TW201703467A - Slave apparatus, and communication method and communication program - Google Patents

Abstract

A slave apparatus (100) determines, in the case where transmission of a high priority frame to a master apparatus (10) conflicts with transmission of a low priority frame to the master apparatus (10), to transmit the high priority frame in a forward direction. In addition, the slave apparatus (100) determines whether to transmit the low priority frame in the forward direction after completion of the forward-direction transmission of the high priority frame, or in a backward direction opposite to the forward direction before completion of the transmission of the high priority frame, and transmits the low priority frame in the determined direction.

Description

Slave device and communication method and communication program product

The present invention relates to the transmission control of a communication frame in a ring network.

In the FA (Factory Automation) system, there are many examples in which a master device and a plurality of slave devices constitute a control system.

In such a control system, in general, the master device transmits a communication frame containing instructions to the slave device according to each slave device, and each slave device transmits a communication frame containing a response to the command to the slave device. Master device.

In this way, the communication frame for transmitting the packet 1 command and the communication frame containing the response between the master device and the slave device are referred to as control communication.

In addition, the time that the control communication bypasses the device from the device is called the communication cycle.

In the control system, the communication cycle must be set in advance, and the control communication of all slave devices is completed within this communication cycle.

In addition, as a network installed in the FA system, there is a field network for I/O (Input/Output) control field control, and more detailed control is required. Dynamic network for motion control.

In dynamic networks, most of them set a shorter communication period than the field network.

Although the field network and the dynamic network actually have other lines, the situation is that the field network and the dynamic network are formed on the same line for the purpose of saving wiring.

The communication carried out on the field network is called field communication.

In addition, the communication that takes place on a dynamic network is called dynamic communication.

When the field network and the dynamic network are formed on the same line, in most cases, the master device and the plurality of slave devices are connected by a line type network or a ring type network.

Therefore, there will be situations where the communication frame is cooperating from the communication port of the device.

When the communication frame of the dynamic communication (hereinafter referred to as the dynamic communication frame) competes with the communication frame of the field network (hereinafter referred to as the field communication frame), there is a situation in which a dynamic communication delay of a shorter communication cycle is set.

In the case of dynamic communication delay, the communication cycle of dynamic communication cannot be satisfied.

As a method for solving the delay of dynamic communication caused by the competition of the communication frame, it is conceivable to set the priority order in the communication frame first, and to preferentially transmit the high priority sequence frame in which the high priority order is set.

In other words, the dynamic communication frame can be preferentially transmitted by classifying the dynamic communication frame into a high priority sequence frame and classifying the field communication frame into a low priority frame.

Thereby, even for dynamic communication with a short communication cycle, dynamic communication can be completed in the communication cycle.

In Patent Document 1, a dynamic communication frame has been disclosed When the field communication frame is engaged, the transmission of the field communication frame is interrupted, and after the transmission of the dynamic communication frame is completed, the manner of transmitting the field communication frame is repeated.

Further, in Patent Document 2, it is disclosed that a standby time of a bus master which is required to perform realtim processing is shared with a bus master other than the bus master. The predetermined time of the row, and preferentially assigning the usage rights of the shared bus to the bus master that needs to be processed in real time.

[Previous Technical Literature] [Patent Literature]

Patent Document 1: International Publication WO2013/111285

Patent Document 2: Japanese Laid-Open Patent Publication No. 2005-309649

As described above, in the method of Patent Document 1, when the dynamic communication frame and the field communication frame collaborate, the transmission of the field communication frame is interrupted, and after the transmission of the dynamic communication frame is completed, the field communication is transmitted again. Frame.

Therefore, the method of Patent Document 1 is inferior in communication efficiency of the field communication frame.

Further, when the method of Patent Document 2 is applied to a network in which dynamic communication and field communication are mixed, it is presumed that the following control is performed.

From the communication cycle of the device from the dynamic communication, set the time (delay allowable time) that can delay the dynamic communication.

When the field communication frame competes with the dynamic communication frame, the device determines whether the transmission of the field communication frame is completed within the delay allowed time.

When the transmission of the field communication frame is completed within the delay allowable time, the slave device first completes the transmission of the field communication frame, and the transmission of the dynamic communication frame is performed after the transmission of the field communication frame is completed.

However, in the environment in which the dynamic communication frame is transmitted at a high frequency, even if the above control by the method of Patent Document 2 is applied, the dynamic communication frame occupies the communication band, and thus the field cannot be completed within the delay allowable time. The transmission of the communication frame.

Therefore, the interruption of the transmission of the field communication frame and the retransmission of the field communication frame after the transmission of the dynamic communication frame occur frequently, and the field communication frame cannot be transmitted efficiently.

As described above, in the methods of Patent Document 1 and Patent Document 2, there is a problem that the field communication frame belonging to the low priority frame cannot be efficiently transmitted.

The present invention has the main object of solving such a problem, and the priority is to preferentially perform high-priority frame transmission, and to efficiently transmit low-priority frame.

The slave device of the present invention is included in a ring network including a master device and a plurality of slave devices, and configured with forward and reverse directions as a direction for transmitting a communication frame from the plurality of slave devices to the master device, The slave device has: a first communication port that transmits the communication frame toward the forward direction; a second communication port that transmits the communication frame in the reverse direction; and a transmission mediation unit that performs the foregoing master device The transmission of the high priority sequence frame of the high priority order communication frame belongs to the foregoing master device When the low-priority frame of the low-priority frame is transmitted, the high-priority sequence frame is transmitted from the first communication port, and the first communication is determined by the first priority in the high-priority frame. After the transmission of the port is completed, the forward transmission of the low priority frame is transmitted from the first communication port, and the low transmission is performed from the second communication port before the transmission of the high priority frame from the first communication port is completed. Which of the reverse transmissions of the priority frame is transmitted to transmit the aforementioned low priority frame.

In the present invention, the low priority sequence frame can be transmitted by reverse transmission when the transmission of the high priority frame and the transmission of the low priority frame are coincident.

Therefore, according to the present invention, the transmission path of the low priority frame can be flexibly selected according to the transmission status of the high priority frame, and the high priority frame can be preferentially transmitted while the low priority is efficiently performed. The transmission of the frame.

10‧‧‧Master equipment

100‧‧‧ slave equipment

101‧‧‧Internet interface

102‧‧‧Network port

103‧‧‧Network port

104‧‧‧Network interface

105‧‧‧buffer

106‧‧‧Transportation Department

107‧‧‧Timekeeping Department

108‧‧‧Network constitutes the Information Management Department

109‧‧‧Communication Frame Generation Department

901‧‧‧ processor

902‧‧‧Auxiliary memory device

903‧‧‧ memory

904‧‧‧Internet interface

905‧‧‧Input interface

906‧‧‧Display interface

907‧‧‧ Input device

908‧‧‧ display

910‧‧‧ signal line

911, 912‧‧‧ cable

9041‧‧‧ Receiver

9042‧‧‧transmitter

1000‧‧‧ ring network

T_c, t_d, t_s‧‧‧ time

T_H, T_L‧‧ cycle

T_r‧‧‧ remaining time

Fig. 1 is a view showing a network configuration example and a forward direction of the first embodiment.

Fig. 2 is a view showing a network configuration example and a reverse diagram of the first embodiment.

Fig. 3 is a view showing an outline of the operation of the slave device of the first embodiment.

Fig. 4 is a view showing an example of the functional configuration of the slave device of the first embodiment.

Fig. 5 is a flow chart showing an example of the operation of the transfer mediation unit of the first embodiment.

Fig. 6 is a flow chart showing an example of the operation of the transfer mediation unit of the first embodiment. Figure.

Fig. 7 is a flow chart showing an operation example of the transfer mediation unit of the first embodiment.

Fig. 8 is a view showing a network configuration example and a forward direction of the first embodiment.

Fig. 9 is a view showing an example of the hardware configuration of the slave device of the first embodiment.

Embodiment 1

***Composed description***

Fig. 1 is a diagram showing an example of a network configuration of this embodiment.

In the present embodiment, a ring network 1000 including one master device 10 and a plurality of slave devices 100 will be described.

The master device 10 and each slave device 100 have two communication ports.

In FIG. 1, although the illustration of the slave device 100 between the slave device (S_H_1) 100 and the slave device (S_H_n) 100 is omitted, between the slave device (S_H_1) 100 and the slave device (S_H_n) 100, There are slave devices (S_H_2) 100 to slave devices (S_H_n-1) 100.

Further, although the illustration of the slave device 100 between the slave device (S_L_1) 100 and the slave device (S_L_m) 100 is omitted, there is a slave device between the slave device (S_L_1) 100 and the slave device (S_L_m) 100. Device (S_L_2) 100 to slave device (S_L_m-1) 100.

In the present embodiment, the main device 10 also transmits a communication frame including the command to the plurality of slave devices 100.

The communication frame from the master device 10 is the master device 10, the slave device (S_H_1) 100 ̇ ̇ ̇ the slave device (S_H_n) 100, and the slave device (S_L_1) 100 ̇ ̇ 转 Transfer from the order of the device (S_L_m) 100.

Each slave device 100 transmits a communication frame containing a response to an instruction from the master device 10.

In the ring network 1000 of the present embodiment, forward and reverse directions are set as directions for transmitting the communication frame from the slave device 100 to the master device 10.

The so-called forward direction, as indicated by the arrow symbol in Fig. 1, is a slave device (S_L_m) 100 ̇ ̇ ̇ slave device (S_L_1) 100, slave device (S_H_n) 100, ̇ ̇ ̇ slave device (S_H_1) 100, master device The order of the transfer direction.

In other words, the forward direction is opposite to the direction in which the communication frame from the host device 10 is forwarded.

On the other hand, the reverse direction, as indicated by the arrow symbol in Fig. 2, is a slave device (S_H_1) 100 ̇ ̇ ̇ slave device (S_H_n) 100, slave device (S_L_1) 100 ̇ ̇ ̇ slave device (S_L_m) 100 The forwarding direction of the main device 10 in the order.

In the present embodiment, each slave device 100 transmits the communication frame to the master device 10 in the forward direction.

Further, in the ring network 1000 of the present embodiment, a dynamic network and a field network are mixed.

In this embodiment, the communication frame for dynamic communication is also referred to as a dynamic communication frame, and the communication frame for field communication is also referred to as a field communication frame.

In addition, in this embodiment, the dynamic communication frame is also processed as a high priority sequence frame, and the field communication frame is treated as a low priority frame.

In Fig. 1, the slave device (S_H_1) 100 ̇ ̇ ̇ slave device (S_H_n) 100 belongs to the dynamic network.

In addition, the slave device (S_L_1) 100 ̇ ̇ ̇ slave device (S_L_m) 100 belongs to the field network.

The slave device (S_H_1) 100 ̇ ̇ ̇ slave device (S_H_n) 100 transmits the dynamic communication frame to the master device 10.

The slave device (S_L_1) 100 ̇ ̇ ̇ slave device (S_L_m) 100 transmits the field communication frame to the master device 10.

The slave device (S_L_1) 100 ̇ ̇ 场 The field frame transmitted from the slave device (S_L_m) 100 is transferred from the slave device (S_H_1) 100 ̇ ̇ ̇ slave device (S_H_n) 100 to the master device 10.

Therefore, in the slave device (S_H_1) 100 ̇ ̇ ̇ slave device (S_H_n) 100, ̇ ̇ ̇ generates a match between the transmission of the dynamic communication frame and the transmission of the field communication frame.

The so-called co-opetition means that the transmission requirements of the dynamic communication frame and the transmission requirements of the field communication frame are repeatedly generated.

Fig. 3 is a view showing an outline of the operation of the slave device 100 when the transmission of the dynamic communication frame and the transmission of the field communication frame are coincident.

In addition, in FIG. 3, the dynamic communication frame is represented as a high priority sequence frame, and the field communication frame is represented as a low priority sequence frame.

It is assumed that during the low priority priority frame 1 transmitted from the device (S_H_1) 100 to the master device 10, the situation of the high priority sequence frame 1 sent to the master device 10 needs to be transmitted.

The slave device (S_H_1) 100 determines whether the transmission of the low priority sequence frame 1 is completed within the delay allowable time of the high priority sequence frame 1.

The delay allowable time is to delay the transmission of the high priority sequence 1 Limited time.

When the transmission of the low priority sequence frame 1 is completed within the delay allowable time, the slave device (S_H_1) 100 continues the transmission of the low priority sequence frame 1 and transmits the high priority order after the transmission of the low priority sequence frame 1 is completed. Frame 1.

On the other hand, when the low priority frame 1 is not completed within the delay allowable time, the slave device (S_H_1) 100 suspends the transmission of the low priority frame 1 (Fig. 3(a)), and starts the high priority. The transmission of the frame 1 is followed.

In addition, in (a) of FIG. 3, it is shown that the transmission of the low priority sequence frame 1 is suspended in the stage in which one of the low priority order frames 1 is transmitted.

Half of the low priority order frame 1 transmitted until the transmission is suspended is indicated as the low priority order frame 1 (1/2).

In the master device 10, the low priority frame 1 (1/2) received from the slave device (S_H_1) 100 is not discarded and held.

Next, the slave device (S_H_1) 100 determines which of the forward transmission and the reverse transmission is to transmit the remaining half of the low priority sequence frame 1.

The remaining half of the low priority frame 1 is indicated as the low priority frame 1 (2/2).

The forward transmission is a transmission mode in which the low priority sequence 1 (2/2) is transmitted from the forward communication port after the transmission from the high priority priority frame 1 of the forward communication port is completed.

The reverse transmission is a transmission mode in which the low priority sequence 1 (2/2) is transmitted from the reverse communication port before the transmission of the high priority frame from the forward communication port is completed.

The slave device (S_H_1) 100 determines which one of the forward transmission and the reverse transmission is to transmit the low priority sequence frame 1 (2/2) in the following order.

The slave device (S_H_1) 100 determines that the low priority sequence frame 1 (2/2) when the low priority frame 1 (2/2) is transmitted by the forward transmission mode and the low transmission mode by the reverse transmission mode Which of the low priority sequence frames 1 (2/2) of the priority frame 1 (2/2) arrives at the master device 10 faster.

Furthermore, when the low priority order frame 1 (2/2) is transmitted by the reverse transmission mode, the low priority order frame 1 (2/2) arrives at the master device 10 relatively quickly, and the slave device (S_H_1) 100 is connected. The low priority sequence frame 1 (2/2) is transmitted by reverse transmission.

On the other hand, when the low priority order frame 1 (2/2) is transmitted by the reverse transmission mode, the low priority order frame 1 (2/2) arrives at the master device 10 faster, or whether it is the forward direction. Transmission or reverse transmission, when the low priority order frame 1 (2/2) arrives at the same time as the master device 10, the slave device (S_H_1) 100 transmits the low priority sequence frame 1 by forward transmission mode (2/). 2).

In Fig. 3, the slave device (S_H_1) 100 transmits the low priority sequence frame 1 (2/2) by reverse transmission (Fig. 3(b)).

In the reverse transmission, the low priority frame 1 (2/2) is the slave device (S_H_2) 100 ̇ ̇ ̇ slave device (S_H_n) 100, slave device (S_L_1) 100 ̇ ̇ ̇ slave device (S_L_m) 100 Transfer to the master device 10.

In the master device 10, the low priority priority frame 1 (1/2) held and the low priority sequence frame 1 (2/2) received from the slave device (S_L_m) 100 are restored to restore the original low. Priority order frame 1.

In addition, it is assumed that a high priority is transmitted on the slave device (S_H_1) 100. During the bit frame 1, the situation of the low priority frame 2 sent to the master device 10 is received.

At this time, the slave device (S_H_1) 100 continues the high priority sequence frame 1 to transmit from the forward communication port.

Further, the slave device (S_H_1) 100 determines which one of the forward transmission and the reverse transmission is to transmit the low priority sequence frame 2.

At this time, the slave device (S_H_1) 100 also determines that the low priority frame 2 when the low priority frame 2 is transmitted by the forward transmission mode and the low priority frame 2 when the low priority frame 2 is transmitted by the reverse transmission mode Which of the lower priority order frames 2 arrives at the master device 10 faster.

Furthermore, when the low priority frame 2 is transmitted to the master device 10 by the reverse transmission mode, the slave device (S_H_1) 100 transmits the low priority frame by the reverse transmission mode. 2.

On the other hand, when the low priority sequence frame 2 is transmitted by the reverse transmission mode, the low priority sequence frame 2 arrives at the master device 10 faster, or whether it is forward transmission or reverse transmission, low priority order message In the case where the block 2 arrives at the same master device 10, the slave device (S_H_1) 100 transmits the low priority frame 2 by the forward transfer mode.

In Fig. 3, the slave device (S_H_1) 100 transmits the low priority sequence frame 2 by reverse transmission (Fig. 3(c)).

The low priority frame 2 is transferred to the master device 10 by the slave device (S_H_2) 100 ̇ ̇ slave device (S_H_n) 100 and the slave device (S_L_1) 100 ̇ ̇ slave device (S_L_m) 100.

In the slave device (S_H_n) 100, the same action is also performed (the 3 (d), (e)).

By the above means, the high priority sequence frame can be reached to the master device 10 before the completion of the period T_H (dynamic communication communication period) of the high priority order communication (Fig. 3(f)).

Furthermore, the low priority sequence frame can be reached to the master device 10 (Fig. 3(g)) before the completion of the period T_L of the low priority order communication (the communication period of the field communication).

Next, an example of the functional configuration of the slave device 100 will be described with reference to FIG.

In Fig. 4, the network interface 101 transmits and receives communication frames to and from the line on the main device 10 side (the forward line) through the network port 102.

Similarly, the network interface 104 transmits and receives the communication frame through the network port 103 to the line (reverse line) on the opposite side of the host device 10.

The network interface 101 transmits the communication frame received at the network port 103 from the network port 102 to the forward line.

Further, the network interface 101 transmits a communication frame generated by the communication frame generating unit 109, which will be described later, from the network port 102 to the forward line.

In addition, the network interface 104 transmits the communication frame received at the network port 102 from the network port 103 to the reverse line when performing reverse transmission.

In addition, the network interface 104 transmits the communication frame generated by the communication frame generating unit 109 from the network port 103 to the reverse line when performing reverse transmission.

The network port 102 is connected to the forward line for transmitting the communication frame in the forward direction.

The network port 102 is equivalent to the first communication port.

The network port 103 is connected to the reverse line for transmitting the communication frame in the reverse direction.

The network port 103 is equivalent to the second communication port.

The communication frame generating unit 109 generates a communication frame to be transmitted to the host device 10.

The communication frame generating unit 109 is configured to generate a dynamic communication frame as long as the slave device 100 is a slave device for performing dynamic communication.

The communication frame generating unit 109 is configured to generate a field communication frame as long as the slave device 100 is a slave device for performing field communication.

The network configuration information management unit 108 manages network composition information pertaining to information on the network configuration of the ring network.

In the network configuration information, for example, it is included in the number of nodes that are disposed between the slave device 100 and the master device 10 in the forward direction, and is interposed between the slave device 100 and the master device 10 in the reverse direction. Information on the number of nodes.

The timer unit 107 supplies timer information to the transfer mediation unit 106. The details of the timer information will be stated later.

The transfer mediation unit 106 performs mediation between the communication frame sent to the host device 10 generated by the communication frame generating unit 109 and the communication frame transmitted from the network port 103 to the host device 10.

In other words, the delivery mediation unit 106 performs mediation between the high priority sequence frame and the low priority sequence frame when the transmission of the high priority frame and the transmission of the low priority frame are coordinated.

In the network configuration of Fig. 1 and Fig. 2, it is the slave that performs dynamic communication. The device 100 (slave device (S_H_1) 100 ̇ ̇ ̇ slave device (S_H_n) 100, the transmission of the high priority sequence frame and the transmission of the low priority sequence frame.

In other words, the transmission mediation unit 106 of the slave device 100 that performs dynamic communication performs mediation between the high priority sequence frame generated by the frame generation unit 109 and the low priority frame received from the network port 103. .

In addition, in the network configuration shown in FIG. 8, the slave device 100 (slave device (S_L_1) 100 ̇ ̇ ̇ slave device (S_L_m) 100, which performs field communication, transmits and low priority to the high priority frame. The transmission of the frame is used for competition.

In other words, the transmission mediation unit 106 of the slave device 100 for performing field communication performs mediation between the low priority frame generated by the frame generation unit 109 and the high priority frame received from the network port 103. .

In addition, whether it is the network composition of Figure 1 and Figure 2 or the network composition of Figure 8, no one will have a high-priority frame with each other in the nature of the network. Match the frames to each other.

The buffer 105 is a memory area for temporarily storing the communication frame reserved by the transmission mediation unit 106.

*** Description of action***

Next, the details of the operation of the transfer mediation unit 106 will be described using FIG. 5, FIG. 6, and FIG.

In Fig. 5, first, the transfer mediation unit 106 confirms whether or not there is a transmission request of the communication frame (S201).

In other words, the transmission mediation unit 106 confirms whether the communication frame has been generated by the communication frame generating unit 109, and whether the communication frame has been received on the network interface 104.

When there is a transmission request in S201 (YES in S201), the transmission mediation unit 106 confirms whether or not the network interface 101 is transmitting a communication frame from the network port 102 (S202).

On the other hand, when there is no transmission request in S201 (NO in S201), the transmission mediation unit 106 repeats the determination of S201.

When the communication frame period is not transmitted in S202 (NO in S202), the transmission mediation unit 106 executes the transmission of the communication frame having the transmission request (S204).

In other words, the transmission mediation unit 106 forwards the communication frame generated by the communication frame generating unit 109 or the communication frame received by the network interface 104 to the network interface 101.

Furthermore, the transport mediation unit 106 causes the network interface 101 to transmit a communication frame from the network port 102.

When the network interface 101 transmits the communication frame period from the network port 102 in S202 (YES in S202), the transmission mediation unit 106 confirms whether the transmission of the high priority sequence frame is generated during the transmission of the low priority sequence frame. Request (S203).

When S203 is Yes, that is, when a high priority sequence frame transmission request is generated during the low priority frame transmission, the transmission mediation unit 106 determines that the current priority is within the delay time of the high priority frame. Whether the transmission of the low priority sequence frame from the network port 102 is completed (S206).

The details of the determination of S206 are set forth in the following.

On the other hand, when S203 is No, that is, when a low priority priority frame transmission request is generated during high priority sequence frame transmission, the transmission mediation is performed. The unit 106 performs the processing of S205.

The processing regarding S205 is stated later.

When Yes in S206, that is, when the transmission of the low priority frame from the network port 102 is completed within the delay allowable time, the transmission mediation unit 106 determines to continue the transmission of the low priority frame, and in the low priority frame. After the transfer is completed, the high priority sequence frame is transmitted from the network port 102 (S209).

Thereafter, the transfer mediation unit 106 returns the process to S201.

In addition, the high priority sequence frame that is reserved for transmission is stored in the buffer 105 until the transmission of the low priority frame is completed.

In addition, the transmission mediation unit 106 forwards the high priority sequence frame in the buffer 105 to the network interface 101 as soon as the transmission of the low priority frame is completed.

Furthermore, the transport mediation unit 106 causes the network interface 101 to transmit a high priority sequence frame from the network port 102.

When S206 is No, that is, when the transmission of the low priority frame from the network port 102 is not completed within the delay allowable time, the transmission mediation unit 106 determines to suspend the transmission of the low priority frame and starts the high priority frame. Transmission of the network port 102 (S207).

In other words, the transmission mediation unit 106 instructs the network interface 101 to suspend the transmission of the low priority sequence frame and forward the high priority sequence frame to the network interface 101.

Furthermore, the transport mediation unit 106 causes the network interface 101 to transmit a high priority sequence frame from the network port 102.

The untransmitted portion of the low priority frame is stored in the buffer 105.

Thereafter, the transfer mediation unit 106 performs the processing of S208, but the details of S208 will be described later.

Next, the processing performed at S205 will be described using FIG.

S205 is performed when a low priority frame transmission request is generated during the transmission of the high priority frame.

In S2051, the transmission mediation unit 106 determines whether the low priority sequence frame can be transmitted by the reverse transmission mode to transmit the low priority sequence frame faster than when the low priority priority frame is transmitted by the forward transmission mode. Master device 10.

The details of S2051 are set forth in the following.

When the details of S2051 are YES, the low priority priority frame can be forwarded to the master device 10 more quickly than the forward transmission. The transmission mediation unit 106 determines the network that belongs to the reverse communication port. The way port 103 transmits a low priority sequence frame (S2053).

In other words, the delivery mediation unit 106 transmits the low priority sequence frame to the network interface 104.

Furthermore, the delivery mediation unit 106 causes the network interface 104 to transmit a low priority sequence frame from the network port 103.

On the other hand, when S2051 is NO, that is, when the low priority sequence frame can be transmitted in the forward direction to reach the master device 10 faster than the reverse transmission, or in the forward transmission or the reverse transmission, When the low priority frame arrives at the same master device 10, the transmission mediation unit 106 determines to transmit the low priority frame from the network port 102 after the transmission of the high priority frame is completed (S2052).

The low priority sequence frame that is reserved for transmission is stored in the buffer 105 until the transmission of the high priority sequence frame is completed.

In addition, the transmission mediation unit 106 performs the transmission of the high priority sequence frame. The low priority frame within the buffer 105 is forwarded to the network interface 101.

Furthermore, the delivery mediation unit 106 causes the network interface 101 to transmit a low priority sequence frame from the network port 102.

Next, the details of S2051 are set forth in the following.

The transmission mediation unit 106 calculates the time required from the transmission of the low priority frame from the device 100 until the first bit of the low priority frame is delivered to the master device 10 based on the network composition information. , that is, network relay time.

Here, the time required for the slave device 100 to transmit the low priority frame from the network port 102 until the low priority frame reaches the master device 10 is set to tp_n.

In addition, the time required for the slave device 100 to transmit the low priority frame from the network port 103 until the low priority frame reaches the master device 10 is set to tp_f.

The transmission mediation unit 106 can form information from the network, and knows the number of slave devices that are interposed between the slave device 100 and the master device 10 in the forward direction, and is disposed in the reverse direction between the slave device 100 and the master device 10. The number of slave devices.

In addition, the transmission mediation unit 106 can learn from the network configuration information whether or not a network switch is provided.

In addition, the transmission mediation unit 106 can know the time required for the relay processing of the other slave devices 100 interposed between the master device 10 and the time required for the relay processing of the network switch from the network configuration information. .

In addition, the transmission mediation unit 106 can know the length of the network cable between the devices and the network cable length between the network switches from the network configuration information.

Further, in the timer information, the time t_c from the transmission request of the low priority frame until the transmission of the high priority frame in the current transmission is completed is displayed.

When the transfer mediation unit 106 is tp_f<tp_n+t_c, it is determined as YES in S2051.

Further, when the transfer mediation unit 106 is tp_f>tp_n+t_c, it is determined to be NO in S2051.

Further, the transmission mediation unit 106 can calculate the network relay time by the following method, instead of calculating the network relay time by using the network configuration information.

For example, in the initial stage, the master device 10 measures the network relay time up to each slave device 100, and from the master device 10, notifies the network relay time between the master device 10 and each slave device 100. All slave devices 100.

Furthermore, the transmission mediation unit 106 uses the network relay time between the master device 10 and the slave device 100 notified from the master device 10, and calculates the network relay time in S2051.

Next, the determination of S206 will be described.

The transfer mediation unit 106 performs network configuration information input from the network configuration information management unit 108 and timer information input from the timer unit 107 to determine S206.

The network composition information is the same as above.

In the timer information, the remaining time t_r of the communication cycle of the dynamic communication is displayed.

Further, in the determination of S206, the transfer mediation unit 106 calculates the result until the mesh The time t_s until the transmission of the low priority frame in the previous transmission is completed.

The transmission mediation unit 106 can obtain the time t_s by dividing the data amount of the untransmitted data in the low priority frame by the communication speed.

Furthermore, when t_r≧tp_n+t_s, even if the transmission of the high priority sequence frame is retained, the high priority sequence frame can be sent to the master device 10 before the completion of the communication cycle of the dynamic communication, so the transmission mediation unit 106 is in S206. The judgment is YES.

On the other hand, when t_r<tp_n+t_s, when the transmission of the high priority sequence frame is reserved, since the high priority sequence frame cannot be sent to the master device 10 before the completion of the communication cycle of the dynamic communication, the transmission mediation unit 106 It is judged as NO at S206.

Next, the processing of S208 will be described with reference to Fig. 7.

S208 is performed when the transmission of the low priority frame is interrupted in order to transmit the high priority frame.

In S2081, the transmission mediation unit 106 determines whether the low priority sequence frame can be transmitted to the master device 10 faster than when the low priority frame is transmitted in the reverse transmission mode as compared to the forward transmission mode.

The details of S2081 are set forth in the following.

When S2081 is YES, that is, when the remaining low priority frame is transmitted to the host device 10 faster than the forward transmission, the transmission mediation unit 106 determines to set the remaining low priority frame. The network port 103 belonging to the reverse communication port transmits (S2083).

In other words, the delivery mediation unit 106 forwards the remaining low priority frame to the network interface 104.

Furthermore, the transport mediation unit 106 causes the network interface 104 to transmit the remaining low priority sequence frames from the network port 103.

On the other hand, when S2081 is NO, that is, when the remaining low priority frame can be transmitted to the host device 10 in the forward direction faster than the reverse transmission, or whether it is forward transmission or reverse When the remaining low priority frame is the same as the arrival of the master device 10, the transmission mediation unit 106 determines to transfer the remaining low priority frame from the network port 102 after the transmission of the high priority frame is completed ( S2082).

The remaining low priority sequence frames that are reserved for transmission are stored in buffer 105 until the transmission of the high priority sequence frame is completed.

In addition, the transfer mediation unit 106 forwards the remaining low priority sequence frames in the buffer 105 to the network interface 101 as soon as the transmission of the high priority sequence frame is completed.

Furthermore, the transport mediation unit 106 causes the network interface 101 to transmit the remaining low priority sequence frames from the network port 102.

Next, the details of S2081 will be described.

The network composition information is the same as that described in S2051.

The timer information indicates the time t_d from the transmission of the interrupted low priority frame to the completion of the high priority frame transmission in the current transmission.

When tp_f<tp_n+t_d, since the low priority frame is transmitted from the network port 103, the low priority frame can be made to reach the master device 10 more quickly, so the determination of S2081 becomes YES.

On the other hand, when tp_f>tp_n+t_d, the lower priority frame is transmitted to the master device faster because the low priority frame is transmitted from the network port 102 after the transmission of the high priority frame is completed. 10, so the determination of S2081 becomes NO.

Further, in S2081, the transmission mediation unit 106 calculates the network relay time by the following method, instead of calculating the network relay time by using the network configuration information.

For example, in the initial stage, the master device 10 measures the network relay time up to each slave device 100, and from the master device 10, notifies the network relay time between the master device 10 and each slave device 100. All slave devices 100.

Furthermore, the transfer mediation unit 106 uses the network relay time between the master device 10 and the slave device 100 notified from the master device 10, and calculates the network relay time in S2081.

*** Description of the effect of the implementation form***

In summary, according to the embodiment, when the transmission of the high priority frame and the transmission of the low priority frame are cooperating, the low priority frame can be transmitted by the reverse transmission mode.

Therefore, according to the embodiment, the transmission path of the low priority frame can be flexibly selected according to the transmission status of the high priority frame, and the high priority frame can be preferentially transmitted while being efficiently performed. Priority transmission of the frame.

Therefore, the real-time performance of the dynamic communication can be maintained, and the delay of the completion time of the field communication can be suppressed.

*** Description of the hardware configuration example***

Finally, an example of the hardware configuration of the slave device 100 will be described with reference to FIG.

The slave device 100 is a computer.

The slave device 100 includes a processor 901, a secondary storage device 902, a memory 903, a network interface 904, an input interface 905, and The hardware of the display interface 906.

The processor 901 is connected to other hardware through the signal line 910 for controlling the other hardware.

The input interface 905 is connected to the input device 907.

Display interface 906 is coupled to display 908.

The processor 901 is an IC (Integrated Circuit) that performs processing.

The processor 901 is, for example, a CPU (Central Processing Unit), a DSP (Digital Signal Processor), and a GPU (Graphics Processing Unit).

The auxiliary memory device 902 is, for example, a ROM (Read Only Memory), a flash memory (Flash Memory), or an HDD (Hard Disk Drive).

The memory 903 is, for example, a RAM (Random Access Memory).

The buffer 105 and the network configuration information management unit 108 of Fig. 4 are realized by, for example, the auxiliary storage device 902.

The network interface 904 includes a receiver 9041 that receives data and a transmitter 9042 that transmits data.

The network interface 904 is equivalent to the network interface 101 and the network interface 104 of FIG.

The network interface 904 is, for example, a communication chip or a NIC (Network Interface Card).

The input interface 905 is a cable 911 connection for the input device 907. Connected port.

The input interface 905 is, for example, a USB (Universal Serial Bus) terminal.

Display interface 906 is a port for cable 912 of display 908.

The display interface 906 is, for example, a USB terminal or an HDMI (registered trademark) (High Definition Multimedia Interface) terminal.

The input device 907 is, for example, a mouse, a keyboard, or a touch panel.

The display 908 is, for example, an LCD (Liquid Crystal Display).

In the auxiliary memory device 902, a program for realizing the functions of the transfer mediation unit 106, the timer unit 107, and the communication frame generating unit 109 (referred to collectively as "parts") shown in Fig. 4 is stored.

This program is loaded into the memory 903 and is read into the processor 901 and executed by the processor 901.

Further, in the auxiliary storage device 902, an OS (Operating System) is also stored.

Further, at least a part of the OS is loaded in the memory 903, and the processor 901 executes a program for realizing the function of the "part" while executing the OS.

In the ninth figure, although one processor 901 is illustrated, the slave device 100 may be provided with a plurality of processors 901.

Furthermore, a program in which a plurality of processors 901 implement the function of "part" can be executed in cooperation.

In addition, the information or data or signal value or variable value indicating the result of the processing of the "part" is stored in the memory 903, the auxiliary memory device 902, or the recorder or the cache memory in the processor 901 ( Cashe memory).

In addition, the program for realizing the functions of the "part" is stored on a magnetic disk, a flexible disk, a magneto-optical disk, a CD (compact disk), and a blue-ray (registered trademark) magnet. Memory media such as discs and DVDs (Digital Versatile Disc).

"Min" can also be provided by "circuitry".

In addition, "Min" may also be referred to as "circuit" or "step" or "sequence" or "processing".

The "circuit" and "circuit diagram" include not only the processor 901 but also a logic IC or a GA (Gate Array) or an ASIC (Application Specific Integrated Circuits) or an FPGA. (Other types of processing circuits such as Field-Programmable Gate Array).

10‧‧‧Master equipment

100‧‧‧ slave equipment

1000‧‧‧ ring network

Claims (7)

A slave device is included in a ring network including a master device and a plurality of slave devices, and configured with forward and reverse directions as a direction for transmitting a communication frame from the plurality of slave devices to the master device, the slave The device has: a first communication port, which transmits the communication frame in the forward direction; a second communication port, which transmits the communication frame in the reverse direction; and a transmission mediation unit that belongs to the foregoing main device When the high-priority sequence frame of the high-priority message frame is transmitted and the low-priority frame of the low-priority frame is transmitted to the master device, the transmission is determined to be transmitted from the first communication port. Priority ordering, and determining to transmit the forward transmission of the low priority frame from the first communication port and the high priority by transmitting the high priority message frame from the first communication port Which of the reverse transmissions of the low priority sequence frame is transmitted from the second communication port before the transmission of the first communication port is completed to transmit the low priority First, the message frame. According to the slave device of claim 1, wherein the foregoing transmission mediation unit reaches the foregoing primary device when the low priority sequence frame is transmitted by the reverse transmission mode, and the foregoing When the low priority sequence frame when transmitting the low priority sequence frame to the transmission mode arrives at the master device faster, it is determined that the low priority sequence frame is transmitted by using the reverse transmission mode; and the reverse transmission is performed by the foregoing reverse transmission. The manner in which the low priority order frame of the low priority order frame is transmitted to the foregoing main device is not higher than the foregoing forward direction When the low priority priority frame of the low priority priority frame is transmitted to the master device, the low priority priority frame is transmitted by the forward transmission mode. The slave device of claim 1, wherein the transfer mediation unit determines to continue from the first communication port when the low priority frame needs to be transmitted during the transmission of the high priority sequence frame from the first communication port. Transmitting the high priority sequence frame and determining which one of the foregoing reverse transmissions is to be transmitted by the forward transmission and the low priority order frame. The slave device of claim 1, wherein the transfer mediation unit determines to suspend the first communication port when the high priority sequence frame needs to be transmitted during the transfer of the low priority frame from the first communication port. Transmitting the low priority sequence frame, and starting to transmit the high priority sequence frame from the first communication port, and determining which one of the forward transmission is to transmit the low priority frame by the forward transmission and the forward transmission . The slave device of claim 4, wherein the transport mediation unit determines that the low priority frame is self-transmitting when the low priority frame needs to transmit the high priority frame during transmission from the first communication port Whether the transmission of the first communication port is completed within the delay allowable time of the high priority sequence frame; and when the transmission of the low priority sequence frame from the first communication port is completed within the delay allowable time, the system determines to continue the low Transferring the priority information frame from the first communication port, and after transmitting the low priority information frame from the first communication port, determining to transmit the high priority sequence frame from the first communication port; When the transmission of the low priority frame from the first communication port is not completed within the delay allowable time, determining to suspend transmission of the low priority frame from the first communication port, and starting the high priority frame from The transmission of the aforementioned first communication port. A communication method is included in a ring network including a master device and a plurality of slave devices, and configured with forward and reverse directions as directions for transmitting a communication frame from the plurality of slave devices to the master device, and The slave device having the first communication port for transmitting the communication frame in the forward direction and the second communication port for transmitting the communication frame to the reverse direction performs the following steps: performing a high priority order on the master device When the transmission of the high priority sequence frame of the communication frame coincides with the transmission of the low priority priority frame of the communication frame belonging to the low priority order for the foregoing master device, determining to transmit the high priority sequence frame from the first communication port And determining to transmit the forward transmission of the low priority frame from the first communication port after the completion of the transmission of the high priority frame from the first communication port, and the high priority sequence frame from the foregoing Which of the reverse transmissions of the low priority sequence frame is transmitted from the second communication port before the completion of the transmission of the first communication port to transmit the low priority order Frame. A communication program product for inclusion in a ring network including a master device and a plurality of slave devices, and having forward and reverse directions as directions for transmitting a communication frame from the plurality of slave devices to the master device, And having a first communication port for transmitting the communication frame in the forward direction and a second communication port for transmitting the communication frame to the reverse direction, belonging to the computer The device performs the following processing: transmitting the high priority sequence frame of the communication frame belonging to the high priority order to the foregoing master device and transmitting the low priority priority frame of the communication frame belonging to the low priority order to the foregoing master device When competing, determining to transmit the high priority sequence frame from the first communication port; and determining to transmit the foregoing from the first communication port after completion of the transmission of the high priority sequence frame from the first communication port The forward transmission of the low priority frame and the transmission of the reverse transmission of the low priority frame from the second communication port before the transmission of the high priority frame from the first communication port is completed The aforementioned low priority order frame.