Fieldbus participant and automation system

Abstract

Fieldbus participant (22, 23) for a tool (16, 17), with a bus address for communication with a control device (3), with a bus node (27) configured for communication with the control device (3), and with a safety module (24), wherein the safety module (24) has a housing (31) in which a communication device (37) for receiving and sending data along a safety-related communication path is accommodated, wherein the housing (31) is provided on opposite side faces (33, 34) with connecting means (35, 36) configured for coupling with an internal communication system of the fieldbus participant (22, 23) comprising the safety-related communication path, wherein the communication device (37) is associated with an adjustment device (30) arranged in the housing,which is configured to establish a safety-related identification address and to feed this identification address into the safety-related communication path, wherein the communication device (37) includes a verification means configured for a functional check of the setting device (30) and which, after successful functional verification, enables the identification address to be forwarded via the communication device (37) in order to identify the bus node (27) with this identification address to the control device (3), wherein the identification address is used to recognize the tool (16, 17) in order to activate safety-related functions for the tool (16, 17) by the control device (3) and otherwise not to activate safety-related functions for the tool (16, 17).

Description

[0001] The invention relates to a fieldbus participant of an automation system that is at least partially safety-oriented. Furthermore, the invention relates to an automation system.

[0002] According to an undocumented prior art, a safety module for insertion or integration into a safety-related fieldbus participant is known. The fieldbus participant consists of several function modules and is equipped with a bus node for communication with a higher-level control unit. The safety module serves to forward safety-related and non-safety-related signals from an internal communication system originating from the bus node to the downstream function modules and / or from the function modules to the bus node. It also processes safety-related signals and forwards the processed signals via the internal communication system to the bus node and / or to the function modules.When using multiple, interchangeable fieldbus devices, which can be attached to differently designed tools of a handling and / or machining system, for example, to control actuators assigned to the tools, such as fluid cylinders, a unique identification address is required for communication between the control unit and the respective fieldbus device. This identification address is used by the control system to distinguish between the interchangeable fieldbus devices, while the communication address of the fieldbus devices on the differently designed, interchangeable tools is always the same with respect to the control system.The identification address, which is defined for each individual, interchangeable unit, serves for the individual transmission of safety-related control commands and sensor data between the control unit and the respective fieldbus participant. The identification address is provided by the safety module upon request from the higher-level control unit via a safety-related communication path. The identification address to be provided by the safety module is defined in a separate junction box, which is connected to the safety module via cables and contains a terminal block. The individual wires of the cable connections can be connected to this terminal block in such a way as to define the identification address.

[0003] DE 10 2009 042 354 A1 discloses an automation system with a communication master (preferably non-safety-related) and several decentralized modules, wherein the decentralized modules are configured as network participants and are networked with the communication master via a communication network, wherein communication between the decentralized modules in the communication network is implemented via telegrams, wherein at least two of the modules are safety modules between which safety-related data is transmitted and which form a logical group of modules for executing a safety-related function, and wherein the preferably non-safety-related communication master maintains a routing table in which logical connections between the decentralized safety modules are stored according to the safety-related function, wherein the communication master is configured toThe system is controlled by the routing table to automatically route data from the sending security module to the receiving security module, so that communication between security modules belonging to a logical group takes place via two point-to-point connections: from the sending security module to the communication master and then from the communication master to the receiving security module. The receiving security module is configured to perform a security-related action according to the received data, and the communication network has a means to query information from the security modules for creating a routing table and to create the routing table based on this information.

[0004] EP 1 847 891 A1 describes a safety circuit device for monitoring safety equipment of a technical plant, comprising an input device for specifying settings of one or more operating parameters of the safety circuit device and an optical display device for displaying the specified operating parameter settings for control purposes, wherein the input device is designed programmatically and / or circuit-wise to release the displayed operating parameters.

[0005] From DE 2 948 644 A1, a device for monitoring the contents of a memory cell of a memory of a microprocessor system is known, in which the memory is connected to the central unit via an externally accessible address and data bus, wherein the device has specific connections for coupling to the address and data bus and wherein a comparator device is provided which compares the addresses appearing on the address bus with a predetermined address and, in case of a match, outputs a signal which is supplied to a control device which causes the data belonging to the address in question to be passed through to a display device and / or storage device.

[0006] US 6,188,181 B1 discloses a signal generator for providing a variety of control schemes to connected ballasts or transformers to adjust the light output of a connected lamp or light source, wherein the control scheme is selected from the group: 0 to 10 V sink, 0 to 10 V source, pulse width modulated and digital serial interface, as well as a lighting control system for selectively controlling the respective light intensities of a variety of lighting loads of different load types.

[0007] The object of the invention is to provide a safety-oriented fieldbus participant and an automation system with such a fieldbus participant.

[0008] This problem is solved according to a first aspect of the invention for a fieldbus participant of the type mentioned at the outset with the features of claim 1. For this purpose, it is provided that the fieldbus participant has a bus address for communication with a control device, a bus node for the communicating connection with the control device, and a safety module, wherein the safety module has a housing with a communication device included therein, which is configured for receiving and sending data along a safety-related communication path, wherein the housing is provided on opposite side surfaces with connecting means designed for coupling with an internal communication system of the fieldbus participant, which comprises the safety-related communication path, and wherein the communication device is associated with an adjustment device arranged in the housing.which is designed to establish a security-related identification address and to feed this identification address into the security-related communication path.

[0009] Furthermore, according to the invention, the communication device includes a verification means designed for a functional check of the setting device and which, after successful functional verification, enables the forwarding of the identification address via the communication device in order to identify the bus node with this identification address to the control device, wherein the identification address is used to recognize the tool in order to activate safety-related functions for the tool by the control device and otherwise not to activate safety-related functions for the tool.

[0010] By arranging the setting device, which determines the identification address of the safety module, within the safety module's housing, the previously necessary plug and cable connections for coupling the control box to the safety module are eliminated. This also simplifies compliance with the protection rating typically required for such components of a fieldbus participant, for example, IP65, since complex cable penetrations or correspondingly sealed plug contacts are no longer necessary. Instead, the setting device is integrated into the safety module's housing, which already meets the required protection rating, thus simplifying the safety module's design. Preferably, the setting device includes at least one switching element for setting the identification address.For example, the setting device has several switching positions through which different identification addresses can be provided.

[0011] It is advantageous if the setting device comprises several switching elements, each of which can be switched between at least a first and a second switching position, so that each switching element serves as a storage unit for the identification address, particularly if it is digitally coded. This allows the user of the safety module to set the desired identification address for the safety module by operating the switching elements. The previously common practice of wiring the safety module's connecting cables to a terminal block to set the identification address, which involves greater effort, a higher risk of errors, and less direct traceability of the set identification address, is eliminated when using such a setting device.Preferably, the switching devices are designed such that they can be set, in particular exclusively, to a first and a second switching position, each representing one digit of a multi-digit, preferably digitally coded, and especially binary-coded, identification address. Advantageously, so-called DIP switches (dual-in-line packaging switches), as known from computer technology, are used as switching devices. These DIP switches are inexpensive, easy to operate, and have the advantage that the set identification address is immediately visible from the position of the individual switches.

[0012] In a further development of the invention, the setting device is designed according to a first safety category of a safety standard, and the communication device is designed according to a second safety category of the same safety standard, the second safety category being at a higher level than the first safety category within the safety standard. National or international standards are available as safety standards, for example, which specify the requirements for the reliability and / or defined behavior of components of the automation system in the event of a fault, and in which the operational reliability or fail-safety of the components is typically classified into clearly distinguishable safety classes or safety categories.Typically, a component that is to be assigned to a specific safety category of a safety standard must be examined and, if necessary, certified by the manufacturer and / or by an independent testing institute to ensure that it meets all the requirements of the respective safety category.

[0013] Designing components of an automation system to meet the requirements of a specific safety category can be quite costly during the design, manufacturing, and, if applicable, integration phases of the components into the respective work system, thus negatively impacting the manufacturing costs for each component. Therefore, it is advisable to design as few components of the automation system as possible according to a high safety category of a safety standard, while the remaining components are designed according to lower safety categories. In practice, this can mean, for example, that components belonging to a higher safety category have a lower probability of failure than components belonging to a lower safety category.

[0014] The verification means according to the invention can, for example, check whether an identification address set on the setting device lies within a predefined address space and / or whether a change in the identification address has occurred within a predefined period. If the verification means conclude that the function of the setting device is correct, they can forward the determined identification address to the bus node, which identifies itself to the control device with this identification address.

[0015] The object of the invention is achieved according to a second aspect of the invention for an automation system with the features of claim 4. This automation system has a control device for controlling fieldbus participants and at least one fieldbus participant according to the invention, which comprises at least one functional module from the group consisting of: input / output module, valve module, control module.

[0016] The input / output modules are used to provide control signals to sensors or actuators and / or to receive sensor signals. Valve modules can be used to influence fluid flows to and / or from actuators. Control modules can be used, for example, to control electric motors. Preferably, the functional modules are arranged along a linear axis and electrically and, if necessary, fluidically coupled to one another using suitable connecting means. A bus node is typically provided at the beginning of such a linear arrangement of functional modules, enabling communication between the functional modules and the higher-level control system. This communication can be carried out, for example, via a fieldbus system. An internal bus protocol, particularly a proprietary one, can be used for communication between the functional modules and the bus node.For the transmission of safety-related signals, a safety-related communication path is provided, which is configured between the bus node, a safety module coupled to the bus node, and at least one function module within an internal communication system. The safety module is responsible for identifying, evaluating, and processing the safety-related signals transmitted via the safety-related communication path and for generating new safety-related signals from them. These signals are used, for example, to control a safety-related function module and / or to forward sensor signals from a safety-related function module to the higher-level control unit via the safety-related communication path and the bus node.

[0017] In an advantageous further development of the automation system, the control unit is configured to process a safety-related identification address of the communication device, which is transmittable via a safety-related communication path. The provision of the identification address from the fieldbus participant to the control unit is a prerequisite for the processing and provision of safety-related signals and control commands within the control unit, which is at least partially safety-related. This is only meaningful if the control unit knows which fieldbus participant can be addressed with safety-related control commands and / or which fieldbus participant can provide safety-related signals, particularly sensor signals.

[0018] Accordingly, in a further configuration of the automation system, the control device is designed, depending on the provided identification address, to provide safety-related control signals to fieldbus participants and to receive safety-related status signals from fieldbus participants.

[0019] An advantageous embodiment of the automation system provides that an interface is included in the communication link between the control unit and a fieldbus participant, which is configured for automated connection and / or disconnection of the fieldbus participant to and / or from the control unit. This is particularly relevant when the control unit in the automation system is assigned to a handling and / or processing system that includes several interchangeable tools.For example, an industrial robot is configured as an automation system and includes a control unit for controlling drives for the individual axes of a robot arm, a tool interface that allows the attachment of interchangeable tools, and several interchangeable tools, at least one of which is equipped with at least one actuator and is therefore equipped with a fieldbus participant for controlling this actuator. For example, the tool is configured as a gripper to grasp objects such as body parts for a motor vehicle. In order to operate the automation system in accordance with the applicable safety regulations, the control unit and the at least one tool equipped with the fieldbus participant are designed to comply with a predefined safety category of a safety standard.This includes, in particular, the safe transmission of control signals from the control unit to the fieldbus participant and, if necessary, also the safe transmission of sensor signals from sensors on the tool via the fieldbus participant to the control unit. To ensure rapid resumption of use of the automation system after a tool change, especially an automated one, the control unit, the fieldbus participant, and the interface between them are designed such that the fieldbus participant's identification address is transmitted to the control unit immediately after it is connected to the interface, allowing the control unit to provide the appropriate control commands to the fieldbus participant without significant delay.

[0020] According to the invention, the control device uses the identification address to recognize the individual tool, on the basis of which a suitable activation of safety-related functions takes place, while in all other cases no such activation takes place, so that no safety-relevant process such as a gripping process is started.

[0021] An advantageous embodiment of the invention is shown in the drawing. Here, the drawing shows: Fig. 1 a schematic representation of an automation system comprising an industrial robot and interchangeable tools for the industrial robot, Fig. 2 a schematic representation of an interchangeable tool for the industrial robot and Fig. 3 A schematic representation of a safety module for a fieldbus participant in the automation system.

[0022] In the Fig. Figure 1 shows an automation system 1, which includes, by way of example, an industrial robot 2 and a control unit 3. The industrial robot 2 is intended for handling workpieces not shown in detail, such as car body parts. Several robot drives 3 to 7, which are designed as rotary drives, are provided for moving the industrial robot 2. The industrial robot 2 can, for example, be fixed to a stationary robot base 8, which may be designed as a foundation in a production plant. The industrial robot 2 includes, by way of example, four robot arm sections 9 to 12, each of which is rotatably connected to one another by means of a robot drive 5 to 7. For coordinated movement of the robot arm sections 9 to 12, the robot drives 4 to 7 are electrically connected to the control unit 3, which may, in particular, be a programmable logic controller (PLC).

[0023] A tool interface 15 is provided on a distally arranged robot arm section 12, enabling the attachment of an interchangeable tool 16, 17 to the industrial robot 2. For this purpose, the tool interface 15 is equipped with an actuator (not shown) that locks and unlocks the respective tool 16, 17. The actuator is integrated into the robot arm section 12 and is electrically connected to the control unit 3. Furthermore, the tool interface 15 is also electrically connected to the control unit 3 to allow the transmission of control commands from the control unit 3 to the tool 16, 17 and, if necessary, the transmission of sensor signals from the tool 16, 17 to the control unit 3.For an electrical connection between the tool interface 15 and the respective tool 16, 17, contact means 18, 19 are provided in the tool interface 15 and on the tool 16, 17. These contact means are designed for the transmission of control commands and sensor signals between the tool 16, 17 and the control unit 3. Furthermore, the contact means can be designed for the transmission of electrical and / or fluidic energy.

[0024] The two in the are exemplary. Fig. The tools 16, 17 shown in Figure 1 are each equipped with a suction gripper arrangement 20 comprising several suction grippers 21. A fieldbus participant 22, 23, also referred to as a valve manifold, is provided for controlling the suction grippers 21. This fieldbus participant is designed to process the control commands from the control unit 3 for forwarding to the suction gripper arrangement 20 and, if necessary, to transmit sensor signals from the suction gripper arrangement 20 to the control unit 3.

[0025] The fieldbus participants 22 and 23 assigned to tools 16 and 17 are each connected to a device in the Fig. 3 equipped with the safety module 24 shown in more detail, which is designed for processing and forwarding safety-related control commands of the control device 3 and, if necessary, for processing and forwarding sensor signals from safety-related sensors, for example proximity sensors 25, 26, which may be provided on the suction gripper arrangement 20.

[0026] Preferably, digital data communication via a fieldbus is provided for the transmission of control commands and sensor signals between the control device 3 and the fieldbus participants 22, 23. The fieldbus is configured to transmit both safety-related and non-safety-related data. In the fieldbus participant 22, 23, the non-safety-related data, i.e., non-safety-related control commands and non-safety-related sensor signals, are processed by a bus node 27.Preferably, for internal data communication in the fieldbus participant 22, 23, which by way of example comprises in addition to the bus node 27 and the safety module 24 a valve module 28 and an input module 29, an internal, in particular proprietary, bus system different from the fieldbus is provided, which as an internal communication system is also designed for forwarding safety-related and non-safety-related control commands and sensor signals.

[0027] To enable a rapid continuation of the machining tasks to be performed by the industrial robot 2 after a tool 16, 17 has been replaced, the fieldbus participants 22, 23 of the tools 16, 17 and, if applicable, other tools not shown, are configured such that they always provide the same process image to the control unit 3. For the control unit 3, this means that after a tool change, it can address the individual functional components of the fieldbus participant 22, 23 now in use with control commands while retaining the bus addresses used previously, and sensor signals from sensors of the tool 16, 17 with bus addresses already used before the tool change are provided to the control unit 3.In order to nevertheless enable a differentiation of tools 16, 17, especially with regard to possibly different safety-related properties, the safety module 24 is given a . Fig. 3. A setting device 30, shown in more detail below, is assigned to the fieldbus participant 22, 23, with the aid of which a safety-related identification address can be defined. This address can be transmitted via the safety module 24 to the bus node 27 and from there to the control device 3. Preferably, a safety-related communication path is provided in the internal bus system of the fieldbus participant 22, 23, starting from the safety module 24, which ensures the secure transmission of the identification address to the bus node 27.

[0028] The safety module 24 is designed for integration into the fieldbus participant 22, 23, which consists of several functional modules, for example the bus node 27, the valve module 28, and the input module 29, and which are interconnected via plug connectors (not shown in detail). These plug connectors can be configured for transmitting electrical signals and, optionally, electrical power and / or pressurized fluid. Accordingly, the electrical signals of the internal bus system are preferably also transmitted via these plug connectors.

[0029] For the integration of the safety module 24 between the other functional modules 27, 28, 29, preferably in the immediate vicinity of the bus node 27, the safety module 24 has, by way of example, a substantially cubic housing 31. A [missing element] is provided in the [missing element] to close the housing 31. Fig. A removable cover (not shown) is provided, which can be placed on the housing 31 in a sealing manner and which can be sealed to the housing 31, for example, by screws that engage in threaded holes 32. A plug 35 and a socket 36 are provided on opposite side surfaces 33, 34 of the housing 31, which serve as plug connections to the Fig. The housing serves three adjacent functional modules 27, 28, 29 (not shown). An electrical circuit 37, designed as a safety circuit, is implemented on a printed circuit board. The electrical circuit 37 is connected, by way of example, to the plug 35 and the socket 36 via solder posts 38. The function of the electrical circuit 37 is to identify and process safety-related control commands contained in the internal bus protocol and to forward them to safety-related functional modules, for example, to the safety-related valve module 28.Furthermore, one task of the electrical circuit can be to prepare signals from a safety-oriented sensor system 25, 26, which are provided to the internal bus system via the input module 29, which is also designed to be safety-oriented, and which are preferably forwarded in the internal bus system by means of the safety-oriented communication path, for forwarding via the bus node 27 to the control device 3.

[0030] To enable a rapid continuation of the movement sequences of the industrial robot 2 after a tool change, the electrical circuit 37, also referred to as a communication device, includes the setting device 30, which is also arranged in the housing 31. By way of example, the setting device 30 is designed as a DIP switch (dual-in-line packaging switch) with, for example, eight individual switches 39 arranged in series. Each of the individual switches 39 can be set to a first or a second switching position. Preferably, the setting of the respective individual switch 39 to the first switching position is interpreted as a digital "low" signal, while the setting of the respective individual switch to the second switching position is interpreted as a digital "high" signal. Thus, with the example shown in the Fig.The setting device 30 shown in the diagram is digitally encoded with a total of 8 bits, thereby determining the identification address for the respective security module 24.

[0031] An advantage here is that no wiring of individual strands on a terminal block is required for encoding the identification address. Furthermore, it is advantageous that the set identification address can be quickly determined from the position of the individual switches 39. The setting device 30, which is preferably not designed for safety purposes, is monitored via the electrical circuit 37.

Claims

[1] Fieldbus participant (22, 23) for a tool (16, 17), with a bus address for communication with a control device (3), with a bus node (27) configured for communication with the control device (3), and with a safety module (24), wherein the safety module (24) has a housing (31) in which a communication device (37) for receiving and sending data along a safety-related communication path is accommodated, wherein the housing (31) is provided on opposite side faces (33, 34) with connecting means (35, 36) configured for coupling with an internal communication system of the fieldbus participant (22, 23) comprising the safety-related communication path, wherein the communication device (37) is associated with an adjustment device (30) arranged in the housing,which is configured to establish a safety-related identification address and to feed this identification address into the safety-related communication path, wherein the communication device (37) includes a verification means configured for a functional check of the setting device (30) and which, after successful functional verification, enables the identification address to be forwarded via the communication device (37) in order to identify the bus node (27) with this identification address to the control device (3), wherein the identification address is used to recognize the tool (16, 17) in order to activate safety-related functions for the tool (16, 17) by the control device (3) and otherwise not to activate safety-related functions for the tool (16, 17). [2] Fieldbus participant (22, 23) according to claim 1, characterized by, that the setting device (30) comprises several switching means (39) which are each switchable at least, in particular exclusively, between a first and a second switching position, so that each switching means (39) serves as a storage unit for the identification address, in particular digitally coded. [3] Fieldbus participant (22, 23) according to claim 1 or 2, characterized by that the setting device (30) is designed in accordance with a first safety category of a safety standard and that the communication device (37) is designed in accordance with a second safety category of the safety standard, the second safety category being at a higher level than the first safety category within the safety standard. [4] Automation system with a control device (3) for controlling fieldbus participants (22, 23) and with at least one fieldbus participant (22, 23) according to one of the preceding claims, comprising at least one function module (28, 29) from the group: input / output module, valve module, control module. [5] Automation system according to claim 4, characterized by , that the control device (3) is set up for processing a security-related identification address of the communication device (27) which is transmissible via a security-related communication path. [6] Automation system according to claim 5, characterized by, that the control device (3) is designed, depending on the provided identification address, to provide safety-related control signals to fieldbus participants (22, 23) and to receive safety-related status signals from fieldbus participants (22, 23). [7] Automation system according to claim 5 or 6, characterized by , that in a communication link between the control device (3) and a fieldbus participant (22, 23) an interface (15) is provided which is designed for automated connection and / or disconnection of the fieldbus participant (22, 23) to and / or from the control device (3). [8] Automation system according to claim 5, 6 or 7, characterized by , that the control device (3) is assigned to a handling and / or processing system (2) which includes several interchangeable tools (16, 17).

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