JP2005070975A - Repeater system and control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a repeater system and a control system for controlling a device to be controlled with a communication port for serial transmission, such as a projection device from various controllers, such as personal computers. <P>SOLUTION: This repeater system 10 is provided with a first communication port 13 being a port for serial transmission connected to a device to be controlled, a second communication port 15 being a port for serial transmission connected to a first controller, corresponding to serial transmission and a second communication port 17 for LAN connected to a second controller corresponding to communication via an LAN cable different from serial transmission. This repeater system 10 is provided with a protocol converting function, such as character data preparation processing 105 and packet preparation processing 108 for relaying communication between the first communication port 13 and the second communication port 17 for LAN. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a control device such as a personal computer, a relay device that relays communication between controlled devices such as video devices remotely controlled by the control device, and a control system using the device, and more particularly to the control device and the controlled device. The present invention relates to a relay device and a control system that convert communication protocols for signals transmitted and received between control devices.

  For example, video devices such as projection devices installed in audiovisual classrooms and theater rooms of schools have communication ports for serial transmission based on standards such as RS-232C and RS-422, and the communication ports for serial transmission are used. By connecting with a control device such as a personal computer and a dedicated centralized operation terminal device, the video device operates as a controlled device that is remotely controlled by the control device.

  In this way, the video device as a controlled device is remotely controlled by the control device, so that the video device that is the controlled device is a personal computer application software that is common with other devices in the theater room and a dedicated central operation terminal An operation by the apparatus is accepted, and the control apparatus can acquire various management information for controlling the controlled apparatus from the controlled apparatus.

  In recent years, there has been an increasing demand to use an existing LAN (Local Area Network) in a building for controlling a video device such as a projection device. In response to these requests, a serial transmission port and a LAN Is a serial-TCP / IP protocol converter that includes a communication port for communication, and has a function of mutually converting a communication protocol that defines LAN communication such as TCP / IP and a communication protocol that defines serial transmission. It has begun to spread.

  Such a relay device called a serial-TCP / IP protocol converter includes one communication port for serial transmission and one communication port for LAN. Each communication port is full-duplex or half-duplex. It is possible to communicate with other devices to be connected to each other and use it for both transmission and reception.

  FIG. 14 is a block diagram showing a configuration of a control system using a conventional relay device. In FIG. 14, reference numerals 10a and 10b denote relay apparatuses. Between the relay apparatus 10a and the relay apparatus 10b, Ethernet (registered trademark) or the like defined by a protocol such as TCP / IP is provided via a LAN communication port. Connected via LAN.

  Further, the relay device 10a is connected to a control device 30 such as a centralized operation panel via a serial transmission communication port, and the relay device 10b is connected to a controlled device 20 such as a projection device via a serial transmission communication port. Connected.

  As shown in FIG. 14, the relay devices 10a and 10b and the LAN are used as virtual serial cables by connecting the relay devices 10a and 10b with a LAN using two relay devices 10a and 10b. Therefore, the controlled device 20 can be controlled by the control device 30 via the LAN.

  FIG. 15 is a block diagram showing a configuration of a control system using a conventional relay device. The control system shown in FIG. 15 has a configuration in which a control device 30 such as a personal computer and a controlled device 20 such as a projection device are connected by a relay device 10, and the controlled device 20 having a communication port for serial transmission is It can be controlled by the control device 30 having a communication port for LAN.

  The relay device used in the control system shown in FIGS. 14 and 15, for example, transmits character data based on a serial transmission protocol (communication protocol) received from a serial transmission communication port to a packet based on a protocol such as TCP / IP. And a protocol conversion function for extracting data packetized from a LAN communication port based on a protocol such as TCP / IP and converting it into character data based on a serial transmission protocol.

A device that connects a personal computer that is a control device and various information devices that are controlled devices having a serial communication function is also disclosed in Patent Document 1, for example.
Japanese Patent Laid-Open No. 10-177547

  However, since the conventional relay device simply replaces the serial transmission communication port provided in the controlled device with the LAN communication port, the conventional relay device has the conventional control over the controlled device provided with one serial transmission communication port. When a device is connected, the controlled device appears to be a controlled device having a single LAN communication port, so control can be performed via the LAN, but conventional hardware resources There is a problem that control cannot be performed via a communication port for serial transmission utilizing the above.

  As described with reference to FIG. 14, this problem can be controlled through the serial transmission communication port by using two relay devices. In this case, the LAN is used as a simple transmission path. However, there is a problem that the characteristic functions of the LAN such as multi-connection and broadcast communication cannot be used.

  The present invention has been made in view of such circumstances, and includes a first communication port for serial transmission for connecting a controlled device, and a plurality of second communication ports for serial transmission and LAN for connecting a controlled device. Since the controlled device can be regarded as a device having a communication port for serial transmission and a communication port for LAN, the characteristic functions of the control system and LAN utilizing the conventional hardware resources can be obtained. It is an object of the present invention to provide a relay device capable of realizing a control system that can be used, and a control system including the relay device.

  The present invention includes a first communication port and a plurality of second communication ports, and a relay device that relays communication between a device connected via the first communication port and a device connected via the second communication port. The first communication port is a serial transmission port, and the second communication port includes a serial transmission port and a different protocol port for performing communication processing based on a communication protocol different from that of serial transmission. And a means for mutually converting a communication protocol of a signal transmitted and received based on the communication protocol of a signal transmitted and received based on a communication protocol different from that of serial transmission.

  In the present invention, by providing a first communication port connected to a controlled device such as a projection device and a plurality of types of second communication ports capable of connecting a control device that controls the controlled device, A control device that performs control based on a communication protocol for serial transmission utilizing popular hardware resources and a control device that performs control based on a communication protocol different from serial transmission are connected to each other and controlled by each control device. It is possible to control the device.

  The present invention is characterized in that there are a plurality of serial transmission ports and / or different protocol ports.

  In the present invention, by providing a plurality of serial transmission ports and / or different protocol ports as the second communication port, the controlled device can be used as a device having a plurality of communication ports, so that a plurality of control devices are connected. In addition, it is possible to control more complicated management and operation.

  The present invention further includes means for selecting one second communication port for relaying communication with the first communication port.

  In the present invention, a controlled device receives control signals from a plurality of control devices at the same time by occupying one selected communication port among a plurality of second communication ports for relaying communication with the first communication port. It is possible to prevent the operation from becoming abnormal due to the above.

  The present invention provides a signal transmission source when another second communication port not selected as one second communication port that relays communication with the first communication port receives a signal from an external device. The apparatus further comprises means for transmitting a signal indicating that communication is impossible.

  In the present invention, when the selected second communication port occupies the relay of the communication and the other second communication port that cannot be relayed receives a signal such as a control signal from the control device, it is received. By invalidating the signal and transmitting a signal such as an ERR signal indicating that communication is not possible to the control device that transmitted the signal, the control device recognizes that the controlled device is busy, It is possible to perform processing such as signal retransmission after waiting for a predetermined time.

  In the present invention, when another second communication port that is not selected as one second communication port that relays communication with the first communication port receives a signal from an external device, the received signal is When the second communication port corresponding to the stored signal and the stored signal is selected as one second communication port for relaying communication, the stored signal is connected via the first communication port. And a means for transmitting to the apparatus.

  In the present invention, when the selected second communication port occupies communication relay and another second communication port that cannot be relayed receives a signal such as a control signal from the connected control device The stored signal is stored (buffered) in the built-in memory, and when the second communication port corresponding to the stored signal is selected after the occupation by the second communication port is released, the stored signal is stored. By transmitting to the controlled device connected to the first communication port, it is possible to improve the certainty of relaying the signal received by the second communication port, and processing on the control device side by signal retransmission Impossibility and an increase in communication load can be prevented.

  The present invention is characterized in that the different protocol port performs communication processing based on a communication protocol defined as TCP / IP.

  In the present invention, it is possible to connect to various communication networks and various control machines by corresponding to the communication protocol defined as TCP / IP which is widely spread.

  The present invention includes the above-described relay device, a control device connected to the relay device via a first communication port, and a control device controlled by the control device and connected to the relay device via a second communication port. And a controlled device.

  In the present invention, a controlled device such as a projection device is connected to a first communication port included in a relay device, and a plurality of control devices such as a personal computer are connected to a second communication port included in the relay device. A control device that performs control based on a communication protocol for serial transmission that utilizes hardware resources that is widely used in Japan and a control device that performs control based on a communication protocol different from serial transmission are connected to each other and are controlled by each control device. It is possible to control the control device.

  In the relay apparatus and control system of the present invention, the controlled apparatus based on the serial transmission communication protocol such as RS-232C is used as the relay apparatus that relays communication between the controlled apparatus such as the projection apparatus and the control apparatus such as the personal computer. A plurality of second communication ports including a first communication port that is a serial transmission port connected to the communication port and a different protocol port based on a communication protocol such as TCP / IP different from the serial transmission port and serial transmission.

  With this configuration, it becomes possible to use a controlled device having only one serial transmission port as a controlled device having a serial transmission port and a different protocol port. It is possible to connect a control device that performs control based on the communication protocol for serial transmission utilized to a control device that performs control based on a communication protocol such as TCP / IP widely used in communication networks such as the Internet and LAN. As a result, it is possible to effectively use the conventional assets and to use the characteristic functions of the LAN such as multi-connection and broadcast communication.

  In the present invention, one second communication port that relays communication with the first communication port is selected, and the selected second communication port is made to occupy the relay of communication with the first communication port. When the other second communication port other than the selected second communication port receives a signal such as a control signal, the received signal is invalidated to control the signal transmission source. A signal such as an ERR signal indicating that relaying is impossible is transmitted to the apparatus.

  With this configuration, the control device recognizes that the controlled device is busy, and can perform processing such as signal retransmission after waiting for a predetermined time. Since the control signals are not received at the same time, it is possible to prevent the operation from becoming abnormal due to the simultaneous reception of a plurality of control signals.

  Further, according to the present invention, when a second communication port other than the selected second communication port that cannot be relayed receives a signal such as a control signal from the control device, the received signal is incorporated. When the second communication port corresponding to the stored signal temporarily recorded in the storage means such as a memory is selected as the second communication port for relaying communication, the stored signal is controlled. Buffering to send to.

  With this configuration, the signal received from the control device can be reliably transmitted to the controlled device, and the received signal does not need to be invalidated, thereby reducing the inability to process the relay device and retransmitting the signal. This eliminates the need for signal re-transmission processing, thus reducing the processing load on the control device side, and further preventing the increase in communication load because re-transmission is not performed. Play.

Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof.
Embodiment 1 FIG.
FIG. 1 is a block diagram showing a configuration of a control system according to Embodiment 1 of the present invention. In FIG. 1, reference numeral 10 denotes a relay device according to the present invention. The relay device 10 is connected to a controlled device 20 such as a projection device and a plurality of control devices 31 and 32 such as a personal computer and a centralized operation panel. Thus, processing for relaying communication between the controlled device 20 and the control devices 31 and 32 is performed.

  The relay device 10 and the controlled device 20 are connected by a serial cable that performs communication processing based on a communication protocol (protocol) for serial transmission such as RS-232C and RS-422.

  Between the relay device 10 and the control devices 31 and 32, a serial cable for performing communication processing for serial transmission, or a communication protocol different from serial transmission, specifically, a LAN such as Ethernet (registered trademark) and a communication network such as the Internet. Are connected by a LAN cable of a standard such as 10BASE-T that performs communication processing based on a communication protocol for LAN such as TCP / IP.

  In the following description, a control device connected to the relay device 10 via a serial cable is referred to as a first control device 31, and a control device connected to the relay device 10 via a LAN cable is referred to as a second control device 32.

  FIG. 2 is a block diagram showing an internal configuration of relay apparatus 10 according to Embodiment 1 of the present invention. The relay device 10 includes a processor 11 that controls the entire device, a controlled-side serial driver receiver 12 that controls communication with the controlled device 20 via a serial cable based on the control of the processor 11, and a terminal that connects the serial cable. A first communication port 13 that is controlled by the controlled serial driver receiver 12 and communicates with the controlled device 20 is provided.

  The first communication port 13 is a serial transmission port based on standards such as RS-232C and RS-422 that serially transmit signals as character data.

  The relay device 10 includes a control-side serial driver receiver 14 that controls communication with the first control device 31 via a serial cable based on the control of the processor 11, and a terminal that connects the serial cable. And a second serial communication port 15 that communicates with the first control device 31 under the control of the first control device 31.

  The serial second communication port 15 is a serial transmission port based on standards such as RS-232C and RS-422.

  Furthermore, the relay device 10 includes a control-side network interface controller 16 that controls communication with the second control device 32 via a LAN cable based on the control of the processor 11 and a terminal that connects the LAN cable. The second communication port 17 for LAN that performs communication with the second control device 32 under the control of the second control device 32 is provided.

  The second LAN communication port 17 is a different protocol port for performing communication processing based on a communication protocol different from that for serial transmission. Here, the LAN port is used for packetizing and transmitting a signal based on a LAN communication protocol such as TCP / IP. It is.

  The relay device 10 is connected to the controlled device 20 connected via the first communication port 13 and the first control device 31 connected via the serial second communication port 15 or the LAN second communication port 17. It relays communication with the second control device 32 to be connected.

  When the processor 11 transmits / receives a signal to / from the first control device 31 via the control-side serial driver receiver 14, the processor 11 temporarily stores a signal to be transmitted / received, such as a control-side serial buffer 101, a control-side network. When transmitting / receiving a signal to / from the second control device 32 via the interface controller 16, the control side LAN buffer 102 which is a means such as a memory for temporarily storing the transmitted / received signal and the controlled side serial driver receiver 12 are used. When a signal is transmitted / received to / from the controlled device 20, the controlled-side serial buffer 103, which is a means such as a memory for temporarily storing the transmitted / received signal, is provided.

  Further, the processor 11 selects a signal to be transmitted to the controlled device 20 from a signal stored in the control-side serial buffer 101 and a signal stored in the control-side LAN buffer 102 as a first selector. 104 is provided.

  When the first selector 104 is switched, a path is set between one of the control-side serial buffer 101 and the control-side LAN buffer 102 and the controlled-side serial buffer 103, and the selected first control is selected. A signal received from the device 31 or the second control device 32 can be transmitted to the controlled device 20.

  Since the signal received via the second LAN communication port 17 is a packetized signal based on the LAN communication protocol, it is characterized by the character data conversion process (or character data conversion circuit) 105. Above, the data is temporarily stored in the character buffer 106 and then sent to the first selector 104.

  Further, the processor 11 selects, from the first control device 31 and the second control device 32, a device that is a transmission destination of a signal received from the controlled device 20 and stored in the controlled-side serial buffer 103. The second selector 107 is provided.

  When the second selector 107 is switched, a path is set between the controlled-side serial buffer 103 and any one of the control-side serial buffer 101 and the control-side LAN buffer 102 and received from the controlled device 20. This signal can be transmitted to the selected first control device 31 or second control device 32.

  Since the signal received via the controlled serial buffer 103 is character data, it is packetized by the packetization process (or packetization circuit) 108 when sent from the second selector 107 to the control-side LAN buffer 102. Is sent to the control-side LAN buffer 102.

  Furthermore, the processor 11 includes a hold timer 109 that synchronizes the switching processing of the first selector 104 and the second selector 107 and manages the time for setting a path.

  In this way, the relay device 10 sets a second communication port for relaying communication by setting a path with the first communication port 13 under the control of the processor 11, the second communication port for serial 15 and the LAN. A first selector 104, a second selector 107, and a hold timer 109 that are selected from the second communication port 17 are provided.

  Further, the relay device 10 should convert the communication protocol of the character data transmitted / received based on the communication protocol for serial transmission and the communication protocol of packetized data transmitted / received based on the communication protocol for LAN, under the control of the processor 11. And various processing programs such as a character data conversion process 105, a character buffer 106, and a packetization process 108.

  Next, signal transmission / reception and path switching between the controlled apparatus 20 and the first control apparatus 31 or the second control apparatus 32 in the relay apparatus 10 of the present invention will be described.

  In communication based on the communication protocol for serial transmission, packets cannot be transmitted simultaneously to a plurality of devices as in communication based on the communication protocol for LAN. Therefore, the relay device 10 selects one control device among the first control device 31 and the second control device 32 as the device that communicates with the controlled device 20, makes the selected control device occupy the communication, and so on. The first selector 104 and the second selector 107 function so as to occupy the selected control device with communication.

  The signal transmitted from the first control device 31 or the second control device 32 to the controlled device 20 via the relay device 10 is a control signal such as an operation and management information request. The signal transmitted to the device 31 or the second control device 32 is a response signal such as operation completion for the control signal, operation inability and management information.

  That is, since the response signal transmitted from the controlled device 20 to the first control device 31 or the second control device 32 is a response to the control signal, the control signal and the response signal can be selected to ensure communication. The one control device must occupy communication with the controlled device 20, and after the communication is completed, the occupied state must be released so that another control device can communicate.

  FIG. 3 is a time chart showing relay processing of the relay device 10 according to Embodiment 1 of the present invention. In the time chart shown in FIG. 3, the communication status by the second communication port 15 for serial, the second communication port 17 for LAN, and the first communication port 13 is shown from the top. Changes.

  The first control device 31 is selected as one control device that communicates with the controlled device 20 at times T0 to T1 in FIG. 3, the first control device 31 occupies communication with the controlled device 20, and the first control device 31 The second control device 32 is selected as one control device in which the route is set between the communication port 13 and the second serial communication port 15 and the times T2 to T3 communicate with the controlled device 20. The second control device 32 occupies communication with the controlled device 20 and a time zone in which a path is set between the first communication port 13 and the second communication port 17 for LAN.

  As shown in FIG. 3, after reaching time T0, the relay device 10 relays the control signal transmitted from the first control device 31 to the controlled device 20, and the control device 20 receives the control signal from the controlled device 20 in response to the control signal. 1 The response signal transmitted to the control device 31 is relayed.

  The relay device 10 releases the occupied state by the first control device 31 at time T1 after the relay of the response signal is completed, and sets a path between the second control device 32 and the controlled device 20 at time T2. .

  Further, after time T2, the relay device 10 relays the control signal transmitted from the second control device 32 to the controlled device 20, and transmits the control signal from the controlled device 20 to the second control device 32. Relay the response signal.

  Then, the relay device 10 releases the occupied state by the second control device 32 at time T3 after the relay of the response signal is completed.

  However, since the communication method described with reference to the time chart of FIG. 3 is originally a communication method premised on communication between one control device and one controlled device 20, an end indicating the end of each communication. It is conceivable that there is no code or no response signal. In such a case, there is a possibility that a problem related to the switching of the route may occur.

  Therefore, when the relay apparatus 10 relays the signal transmitted to the controlled apparatus 20, the occupation of the path and the measurement of the occupation time by the hold timer 109 of the processor 11 are started, and the measured occupation time is set in advance. A communication method is considered in which the occupation of the route is released when the predetermined time is reached.

  In that case, the preset occupation time is set in anticipation of some margin time in the minimum necessary time. The occupation time can be set to an arbitrary value by the user's operation. The relay of the control signal can be started only when the occupation time is not counted.

  FIG. 4 is a time chart showing relay processing of the relay device 10 according to Embodiment 1 of the present invention. In the time chart shown in FIG. 4, the communication status by the serial second communication port 15, the LAN second communication port 17, and the first communication port 13 is shown from the top. Changes.

  At time T0 in FIG. 4, the relay device 10 starts relaying a signal transmitted from the first control device 31 to the controlled device 20, and simultaneously starts occupying the route and measuring the occupied time. At time T1, The occupied time being measured reaches a predetermined time set in advance, and the occupation of the route is released.

  As shown in FIG. 4, the interval between time T0 and time T1 defined as the occupation time relays a control signal transmitted from the first control device 31 to the controlled device 20, and the first time from the controlled device 20 is the first. Compared to the time for relaying the response signal transmitted to the control device 31, a slight margin is expected.

  Then, after reaching time T1, since the occupation is released, both the first control device 31 and the second control device 32 can transmit a control signal to the controlled device 20, and in FIG. Since the control signal is transmitted from the second control device 32 to the controlled device 20 at the time of, the path is occupied for communication between the second control device 32 and the controlled device 20 between time T2 and time T3. Will be.

  Next, the details of the occupation time measurement method will be described. FIG. 5 is a time chart showing relay processing of the relay device 10 according to Embodiment 1 of the present invention. In the time chart shown in FIG. 5, the upper side shows the communication status by the second communication port 15 for serial and the lower side shows the communication status by the first communication port 13, and shows the time-dependent change of the communication status by taking time in the horizontal direction. .

  As shown in FIG. 5, the occupation time is measured from the time when the relay of the control signal is started from the first control device 31 to the controlled device 20. However, as shown in FIG. 5, the control signal is transmitted as a plurality of character data, which is a unit of information to be transmitted, and is composed of five character data in the example shown in FIG.

  Since the occupation time starts from the time when each character data is relayed, in the example shown in FIG. 5, the measurement of the occupation time is started from each time indicated as T11, T12, T13, T14, and T15. The end of the time is a time point T20 after a predetermined time has elapsed from the time point T15 when the last character data is transmitted.

  As shown in FIG. 5, the response signal is also composed of a plurality of character data, and the occupation time is the time required for the marginal time from the minimum required time from the start of transmission of the control signal to the completion of transmission of the response signal. Is set.

  Next, the other communication that cannot be relayed when the communication with the controlled device 20 is occupied by one control device will be described.

  In the relay device 10 of the present invention, when communication with one controlled device 20 is occupied by one control device, a control signal to be transmitted from the other control device to the controlled device 20 that cannot be relayed Is received, an ERR signal indicating that communication is not possible with respect to the control signal is transmitted without transmitting the received control signal to the controlled apparatus 20.

  The ERR signal is a signal that is originally transmitted from the controlled device 20 to the control device when an error in communication content and communication cannot be accepted. In the relay device 10 of the present invention, the ERR signal is transmitted when the relay cannot be performed. , The control device 20 recognizes that the controlled device 20 is in a busy state where communication is impossible.

  On the control device side, when receiving the ERR signal and recognizing that the controlled device 20 is in a busy state where communication is not possible, after waiting for a predetermined time, the control device transmits the control signal again.

  FIG. 6 is a time chart showing relay processing of the relay device 10 according to Embodiment 1 of the present invention. In the time chart shown in FIG. 6, the communication status by the second communication port 15 for serial, the second communication port 17 for LAN, and the first communication port 13 is shown from the top. Changes.

  FIG. 6 shows a situation in which a control signal is received from the second control device 32 during the time T0 to time T1 when the route is occupied by relaying communication between the first control device 31 and the controlled device 20 in FIG. As shown in FIG. 6, the relay apparatus 10 of the present invention transmits an ERR signal indicating that communication is not possible for the received control signal.

  Then, the second control device 32 recognizes that the controlled device 20 cannot communicate by receiving the ERR signal, transmits a control signal again after waiting for a predetermined time, and the relay device 10 again Since the transmitted control signal is received after the occupation time has expired, a relay process for transmitting the received control signal to the controlled apparatus 20 is started.

  Next, processing of the relay apparatus 10 according to the present invention will be described using a flowchart. FIG. 7 is a flowchart showing a relay process of communication between the first control device 31 and the controlled device 20 by the relay device 10 according to the first embodiment of the present invention.

  The relay device 10 receives the control signal from the first control device 31 connected to the serial second communication port 15 under the control of the processor 11 (S101), determines whether relaying is possible (S102), and can relay. Is determined (S102: YES), the first selector 104 and the second selector 107 start occupying only the communication between the second serial communication port 15 and the first communication port 13 that can be relayed ( S103), the hold timer 109 starts measuring the occupation time (S104), and the first control device 31 connected to the second serial communication port 15 and the controlled device 20 connected to the first communication port 13. Relay of communication between them is started (S105).

  Whether or not relaying is possible is determined in step S102 as to whether or not other communication is being relayed, that is, the occupation time for relaying communication between the second communication port 17 for LAN and the first communication port 13 is being measured. This is done by determining whether or not there is.

  When the relay device 10 detects that the measured occupation time has reached a predetermined time under the control of the processor 11 (S106), the relay device 10 releases the occupation by the second serial communication port 15 (S107). ), The process is terminated.

  If it is determined in step S102 that relaying is not possible (S102: NO), the relay device 10 cannot communicate with the first control device 31 that is the transmission source of the control signal under the control of the processor 11. An ERR signal is transmitted (S108), and the process is terminated.

  FIG. 8 is a flowchart showing a relay process of communication between the second control device 31 and the controlled device 20 by the relay device 10 according to the first embodiment of the present invention.

  The relay device 10 receives the control signal from the second control device 32 connected to the second LAN communication port 17 under the control of the processor 11 (S201), determines whether or not relaying is possible (S202), and can relay. (S202: YES), occupancy is started so that only communication between the second LAN communication port 17 and the first communication port 13 can be relayed (S203), and measurement of the occupancy time is started. (S204), relay of communication between the second control device 32 connected to one LAN second communication port 17 and the controlled device 20 connected to the first communication port 13 is started (S205).

  When relaying communication, the relay device 10 mutually converts the communication protocol of signals to be relayed under the control of the processor 11 (S206).

  That is, since the control signal received from the second control device 31 via the second LAN communication port 17 is a packetized signal based on the LAN communication protocol, it is converted into character data by the character data conversion processing 105. .

  Further, since the response signal received from the controlled device 20 via the first communication port 13 is character data, it is packetized by the packetizing process 108.

  In this way, a function for mutually converting the communication protocol is realized by processing of the program such as the character data conversion processing 105 and the packetization processing 108.

  When the relay device 10 detects that the measured occupation time has reached a predetermined time under the control of the processor 11 (S207), the relay device 10 releases the occupation by the second LAN communication port 17 (S208). ), The process is terminated.

  If it is determined in step S202 that relaying is not possible (S202: NO), the relay device 10 determines that communication to the second control device 32 that is the transmission source of the control signal is not possible under the control of the processor 11. An ERR signal is transmitted (S209), and the process is terminated.

  If communication with the controlled device 20 is occupied by one control device, the ERR signal is not transmitted to the other control device that cannot be relayed as described above, but from the other control device. The received control signal may be buffered, and the buffered control signal may be transmitted to the controlled device 20 when the occupation is released.

  Next, processing for controlling communication relay by buffering will be described with reference to a flowchart. FIG. 9 is a flowchart showing a relay process of communication between the first control device 31 and the controlled device 20 by the relay device 10 according to the first embodiment of the present invention.

  The relay device 10 receives a control signal from the first control device 31 connected to the serial second communication port 15 under the control of the processor 11 (S301), determines whether relaying is possible (S302), and can relay. (S302: YES), occupancy is started so that only communication between the second serial communication port 15 and the first communication port 13 can be relayed (S303). Measurement is started (S304), and relaying of communication between the first control device 31 connected to one serial second communication port 15 and the controlled device 20 connected to the first communication port 13 is started (S305). .

  Then, in the relay device 10, when it is detected by the control of the processor 11 that the measured occupation time has reached the predetermined time (S306), the occupation by one serial second communication port 15 is released (S307). ), The process is terminated.

  If it is determined in step S302 that relaying is not possible (S302: NO), the relay device 10 temporarily stores the received control signal in the control-side serial buffer 101 as buffering processing under the control of the processor 11. (S308).

  When the relay device 10 detects the release of occupation by relay of another communication under the control of the processor 11 (S309), the process proceeds to step S303, and the control signal temporarily stored in the control serial buffer 101 is received. It transmits to the control apparatus 20.

  FIG. 10 is a flowchart showing a relay process of communication between the second control device 31 and the controlled device 20 by the relay device 10 according to the first embodiment of the present invention.

  The relay device 10 receives the control signal from the second control device 32 connected to the second LAN communication port 17 under the control of the processor 11 (S401), determines whether relaying is possible (S402), and can relay. (S402: YES), occupancy is started so that only communication between the second LAN communication port 17 and the first communication port 13 can be relayed (S403), and measurement of the occupancy time is started. (S404), relay of communication between the second control device 32 connected to the second LAN second communication port 17 and the controlled device 20 connected to the first communication port 13 is started (S405).

  When relaying communication, the relay device 10 mutually converts the communication protocol of signals to be relayed under the control of the processor 11 (S406).

  When the relay device 10 detects that the measured occupation time has reached a predetermined time under the control of the processor 11 (S407), the relay device 10 releases the occupation by the second LAN second communication port 17 (S408). ), The process is terminated.

  If it is determined in step S402 that relaying is not possible (S402: NO), the relay device 10 temporarily stores the received control signal in the control-side LAN buffer 102 as buffering processing under the control of the processor 11. (S409).

  When the relay device 10 detects the release of occupation by relay of another communication under the control of the processor 11 (S410), the process proceeds to step S303, and the control signal temporarily stored in the control-side LAN buffer 102 is received. It transmits to the control apparatus 20.

  By performing buffering in this way, it becomes possible to reliably transmit the signal received from the control device to the controlled device 20, and it is not necessary to invalidate the received signal, thereby reducing the inability to process the relay device 10. However, since there is no need to retransmit the signal, the signal retransmission process is not required, so that the processing load on the control device side is reduced, and further, the retransmission is not performed, thereby preventing an increase in communication load. Is possible.

  However, when applying the processing of invalidating the received signal and transmitting the ERR signal, the capacity of the control serial buffer 101 and the control-side LAN buffer 102 can be reduced, thereby reducing the manufacturing cost of the relay device 10. Is possible.

  As described above, in the first embodiment of the present invention, the controlled device 20 having only one serial transmission port can be used as the controlled device 20 having a serial transmission port and a different protocol port. Therefore, the first control device 31 that performs control based on the communication protocol for serial transmission utilizing the hardware resources that have been widely used, and the communication protocol such as TCP / IP widely used in communication networks such as the Internet and LAN. Since it is possible to connect to the second control device 32 that performs control based on each of them, it is possible to make effective use of conventional assets and to use characteristic functions of the LAN such as multi-connection and broadcast communication.

Embodiment 2. FIG.
The relay device 10 according to the second embodiment is a mode including a plurality of second communication ports for serial transmission in the first embodiment. FIG. 11 is a block diagram showing an internal configuration of relay apparatus 10 according to Embodiment 2 of the present invention.

  The relay device 10 includes a plurality of control-side serial driver receivers 14 and a second serial communication port 15, and has a plurality of control-side serial buffers 101 in the processor 11, thereby connecting a plurality of first control devices 31. It is the structure which enabled it to do. In addition, about the component similar to Embodiment 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In the second embodiment, the route to the first communication port 13 is set by selecting one second communication port selected from the plurality of second communication ports 15 for serial and the second communication port 17 for LAN. Only.

  Note that the relay process in the second embodiment is the same as that in the first embodiment, so the first embodiment will be referred to and the description thereof will be omitted.

Embodiment 3 FIG.
The relay device 10 according to the third embodiment is a mode provided with a plurality of second communication ports for LAN in the first embodiment. FIG. 12 is a block diagram showing an internal configuration of relay apparatus 10 according to Embodiment 3 of the present invention.

  The relay device 10 includes a plurality of control-side network interface controllers 16 and a second LAN communication port 17, and has a plurality of control-side LAN buffers 102 in the processor 11, thereby connecting a plurality of second control devices 32. It is the structure which enabled it to do. In addition, about the component similar to Embodiment 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In the third embodiment, the route to the first communication port 13 is set by selecting a second communication port selected from the second communication port 15 for serial and the second communication port 17 for LAN. Only.

  Note that the relay processing in the third embodiment is the same as that in the first embodiment, so that the first embodiment is referred to and the description thereof is omitted.

  In the third embodiment, a set of character data conversion processing 105, character buffer 106, and packetization processing 108 is shared for both transmission and reception of signals using the plurality of LAN second communication ports 17. However, the same number of character data conversion processes 105, character buffers 106, and packetization processes 108 as the number of LAN second communication ports 17 are prepared, and these are different for each LAN second communication port 17. The processing program may be used.

Embodiment 4 FIG.
The relay device 10 according to the fourth embodiment has a configuration in which an Ethernet hub controller having a concentration function is provided in the third embodiment. FIG. 13 is a block diagram showing an internal configuration of relay apparatus 10 according to Embodiment 4 of the present invention.

  The relay device 10 includes an Ethernet hub controller 18 that is connected to a plurality of second LAN communication ports 17 and has a concentrating function. The Ethernet hub controller 18 connects the plurality of second LAN communication ports 17 and one The control-side network interface controller 16 is connected. In addition, about the component similar to Embodiment 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In the fourth embodiment, the route to the first communication port 13 is set by selecting a second communication port selected from the second communication port 15 for serial and the second communication port 17 for LAN. Only.

  Note that the relay process in the fourth embodiment is the same as that in the first embodiment, so the first embodiment will be referred to and the description thereof will be omitted.

  In the relay apparatus 10 according to the fourth embodiment, since the Ethernet hub controller 18 is provided, the network interface controller 16 and the control-side LAN buffer 102 can cope with each, so the relay apparatus according to the third embodiment. When the number of second control devices 32 to be connected is large compared to 10, the configuration can be simplified and the manufacturing cost can be suppressed.

  In the third embodiment, each network interface controller 16 is assigned a different IP address. However, in the fourth embodiment, since the network interface controller 16 is one, one IP address is shared in a time-sharing manner. Will be.

  In the second to fourth embodiments, the embodiment has been described in which a plurality of the second serial communication port 15 and the second LAN communication port 17 are provided. However, the second serial communication port 15 and the second LAN communication port 17 are provided. The two communication ports 17 may be plural.

  In the first to fourth embodiments, the relay device 10 that relays communication between the controlled device 20 such as a projection device and the control devices 31 and 32 such as a personal computer has been described. The present invention is not limited to this, and it is expanded to various uses for connecting a device having a serial transmission port, a device having a serial transmission port, and a device having a different protocol port for performing communication processing based on a communication protocol different from that of serial transmission. It is possible.

It is a block diagram which shows the structure of the control system in Embodiment 1 of invention. It is a block diagram which shows the internal structure of the relay apparatus in Embodiment 1 of this invention. It is a time chart which shows the relay process of the relay apparatus in Embodiment 1 of this invention. It is a time chart which shows the relay process of the relay apparatus in Embodiment 1 of this invention. It is a time chart which shows the relay process of the relay apparatus in Embodiment 1 of this invention. It is a time chart which shows the relay process of the relay apparatus in Embodiment 1 of this invention. It is a flowchart which shows the relay process of the communication between the 1st control apparatus and controlled apparatus by the relay apparatus in Embodiment 1 of this invention. It is a flowchart which shows the relay process of communication between the 2nd control apparatus and controlled apparatus by the relay apparatus in Embodiment 1 of this invention. It is a flowchart which shows the relay process of the communication between the 1st control apparatus and controlled apparatus by the relay apparatus in Embodiment 1 of this invention. It is a flowchart which shows the relay process of communication between the 2nd control apparatus and controlled apparatus by the relay apparatus in Embodiment 1 of this invention. It is a block diagram which shows the internal structure of the relay apparatus in Embodiment 2 of this invention. It is a block diagram which shows the internal structure of the relay apparatus in Embodiment 3 of this invention. It is a block diagram which shows the internal structure of the relay apparatus in Embodiment 4 of this invention. It is a block diagram which shows the structure of the control system using the conventional relay apparatus. It is a block diagram which shows the structure of the control system using the conventional relay apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Relay apparatus 11 Processor 12 Controlled serial driver receiver 13 1st communication port 14 Control side serial driver receiver 15 2nd serial communication port 16 Control side network interface controller 17 2nd communication port for LAN 18 Ethernet hub controller 101 Control side Serial buffer 102 Control side LAN buffer 103 Controlled side serial buffer 104 First selector 105 Character data conversion processing 106 Character buffer 107 Second selector 108 Packetization processing 109 Hold timer 20 Controlled device 31 First control device 32 Second control device

Claims (7)

In a relay device comprising a first communication port and a plurality of second communication ports, relaying communication between a device connected via the first communication port and a device connected via the second communication port,
The first communication port is a serial transmission port;
The second communication port includes a serial transmission port and a different protocol port for performing communication processing based on a communication protocol different from serial transmission,
A relay apparatus comprising: means for mutually converting a communication protocol of a signal transmitted / received based on a communication protocol for serial transmission and a signal transmitted / received based on a communication protocol different from serial transmission.   The relay apparatus according to claim 1, wherein there are a plurality of serial transmission ports and / or different protocol ports.   The relay apparatus according to claim 1 or 2, further comprising means for selecting one second communication port for relaying communication with the first communication port.   When another second communication port not selected as one second communication port that relays communication with the first communication port receives a signal from an external device, communication to the signal transmission source is not possible The relay apparatus according to claim 3, further comprising means for transmitting a signal indicating that When another second communication port not selected as one second communication port that relays communication with the first communication port receives a signal from an external device,
Means for storing the received signal;
Means for transmitting a stored signal to a device connected via the first communication port when the second communication port corresponding to the stored signal is selected as one second communication port for relaying communication. The relay apparatus according to claim 3, further comprising:   6. The relay device according to claim 1, wherein the different protocol port performs communication processing based on a communication protocol defined as TCP / IP. A relay device according to any one of claims 1 to 6;
A control device connected to the relay device via a first communication port;
A controlled apparatus controlled by the control apparatus and connected to the relay apparatus via a second communication port.

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