Transmission / reception device and control system

Abstract

Provided is a transmission / reception device capable of more stably performing communication via a network. According to the present embodiment, a transmission / reception device is provided with a connection unit and a determination unit. The connection unit establishes a communication link with a communication partner via a network. The determination unit determines the state of the communication link, and causes the connection unit to change the communication link to another communication link when the state is a predetermined state.

Description

Technical Field

[0001] Embodiments of the present invention relate to a transceiver and a control system. Background Art

[0002] This paper discusses control systems that execute sequence control and process control by PLC (Programmable Logic Controller) in server devices via networks such as the Internet. Control systems in factories and industrial systems operate in real time at a fixed cycle. In order to control the system normally, it is required to transmit input and output data within a certain time even if network delays occur.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1 Patent Publication No. 5959452 Summary of the invention

[0006] Problems to be solved by the invention

[0007] However, the communication bandwidth and communication delay are not guaranteed in networks such as the Internet. Therefore, if communication is performed via the network, it may not be possible to perform the target communication within a fixed period. In addition, even if multiple server devices are used, sudden communication delays may occur, and it may not be possible to perform fixed-period communication. Moreover, even if congestion control and delivery confirmation of TCP (Transmission Control Protocol) are used, it may not be possible to perform fixed-period communication if there is a problem with the communication line itself.

[0008] In order to solve such a problem, an object of the present embodiment is to provide a transceiver and a control system that can perform communication via a network more stably.

[0009] Means for solving problems

[0010] According to this embodiment, the transceiver includes a connection unit and a determination unit. The connection unit establishes a communication link with a communication partner via a network. The determination unit is a determination unit that determines the state of the communication link, and when it is a predetermined state, the determination unit causes the connection unit to change the communication link to another communication link.

[0011] Effects of the Invention

[0012] Communication via the network can be performed more stably. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1It is a diagram showing a configuration example of a control system according to the first embodiment.

[0014] Figure 2 This is a table showing an example of connection information used by the connection management unit.

[0015] Figure 3 This is a diagram showing an example of the structure of an input signal data packet transmitted by the transmission management unit.

[0016] Figure 4 This is a table showing an example of a method for referring to connection information using the sending flag.

[0017] Figure 5 It is a diagram showing a configuration example of a control system according to the second embodiment.

[0018] Figure 6 It is a diagram showing a configuration example of a control system according to a third embodiment. DETAILED DESCRIPTION

[0019] Hereinafter, the transceiver and control system of the embodiment of the present invention will be described in detail with reference to the accompanying drawings. In addition, the embodiment shown below is an example of the embodiment of the present invention, and the present invention is not limited to these embodiments for interpretation. In addition, in the drawings referred to in the present embodiment, the same parts or parts with the same functions are given the same symbols or similar symbols, and their repeated descriptions are sometimes omitted. In addition, for the convenience of explanation, the dimensional ratio of the drawings is sometimes different from the actual ratio, and a part of the structure is sometimes omitted from the drawings.

[0020] (First Embodiment)

[0021] (constitute)

[0022] Figure 1 FIG. 2 is a diagram showing an example of the configuration of a control system according to the first embodiment. Figure 1 As shown, the control system 1 includes a transceiver 10 and a transceiver 20. The transceiver 10 and the transceiver 20 are connected via a network 30. That is, the transceiver 10 is, for example, a server device, and includes a CPU (Central Processing Units), a memory, a storage, etc., and controls devices such as actuators via the network 30 and the transceiver 20. The transceiver 20 is, for example, a communication device, and includes a CPU (Central Processing Units), a memory, a storage, etc.

[0023] The input device 22 inputs an input signal which is data obtained from a sensor or the like which generates state information of a device such as an actuator. The output device 24 is, for example, a device such as an actuator which is a control target of the transceiver 10. That is, the transceiver 10 generates an output signal for control based on the input signal obtained via the transceiver 20 and the network 30. Then, the transceiver 10 outputs the output signal to the output device 24 via the network 30 and the transceiver 20. In addition, the input signal of the present embodiment corresponds to the first signal, and the output signal corresponds to the second signal.

[0024] The network 30 is, for example, the Internet, but is not limited thereto. For example, a local communication line such as a LAN (Local Area Network), a wide area wired communication line such as a WAN (Wide Area Network), or a wireless communication line of a communication standard such as 3G (Generation), 4G, or 5G may be used.

[0025] More specifically, the transceiver 10 includes a control operation unit 11, a connection management unit 12, a transmission unit 13, a reception unit 14, a determination unit 15, and a communication unit 16. The transceiver 10 may be configured by, for example, executing a program stored in a memory to configure the control operation unit 11, the connection management unit 12, the transmission unit 13, the reception unit 14, the communication unit 16, and the determination unit 15.

[0026] The transceiver 20 includes a control operation unit 11, a connection management unit 12, a transmission unit 13, a reception unit 14, a communication unit 16, a signal input unit 21, and a signal output unit 23. That is, the transceiver 20 also includes a signal input unit 21 and a signal output unit 23, and is different from the transceiver 10 in that it does not include the control operation unit 11. The transceiver 20 can be configured by executing a program stored in a memory, for example. In the following description, the connection management unit 12, the transmission unit 13, the reception unit 14, the communication unit 16, and the determination unit 15 of the transceiver 10 are described. On the other hand, regarding the connection management unit 12, the transmission unit 13, the reception unit 14, the communication unit 16, and the determination unit 15 of the transceiver 20, the differences from the transceiver 10 are described.

[0027] In addition, in the present embodiment, the transceiver 20 is described as a client side that requests a connection of TCP (Transmission Control Protocol) or the like, and the transceiver 10 is described as a server side that accepts a connection of TCP or the like, but the present invention is not limited thereto. For example, the transceiver 10 may be a client side that requests a connection of TCP or the like, and the transceiver 20 may be a server side that accepts a connection of TCP or the like.

[0028] The control calculation unit 11 generates an output signal for controlling the output device 2 based on an input signal.

[0029] Figure 2 is a table showing an example of connection information used by the connection management unit 12. Figure 2 As shown, the connection information is a unique number assigned to a device that performs transmission. ID0 to 4 correspond to independent transmission units or independent communication devices. For example, 10 to 14 are assigned as connection information to ID0 to 4, respectively. That is, for example, an independent transmission unit or an independent communication device can correspond to ID0 to 4 of this embodiment, respectively. Thus, the transceiver 20 of this embodiment is one device, but the transceiver 20 can also be subjected to the same communication processing as the communication processing of multiple communication devices or multiple transmission units. In addition, the connection management unit 12 of this embodiment corresponds to the connection unit.

[0030] The transceiver 10 and the transceiver 20 can establish communication using, for example, TCP (Transmission Control Protocol). The connection management unit 12 of the transceiver 10 accepts a connection request from the connection management unit 12 of the transceiver 20 via the network 30. When the connection process is normally performed, the transceiver 10 responds to the transceiver 20 via the network 30. The transceiver 10 also stores connection information for communication assigned from the OS, for example, Figure 2 The connection management unit 12 of the transceiver 20 that has received the connection response from the transceiver 10 holds the connection information for communication assigned from the OS, etc., such as Figure 2 That keeps the Socket's file descriptor.

[0031] Thus, the connection information for mutual communication between the transceiver 10 and the transceiver 20 can be maintained, and communication using the connection information 10 is established between the transceiver 10 and the transceiver 20. In addition, in this embodiment, the communication path established between the transceiver 10 and the transceiver 20 via the network 30 is referred to as a communication link.

[0032] Figure 3This figure shows an example of the structure of an input signal data packet sent by the connection management unit 12 of the transceiver 20. The input signal data packet is composed of a device ID which is an identification number of the communication device, a transmission cycle which indicates the transmission cycle number, a transmission count which indicates how many times the transmission is performed in the same cycle, and input signal data.

[0033] Figure 4 1 is a diagram showing an example of the structure of an output signal data packet sent by the connection management unit 12 of the transceiver 10. The output signal data packet has the same structure as the input signal data packet. That is, the output signal data packet is different in that it contains an output signal, while the input signal data packet contains an input signal. Thus, the output signal data packet is composed of a device ID as an identification number of the communication device, a transmission cycle indicating the transmission cycle number, a transmission count indicating how many times the transmission is performed in the same cycle, and data of the output signal.

[0034] When the connection management unit 12 of the transceiver 10 and the transceiver 20 transmits in the next cycle, the transmission cycle is incremented by 1. In addition, when the connection management unit 12 continuously transmits the same transmission signal in the same cycle, the same value is stored in the transmission cycle, and the number of transmissions may be incremented by 1. In this case, when the connection management unit 12 transmits in the next cycle, the transmission cycle is incremented by 1, and the number of transmissions may be returned to the initial value.

[0035] The transmission unit 13 on the transmission and reception device 10 side transmits the output signal packet (see Figure 4 ) includes the output supplied from the control operation unit 11, and supplies the output signal packet to the communication unit 16. On the other hand, the transmission unit 13 on the transceiver side transmits the input signal packet supplied from the connection management unit 12 (refer to Figure 3 ) includes the input signal supplied from the signal input unit 21, and then supplies the input signal data packet to the communication unit 16.

[0036] The receiving unit 14 on the transceiver 10 side supplies information related to the input signal packet supplied from the communication unit 16 to the control operation unit 11, the connection management unit 12, and the determination unit 15. On the other hand, the receiving unit 14 on the transceiver 20 side supplies the information to the connection management unit 12, the determination unit 15, and the signal output unit 23. In particular, the receiving unit 14 on the transceiver 20 side outputs the output signal included in the output signal packet to the signal output unit 23.

[0037] The determination unit 15 determines the communication state between the transmission and reception device 10 and the transmission and reception device 20 based on the state of the signal received by the reception unit 14. The determination unit 15 will be described in detail later.

[0038] The communication unit 16 of the transceiver 10 communicates with the communication unit 16 of the transceiver 20 via the network interface. Similarly, the communication unit 16 of the transceiver 10 communicates with the communication unit 16 of the transceiver 20 via the network interface.

[0039] In addition, the transceiver 10 can be a physical server or a virtual server or cloud server. The protocol accepted by the connection management unit 12 is not only TCP (Transmission Control Protocol), but also HTTP (Hypertext Transfer Protocol), HTTPS (Hypertext Transfer Protocol Secure), MQTT (Message Queueing Telemetry Transport) and other TCP-based protocols or QUIC, MQTT-SN (MQTT for Sensor Networks) and other UDP-based protocols. In addition, the sending unit 13 and the receiving unit 14 can be assigned to different threads of the OS to operate in parallel. In addition, QUIC is one of the communication protocols (protocols) used on IP networks such as the Internet, and aims to achieve both high speed and security.

[0040] In addition, the output device 24 may be an IO module that transmits an output signal to an actuator or other device. Alternatively, the output device 24 may be a module that transmits an input signal or an output signal to an IO module. Furthermore, the transmission method in the network 30 may be a method via a network, a field bus, or the like, or may be a method via an ASIC, an FPGA, or the like. The above is an explanation of the configuration of the control system 1 of the first embodiment, and the following is an explanation of the function.

[0041] (effect)

[0042] A more specific operation example of the control system 1 of the first embodiment will be described. First, the connection management unit 12 of the transceiver 10 and the connection management unit 12 of the transceiver 20 establish a communication link, for example, using TCP. The connection management units 12 of both parties store, for example, a file descriptor, which is an identifier when communicating through a socket, etc., as connection information (see Figure 3 , 4 ). In addition, the connection management unit 12 may also maintain a group of IP addresses (IP address), MAC addresses (Media Access Control address: Media Access Control address), etc.

[0043] After the connection management unit 12 of the transceiver 10 and the connection management unit 12 of the transceiver 20 establish a communication link, they perform regular communication using, for example, HTTPS (Hypertext Transfer Protocol Secure). For example, in the transceiver 10, the control operation unit 11 sends an output signal as control information to the transmission unit 13 through a transmission cycle of 100ms, and the transmission unit 13 creates an output signal data packet (see Figure 4 ), and transmits the output signal data packet to the transceiver 20 via the communication unit 16. For example, the output signal data packet may also be formed by an HTTP RESPONSE frame. In addition, the serial number of the data may be included in the BODY of the HTTP RESPONSE frame. For example, in the case where the communication line is route 1, the connection information (refer to Figure 2 ) is 10, and the number of transmissions is 1 and fixed, you can set (connection information, transmission cycle, number of transmissions) (refer to Figure 4 ) is assigned to the data header of each output signal data packet with the sending period as the serial number of the data, such as (10,0,1), (10,1,1), (10,2,1), (10,3,1), (10,4,1), (10,5,1), (10,6,1), (10,7,1), (10,8,1), (10,9,1).

[0044] On the other hand, in the transceiver 20, the signal input unit 21 delivers the input signal to the transmitter 13 through the transmission cycle of 50 ms intervals, and the transmitter 13 creates an input signal data packet (refer to Figure 3 ), and transmits the data including the input signal to the transceiver 10 via the communication unit 16. For example, the input signal data packet may also be formed by an HTTP POST frame. In addition, the serial number of the data may be included in the BODY of the HTTP POST frame. For example, in the case where the communication line is route 1, the connection information (refer to Figure 2 ) is 10, and the number of transmissions is 1 and fixed, you can set (connection information, transmission cycle, number of transmissions) (refer to Figure 2 ) information such as (10,0,1), (10,1,1), (10,2,1), (10,3,1), (10,4,1), (10,5,1), (10,6,1), (10,7,1), (10,8,1), (10,9,1) is assigned to the data header of each input signal data packet with the sending period as the serial number of the data.

[0045] The receiving unit 14 of the transceiver 10 receives the input signal data packet transmitted from the transceiver 20 via the communication unit 15. The receiving unit 14 supplies the input signal contained in the received input signal data packet to the control operation unit 11. Then, the control operation unit 11 delivers the output signal as the control operation result of the input signal to the transmitting unit 13, and the transmitting unit 13 creates an output signal data packet (see Figure 4 ) and sends the data containing the output signal to the transceiver 20 via the communication unit 16.

[0046] In this way, the transceiver 10 periodically sends the output signal data packet to the transceiver 20, and the transceiver 20 periodically sends the input signal data packet to the transceiver 10. Therefore, if there is no problem with the network 30, the communication unit 16, etc., the transceiver 10 periodically receives the input signal data packet, and the transceiver 20 periodically receives the output signal data packet. However, if there is a certain failure in the network 30 or the communication unit 16, even if the transceiver 10 and the transceiver 20 periodically send signal data packets, the transceiver 20 and the transceiver 10 cannot periodically receive the signal data packets. Hereinafter, the judgment method 1 to 3 of the judgment unit 15 on the state of at least one of the network 30 and the communication unit 16 will be described.

[0047] (Judgment method 1)

[0048] The determination unit 15 of the transceiver 10 receives the reception history from the receiving unit 14. The reception history includes, for example, the history of the reception time of the input signal data packet. The determination unit 15 of the transceiver 10 counts the number of occurrences of the event that the interval between the reception times of two consecutive input signal data packets exceeds a predetermined time. For example, since the input signal data packets are transmitted at an interval of 50 ms, the determination unit 15 of the transceiver 10 counts the number of times the reception interval exceeds 100 ms, using 100 ms, which is a multiple of the transmission interval, as a threshold. Then, when the number of times the reception interval exceeds 100 ms exceeds 10 times within 1 minute, the determination unit 15 of the transceiver 10 determines that an abnormality exists in at least one of the network 30 and the communication unit 16. In addition, when the occurrence ratio of the event that the reception interval exceeds 100 ms within 1 minute exceeds 10%, the determination unit 15 of the transceiver 10 determines that an abnormality exists in at least one of the network 30 and the communication unit 16.

[0049] (Judgment method 2)

[0050] In addition, to the determination unit 15 of the transceiver 10, the transmission unit 13 transmits an output signal data packet, for example, the response data having the header information of the output signal data packet is transmitted from the transceiver 20. The reception history received from the receiving unit 14 includes the header information of the response data and the history of the reception time. Thus, the determination unit 15 can determine the state of at least one of the network 30 and the communication unit 16 based on the time difference between the timing of transmitting the output signal data packet and the timing of receiving the response data of the output signal data packet. For example, when the threshold of the response time is set to 500ms, and the number of times the time difference exceeds the threshold of 500ms exceeds 10 times within 1 minute, the determination unit 15 determines that there is an abnormality in at least one of the network 30 and the communication unit 16.

[0051] (Judgment method 3)

[0052] Furthermore, the determination unit 15 of the transceiver 10 uses the serial number of the data included in the input signal packet to determine the status of the network 30 and the communication unit 16. More specifically, the determination unit 15 of the transceiver 10 uses (connection information, transmission cycle, number of transmissions) (see Figure 3 ) and judges the status of the network 30 and the communication unit 16 by the number of signal packets that have not been received. For example, if the number of data leaks exceeds 10 within 1 minute, the judgment unit 15 judges it as abnormal. In addition, for example, if the data loss rate exceeds 10% within 1 minute, the judgment unit 15 judges it as abnormal. In addition, the communication history can also be composed of driver information of the device used in the communication of the communication unit 16.

[0053] In addition, the threshold used in the judgment unit 15 can also be determined by, for example, an abnormal judgment learning unit that performs machine learning. In addition, the judgment unit 15 can also judge the state of the network 30 based on information obtained via the network 30. For example, the information judged as abnormal by the judgment unit 15 can also be information obtained from the outside of the transceiver 10 via the network 30. For example, the judgment unit 15 can judge that it is abnormal based on information sent from the official RSS source (feed) of the cloud service used, the mail service, and the SNS. Moreover, the judgment unit 15 can also obtain information from an informal SNS to judge that it is abnormal.

[0054] Next, when the determination unit 15 determines that there is an abnormality, the determination unit 15 instructs the connection management unit 12 to reconnect. As a result, the connection path of the network 30 may be changed, and the network environment may be improved. On the other hand, the transmission queue stored in the memory of the transceiver 10, 20 may be reset, and the network environment may be improved.

[0055] In addition, the judgment unit 15 may also notify the occurrence of the abnormality and its cause to a pre-specified email address when it is judged to be abnormal. In addition, the judgment unit 15 may also pop up a message box to notify the occurrence of the abnormality and its cause to a control screen not shown in the figure. Moreover, the judgment unit 15 may also control the external LED lighting to light it when it is judged to be abnormal. In addition, the judgment unit 15 may also control the control operation unit 11 in a manner of generating an output signal of a fail safe control when it is judged to be abnormal.

[0056] The operation of the determination unit 15 of the transceiver 10 has been described, and the determination unit 15 of the transceiver 20 can also perform the same determination operation. That is, the determination unit 15 of the transceiver 20 makes a determination based on the reception history received from the receiving unit 14, according to the number of occurrences of the event that the reception time interval of the output signal data packet exceeds the prescribed time. In addition, the determination unit 15 of the transceiver 20 can determine the state of at least one of the network 30 and the communication unit 16 based on the time difference between the timing of sending the input signal data packet and the timing of receiving the response data of the input signal data packet. In addition, the determination unit 15 of the transceiver 20 can determine the state of the network 30 and the communication unit 16 using the serial number of the data included in the output signal data packet.

[0057] (Effect)

[0058] As described above, the judgment unit 15 judges whether an abnormality has occurred based on the communication state, and instructs the connection management unit 12 to reconnect when it is judged to be abnormal. Thus, even if the communication state deteriorates due to a sudden communication delay, the connection path of the network 30 will change, so that fixed-cycle control can be achieved without delay or loss of control data. In addition, when the judgment unit 15 judges to be abnormal, it notifies the abnormality. Thus, the operator can understand the delay in data transmission and the occurrence of defects.

[0059] (Second Embodiment)

[0060] Unlike the transceiver 10 and the transceiver 20 in the control system 1 of the first embodiment, which each has a single transmitter 13, the transceiver 10 and the transceiver 20 in the control system 2 of the second embodiment each have a plurality of transmitters 13. The differences from the control system 1 of the first embodiment will be described below.

[0061] (constitute)

[0062] Figure 4 1 is a diagram showing a configuration example of a control system 2 according to the second embodiment. The receiving device 10 and the transmitting and receiving device 20 each include two transmitting units 13 .

[0063] (Function 1)

[0064] The connection management unit 12 of the transceiver 10 and the connection management unit 12 of the transceiver 20 establish a communication link with each of the two transmission units 13 of the transceiver 10. For example, the connection information 11 (see Figure 2 ), the connection information 12 is assigned to the other of the two sending units 13 (refer to Figure 2 ).

[0065] The connection management unit 12 of the transceiver 10 allocates the connection information 11 (see Figure 2 ) is used for normal communication. On the other hand, the connection information 12 (refer to Figure 2 )’s communication link is used as a standby communication link.

[0066] When the determination unit 15 of the transmission / reception device 10 determines that the normal communication link is abnormal, the determination unit 15 causes the connection management unit 12 to switch to the standby communication link.

[0067] (Function 2)

[0068] The connection management unit 12 of the transceiver 10 allocates the connection information 11 (see Figure 2 ) of the communication link and the connection information 12 (reference Figure 2 ) communication link is used for normal communication. Thus, the two sending units 13 of the transceiver 10 are used simultaneously to send the output signal data packet containing the same output signal to the transceiver 20.

[0069] The receiving unit 14 of the transceiver 20 checks the output signals in the output signal packets transmitted from the plurality of transmitting units 13 , adopts the output signals only when they are identical, and outputs the output signals to the signal output unit 23 .

[0070] Furthermore, when the output signals of the transceiver 10 are different, the determination unit 15 of the transceiver 20 notifies the transceiver 10 via the transmitter 13 that the two transmitters 13 of the transceiver 10 are not operating normally. In addition, the method of using the two transmitters 13 of the transceiver 10 has been described, but the two transmitters 13 of the transceiver 20 can also be used in the same manner.

[0071] (Effect)

[0072] As described above, the connection management unit 12 of the transceiver 10 and the connection management unit 12 of the transceiver 20 establish a communication link with each of the two transmission units 13 of the transceiver 10, and use one of them for normal communication and put the other on standby. Thus, when the judgment unit 15 judges that there is an abnormality in the normal communication path, the connection management unit 12 can change the normal communication path to the standby communication path. Therefore, even if a sudden communication delay occurs, it is possible to achieve fixed cycle control without delay or loss of control data.

[0073] In addition, the connection management unit 12 of the transceiver device 10 establishes a communication link with each of the two transmission units 13, and uses both for common communication, checks the output signals contained in the output signal data packets of both, and adopts the output signal only when they are the same, and outputs the output signal to the signal output unit 23. In this way, the accuracy of the output signal can be further improved, and control can be performed in consideration of the functional safety of the output device 24. In addition, the detection of failure of the two transmission units 13 can be performed.

[0074] (Third Embodiment)

[0075] Unlike the transceiver 10 and the transceiver 20 in the control system 1 of the first embodiment, which each has a single transmitter 13, the transceiver 10 and the transceiver 20 in the control system 2 of the second embodiment each has three transmitters 13. The differences from the control system 1 of the first embodiment will be described below.

[0076] (constitute)

[0077] Figure 5 1 is a diagram showing a configuration example of a control system 2 according to a third embodiment. The receiving device 10 and the transceiver 20 each have three transmitters 13. In addition, in this embodiment, an example having three transmitters 13 is described, but the present invention is not limited thereto. For example, the number of transmitters 13 may be four or more.

[0078] (Function 1)

[0079] The connection management unit 12 of the transceiver 10 and the connection management unit 12 of the transceiver 20 establish a communication link with each of the three transmission units 13 of the transceiver 10. For example, the connection information 11, 12, 13 (see Figure 2 )

[0080] The connection management unit 12 of the transceiver 10 allocates the connection information 11 (see Figure 2 ) is used for normal communication. On the other hand, the connection information 12 and 13 (refer to Figure 2)’s communication link is used as a standby communication link.

[0081] When the determination unit 15 of the transmission / reception device 10 determines that the normal communication link is abnormal, the determination unit 15 causes the connection management unit 12 to switch to one of the communication links of the standby type.

[0082] (Function 2)

[0083] The connection management unit 12 of the transceiver 10 allocates the connection information 11 (see Figure 2 ) of the communication link and the connection information 12 (reference Figure 2 ) are used for normal communication. Thus, the two sending units 13 of the transceiver 10 are used simultaneously to send the output signal data packet containing the same output signal to the transceiver 20. On the other hand, the connection information 13 (refer to Figure 2 )’s communication link is used as a standby communication link.

[0084] The receiving unit 14 of the transceiver 20 checks the output signals in the output signal packets transmitted from the plurality of transmitting units 13 , adopts the output signals only when they are identical, and outputs the output signals to the signal output unit 23 .

[0085] Furthermore, when the output signals of the transceiver 20 are different, the determination unit 15 of the transceiver 20 notifies the transceiver 10 via the transmitter 13 that the two transmitters 13 of the transceiver 10 are not operating normally.

[0086] Furthermore, when the determination unit 15 of the transmission / reception device 10 determines that the communication link that is normally used is abnormal, the determination unit 15 causes the connection management unit 12 to switch to the communication link of the standby type.

[0087] (Function 3)

[0088] The connection management unit 12 of the transceiver 10 allocates the connection information 11, 12, 13 (see Figure 2 ) is used for common communication. Thus, the three sending units 13 of the transceiver 10 are used simultaneously to send output signal data packets containing the same output signal to the transceiver 20.

[0089] The receiving unit 14 of the transceiver 20 compares the output signals in the output signal packets transmitted from the three transmitting units 13 , and adopts the output signal only when two or more output signals are the same, and outputs the output signal to the signal output unit 23 .

[0090] Furthermore, when the three output signals of the transceiver 10 are different, the determination unit 15 of the transceiver 20 notifies the transceiver 10 via the transmitter 13 of the transmitter 13 of the identifier for identifying the transmitter 13 that has transmitted the different output signals, together with the fact that the transmitter 13 is not operating normally. In addition, the method of using the two transmitters 13 of the transceiver 10 has been described, but the two transmitters 13 of the transceiver 20 can also be used in the same manner.

[0091] (Effect)

[0092] As described above, the connection management unit 12 of the transceiver 10 and the connection management unit 12 of the transceiver 20 establish a communication link with each of the three transmission units 13 of the transceiver 10, use one transmission unit for normal communication, and put the remaining two transmission units on standby. Thus, when the judgment unit 15 judges that there is an abnormality in the normal communication path, the connection management unit 12 can change the normal communication path to one of the communication paths on standby. Therefore, even if a sudden communication delay occurs, fixed-cycle control can be achieved without delay or loss of control data.

[0093] In addition, the connection management unit 12 of the transceiver 10 establishes a communication link with each of the three transmission units 13, and uses two communication links for common communication, checks the output signals contained in the two signal data packets, and adopts the output signal only when the two output signals are the same, and outputs the output signal to the signal output unit 23. In this way, the accuracy of the output signal can be further improved, and control considering the functional safety of the output device 24 can be performed. In addition, when the judgment unit 15 judges that there is an abnormality on one side of the common communication path, the connection management unit 12 can change the common communication path to a communication path in standby. Therefore, even if a sudden communication delay occurs, fixed-cycle control can be achieved without delay or loss of control data.

[0094] In addition, the connection management unit 12 of the transceiver device 10 establishes a communication link with each of the three transmission units 13, and uses the three communication links for common communication, checks the output signals included in the three signal data packets, and adopts the output signal only when two or more output signals are the same, and outputs the output signal to the signal output unit 23. In this way, the accuracy of the output signal can be further improved, and control can be performed in consideration of the functional safety of the output device 24.

[0095] Furthermore, when the three output signals of the transceiver 10 are different, the determination unit 15 of the transceiver 20 notifies the transceiver 10 via the transmitter 13 of the identifier for identifying the transmitter 13 that has transmitted the different output signals, together with the fact that the transmitter 13 is not operating normally. In this way, it is possible to detect the presence of an abnormal communication link.

[0096] Several embodiments have been described above, but these embodiments are disclosed only as examples and are not intended to limit the scope of the invention. The novel devices, methods, and programs described in this specification may be implemented in various other ways. In addition, various omissions, substitutions, and changes may be made to the devices, methods, and programs described in this specification without departing from the scope of the invention.

Claims

1. A transceiver device, comprising: a connection unit that establishes a communication link with a communication partner via a network; and The determination unit determines the state of the communication link, and causes the connection unit to change the communication link to another communication link when the state is a predetermined state.

2. The transceiver according to claim 1, wherein: In the case of the predetermined state, the connection unit establishes a new communication link via the network as the other communication link.

3. The transceiver according to claim 1, wherein: The connection unit establishes two or more different communication links via the network in advance, and uses at least one of the two or more different communication links for normal transmission and reception. When the communication link used for normal transmission and reception is in a predetermined state, the connection unit can use one of the other communication links among the two or more different communication links for normal transmission and reception.

4. The transceiver according to claim 3, further comprising: The plurality of transmission units correspond to the two or more different communication links, respectively, and can transmit signals via the corresponding communication links.

5. The transceiver according to claim 4, wherein: At least one of the plurality of transmitting units is used as a normal type transmitting unit for the normal transmission and reception, and at least one of the plurality of transmitting units is used as a standby type transmitting unit not used for the normal transmission and reception.

6. The transceiver according to claim 4, wherein: The plurality of transmission units transmit signals including at least the same data via corresponding communication links.

7. The transceiver according to claim 3, wherein: The determination unit checks signals including at least the same data respectively received via the two or more different communication links, and adopts the signal when the data are consistent.

8. The transceiver according to claim 4, wherein: The determination unit checks signals including at least the same data received through three different communication links, and when two or more of the data match, uses the signal to determine that an abnormality exists in the sending unit that sent the different data.

9. The transceiver according to claim 7, wherein: The determination unit determines that the predetermined state is the state when the number of events in which the data do not match exceeds a predetermined number.

10. The transceiver according to any one of claims 1 to 8, wherein: The determination unit determines that the predetermined state is a case where an interval between receptions of signals received via the same communication link exceeds a threshold value more than a predetermined number of times.

11. The transceiver according to any one of claims 1 to 8, wherein: The determination unit determines that the predetermined state is in the above-mentioned condition when the number of unreceived signals among the signals to which serial numbers are assigned and which are received via the same communication link exceeds a predetermined number of times.

12. The transceiver according to any one of claims 1 to 8, wherein: The determination unit determines that the predetermined state is the state in which the response time exceeds a threshold value more than a predetermined number of times, wherein the response time is a difference between a transmission timing of a transmitted transmission signal and a reception timing of a response signal received to the transmission signal.

13. The transceiver according to any one of claims 1 to 8, further comprising: The control operation unit generates a second signal for control based on the first signal received via the communication link.

14. The transceiver according to claim 13, wherein: The determination unit further determines the state based on information obtained via a network.

15. The transceiver according to claim 13, wherein: In the above-mentioned state, the above-mentioned determination unit performs at least one of the following actions: notifying a pre-specified email address of the abnormal situation, causing the display unit to pop up a message box, lighting the lighting, and causing the above-mentioned control operation unit to generate a second signal as a failsafe.

16. The transceiver according to any one of claims 1 to 8, wherein: The second signal for control received via the communication link is output to the output device.

17. A control system comprising a server device and a communication device, wherein: The server device has: A connection unit that establishes a communication link with a communication partner via a network; a determination unit that determines a state of the communication link and, when the state is a predetermined state, causes the connection unit to change the communication link to another communication link; as well as The control operation unit generates a second signal for control based on the first signal received via the communication link. The communication device is configured to: Sending the first signal obtained from the input device to the first transceiver via the communication link; The second signal received via the communication link is output to an output device.

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