1 'based on the RS232C communication protocol. Here, since the application software installed in the control PC 1 'is compatible with serial communication, it cannot communicate with the field device 3 whose communication protocol is RS232C as it is. As a solution, the control PC 1 ′ can communicate without modifying existing application software by installing driver software called virtual COM that converts RS232C → TCP / IP.

  Next, the operation of the present embodiment will be described. Control signals such as start / stop and operation instructions for the field device 3 generated by the control PC 1 ', status inquiry signals to the field device 3, or log information (alarm information) siphoning request commands for the field device 3 are After being received by the RS232C communication unit 23 ′ in the protocol conversion device 2 b by RS232C communication, it is supplied to the protocol conversion unit 22 ′ and supplied to the field device 3 through the RS232C communication unit 23 with the protocol as it is.

  In addition, the control signal, status inquiry signal or log information download request command supplied from the control PC′1 to the RS232C communication unit 23 ′ has been converted from RS232C to TCP / IP by the protocol conversion unit 22 ′. Thereafter, the data is transmitted to the external device 4 by the TCP / IP communication unit 21 in accordance with the TCP / IP communication protocol and supplied to the monitor data copy processing unit 24.

  Further, when the field device 3 receives a control signal, a status inquiry signal, a log information siphoning request command, or the like from the control PC 1 ', it performs an operation corresponding to the received signal and transmits a response signal to the control PC 1'. The response signal is received by the RS232C communication unit 23 in the protocol conversion device 2b according to the RS232C communication protocol, and then supplied to the control PC 1 through the protocol conversion unit 22 'and the RS232C communication unit 23'.

  At that time, after all the data transmitted / received between the control PC 1 ′ and the field device 3 in the protocol conversion unit 22 ′ is copied by the monitor data copy processing unit 24, the TCP / IP communication unit 21 is operated. To the external device 4. Further, when the switching signal is transmitted from the external device 4 to the protocol conversion unit 22 ′, the data of the external device 4 transmitted subsequently passes through the TCP / IP communication unit 21, the protocol conversion unit 22 ′, and the RS23C communication unit 23 ′. Is transmitted to the field device 3 as it is. Thereby, the operation of the field device 3 can be controlled by the external device 4.

  In the present embodiment, the communication between the control PC 1 'and the field device 3 can be made offline, and then the communication between the field device 3 and the control PC 1' can be performed. Thereby, the protocol conversion device 2b of the present embodiment has the same features as the protocol conversion device 2a of FIG. In this embodiment, the control PC 1 'can be applied to a PC based on the RS232C communication protocol.

(Third embodiment)
Next, a third embodiment of the present invention will be described in detail with reference to the drawings. FIG. 3 shows a block diagram of a third embodiment of the protocol conversion apparatus according to the present invention. In the figure, the same components as those in FIG. In FIG. 3, the protocol conversion device 2 c includes a control PC 1 ′ that transmits a control signal and the like, a field device 3 that is controlled by the control PC 1 ′, and an external device 4 that monitors communication data between the control PC 1 ′ and the field device 3. And a TCP / IP communication unit 21, a protocol conversion unit 22 ″, and an RS232C communication unit 23 and 23 ′, which perform protocol conversion between TCP / IP and RS232C. The protocol conversion device 2c does not have the monitor data copy processing unit 24 which is shown in FIGS.

  In this embodiment, in the data flow in the second embodiment shown in FIG. 2, the control PC 1 ′ and the field device 3 do not directly pass through the protocol conversion unit 22 ″, but directly the RS232C communication unit 23 and the RS232C. Data is transmitted and received by the communication unit 23 ', and data transmission to the external device 4 is not performed via the monitor data copy processing unit 24 used in Fig. 1 and Fig. 2. The RS232C communication unit 23' is RS232C. Data is transmitted / received to / from the communication unit 23 or the protocol conversion unit 22.

  Next, the operation of the protocol conversion device 2c of this embodiment will be described. In FIG. 3, control signals such as start / stop and operation instructions for the field device 3 generated by the control PC 1 ′, a status inquiry signal to the field device 3, or log information (alarm information) download request command for the field device 3. Are received by the RS232C communication unit 23 ′ in the protocol conversion device 2c by RS232C communication, and then transmitted to the field device 3 through the RS232C communication unit 23.

  On the other hand, upon receiving a control signal, a status inquiry signal, or a log information siphoning request command from the control PC 1, the field device 3 performs an operation corresponding to the received signal and transmits a response signal to the control PC1. The response signal is received by the RS232C communication unit 23 in the protocol conversion device 2c according to the RS232C communication protocol, and then transmitted through the RS232C communication unit 23 'to the control PC 1' according to the RS232C communication protocol.

  Here, all signals between the control PC 1 ′ and the field device 3 are supplied to the protocol conversion unit 22 ″, where the protocol conversion is performed from RS232C to TCP / IP, and then the TCP / IP communication unit is connected via 21. Thus, in this embodiment, the external device 4 can monitor and copy the data transmission / reception contents between the control PC 1 ′ and the field device 3 in the present embodiment.

  Further, the communication between the control PC 1 ′ and the field device 3 can be made offline, and thereafter the field device 3 and the external device 4 can be communicated. In this case, the communication between the control PC 1 ′ and the field device 3 is made offline, and the field device 3 and the external device 4 are connected. As a result, detailed alarm information from the field device 3 can be provided to the external device 4. However, during this time, communication between the field device 3 and the control PC 1 'is interrupted.

  Thus, according to the present embodiment, bidirectional communication between the control PC 1 ′ and the field device 3 is enabled, and the external device 4 performs communication between the field device 3 and the control PC 1 ′. In addition to monitoring, after the communication between the field device 3 and the control PC 1 ′ is made offline, bidirectional communication can be performed between the external device 4 and the field device 3 having different communication methods by protocol conversion.

It is a block diagram of a 1st embodiment of the present invention. It is a block diagram of the 2nd Embodiment of this invention. It is a block diagram of the 3rd Embodiment of this invention.

Explanation of symbols

1, 1 'control PC (personal computer)
2a, 2b, 2c Protocol conversion device 3 Field device 4 External device 21 TCP / IP communication unit 22, 22 ', 22 "Protocol conversion unit 23, 23' RS232C communication unit 24 Monitor data copy processing unit

Claims (6)

A protocol conversion between the first terminal and the second terminal is performed between the first terminal communicating with the first protocol and the second terminal communicating with the second protocol. A protocol conversion device that performs protocol conversion between the external device and the second terminal connected to an external device by a third party that communicates with the first protocol,
A first communication unit that communicates with the first terminal or the external device using the first protocol;
A second communication unit that communicates with the second terminal using the second protocol;
Connected to the first communication unit and the second communication unit, and performs protocol conversion between the first transmission / reception signal of the first communication unit and the second transmission / reception signal of the second communication unit. A protocol converter,
A monitor data copy processing unit that outputs the first or second transmission / reception signal whose protocol has been converted by the protocol conversion unit to the external device via the first communication unit. Feature protocol converter.   Based on the switching signal from the external device, the first communication unit sets communication between the first terminal and the protocol conversion unit offline, and the protocol conversion unit causes the external device to communicate with the second device. The protocol conversion apparatus according to claim 1, wherein protocol conversion with a communication unit is performed. A first terminal connected between the first and second terminals communicating with the first protocol, performing protocol conversion between the first terminal and the second terminal, and communicating with the second protocol; A protocol conversion device that is connected to an external device by three parties and performs protocol conversion between the external device and the second terminal,
A first communication unit that communicates with the first terminal using the first protocol;
A second communication unit that communicates with the second terminal using the first protocol;
A third communication unit that communicates with the external device using the second protocol;
The first communication unit, the second communication unit, and the third communication unit are connected to each other, transfer a transmission signal from the first communication unit to the second communication unit, and the second communication unit. A protocol conversion unit that transfers a transmission signal from the communication unit to the first communication unit and performs protocol conversion between the transmission / reception signal of the second terminal and the transmission / reception signal of the third communication unit;
A monitor data copy processing unit that copies a transmission / reception signal between the first and second communication units that are protocol-converted by the protocol conversion unit and then outputs the signals to the external device via the third communication unit And a protocol converter characterized by comprising:   Based on the switching signal from the external device, the third communication unit sets communication between the first terminal and the protocol conversion unit offline, and the protocol conversion unit causes the external device to communicate with the third device. The protocol conversion apparatus according to claim 3, wherein protocol conversion with the communication unit is performed. A first terminal connected between the first and second terminals communicating with the first protocol, performing protocol conversion between the first terminal and the second terminal, and communicating with the second protocol; A protocol conversion device that is connected to an external device by three parties and performs protocol conversion between the external device and the second terminal,
A first communication unit that communicates with the first terminal using the first protocol;
A second communication unit that communicates with the second terminal using the first protocol and communicates with the first communication unit;
A third communication unit that communicates with the external device using the second protocol;
Connected to the first communication unit, the second communication unit, and the third communication unit, and performs protocol conversion of transmission / reception signals between the first communication unit and the second communication unit. A protocol converter that outputs to the external device via the third communication unit.   The first terminal is a control personal computer, the second terminal is a field device, and the control personal computer transmits control signals such as start / stop of the field device, operation instructions, and the field device. 2. A state inquiry signal or a log information siphoning request command for the field device is generated, and the field device responds and transmits a signal corresponding to the signal from the control personal computer. 6. The protocol converter according to any one of items 5 to 5.

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