Method for automatically assigning identifiers to controlled nodes in a fieldbus network

Abstract

The present invention relates to a method for automatically assigning identifiers to controlled nodes of a fieldbus network, the controlled nodes comprising a plurality of electric motor drive systems, IO devices and / or feedback sensors, wherein the method comprises the following steps: ‑setting the fieldbus network to a service mode; ‑scanning the fieldbus network; ‑decomposing the fieldbus network into linear branches and switches; ‑scanning each linear branch; and ‑assigning a unique identifier to the controlled nodes of the fieldbus network, wherein the identifier comprises a relative position and a node number of the controlled node in the fieldbus network. The present invention also relates to a fieldbus network comprising a plurality of controlled nodes, preferably comprising an electric motor drive system, wherein the fieldbus network is configured to perform the method for automatically assigning identifiers.

Description

Technical Field

[0001] The present invention relates to a method for automatically assigning identifiers to controlled nodes of a fieldbus network, the controlled nodes comprising a plurality of electric motor drive systems, IO devices and / or feedback sensors, wherein the method comprises the following steps: - placing said fieldbus network into service mode; - scanning the fieldbus network; - decomposing the fieldbus network into linear branches and switches; - Scan each linear branch; and - assigning a unique identifier to the controlled node of the fieldbus network, wherein the identifier comprises a relative position and a node number of the controlled node in the fieldbus network.

[0002] The invention further relates to a fieldbus network comprising a plurality of controlled nodes, preferably an electric motor drive system, wherein the fieldbus network is arranged for performing a method for automatically assigning identifiers. Background Art

[0003] The establishment of a fieldbus network, such as for example the Ethernet Powerlink fieldbus, requires the assignment of identifiers to the components of the fieldbus. This usually requires a number of manual assignment steps performed by an operator.

[0004] A problem with this procedure is that it is susceptible to errors introduced by the operator during the dispensing process. Summary of the invention

[0005] The object of the invention is to improve the establishment of a fieldbus network by reducing the number of errors that may occur during the establishment. This object is achieved by a method according to claim 1 and a fieldbus network according to claim 10. Preferred embodiments of the invention are subject to the dependent claims.

[0006] According to claim 1, a method for automatically assigning identifiers to controlled nodes of a fieldbus network is provided. The controlled nodes include a plurality of electric motor drive systems, IO devices and / or feedback sensors. The method comprises the following steps: - placing said fieldbus network into service mode; - scanning the fieldbus network; - decomposing the fieldbus network into linear branches and switches; - Scan each linear branch; and - assigning a unique identifier to the controlled node of the fieldbus network, wherein the identifier comprises a relative position and a node number of the controlled node in the fieldbus network.

[0007] The scanning of the fieldbus network and the assignment of identifiers can be performed completely or almost completely automatically, reducing the risk of manual errors.

[0008] In a preferred embodiment of the invention, at least one of the steps is performed automatically and / or the steps of the method comprise manually setting an identifier of a specific controlled node selected by means of a location index.

[0009] In this embodiment, specific controlled nodes may be manually set to desired identifiers, thereby providing flexibility in the establishment of a fieldbus network.

[0010] The location index and the node number are two different entities. Each node on a fieldbus network can have a location index and a node number (or ID). For example, in the configuration "PLC-CN1-CN2-CN3", CN2 is the second node (location index 2), but it can have any ID or node number. For example, you may decide to assign IDs in ascending order starting from the value 100. So, for the above configuration, the location index and ID may become: PLC-CN1 (ID 100) - CN2 (ID 101) - CN3 (ID 102).

[0011] In another preferred embodiment of the present invention, at least some of the steps are performed by a software application running on a computer connected to the fieldbus network, wherein preferably some or all of the controlled nodes are assigned unique identifiers as incremental or decremental values ​​starting from a selected node number.

[0012] The computer may be an integral component of the Fieldbus network, or it may be an external device, such as a laptop, tablet or smartphone, connectable to the Fieldbus network.

[0013] In another preferred embodiment of the present invention, at least some of the steps are performed by at least one Power Supply Module (PSM) and / or at least one Decentral Access Module (DAM) triggered by a Local Control Panel (LCP), wherein preferably some or all of the controlled nodes are assigned a unique identifier as an incremented or decremented value starting from a selected node number.

[0014] In another preferred embodiment of the present invention, at least some of the steps are performed by a decentralized access module (DAM) triggered by a programmable logic controller (PLC), wherein preferably, some or all of the controlled nodes are assigned a unique identifier as an incremented or decremented value starting from a selected node number, and wherein the assigned controlled nodes are connected to the same hybrid cable of the decentralized access module (DAM).

[0015] In another preferred embodiment of the present invention, setting the fieldbus network to the service mode comprises: automatically setting at least some or preferably all of the controlled nodes to the service mode.

[0016] In another preferred embodiment of the present invention, the controlled node comprises at least one multi-axis servo drive system (MSD), preferably comprising one or more integrated servo drives (ISD) and / or decentralized servo drives (DSD), and / or the fieldbus network is an Ethernet Powerlink fieldbus.

[0017] In another preferred embodiment of the present invention, the multi-axis servo drive system (MSD) comprises the power supply module (PSM) and the decentralized access module (DAM), and / or one or more auxiliary capacitor modules (ACM) and / or one or more servo drive modules (SDM).

[0018] In another preferred embodiment of the present invention, the controlled node is set into the operational mode after being assigned its unique identifier.

[0019] The network and / or all of its controlled nodes may be automatically set to service mode at the start of the process. Once a controlled node is assigned a unique identifier, the node may be requested to exit service mode, i.e., be set to operational mode. Once all nodes have been assigned their identifiers, a broadcast "service mode off" command may be sent to them to ensure that the entire network returns to normal operating conditions. Operation of the network may begin immediately without requiring any manual steps, such as resetting or restarting or power cycling the entire network to exit service mode. All of these steps may be performed automatically.

[0020] The invention also relates to a fieldbus network comprising a plurality of controlled nodes, preferably an electric motor drive system, wherein the fieldbus network is arranged for performing a method according to any one of claims 1 to 9. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Further details and advantages of the invention are described with reference to the embodiments shown in the accompanying drawings. The drawings show:

[0022] Figure 1: Ethernet Powerlink fieldbus with connected devices;

[0023] Figure 2a : ID allocation of the entire fieldbus network managed by the toolbox;

[0024] Figure 2b : ID assignment of devices visible from PSM eth2 port triggered by LCP;

[0025] Figure 2c : ID assignment of devices visible from PSM eth1 port triggered by LCP;

[0026] Figure 3a : ID assignment of drives visible from the DAM hybrid port triggered by LCP;

[0027] Figure 3b : ID assignment of drives visible from the DAM hybrid port triggered by the PLC;

[0028] Figure 4a : Central and decentral forwarding for configuration;

[0029] Figure 4b : Manual ID allocation;

[0030] Figure 5a : More details on the service model;

[0031] Figure 5b : State diagram for broadcast requests issued by DAM devices;

[0032] Figure 6a : State diagram for broadcast requests issued by other devices;

[0033] Figure 6b : State diagram for unicast requests issued by DAM devices;

[0034] Figure 7 : The identities of all nodes connected to the partition segment;

[0035] Figure 8a , 8b : Scanners for central and decentral lines;

[0036] Fig. 9 : A summary of the complete algorithms implemented by the toolbox;

[0037] Fig.10 : ID allocation procedure for central lines;

[0038] Fig.11a : ID allocation procedure for non-central lines;

[0039] Fig.11b : Automatic ID allocation using PSM;

[0040] Fig.12 : Non-central line ID allocation via LCP-triggered DAM;

[0041] Fig.13 : Non-central line ID allocation by DAM with ID x;

[0042] Fig.14 , 15a : Manual ID assignment via Toolbox / PSM;

[0043] Fig.15b : Manual ID assignment via PSM;

[0044] Fig.16a : Manual ID assignment via DAM; and

[0045] Fig.16b : Check the execution status. DETAILED DESCRIPTION

[0046] Figure 1 An Ethernet Powerlink fieldbus with connected devices is shown. The invention relates to establishing such a fieldbus network. In order to perform the establishment, identifiers (IDs) need to be assigned to the fieldbus components of the network. In particular, the assignment of identifiers has the following purpose: setting the node ID on all integrated servo drives (ISD), decentral servo drives (DSD) and / or multiaxis servo drive systems (MSD510) devices installed on the Ethernet Powerlink fieldbus.

[0047] ISD is a device that integrates control logic and controlled motors. DSD can be a device that integrates control logic for controlling external motors. MSD510 is a system that includes some or all of the following modules: - PSM——Power Supply Module - DAM - Decentral Access Module. A smart three-port switch capable of distributing power and network data to other devices. Having three ports means it can be used to create a tree-shaped network by adding corresponding sub-branches. - ACM——Auxiliary Capacitor Module - SDM——Servo Drive Module

[0048] In view of the described Ethernet Powerlink fieldbus, the presently described method comprises the following steps: - Set the fieldbus network to service mode; - Scan fieldbus network; - Decomposition of fieldbus networks into linear branches and switchers; - scan each linear branch; and - Assign a unique identifier to a controlled node of a fieldbus network, wherein the identifier includes the relative position and node number of the controlled node in the fieldbus network.

[0049] At least one of the steps may be performed automatically. Additionally or alternatively, another step of the method may include manually setting an identifier of a specific controlled node selected by the location index. Thus, depending on the circumstances, the present invention provides flexibility in establishing a fieldbus network.

[0050] Furthermore, at least some of the steps described may be performed by a software application running on a computer connected to the fieldbus network.Preferably, some or all of the controlled nodes may be assigned a unique identifier which is an incremented or decremented value starting from a selected node number.

[0051] The computer may be an integrated component of the fieldbus network or it may be an external device such as a portable computer, tablet or smartphone that can be connected to the fieldbus network. Thus, the assignment of identifiers can be easily performed under field conditions using already acquired equipment.

[0052] At least some of the steps may be performed by at least one power supply module (PSM) and / or at least one decentralized access module (DAM), preferably triggered by a local control panel (LCP).

[0053] At least some of the steps of the method may be performed by a decentralized access module (DAM) triggered by a programmable logic controller (PLC). As with other embodiments, some or all of the controlled nodes are assigned a unique identifier that is an increment or decrement value starting from a selected node number. The assigned controlled nodes may be connected to the same hybrid cable of the decentralized access module (DAM).

[0054] The controlled node may include at least one multi-axis servo drive system (MSD), preferably including one or more integrated servo drives (ISD) and / or decentralized servo drives (DSD), and / or the fieldbus network may be an Ethernet Powerlink fieldbus. The multi-axis servo drive system (MSD) may include a power supply module (PSM) and a decentralized access module (DAM) and / or one or more auxiliary capacitor modules (ACM) and / or one or more servo drive modules (SDM).

[0055] Once a unique identifier has been assigned to a controlled node, the node can be set to an operational mode. The network can be automatically set to a service mode at the start of the process and before the identifier is assigned. Once a controlled node is assigned a unique identifier, the node can also be requested to exit the service mode, i.e., set to an operational mode.

[0056] Once all nodes have been assigned their identifiers, a broadcast "Service Mode OFF" command can be sent to them to ensure that the entire network returns to normal operating conditions. Operation of the network can begin immediately without requiring any manual steps such as resetting or restarting or power cycling the entire network to exit service mode. All of these steps can be performed automatically.

[0057] In a Powerlink network, before the system can be set to an operating state or operating mode, each controlled node (CN) can be assigned a unique ID, for example in the range of 1 to 239. Thus, the invention provides the possibility to perform one or more of the following operations via a local control panel (LCP), a tool box or a programmable logic controller (PLC): - Automatically set the node ID on all connected devices via the toolbox as an increment / decrement value starting from the selected ID, e.g. Figure 2a shown. - Automatically set the node ID on all devices connected to the network branch by using LCP-triggered PSM / DAM, such as Figure 2b , Figure 2c and Figure 3a shown. - Automatically set the node ID on the drive devices of the same hybrid cable connected to a single DAM via the PLC as an increment / decrement value starting from the selected ID, e.g. Figure 3b shown. - Manually set the Node ID via the Toolbox or LCP on a specific device selected by the location index.

[0058] The LCP may be an external device with, for example, a display and / or keyboard, used as a human-machine interface. It may be connected to a single device of a fieldbus network, for example, by a cable.

[0059] Toolbox can be understood as a software application running on a normal PC connected to the fieldbus network, for example via Ethernet. The toolbox software can act as a management node and can perform network scanning and node ID assignment algorithms.

[0060] The LCP itself may not have the ability to execute any of the algorithms or steps of the presently described invention. It can only be used to specify input parameter values ​​and then prompt the connected device (PSM or DAM device) to apply these input parameter values ​​to execute the ID allocation algorithm.

[0061] Implementing a full network scan and node ID assignment algorithm on a PLC presents some challenges. The use of LCP described herein enables input parameter values ​​to be specified on the PLC. Once the input parameter values ​​are specified, the PLC prompts or prompts a specific DAM device to apply these input values ​​to execute the ID assignment algorithm.

[0062] Figure 2a to Figure 2c , Figure 3a and Figure 3b Various possibilities for node ID assignment of the present invention are shown. Figure 2a Shows the ID assignment for a fieldbus network managed by the toolbox. Figure 2b Node ID assignment for a device visible from the PSM eth2 port and triggered via LCP is shown. Figure 2c Node ID assignment for a device visible from the PSM eth1 port and triggered via LCP is shown. Figure 3a Shown is the Node ID assignment for the drives visible from the DAM hybrid port and triggered via the LCP. Figure 3b Shown is the Node ID assignment for the drives visible from the DAM hybrid port and triggered by the PLC.

[0063] Figure 4aAt the top, central forwarding of packets configured for the DAM device is shown, and at the bottom, non-central forwarding of packets configured for the DAM device is shown. In order for both automatic ID assignment and manual ID assignment to work properly, the DAM device is correctly configured by the toolbox or PSM so that incoming packets are forwarded on the central line or the non-central line as shown.

[0064] For this purpose, a set of 32-bit registers is implemented in a field programmable gate array (FPGA). The high order 16 bits of the first register may contain the bits to mask the port connection, as shown in the following table:

[0065] Each bit is used to disable / enable the corresponding connection between ports. For example, setting bit 23 high disables the forwarding of packets in the hub from port 1 to port 3.

[0066] In order to perform network scanning and ID assignment algorithms on complex network topologies, it is necessary to control the routing and forwarding of Ethernet frames or packets on the network. This is feasible for all devices belonging to the currently described method and fieldbus network. This is a feature that can be considered generally available on any advanced multi-port network device.

[0067] An important feature of the invention is the creation of specific routing paths, which make it possible to divide a complex tree network into individual linear sub-branches.

[0068] Manual ID assignment is achieved by setting all devices connected on the fieldbus network to "Service Mode". Service Mode means that messages introduced at the input of any port will not appear at the output of other external ports, such as Figure 4b shown.

[0069] The service mode is implemented by some special TFTP (Trivial File Transfer Protocol) write transfer commands. This requires a dedicated continuous task in the device NIOS firmware, which is an instance of a class called CserviceModeTftpD.

[0070] In particular, the following commands may be managed by this class, concerning central or non-central forwarding of packets: - Service Mode ON - Service Mode OFF - ServiceMode CentralOFF (DAM only) - ServiceMode CentralON (DAM only) - ServiceMode DecentralOFF (DAM only) - ServiceMode DecentralON (DAM only).

[0071] Commands can always be sent to a broadcast destination (e.g., node ID 255). For DAMs only, a single DAM device can be addressed, specifying the device MAC address as the command variable. The MAC address, by definition, can be a unique "burned-in" address assigned by the manufacturer of the corresponding hardware. When performing a network scan of the present invention, the uniqueness of the MAC address can be checked anyway, as it may be necessary to check the uniqueness of the DAM's MAC address for some reason. If no MAC address is specified, the command can be processed in a broadcast manner by any DAM that receives it.

[0072] like Figure 5a As shown in more detail in , a service-mode on / off disables / enables forwarding of packets on all ports of each device that receives the corresponding request. The remaining commands make sense only for the DAM: a non-central off / on of service-mode disables / enables forwarding on the DAM driver port (eth2), while a central off / on of service-mode keeps forwarding of packets enabled / disabled on only the DAM driver port (eth2).

[0073] For DAM devices only, it is possible to change the service mode configuration using requests addressed to all or exactly one specific device. In particular, when a broadcast request (without specifying a MAC address) is issued on the fieldbus network, Figure 5b The state diagram is applicable.

[0074] An invalid transition request can be any request that is not reported in the list of valid "Broadcast" transitions. Such requests may simply be ignored. For all other devices, i.e. devices other than DAMs, the only valid broadcast service mode commands may be service mode on and service mode off. Any other commands may simply be ignored, such as Figure 6a As indicated.

[0075] For DAM only, when using a single device request, Figure 6b The state diagram is applicable.

[0076] An invalid transition request may be any request that is not reported in the list of valid "Unicast" transitions. Such requests may again simply be ignored. Broadcast requests received while in Service Mode Uni may also be ignored. A Unicast Service Mode On request received while in Service Mode Uni Centrall OFF may be broadcast over the driver (eth2) port, leaving the DAM itself in Service Mode Unicast Centrall OFF. All devices, DAM devices or non-DAM devices, that receive "Unicast" commands that are addressed to different recipients may simply ignore them, since "Unicast" commands may be sent using broadcast transmissions anyway.

[0077] For both automatic ID assignment and manual ID assignment, it may be required to identify all devices reachable on the fieldbus network. This can be achieved through a network scan operation. During a network scan, the full network can be divided into central and non-central segments using service mode commands. Any divided segments are checked to identify all nodes connected to the segment itself, such as Figure 7 The flowchart is shown in FIG.

[0078] Scanning each segment via a central or non-central machine may require some additional special TFTP messages, such as Figure 8a and Figure 8b In particular, GetInfo request and Info packet reply messages may be used. The Info packet reply data may provide a complete device identification, including device type, software version, and MAC address.

[0079] When performing network-wide automatic ID assignment either through the toolbox or through PSM, the network can be divided into central and non-central segments using service mode commands and using an algorithm similar to the one previously described for the network scan operation. Any segment that has been divided can have IDs assigned to all of its nodes. A scan can then be performed after the IDs have been assigned to detect the presence of DAM devices, which can be the origin of new non-central line branches. The procedure is iterated until all discovered non-central lines have been processed. Fig. 9 The flowchart of summarizes the possible complete correspondence algorithms performed by the toolbox.

[0080] The assignment of IDs to nodes belonging to any segment (whether central or not) may require some additional special TFTP messages. In particular, NodeIdSet request and NodeId set / not set reply messages may be required, such as Fig.10 and Fig.11a The ID allocation procedure for central lines and non-central lines is described as shown in the flowchart of FIG.

[0081] In the event of an ID overflow / underflow (value 239 / 1 reached) or general error (ID not set), it may be necessary to verify the presence of additional nodes on the fieldbus network. Any nodes that are discovered should be taken out of service mode. The system user should then be informed of the incomplete ID assignment error. The same ID overflow handling can be applied to non-central line ID assignments.

[0082] In case the ID assignment is triggered on a PSM device by LCP or the toolbox, the algorithm executed by the toolbox may be the same, with the addition of disabling the Ethernet ports that were not selected for assignment before starting the execution of the procedure. Once all IDs have been assigned, the same port may be re-enabled. The handling of the entire procedure may be managed by a dedicated event task in the PSM firmware, which is an instance of the CNodeIdAssign class, such as Fig.11b Here, * indicates that the PSM will additionally ensure that the assigned ID is different from its own ID.

[0083] For ID assignment on a DAM device triggered by LCP or Toolbox, the algorithm can be similar to Fig.12 The algorithm described in the flowchart for non-central line ID assignment is as follows. Also, in this case, the DAM will ensure that overlaps with its own IDs are avoided. The handling of the entire procedure can be managed by a dedicated event task in the DAM firmware, which can be an instance of the CNodeIdAssign class.

[0084] For PLC-triggered ID assignment on a DAM device, the algorithm may be similar to the algorithm described above, with some relevant additions. Before the addressed DAM device begins executing the assignment algorithm, it may be necessary to: - Completely disable Eth1 ports and Eth3 ports (in both tx and rx directions); - Power off all drivers and shut down the UAUX 24V supply line; - Perform a software reset; and / or - Wait for all drives to be turned on and enter the network management (NMT) basic Ethernet state.

[0085] Once the assignment is complete, the DAM device can reset itself. This will also produce a final power cycle to all drivers via the UAUX 24V supply line. Fig.13 The entire procedure is summarized in the figure.

[0086] Manual assignment of node IDs is available on the toolbox after the fieldbus network has been scanned. The system user will then be able to manually select any device found on the network and assign a new ID to that device. Once the device has been selected and the new ID value has been inserted, the toolbox will have to use the appropriate procedure to reach the device and set the new ID, which will depend on the location of the device on the network. Two different procedures can be envisaged for this: one procedure is carried out if the selected device is connected to a fieldbus central line, and another procedure is for devices connected to non-central lines, such as Fig.14 and Fig.15a shown.

[0087] In case of manual ID assignment triggered by LCP on PSM devices, the algorithm is the same with the addition of disabling the Ethernet ports that were not selected for assignment before starting the procedure. Once all IDs have been assigned, the same port should be re-enabled. In addition, the relative device location index ( Fig.15a The x value in the flowchart can be an index selected by the user instead of a parameter being evaluated.

[0088] For manual ID assignment triggered by LCP on DAM devices, the algorithm remains similar to that performed by the toolbox. Fig.16a The x values ​​in the flowchart can be user selections rather than parameters being evaluated.

[0089] The toolbox provides PSM and DAM sub-tools for performing automatic ID assignment and manual ID assignment through the selected PSM or DAM device. The toolbox can be used to request PSM / DAM to perform ID assignment. That is, it can be used like LCP. When performing manual ID assignment through the PSM / DAM sub-tool, the position index value of the node to be assigned will be provided as a relative position value relative to the selected PSM / DAM. During the execution of ID assignment through PSM / DAM, the toolbox will accurately check the execution status, for example every one second, to avoid conflicts on the bus, such as Fig.16b shown.

Claims

1. A method for automatically assigning identifiers to controlled nodes of a fieldbus network, the controlled nodes comprising a plurality of electric motor drive systems, IO devices and / or feedback sensors, wherein the method comprises the following steps: - placing said fieldbus network into service mode; - scanning the fieldbus network; - decomposing the fieldbus network into linear branches and switches; - Scan each linear branch; as well as - assigning a unique identifier to the controlled node of the fieldbus network, wherein the identifier comprises a relative position and a node number of the controlled node in the fieldbus network.

2. The method according to claim 1, characterized in that At least one of the steps is performed automatically and / or the steps of the method include manually setting an identifier of a specific controlled node selected by means of a location index.

3. The method according to any one of the preceding claims, characterized in that At least some of the steps are performed by a software application running on a computer connected to the fieldbus network, wherein preferably some or all of the controlled nodes are assigned a unique identifier which is an incremented or decremented value starting from a selected node number.

4. The method according to any one of the preceding claims, characterized in that At least some of the steps are performed by at least one power supply module (PSM) and / or at least one decentralized access module (DAM) triggered by a local control panel (LCP), wherein preferably some or all of the controlled nodes are assigned a unique identifier as an incremented or decremented value starting from a selected node number.

5. The method according to any one of the preceding claims, characterized in that At least some of the steps are performed by a decentralized access module (DAM) triggered by a programmable logic controller (PLC), wherein preferably some or all of the controlled nodes are assigned a unique identifier as an incremented or decremented value starting from a selected node number, and wherein the assigned controlled nodes are connected to the same hybrid cable of the decentralized access module.

6. The method according to any one of the preceding claims, characterized in that Setting the fieldbus network to service mode comprises automatically setting at least some, or preferably all, of the controlled nodes to service mode.

7. The method according to any one of the preceding claims, characterized in that The controlled node comprises at least one multi-axis servo drive system (MSD), preferably comprising one or more integrated servo drives (ISD) and / or decentralized servo drives (DSD); and / or, the fieldbus network is Ethernet Powerlink fieldbus Ethernet.

8. The method according to at least one of claims 4 and 7, characterized in that The multi-axis servo drive system (MSD) comprises the power supply module (PSM) and the decentralized access module (DAM), and / or one or more auxiliary capacitor modules (ACM) and / or one or more servo drive modules (SDM).

9. The method according to any one of the preceding claims, characterized in that A controlled node is set into operational mode after being assigned its unique identifier.

10. A fieldbus network comprising a plurality of controlled nodes, preferably comprising an electric motor drive system, wherein the fieldbus network is arranged for performing the method according to any one of claims 1 to 9.

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