Transmission method of message in automated system

The present invention relates to a method of transmitting a message in an automated system. The present invention also relates to an automated system.

In an automated system, it is preferable to use a real-time system as a communication link. This is because the real-time system guarantees excellent performance and high usefulness for communication. In some cases, the data is relevant not only to the individual network components of the automation system, but also to a set of applications. In this case, communication between the individual network components of the automation system is ideal, in which the required data is delivered to its destination with as little delay as possible. At this time, the data transmission speed of the communication link inevitably brings a limit. However, data transmission delays should not be critically limited by other influencing factors. This must be true even if individual network components on the path between the source and the destination fail.

In automated systems, data is transferred between individual network components, for example in the form of messages. As the data line, the fieldbus defined in the international standard IEC61158 is generally used. For example, an Ethernet® link is used for this purpose, which has a corresponding switch that transmits data directly from source to destination with the help of address information at the beginning of the message. Therefore, the minimum delay of the switch must be taken into account. The so-called "stre-and-forward principle" is often used to intermediately buffer individual messages into each network component so that the appropriate decoupling can be guaranteed in the event of a failure. To. This results in a total transmission time, typically in the range of a few milliseconds. An Ethernet link is basically an active network in which the required effectiveness in the event of a failure of one network component or one network segment is achieved by redundant routing. This is, for example, structurally linear topology (linear) This is achieved by integrating topology) into one ring.

In a series of applications, one data transmitter sends to multiple data receivers (multicast). This is the case, for example, when current measurements are required for various protection functions. Such a multicast communication link is premised on transmitting data only once for efficiency reasons. An even more important aspect is data synchronization. If the data is distorted in time, the result of the logical operation is unreliable. In addition, it is necessary that data for which speed is not important can be transmitted on the same communication channel.

Other real-time systems such as EtherCAT use pack transmission. However, multicast links can only be implemented starting from one master. Similarly, the order plays a decisive role due to the direction dependence.

Many real-time systems, such as Profinet, require specific data transmission rates for periodic services. The rest of the data can then be exchanged over a standard Ethernet link. This does not change the efficiency of data transmission in principle, but the exchange limits the minimum cycle time. Another problem is the so-called frame overhead. In a client-server communication relationship, this is resolved by dynamic packing, where the selected component is either the source or destination of the data. Individual transmission is generally available for multicast links, but in this case the data transmission rate and system load are limited.

Patent Document 1 discloses, in its embodiment, an automated system in which only one message reaches a large number of network components. In this case, when one message is received, the payload contained in the message for the network component, that is, the datagram, is retrieved and the message is shortened by the retrieved datagram. In this way, an increase in the amount of data processing can be achieved.

<p><patcit num="1"><text>International Publication No. 2008/09 2805</text></patcit></p>

<p> An object of the present invention is to achieve efficient data transmission between individual network components in an automated system as described at the beginning including a plurality of network components.</p>

<p> The above problem is solved by the method according to claim 1. That is, it is a method of transmitting a message in an automated system in which a large number of network components are connected to form a network. In the message, a datagram is associated with each of the network components. By each of the network components mentioned above Receive the first message in the message, Remove the datagram associated with the network component from the first message. Generate a second message by inserting the update datagram associated with the network component into the first message. Transmit the second message to at least one of the network components of the network. The way the steps are performed.</p><p> In the method according to the invention, the automation system comprises a number of similarly authorized network components connected to form a network. No hierarchy is required between the individual network components. The individual network components are located on the multicast link. First, each network component generates a corresponding frame with its own datagram. In parallel with this, each network component receives a first message, which contains the corresponding datagram for each network component. Each network component strips the self-related datagram and inserts a self-related update datagram. The second message generated by this is sent to the other network components of the network. The received data is optionally available by each network component.</p><p> Such a datagram can be, for example, a data frame, a data packet or a data segment. In an automated system, it may contain the relevant measurements or quantities (variables) that characterize the operational state of individual network components. In this way, high-speed data transmission between individual network components and increased utility can be achieved.</p><p> The datagram contained in the first message received by the network component was previously inserted by the network component, and this datagram is removed by the network component and an updated datagram is inserted. Is preferable. The individual network components are connected to each other in the network as follows. That is, the datagrams previously inserted by one network component are connected to each other so that they are received again by that network component. In this case, the network component may update its own datagram (if required) and insert it into the message as appropriate. Therefore, each network component monitors and updates only its own datagrams as appropriate. In this way, efficient data transmission can be achieved between the individual network components of the automation system.</p><p> In a preferred embodiment, the datagrams associated with other network components of the network that the network component receives in the first message are transferred from the network component in the second message. Each network component receives the corresponding datagram of the other network components of the network in the first message. This allows the relevant datagrams to be easily exchanged and used between individual network components. Datagrams of other network components received by each network component are, for example, appropriately intermediately stored (buffered) in the storage element of the network component and transmitted in a second message. These datagrams do not change. The transmission of datagrams of other network components can be done in conjunction with the insertion of updated datagrams of own network components. Therefore, datagrams can be easily and efficiently exchanged between individual network components.</p><p> In another aspect, each network component is given a minimum time in advance for the interval between the receipt of the first message and the transmission of the second message. When transmitting datagrams between individual network components in a time-controlled manner, it is possible that the first message arrives later than the second message has already been transmitted. In order to avoid this, it is preferable that a corresponding minimum time is given in advance. This allows secure and reliable transmission of datagrams between individual network components. Similarly, the maximum delay between the receipt of the first message and the transmission of the second message should be considered. The time given in advance for this purpose may be statically determined when the automation system is configured, or may be dynamically determined according to the measurement of the corresponding delay time.</p><p> In a preferred embodiment, the message is transmitted synchronously by all network components. In this case, message transmission is initiated by all network components at a given point in time, which allows for harmonious circulation. Synchronous transmission of messages can minimize the corresponding delay time and transmit data safely and reliably.</p><p> In another aspect, the transmission of a message by one of the network components is initiated depending on the event. The method for transmitting a message in an automated system may also be performed by event control. In doing so, the process should first be initiated by one of the network components that sends its datagrams to other network components. In this case, for example, the individual datagrams of each network component may be included in the message during the first cycle, allowing distribution of the individual datagrams during the second cycle. Therefore, the automation system can be controlled depending on specific events, thereby initiating data transfer between individual network components. That is, the automation system can be operated effectively.</p><p> According to the present invention, it is an automation system in which a large number of network components are connected to form a network. Each of the network components A first message is received, in which the datagram is associated with each of the network components. Remove the datagram associated with the network component from the first message A second message is generated by inserting the update datagram associated with the network component into the first message. Send the second message to at least one of the network components of the network, An automated system is provided that is configured to. The above-described aspects related to the method of the present invention for transmitting a message in an automated system can also be diverted to the automated system of the present invention.</p><p> In a preferred embodiment, each datagram of the first and second messages has a predetermined amount of data. By predetermining the amount of data, it is possible to prevent the first message from being received by the network component after the second message is transmitted. Therefore, secure and reliable communication between individual network components can be achieved. Similarly, the datagram may be divided into, for example, two or more frames. This can be used, for example, as long as the maximum frame amount of the data link used is not exceeded. In this case, appropriate delay times may also be considered to ensure reliable transmission of individual frames to the network components.</p><p> In the network, the network components are preferably arranged in a ring connection. In the case of this topology, the transmission of the second message begins at the time specified by each network component. Therefore, exchanging datagrams between individual network components can be achieved in a simple way.</p><p> In another aspect, the network components are arranged in a linear connection in the network. The individual network components are similarly arranged in a linear topology. In this arrangement, message transmission may start, for example, at the network component at the end of the column. Similarly, an automated system can implement a corresponding hierarchical system.</p>

<figref num="1">FIG. 1 is a schematic diagram showing an automation system for a large number of network components arranged in a ring connection.</figref><figref num="2">FIG. 2 is a schematic diagram showing the automation system according to FIG. 1 in another embodiment.</figref><figref num="3">FIG. 3 is a schematic diagram showing an automated system in which network components are arranged in a linear connection.</figref><figref num="4">FIG. 4 is a schematic diagram showing an automated system in which network components are arranged in a hierarchical connection.</figref><figref num="5">FIG. 5 is a diagram of a table showing a concrete example of the aspect of the datagram in the message of the network component.</figref>

The present invention will be described in more detail with reference to the accompanying drawings.

An exemplary embodiment described in more detail below is a preferred embodiment of the present invention.

FIG. 1 shows a schematic diagram of an automation system 10, in which a large number of network components 12 are connected to form a network. In this example, the network components 12 are arranged in a ring connection. The ring connection shown in FIG. 1 contains eight network components 12, which are numbered and labeled. Each network component 12 has two ports, indicated by x1 and x2.

Data is exchanged between the individual network components 12. This data exchange will be described here with an example of the (No. 1) network component 12 numbered 1. The first network component 12 receives the first message 14 over its port x1. This first message 14 contains one datagram 16 for each network component 12. In the example of FIG. 1, each datagram 16 is represented by a number for each of the network components 12, and these numbers are distinguished from each other by commas. That is, the number in each datagram 16 corresponds to the network component 12 with the corresponding number. It should be understood that the datagram 16 described herein is a corresponding data frame, data packet or data segment. The datagram 16 may include, for example, the relevant measurements of individual network components 12, or the datagram 16 may contain quantities (variables) that characterize the operational state of each network component 12. , Or both.

When the first network component 12 receives the first message 14, the first network component 12 removes the datagram 16 represented by the number 1 associated with it. Then, the first network component 12 sends a second message 18 in which the update datagram 16 related to the network component 12 is inserted. This second message 18 is forwarded to the second network component 12.

In the illustrated embodiment, messages 14 and 18 are exchanged clockwise between each network component 12. In this case, the datagram 16 associated with each network component 12 is updated by the corresponding network component 12. At that time, the datagram 16 of the remaining (other than itself) network component 12 is transferred unchanged as the second message 18. Therefore, each network component 12 updates only the datagram 16 associated with that network component 12 when the first message 14 is received. For this reason, the data contained in the datagram 16 is correspondingly erased and newly inserted or overwritten.

In Figure 5, Tables 22,24,26,28 show the corresponding messages 14,18 for each network component 12. The first Table 20 shows the numbers of the individual network components 12 side by side. In Table 22 below, each first message 14 (received message) of the network component 12 having the numbers 1 to 8 is shown in each column. Then, Table 24 shows each second message 18 (outgoing message) of each network component 12. Tables 22-24 apply when messages 14 and 18 are exchanged clockwise between eight network components 12. On the other hand, Tables 26-30 shown in FIG. 5 apply when messages 14 and 18 are exchanged counterclockwise in the ring connection described above. Each column of Table 26 shows the first message 14 of each network component 12, and each column of Table 28 shows the second message 18 of each network component 12. The numbering of each network component 12 is shown in Table 30.

In the example shown in FIG. 1, the second message 18 is transmitted from each network component 12 to the adjacent network components 12 in synchronization at a predetermined time point. Similarly, it is conceivable that the messages 14 and 18 are transmitted between the individual network components 12 by event control. An example of this is shown in Figure 2. In this case, the transmission of messages 14 and 18 starts from the first network component 12. Messages 14 and 18 are each forwarded clockwise between the individual network components 12. Then, during the first cycle, the datagrams 16 of the individual network components 12 are each written into the second message 18. After this first cycle, when messages 14 and 18 arrive again under the first network component, the data exchange as described above can be performed.

FIG. 3 shows a schematic diagram of an automation system 10 in which individual network components 12 are arranged in a linear connection. In this case, the transmission of messages 14 and 18 is performed by time control or event control. Transmission of messages 14 and 18 begins, for example, at one of the network components 12 at the beginning or end of the linear connection.

FIG. 4 shows a schematic diagram of an automation system 10 in which individual network components 12 are arranged in a hierarchical connection. In the illustrated example, the fourth network component 12 in the upper row is configured as the upper layer network component 12. Again, messages 14 and 18 can be exchanged between network components 12 as described above.

1 ~ 8 Network component number 10 Automation system 12 Network components 14 First message 16 datagrams 18 Second message 20 ~ 30 table x1, x2 ports