Automation network based on packet communication between host and client and operation method thereof

Abstract

The invention relates to an automation network with packet-based communication between a host and a client and a method for operating the same. In an automation network (1) with packet-based communication between a host (110) and a client (210), in the event of a communication error between the host and the client, the client takes over the determination of output values ​​of the host (110). The determination of the output data can be carried out in a separate local processing module according to a more complex method than on the host (110). Even in the case of mobile or otherwise poorly wired clients (210), complex control and regulation tasks can be carried out on the host (110).

Description

Technical Field

[0001] The invention relates to an automation network in which packet-based communication between a host and a client is implemented, a host and a client in the automation network, and a method for operating such an automation network. Background Art

[0002] In automation networks, host-client systems are used. Here, the host usually undertakes complex control tasks including data from many clients. The input data of these clients are provided to the clients by the systems controlled by the respective clients. The systems controlled by the clients can be, for example, drones, individual forklifts in warehouses, or components of complex production machines, such as drive motors, pumps, switches, valves, etc. The input data mentioned can be data describing the properties of the connected systems, such as switch states (e.g. limit switches), motor speeds, speeds, temperatures, pressures, and levels. These input data are processed in the host. In the next step, the host provides data to the individual clients, which forward these data as output data to the connected systems, for example as switch outputs for controlling actuators, digital rated values ​​for controlling motors, etc.

[0003] This host-client architecture was chosen for two reasons. On the one hand, the capacity (number of computing operations, memory, etc.) required for controlling complex systems in a computing center or cloud can be provided centrally on a large number of servers, for example. In this way, the interaction of the (sub)systems controlled by the individual clients can be fully taken into account. On the other hand, the clients in the field system should be as simple as possible in terms of technology, that is, equipped with as few electronic components as possible and low capacity. Therefore, control and regulation tasks are best performed by a central entity rather than by the clients in the field.

[0004] Communication in such a host-client system can be achieved by wired means (e.g. via Profibus, Profinet or Ethernet). However, wireless communication via radio is more suitable for controlling and regulating mobile systems. For this purpose, packet-based digital radio transmission standards are used, such as the wireless versions of the above connections as well as 3G, 4G, 5G, etc.

[0005] In order to divide the tasks between client and host for controlling and regulating the systems connected to the automation network, the latency of wireless communication is significantly limited. With the standards that have been widely used so far, the client must process the tasks to be completed on site in the millisecond range, because the transmission to the host and back would take too long to be able to be processed on the host. In this way, sensor data can be transmitted from the client to the host, such as the position and speed of a forklift. The host can use this data, for example, for tracking and archiving the movements of the forklift.

[0006] As latency times in wireless communications are gradually reduced, e.g. to less than 1 ms for standard 5G URLLC, there are more possibilities to perform tasks on the host. For example, if wireless digital communication is carried out according to this standard, the path of a transport or a control process can be recalculated on the host. This is particularly advantageous because it is easier to maintain the corresponding capacity (computing operations, amount of memory, etc.) on a fixed host than on a client of a light mobile system. Therefore, more complex control algorithms can be executed on the host than on the client. This expands and improves the possibilities of control and regulation.

[0007] However, the problem that arises is that in the case of packet communication, not all packets can always be sent immediately. There is a delay in the transmission from the host to the client or from the client to the host. Although all data packets are transmitted normally, when there is a delay, then the delay means, for example, that a transport vehicle does not have enough data to continue its transport path, or that the control quality is impaired. Summary of the invention

[0008] Against this background, it is an object of the present invention to improve the operation of an automation network by means of packet-based communication between hosts and clients.

[0009] Therefore, a method for operating an automation network is proposed, which has a host device, at least one client device and a packet-based communication link between the host device and the client device, the method comprising the following steps: generating an input value packet by the client device and sending it to the host device via the communication link; generating an output value packet by the host device and sending it to the client device via the communication link; and if the client device does not receive at least one output value packet via the communication link within a predetermined time period, generating a replacement output value packet by the client device.

[0010] If a delay occurs during the transmission of an input value data packet from the client to the host, the result is that the host is no longer able to process control and / or regulation tasks that need to be solved quickly and transmit the corresponding output value data packets to the client. As a result, the input value data packet does not reach the host within the expected number of processing cycles. Transmission delays of output value data packets can also occur in the direction from the host to the client. It can happen that after sending an input value data packet, after a predetermined number of processing cycles, the client does not register the receipt of the expected corresponding output value data packet. This predetermined number of processing cycles, i.e. the predetermined time, is then regarded as a failure to receive a packet on time, both in the direction from the client to the host and from the host to the client. The failure to receive a data packet in this way means that the client cannot provide the required output data for the system connected to the automation network. In order to avoid the above-mentioned negative effects, if a data packet is not received on time, the client itself will assume the generation of the necessary output value data packets, i.e. the so-called substitute output value data packets. If the host still does not receive the expected input value packet after a specified number of processing cycles, it can send a signal to the client to generate a substitute output value packet itself.

[0011] According to a second exemplary embodiment, the method is extended by the client device generating a substitute output value package as a function of at least one basic operating point predetermined by the host device.

[0012] Control and regulation processes usually take place in the region of operating points where specific characteristics of the control or regulation can be predicted. In this case, the operating point is a predefined state defined by the system properties controlled by the client, which are also influenced by environmental parameters. In simple electric drives, the operating point is determined, for example, by the rotational speed of the driven component and the torque of the electric motor. The operating point of a forklift is determined by internal parameters such as speed and steering angle as well as external parameters such as the mass of the transported load. For example, for drones, speed, position, altitude, wind speed and temperature are parameters that determine the operating point. For production machines, the operating point is determined by the position of switches, valves, flow rates and drive speeds. As mentioned above, the operating point can also be formed by more complex parameters, such as derivatives of simple parameters.

[0013] More precisely, the replacement output value package is determined based on the actual current operating point, i.e. the state of the system relative to an operating point known as the base operating point. This base operating point is predetermined by the host computer. Of course, multiple base operating points can also be determined. For forklifts and drones, such base operating points can be travel or flight without load, or travel or flight with low, medium or high load.

[0014] During the normal communication process of the input value packet and the output value packet, the host can determine this basic working point with predictable characteristics. Then, the host can transmit other data to the client independently of the normal processing of the current control and / or regulation task. For example, these data contain control or regulation characteristics for the area around the basic working point. This characteristic can be based on an algorithm with a lower complexity than the algorithm running on the host. However, this cannot obtain the same control quality as the control on the host. But the failure or pause of the control in the case of delayed reception of the packet can be avoided. According to the behavior rules of the area around this basic working point, the client can generate the output value packet by itself, that is, create an alternative output value packet. This regulation performed by the client can also be continued in parallel with the generation of the output value data packet on the host.

[0015] According to a third exemplary embodiment, one of the above-described methods is expanded by the client device generating the substitute output value package by means of a local processing module assigned to the client device.

[0016] A module is understood here as an element that can be implemented in hardware, firmware or software. When implemented in software, it can be a program module, i.e., an executable code.

[0017] The less complex algorithm mentioned in the second embodiment can be implemented in a separate module on the client, which the client uses to generate the alternative output value package. Such a local processing module on the client can be provided as a software program, as firmware or as separate hardware. Another algorithm that is independent of the working point can also be used.

[0018] According to a fourth exemplary embodiment, the method according to the third exemplary embodiment is extended by transmitting parameters for the local processing module from the host device to the client device.

[0019] Such parameters for the local processing module may be, for example, suitable parameters for a fixed algorithm processed by the local processing module. The algorithm in the local processing module may, for example, be based on a low-order system of equations that reproduces approximately stationary states at the base operating point with sufficient accuracy. In more complex cases, the local processing module may contain a state machine. Parameter sets are required to run this state machine. These parameter sets have been previously determined by the host based on the state of the systems connected to the client, the internal state of the host, and / or the state of other clients.

[0020] According to a fifth embodiment, the method according to the third or fourth embodiment is extended by the following scheme, that is, the host device sends the local processing module to the client device.

[0021] The host also has the possibility to completely transfer local processing modules to the client. The host creates local processing modules based on the current state of the regulation or control system. This can be advantageously implemented on the client in the form of a flexible, application-based runtime.

[0022] According to a sixth embodiment, the method according to the second embodiment is expanded by the following solution: at least one predetermined basic operating point is derived by the host device at a predetermined time point.

[0023] In the method according to the second embodiment, it is important to take changes in the operating point into account. In order to be able to detect such changes, the host repeatedly determines the basic operating point that is predicted to be effective next at specific points in time (for example periodically). The time point in time for the determination or the time interval between consecutive working point determinations depends on the system to be monitored. The basic operating point can also be determined based on input value packages of the corresponding client and / or other clients or based on the state of the entire automation network. As has already been described in conjunction with the second embodiment, it is of course possible to determine a plurality of suitable basic operating points.

[0024] According to the seventh embodiment, the method according to one of the first to sixth embodiments is extended by the following scheme, namely, when at least one input value packet is not received within a predetermined time period on the communication link in the direction from the client device to the host device, the host device accelerates the generation of output value packets until the host device processes the current (aktuell, or latest) input value packet on time; the client device continues to generate alternative output value packets until the current input value packet is received on the host device, and the host device starts generating output value packets from this point in time.

[0025] If during the communication from the client to the host, the delayed input value packet eventually arrives at the host, the corresponding routine on the host will accelerate the corresponding regulation or control process. This means that the corresponding regulation or control is faster than normal operation. In this way, the regulation or control process that was not executed during the delay time can be made up again until the internal state of the control or regulation is established for the current clock cycle. From this point in time, the control or regulation can run normally again. Therefore, the regulation or control can be taken over by the host again, and the regulation or control on the client can stop outputting the alternative output value packet to the connected system, and instead output the output value packet received from the host.

[0026] According to an eighth embodiment, the method according to one of the first to seventh embodiments is extended by the following scheme, namely, the client device generates control variables for a controlled system from an output value package, the controlled system receives the control variables from the client device and the client device creates an input value package from the measurement variables received by the measurement link.

[0027] According to a ninth embodiment, the method according to the eighth embodiment is extended by generating, by the host device, an output value packet for determining a control variable while processing an input value packet created by the client device from the measured variables.

[0028] According to a tenth embodiment, the method according to the fifth embodiment is extended by sending the local processing module by the host device to the client device via an alternative communication link.

[0029] The transmission of the local processing module does not have to take place with the same low latency as the transmission of the input value packets or output value packets. Therefore, a standard communication link with a higher latency can be used here via the air interface. If the client is not integrated into the mobile system or the mobile system containing the client is temporarily connected to the automation network via a plug connection, wired communication can also be used to transmit the local processing module.

[0030] According to an eleventh embodiment, the method according to the fifth embodiment is extended by the following scheme: the host device creates a local processing module according to a basic working point predetermined by the host device.

[0031] Depending on the current operating point, it may be necessary to adapt the local processing module to the corresponding conditions. In approximately stationary conditions, the system of linear equations in the local processing module algorithm is sufficient. However, for more complex conditions, a different algorithm may be required. Therefore, it is advantageous to take the corresponding operating point into account when creating the local processing module on the host.

[0032] According to a twelfth embodiment, the method according to one of the first to eleventh embodiments is extended by generating a substitute output value packet by the client device in case at least one packet is not received within a predetermined time period on the communication link until a time or location limit.

[0033] If only the sending of the data packet is delayed, and the client performs the creation of the output value packet, it is meaningful that the client performs control or regulation only within certain predetermined time or location limits. Therefore, it can be ensured that the mobile system containing the client stays in a predetermined location area, for example, within the range of the radio link. By limiting the time when the client creates an alternative output value packet, the deviation from the predetermined basic working point may not be too large. Similarly, the time limit for the time used by the client to create an alternative output value packet can prevent operational interference. For example, since the client must have parameters known only to the host in order to operate the connected system, the above-mentioned operational interference is generated. If the host creates an output value packet, these parameters are considered when creating the output value packet. In contrast, if the client creates an alternative output value packet, these parameters cannot be considered. In the latter case, interference may occur. These interferences can be avoided by limiting the time to generate an alternative output value packet.

[0034] According to another embodiment, an automation network is proposed, which is configured to perform a method according to one of the first to twelfth embodiments, the automation network comprising a host device, at least one client device, and a packet-based communication link between the host device and the client device, wherein the client device is configured to generate an input value packet and send it to the host device via the communication link, and the host device is configured to generate an output value packet and send it to the client device via the communication link, and if the client device does not receive at least one output value packet via the communication link within a predetermined time period, the client device is also configured to generate a replacement output value packet.

[0035] According to another embodiment, a host device is provided, which is configured to execute a method according to one of the first to twelfth embodiments.

[0036] According to another embodiment, a client device is provided, which is configured to perform a method according to one of the first to twelfth embodiments.

[0037] Other possible implementations of the present invention also include the features described above or below with respect to the embodiments or combinations not explicitly mentioned in the embodiments. Those skilled in the art will also add various aspects as improvements or supplements to various basic forms of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Other advantageous embodiments and aspects of the present invention are the subject of the exemplary embodiments of the present invention described below. The present invention will be explained in more detail below based on preferred exemplary embodiments and with reference to the accompanying drawings.

[0039] Figure 1 An automation network is schematically shown;

[0040] Figure 2 Schematically showing a host and a client from a degree of automation and a communication link between the host and the client;

[0041] Figure 3 A host is schematically shown;

[0042] Figure 4 A client is schematically shown;

[0043] Figure 5 A schematic timing diagram showing communications between a host, a client and a connected system;

[0044] Figure 6 A schematic timing diagram showing communications between a host, a client and a connected system if an outgoing value packet is not received by the client within a predetermined time period;

[0045] Figure 7 A schematic timing diagram showing communications between a host, a client and a connected system in the event that the host does not receive an input value packet within a predetermined time period;

[0046] Figure 8 A flow chart with a method for operating an automation network is shown;

[0047] Fig. 9 A flowchart of the method process on the host is shown;

[0048] Fig.10 A flow chart showing a method process on a client is shown.

[0049] In the drawings, elements that are the same or have the same function are given the same reference numerals unless otherwise specified. DETAILED DESCRIPTION

[0050] exist Figure 1 , schematically shows an automation network 1 having a host 110, which is connected to clients 210, 220, 230, 240 ... 290 via communication links 910, 920, 930, 940 ... 990. By way of example, Figure 2 The schematic diagram shows that the host 110 receives information sent by the client 210 from its antenna 212 via the communication link 912 via the antenna 112, and sends information to the client via the communication link 911. The communication links 911 and 912 are Figure 1 910 in FIG. 914 . In parallel with this communication link, there is a communication link 915 between the host and the client, which is divided into: a communication link 913, via which the host sends information to the client; and a communication link 914, via which the host receives information from the client. This communication link 915 is preferably also implemented by radio. For this communication link 915, there is an antenna 113 on the host and an antenna 213 on the client.

[0051] Figure 3The structure of the host 110 is shown in detail, and the host sends output value packets 999 to the client via the communication link 911 in the downlink direction via the antenna 112, and receives input value packets 998 from the client via the communication link 912 in the uplink direction. Communication links 911 and 912 are part of the communication link 910 between the host 110 and the client 210. In parallel, information can be exchanged between the host 110 and the client 210 via another communication link 915. The automation module 310 for controlling and regulating the process on the client 210 is located on the host 110. This information, that is, the input value packets from other clients are also taken into account. There are also other modules (not shown in the figure) on the host for controlling and regulating the processes of other clients 220 to 290. Communication with the client 210 is realized via the communication module 319 via links 910 (composed of communication links 911 and 912) and 915 (composed of communication links 913 and 914). Other communication modules not shown here are provided for other clients.

[0052] Figure 4 4 is a detailed illustration of a client 210, which exchanges input value packets 998 and output value packets 999 with a host via communication links 911 and 912 by means of an antenna 212. The communication module 419 is contained in the module 401 for controlling and regulating the client and the system connected to the client, and controls the communication with the host. The client 210 outputs its output signal via a link 818 via the communication module 418 via the client 210 to an input 813 of a system 812 controlled by the automation network 1. The system 812 in turn sends a signal to the input of the client 210 via an output 814 by means of the communication link 819. In addition to the radio-based communication links 911 and 912, the client 210 also has a communication link 915 to the host. If necessary, the local processing module 412 generates an output value packet 999 for output to the input 813 of the connected system 812.

[0053] The local processing module 412 may be implemented as an application. Other possible implementations include implementing the module as hardware in the form of, for example, an ASIC or FPGA. Of course, the module may also be provided in the form of software, firmware, or hardware in a multi-function processor or dedicated hardware. The local processing module 412 may be sent via an alternative communication link 915. The communication link may be implemented as a broadband radio link with lower latency requirements (e.g., according to the 5G eMBB standard).

[0054] In general, an output value packet on a client does not necessarily have to be executed directly at the output of the automation network. The output value packet can also be a parameter of a control process. An example is an instruction for changing direction from the host, which is output via the client to the vehicle as a connected system. Depending on the current state of the vehicle, the client can then execute this instruction in different ways, for example, by issuing commands to control elements in the vehicle or by changing the speed of individual drives of the vehicle, without the host having to explicitly describe the details of the execution on the client in the output value packet.

[0055] The same applies to input value data packets transmitted from the client to the host. The client may also transmit data received from a connected system to the host without change. However, the client may also evaluate and process data that has been received from, for example, a vehicle as a connected system before forwarding it to the host. For example, the client may convert the rotation speed and data for the spatial orientation of the vehicle into an input value packet that contains only the current speed and direction of movement of the vehicle.

[0056] Figure 5 The normal time course of the communication between the system 812, the client 210 and the host 110 according to the prior art is shown. For this purpose, the time arrows corresponding to these systems are marked with the reference symbols of the corresponding components. The input values ​​814 of the automation network (i.e. the outputs of the connected system 812) are transmitted by the client as input value packets 998 to the host, and the host sends the output value packets 999 to the client after appropriate processing. The client then determines the output value 813 and transmits it to the input end of the system 812. After the client sends the input value packet 998 to the host, a timer with a delay time 995 is started on the client. Of course, other events can also be used to start the timer.

[0057] Corresponds to Figure 5 , Figure 6 The time course according to the invention is shown, in which the transmission of an output value packet 999 is interrupted and / or occurs only delayed. This may occur, for example, due to a burst error on the radio transmission link. The wavy lines represent interference with the direct transmission of the input value data packet. After a predetermined delay time 995 has elapsed, the client generates a replacement output value packet 991 and outputs the corresponding output value 813 to the system 812. Figure 6 The process not shown in the figure is that, on the one hand, if there is no expected input value packet, the host sends a repeat request to the client, and on the other hand, when there is no expected output value packet, the client can send a repeat request to the host.

[0058] Figure 7 998 is shown as the process when the input value packet 998 is sent to the client with a delay. Figure 6 As in , here too, after a delay time 995, the client takes over the generation of an alternative output value packet 991, since the host did not provide it with a corresponding packet on time, and accordingly outputs data 813 to the system. This delayed transmission of two input value data packets to the host is represented by the inclination of the arrow representing the transmission of the input value data packet 998. If an input value packet arrives at the host with a delay, the host accelerates the evaluation of the input value packet 998. When the host, after processing all the delayed processed input value packets 998 distinguished by timestamps, now has a current output value packet 999 due to the accelerated processing, it outputs it to the client. The client then passes these output value packets 999 again to the system as output 813. This situation applies to the third input value packet, in Figure 7 The bottom is shown.

[0059] Figure 8 Contains a flow chart for describing a method for a fifth embodiment. The method starts in step S11. First, the current actual operating point is determined in step S13. In step S14, the host creates a new set of parameters for the local processing module for this operating point. In step S15, it is checked whether the basic operating point is still current, that is, the actual operating point has not moved so far from the basic operating point that the alternative control via the assigned processing module with the new parameterization can no longer foreseeably provide valid output values. If this is the case, if the basic operating point is still current, then in step S17 the new parameters are sent to the client, which uses these new parameters to parameterize and execute its local processing module 412 (see Figure 4 If it is determined in step S15 that the actual working point has moved too far from the basic working point, then in step S18 a local processing module 512 including an associated local processing module is created based on the actual working point (see Figure 3 ) and checks whether the processing module provides a sufficiently high control quality for the actual operating point in a sufficiently large area around the basic operating point. If this is not the case, the information is returned to step S18 in order to generate a more suitable processing module there. If the processing module is suitable for the regulation, it is transmitted to the client in step S16 and then returns to step 14 in order to now generate parameters for the current actual operating point based on the new processing module, which was sent to the client in step S17 after successful verification in step S15. The method ends in step S20.

[0060] Fig. 9is a description of the host operation for communicating with the client. The method starts in step S21. In step S22, it is checked whether an input value package 998 has been sent from the client. If this is not the case, the method returns to step S21. Otherwise, in step S23, the host generates an output value package 999 by appropriate processing, and data from other clients may also be used. If it is determined in step S24 that the timestamp of the input value package is current, it is checked in step S25 whether there is just no operation via the local processing module 412 on the client. The host can then output the output value package 999 just calculated to the client in step S26. If the operation via the local processing module is determined in step S25, the system returns to step S22 to determine whether there are other input value packages that have not yet been processed. The method ends in step S27.

[0061] It must be taken into account that the loss of input value packets is critical and should not occur, especially if the host has tasks such as recording or archiving system status. Therefore, if there are no expected input value packets, the host sends a request to the client, in which the host requests the client to repeat the transmission. Therefore, the client must have a buffer in which the input value packets sent by it are kept in a storage manner for a period of time, so that they can be sent again in case of a repeated request from the host.

[0062] exist Fig.10 , the operation on the client is shown. The method starts at step S31. In step S32, the client sends the current input data packet 998 to the host. At the delay time 995 (see step S33), the client sends the current input data packet 998 to the host. Figure 5-7 ) After that, the method checks in step S34 whether there is a corresponding output value packet 999 from the host. If this is the case, the packet is used as output data 813 (see Figure 4 ) is transmitted to the system. If the check result in step S34 is negative, it is checked in step S36 whether the local processing module 412 is ready. In addition, in this step S36, it is also checked whether the system moves within the time limit or position limit for the operation of the local processing module 412. If both conditions are met, the local processing module 412 generates an output value package 999 in step S37, which can then be output to the system in step S35. If no local processing module is ready, or the system has exceeded a predetermined time limit or position limit, the client executes an emergency procedure in step S39. Such an emergency procedure can, for example, stop a forklift or land a drone immediately. The method ends in step S40.

[0063] The above disclosure makes it possible to perform complex control tasks on a host when the host communicates with a client that outputs control variables via a packet-based digital radio link. This means that complex control tasks can be performed on a non-local automation system in mobile systems or other systems that are difficult to wire. Non-local here means that it is an external automation system for the client to be directly connected to the system to be controlled or regulated. Thus, for example, a compact drone whose client is limited in terms of system resources can be controlled and regulated using complex processes with high resource requirements.

[0064] Another advantage of the present disclosure is the adaptability of the control or regulation system implemented in the client device and with lower complexity compared to the host to adapt to the current situation, ie the actual operating point.

[0065] In the case of purely digital radio transmission, alternatively or in addition to the above-described methods, redundant radio channels that differ from one another may be used, for example in widely spaced frequency bands with different modulation methods and / or with different spatial transmission modes.

[0066] As an alternative to the digital radio process described above, optical communication methods can also be used. In this case, the sensitivity to interference can be reduced.

[0067] Although the present invention has been described based on embodiments, it can be modified in many ways.

[0068] Reference Numbers List

[0069] 1 Automation Network

[0070] 110 Host device

[0071] 112 Antenna on the host device

[0072] 210 Client Device 1

[0073] 212 Antenna 212 on client device 1

[0074] 220 Client Device 2

[0075] 230 Client Device 3

[0076] 240 Client Device 4

[0077] 290 Client Devices

[0078] Control and / or regulation module on 301 110

[0079] 319 Communication module of client 210

[0080] 401 Module on client 210

[0081] 412 Module on client 210

[0082] 418 Communication module on client 210 (to system)

[0083] 419 Communication module on client 210 (to host)

[0084] 512 Client 210 module

[0085] 812 System (with controlled system / switching path)

[0086] 813 System input (actuator / control element (e.g. relay coil))

[0087] 814 System output (sensor / measuring element / signal transmitter (e.g. limit switch))

[0088] 818 Communication link for output data (e.g. control variables / actuator signals) to the automation network of the system

[0089] 819 Communication link for input data (e.g. measured variables / encoder signals) to the automation network of the system

[0090] 910 Host-Client Communication Link

[0091] 911 Communication link to client 210 Downlink (part of 910)

[0092] 912 Communication link uplink from client 210 (part of 910)

[0093] 913 Downlink of alternative communication link to client 210 (part of 915)

[0094] 914 Downlink of alternative communication link to client 210 (part of 915)

[0095] 915 Host-Client Alternative Communication Link

[0096] 920 Host-Client Communication Link

[0097] 930 Host-Client Communication Link

[0098] 940 Host-Client Communication Link

[0099] 990 Host-Client Communication Link

[0100] 991 Alternative Output Value Package

[0101] 998 Data packets sent in the upstream direction

[0102] 999 Data packets sent in the downstream direction.

Claims

1. A method for operating an automation network (1), the automation network (1) having: A host device (110), at least one client device, and a packet-based communication link (910) between the host device (110) and the client device, The method comprises the following steps: generating an input value packet by the client device and sending the input value packet to the host device (110) via the communication link (910), generating an output value packet by the host device (110) and sending the output value packet to the client device via the communication link (910), and, If the client device does not receive at least one of the output value packets via the communication link (910) within a predetermined time period, the client device generates a substitute output value packet (991); the client device generates the substitute output value packet (991) based on at least one basic working point predetermined by the host device (110); the host device (110) derives the predetermined at least one basic working point at a predetermined time point; if at least one input value packet is not received within a predetermined time period on the communication link (910) in the direction from the client device to the host device (110), the host device (110) accelerates the generation of the output value packet until the host device (110) processes the current input value packet on time; and the client device continues to generate the substitute output value packet (991) until the current input value packet is received on the host device (110) and the host device (110) starts generating the output value packet from the time point.

2. The method according to claim 1, characterized in that The substitute output value package (991) is generated by the client device with the aid of a local processing module assigned to the client device.

3. The method according to claim 2, characterized in that Parameters for the local processing module are transmitted from the host device (110) to the client device.

4. The method according to claim 2 or 3, characterized in that: The host device (110) transmits the local processing module to the client device.

5. The method according to claim 1 or 2, characterized in that: generating, by the client device, a control variable for a controlled system from the output value packet, the controlled system receiving the control variable from the client device, and The input value packet is created by the client device based on measurement variables received from a measurement link.

6. The method according to claim 5, characterized in that The output value packet for deriving the control variable is generated by the host device (110) upon processing the input value packet created by the client device based on the measured variable.

7. The method according to claim 4, characterized in that The local processing module is sent by the host device (110) to the client device via an alternative communication link (915).

8. The method according to claim 4, characterized in that The local processing module is created by the host device (110) according to a basic working point predetermined by the host device (110).

9. The method according to claim 1, characterized in that: The substitute output value packet (991) is generated by the client device in the event that at least one packet is not received over the communication link (910) within a predetermined period of time until a time limit or a location limit is reached.

10. An automation network (1) comprising: A host device (110), at least one client device, and a packet-based communication link (910) between the host device (110) and the client device, in, The automation network (1) is configured to carry out the method according to any one of claims 1 to 9, The client device is configured to generate an input value packet and send the input value packet to the host device (110) via the communication link (910), and the host device (110) is configured to generate an output value packet and send the output value packet to the client device via the communication link (910), and, The client device is further configured to generate a replacement output value packet (991) if the client device does not receive at least one output value packet via the communication link (910) within a predetermined period of time.

11. A host device (110), configured to execute the method according to any one of claims 1 to 9. 12 . A client device, configured to execute the method according to claim 1 .

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