Title of Invention	AN AUTOMATION SYSTEM HAVING AT LEAST ONE MEASURED-VALUE DETECTION DEVICE
Abstract	The invention relates to an automation system comprising at least one device (2a, 2b, 2c) that detects measured values and is connected to a automated process (1), at least one field device (5, 6) which is connected to the at least one device (2a, 2b, 2c) detecting measured values, and a master computer (7) that is connected to the at least one field device (5, 6). In order to simplify the design of such an automation system as much as possible, the at least one device (2a, 2b, 2c) detecting measured values, the at least one field device (5, 6), and the master computer (7) are connected to a common data transmission network (3) which is equipped for transmitting digital measured data from the at least device (2a, 2b, 2c) detecting measured values to the at least one field device (5, 6) according to a first communication protocol and transmitting digital control data between the at least one field device (5, 6) and the master computer (7) according to a second communication protocol.

Title of Invention

AN AUTOMATION SYSTEM HAVING AT LEAST ONE MEASURED-VALUE DETECTION DEVICE

Abstract

The invention relates to an automation system comprising at least one device (2a, 2b, 2c) that detects measured values and is connected to a automated process (1), at least one field device (5, 6) which is connected to the at least one device (2a, 2b, 2c) detecting measured values, and a master computer (7) that is connected to the at least one field device (5, 6). In order to simplify the design of such an automation system as much as possible, the at least one device (2a, 2b, 2c) detecting measured values, the at least one field device (5, 6), and the master computer (7) are connected to a common data transmission network (3) which is equipped for transmitting digital measured data from the at least device (2a, 2b, 2c) detecting measured values to the at least one field device (5, 6) according to a first communication protocol and transmitting digital control data between the at least one field device (5, 6) and the master computer (7) according to a second communication protocol.

Full Text	Automation system The invention relates to an automation system having at least one measured-value detection device which is connected to an automated process, and having at least one field device, which is connected to the at least one measured-value detection device, and a host computer which is connected to the at least one field device. An automation system such as this is known, for example, from the "SICAM HV - Digitale Leistungsschaltersteuerung (Digital Breaker Control DBC)", Information Sheet Order NO.E5001-U113-A230/1 from Siemens AG. The Information Sheet discloses, specifically an automation system having a plurality of bus levels for an automated process, in this case relating to a power supply system. Converters, as measured-value detection devices and switch controls, are connected via a so-called process bus to field devices in the form of process controllers and protective devices. The field devices are in turn connected via a so-called field bus to a local controller, as a host computer. In addition to control commands for the switch controllers, the measured data detected by the converters, such as current and voltage measured-values are normally transmitted to the field devices via the process bus. Furthermore, the field devices can receive control commands via the field bus ' from the host computer and, in the opposite direction, can pass on information about the automated process to the local controller, for example in order to display information on a display system in a control panel. FIELD OF THE INVENTION The invention relates to an automation system having at least one measured-value detection device which is connected to an automated process, and having at least one field device, which is connected to the at least one measured-value detection device, and a host computer which is connected to the at least one field device. BACKGROUND OF THE INVENTION An automation system such as this is known, for example, from the "SICAM HV -Digitale Leistungsschaltersteuerung (Digital Breaker Control DBC)", Information Sheet Order No.E5001-U113-A230/l from Siemens Aktiengeselischaft. The Information Sheet discloses, specifically an automation system having a plurality of bus levels for an automated process, in this case relating to a power supply system. Converters, as measured-value detection devices and switch controls, are connected via a so-called process bus to field devices in the form of process controllers and protective devices. The field devise are in turn connected via a so-called field bus to a local controller, as a host computer. In addition to control commands for the switch controllers, the measured data detected by the converter, such as current and voltage measured-values are normally transmitted to the field devices via the process bus. Furthermore, the field devices can receive control commands via the field bus from the host computer and, in the opposite direction, can pass on information about the automated process to the local controller, for example in order to display information on a display system in a control panel. US4901218 teaches communications adaptor for automated factory machines such as CNC machine tools, co-ordinate measuring machines and industrial robots are connected in a local area network. Each machine controller is interfaced to the network via a communications adaptor which translates data, commands and programs between the Manufacturing Automation Protocal used by the network and the necessary machine-specific format. The communications adaptors are microprocessor-based and have additional input/output ports for controlling probes, other sensors such as temperature sensors and workpiece presence sensors, peripheral devices such as conveyors, and the "electronic handwheel" inputs of the machine controller. Controlling such devices from a program run in the communications adaptor rather than from the machine controller or from a computer on the network gives greater power, flexibility, convenience and potential for real-time control. US2002103946 teaches a master or slave devices for data communication on a bus, to which bus various devices are attached. The master device is able to address a slave device attached to the bus with messages using a plurality of different protocols and to ascertain whether the slave device responds correctly to the protocol. Thus it can work together with slave devices which command only a single protocol, and the protocols employed by the different slave devices can be different ones. At the same, a slave device capable of using a plurality of protocols is proposed, which is able to evaluate messages received over the bus according to a plurality of different protocols and, when the evaluation according to one of the employed protocols yields an executable instruction, the slave device is able to execute that instruction. W098/14853 describes a process control network with redundant field devices and buses. According to this invention, functional elements within a two-wire, loop-powered, two-way digital communications environment are interconnected using selective redundant connections and selective redundant functional elements. The redundant functional elements and redundant connections provide a smooth transition from operation of a primary process loop element to a secondary process loop element in the event of a failure of the primary process loop element. Redundancy is selectively implemented using a redundant pair of field devices or a redundant bus pair having a primary bus and a redundant bus. In a first case, redundancey is selectively implemented using a single set of communication media, such as a single communication loop, but implementing redundant functional elements, such as field devices, so that recovery is achieved upon failure of a functional element but not upon failure of the communication media. In a second case, redundancy is selectively implemented using a redundant set of communication media in addition to use of redundant devices so that recovery is attained both for a failing device and a failing communication media. In a third case, redundancy is selectively implemented using a redundant set of communication media but using a single device so that recovery is attained for a failing communication media but not for a failing device. Network interface has three ports that are hard-wired together via an interface circuit. One of the ports is an internal port with which a terminal is connected to the interface. Two of the ports are external ports with which network lines are connected to the interface. The ports operate in full duplex mode. Data can be distributed to the ports before a data packet is completely received. The invention is based on the object of simplifying even further a design of an automation system of this generic type. According to the invention, this object is achieved by an automation system of the type mentioned above, in which the at least one measured-value detection device, the at least one field device and the host computer are connected to a common data transmission network which is designed to transmit digital measured data from the at least one measured-value detection device to the at least one field device using a first communication protocol, and to transmit digital control data between the at least one field device and the host computer using a second communication protocol. The automation system according to the invention now has only one data transmission network, to which all of the components of the automation system are connected, instead of two mutually independent bus systems. In order to allow both digital measured data and digital control data to be transmitted via the data transmission network, it is suitable for transmitting the respective data using different communication protocols. Since there is only one network, to which all of the components of the automation system are connected, this further simplifies the design of the automation system. According to one advantageous embodiment of the automation system according to the invention, the data transmission network is a, Real-Time Ethernet network. Because of its high transmission rates and predictable transmission durations, the use of a Real-Time Ethernet network allows real time applications to be carried out in the automation system. Furthermore, the Real-Time Ethernet network also allows synchronization of measured data and control commands that are passed to the data transmission network. Furthermore, one advantageous development of the automation system according to the invention provides that actuator devices are also connected to the data transmission network, and are connected on the output side to the automated process. In this case, it is also possible to include actuators such as circuit breaker controllers in the common data transmission network. A further advantageous embodiment of the automation system according to the invention provides for the data transmission network to have a ring structure. A network structure such as this generally corresponds best to the design and local characteristics of an automation system. According to a further advantageous embodiment of the automation system according to the invention, the data transmission network comprises at least two mutually redundant network elements. This allows the availability and reliability of the installation to be further increased. One advantageous embodiment of the automation system according to the invention furthermore provides for the at least one measured-value detection device to have an analog/digital converter and a network connecting device for connection to the data transmission network. This allows measured-value detection devices to be connected to . the data transmission network particularly easily, and without additional components. In order to allow already existing measured-value detection devices to still be operated in the automation system according to the invention, one alternative embodiment provides' for the at least one measured-value detection device for conversion of the measured data to the first communication protocol to be connected to the conversion device which is connected on the output side to the data transmission network. Finally a further advantageous embodiment of the automation system according to the invention provides for the at least one field device and/or the at least one measured-value detection device to each be connected via a network connecting device to the data transmission network, with the network connecting device having one and only one internal port, which is connected to the at least one field device or to the measured-value detection device and two, and only two, external, ports which are connected to the data transmission network. Network connecting devices such as these such as those known from DE 102 60 806 Al ensure a simple capability to connect the field devices and/or the measured-value detection device to the data transmission network. In order to explain the invention further, the figure provides a schematic illustration of the design of an automation system. In this case the figure shows an automated process 1, which is not specified in any more detail, illustrated in a very highly schematic form. An automated process 1 such as this may, for example, be a chemical, technical or biotechnological process, an industrial manufacturing process or else a process for transmitting and distributing water, gas or electrical power. For the following statements, it should be assumed that the process 1 is a process for transmitting and distributing electrical power, for example an electrical power transmission system. In addition to actuator devices 11, such as switch controllers, measured-value detection devices 2a to 2c are connected to the process. These measured-value detection devices may be sensors as well as conventional current transformers or voltage transformers, for example toroidal-core transformers, or so-called unconventional converters, such as uniform-field coils or optical transducers. The measured-value detection devices 2a to 2c are connected to the process 1 in a manner corresponding to their embodiment; this is indicated by a dashed line in the figure. The measured-value detection devices 2a to 2c are also connected directly or indirectly to a data transmission network 3, which comprises two mutually redundant network elements 3a and 3b, of which the network element 3b is illustrated by dashed lines in the figure, for the sake of clarity. Although this exemplary embodiment makes reference to two network elements, there may, of course, be any desired number of network elements in practice. As shown in figure 1, the network elements 3a, 3b are networks with a ring structure; alternatively, of course, a conventional star structure can also be used. The two network elements 3a and 3b are connected to one another via a switch 4, so that data can be transmitted from one network element 3a to the other network element 3b, and vice versa. The data transmission network 3 is preferably an Ethernet network in the form of a so-called Real-Time Ethernet network. An IEC international working group are currently working on standardization of this Ethernet standard. Field devices 5 and 6 are also connected to the data transmission network 3. In this case, by way of example, the field device 5 may be an electrical protective device, and the field device 6 a process controller. Furthermore, the data transmission network 3 is connected to a host computer 7 which, for example, may be a station host computer or a central host computer in a so-called control center. The method of operation of the described automation system will be explained in the following text: Measured values which describe the process 1 are detected via the measured-value detection devices 2a to 2c, with this being, for example, current or voltage measured values. In this case, the measured-value detection devices 2a and 2c already have an analog/digital conversion device and a device for network connection. The measured-value detection devices 2a and 2c can therefore be connected directly to the data transmission network 3, and supply digital measured data corresponding to the recorded measured values to the data transmission network 3 using a first communication protocol. By way of example, this first communication protocol may be the IEC 61850-9-2 communication protocol, by means of which the IEC has defined the transmission of digital sample values in systems which are designed in accordance with IEC Standard 61850. In contrast, the measured-value detection devices 2b have no integrated analog/digital converter and no network connection, so that they first of all transmit their recorded measured values to a conversion device 8, also referred to as a so-called "merging unit", which then carries out analog/digital conversion and conversion of the measured values to digital measured data, using the first communication protocol that is used in the data transmission network 3. The conversion device has a network connection via which it can pass measured data directly to the data transmission network 3. The digital measured data is transmitted in the data transmission network 3 to the field devices 5 and 6, which carry out automation and control functions on the basis of the transmitted measured data. The field devices 5 and 6 can in turn pass control data to the data transmission network 3, with this data being transmitted using a second communication protocol for example the IEC 61850-8-1 communication protocol. In this protocol the IEC has defined the transmission of digital monitoring data, control data and control center data for systems which comply with IEC-61850, referred to in a summarized form here as control data. The digital control data can be transmitted on the one hand to the host computer 7, which can carry out further processing, archiving and conditioning of the data. In addition, digital control data can be transmitted to the actuator devices, such as circuit breaker controllers, which can in turn act on the process. The field devices 5 and 6 can therefore directly influence the process 1 via the data transmission network 3. In industrial automation systems such as the automation system described here, time synchronization of the individual data items transmitted via the data transmission network 3 often plays a very important role. In previous automation systems, a 'separate synchronization network generally had to be set up for this purpose, which distributed a clock generated by a central timer sender, for example one pulse per second, to the individual components of the automation system, thus allowing accurate time stamping of the transmitted and received digital data. The Real-Time Ethernet network standard does not require any such separate synchronization network. In this case, appropriate controllers or specifically designed integrated circuit modules in the form of ASICs (application specific integrated circuit), FPGAs (field programmable gate array) or EPLDS (electrically programmable logic device) are used within the network connection for all of the components which are connected to the data transmission network, and can implement appropriate time identification for the digital and measured or control data in accordance with the Real-Time Ethernet-Standard. This represents a major simplification to the design of the automation system. As is indicated only schematically in the figure, the network connection of the field devices 5 and 6 may, for example have a network connecting device with two and only two external ports 91, 9b, by means of which the field device is connected to the data transmission network 3. In addition, the network connecting device may have one and only one internal port 10, by means of which it is connected to the appropriate field device. The ports 9a, 9b and 10 are connected to one another via an appropriate hard-wired circuit which, for example is described in German Application DE 102 60 806 Al. A network connecting device such as this at the same time provides a switch functionality, so that received and transmitted data can be transmitted without any time delay between the individual ports of network connecting device, as a result of which no relevant time loss occurs during the data transmission in the data transmission network 3. Appropriate network connecting devices maybe provided in the measured-value detection devices 2a, 2b, 2c and/or in the actuator devices 11. WE CLAIM 1. An automation system having at least one measured-value detection device (2a, 2b, 2c) which is connected to an automated process (1), and having at least one field device (5, 6), which is connected to the at least one measured-value detection device (2a, 2b, 2c), and a host computer (7) which is connected to the at least one field device (5, 6), characterized in that - the at least one measured-value detection device (2a, 2b 2c), the at least one field device (5, 6) and the host computer (7) are connected to a common data transmission network (3) which is designed to transmit digital measured data from the at least one measured-value detection device (2a, 2b, 2c) to the at least one field device (5, 6) using a first communication protocol, and to transmit digital control data between the at least one field device (5, 6) and the host computer (7) using a second communication protocol. 2. The automation system as claimed in claim 1, wherein the data transmission network (3) is a Real-Time-Ethernet Network. 3. The automation system as claimed in claim 1 or claim 2, comprising actuator devices (11) connected to the data transmission network (3), and connected on the output side to the automated process (1). 4. The automation system as claimed in one of the preceding claims, wherein the data transmission network (3) has a ring structure. 5. The automation system as claimed in one of the preceding claims, wherein the data transmission network (3) comprises at least two mutually redundant network elements (3a, 3b). 6. The automation system as claimed in one of the preceding claims, wherein the at least one measured-value detection device (2a, 2b, 2c) has an analog/digital converter and a network connecting device for connection to the data transmission network. 7. The automation system as claimed in one of claims 1 to 5, wherein the at least one measured-value detection device (2a, 2b, 2c) is connected to a conversion device (8) for converting the measured data to the first communication protocol, which conversion device (8) is connected on the output side to the data transmission network (3). 8. The automation system as claimed in one of the preceding claims, wherein the at least one field device (5, 6) and/or the at least one measured-value detection device (2a, 2b, 2c) are each connected via a network connecting device to the data transmission network (3) with the network connecting device having one and only one internal port (10), which is connected to the at least one field device (5, 6) or to the measured-value detection device (2a, 2b, 2c) and two, and only two, external ports (9a, 9b) which are connected to the data transmission network (3). ABSTRACT TITLE : "AN AUTOMATION SYSTEM HAVING AT LEAST ONE MEASURED-VALUE DETECTION DEVICE" The invention relates to an automation system comprising at least one device (2a, 2b, 2c) that detects measured values and is connected to a automated process (1), at least one field device (5, 6) which is connected to the at least one device (2a, 2b, 2c) detecting measured values, and a master computer (7) that is connected to the at least one field device (5, 6). In order to simplify the design of such an automation system as much as possible, the at least one device (2a, 2b, 2c) detecting measured values, the at least one field device (5, 6), and the master computer (7) are connected to a common data transmission network (3) which is equipped for transmitting digital measured data from the at least device (2a, 2b, 2c) detecting measured values to the at least one field device (5, 6) according to a first communication protocol and transmitting digital control data between the at least one field device (5, 6) and the master computer (7) according to a second communication protocol.

Full Text

Automation system
The invention relates to an automation system having at least one measured-value detection device which is connected to an automated process, and having at least one field device, which is connected to the at least one measured-value detection device, and a host computer which is connected to the at least one field device.
An automation system such as this is known, for example, from the "SICAM HV - Digitale Leistungsschaltersteuerung (Digital Breaker Control DBC)", Information Sheet Order NO.E5001-U113-A230/1 from Siemens AG. The Information Sheet discloses, specifically an automation system having a plurality of bus levels for an automated process, in this case relating to a power supply system. Converters, as measured-value detection devices and switch controls, are connected via a so-called process bus to field devices in the form of process controllers and protective devices. The field devices are in turn connected via a so-called field bus to a local controller, as a host computer. In addition to control commands for the switch controllers, the measured data detected by the converters, such as current and voltage measured-values are normally transmitted to the field devices via the process bus. Furthermore, the field devices can receive control commands via the field bus ' from the host computer and, in the opposite direction, can pass on information about the automated process to the local controller, for example in order to display information on a display system in a control panel.

FIELD OF THE INVENTION
The invention relates to an automation system having at least one measured-value detection device which is connected to an automated process, and having at least one field device, which is connected to the at least one measured-value detection device, and a host computer which is connected to the at least one field device.
BACKGROUND OF THE INVENTION
An automation system such as this is known, for example, from the "SICAM HV -Digitale Leistungsschaltersteuerung (Digital Breaker Control DBC)", Information Sheet Order No.E5001-U113-A230/l from Siemens Aktiengeselischaft. The Information Sheet discloses, specifically an automation system having a plurality of bus levels for an automated process, in this case relating to a power supply system. Converters, as measured-value detection devices and switch controls, are connected via a so-called process bus to field devices in the form of process controllers and protective devices. The field devise are in turn connected via a so-called field bus to a local controller, as a host computer. In addition to control commands for the switch controllers, the measured data detected by the converter, such as current and voltage measured-values are normally transmitted to the field devices via the process bus. Furthermore, the field devices can receive control commands via the field bus from the host computer and, in the opposite direction, can pass on information about the automated process to the local controller, for example in order to display information on a display system in a control panel.
US4901218 teaches communications adaptor for automated factory machines

such as CNC machine tools, co-ordinate measuring machines and industrial robots are connected in a local area network. Each machine controller is interfaced to the network via a communications adaptor which translates data, commands and programs between the Manufacturing Automation Protocal used by the network and the necessary machine-specific format. The communications adaptors are microprocessor-based and have additional input/output ports for controlling probes, other sensors such as temperature sensors and workpiece presence sensors, peripheral devices such as conveyors, and the "electronic handwheel" inputs of the machine controller. Controlling such devices from a program run in the communications adaptor rather than from the machine controller or from a computer on the network gives greater power, flexibility, convenience and potential for real-time control.
US2002103946 teaches a master or slave devices for data communication on a bus, to which bus various devices are attached. The master device is able to address a slave device attached to the bus with messages using a plurality of different protocols and to ascertain whether the slave device responds correctly to the protocol. Thus it can work together with slave devices which command only a single protocol, and the protocols employed by the different slave devices can be different ones. At the same, a slave device capable of using a plurality of protocols is proposed, which is able to evaluate messages received over the bus according to a plurality of different protocols and, when the evaluation according to one of the employed protocols yields an executable instruction, the slave device is able to execute that instruction.
W098/14853 describes a process control network with redundant field devices and buses. According to this invention, functional elements within a two-wire,

loop-powered, two-way digital communications environment are interconnected using selective redundant connections and selective redundant functional elements. The redundant functional elements and redundant connections provide a smooth transition from operation of a primary process loop element to a secondary process loop element in the event of a failure of the primary process loop element. Redundancy is selectively implemented using a redundant pair of field devices or a redundant bus pair having a primary bus and a redundant bus. In a first case, redundancey is selectively implemented using a single set of communication media, such as a single communication loop, but implementing redundant functional elements, such as field devices, so that recovery is achieved upon failure of a functional element but not upon failure of the communication media. In a second case, redundancy is selectively implemented using a redundant set of communication media in addition to use of redundant devices so that recovery is attained both for a failing device and a failing communication media. In a third case, redundancy is selectively implemented using a redundant set of communication media but using a single device so that recovery is attained for a failing communication media but not for a failing device.
Network interface has three ports that are hard-wired together via an interface circuit. One of the ports is an internal port with which a terminal is connected to the interface. Two of the ports are external ports with which network lines are connected to the interface. The ports operate in full duplex mode. Data can be distributed to the ports before a data packet is completely received.

The invention is based on the object of simplifying even further a design of an automation system of this generic type.
According to the invention, this object is achieved by an automation system of the type mentioned above, in which the at least one measured-value detection device, the at least one field device and the host computer are connected to a common data transmission network which is designed to transmit digital measured data from the at least one measured-value detection device to the at least one field device using a first communication protocol, and to transmit digital control data between the at least one field device and the host computer using a second communication protocol. The automation system according to the invention now has only one data transmission network, to which all of the components of the automation system are connected, instead of two mutually independent bus systems. In order to allow both digital measured data and digital control data to be transmitted via the data transmission network, it is suitable for transmitting the respective data using different communication protocols. Since there is only one network, to which all of the components of the automation system are connected, this further simplifies the design of the automation system.
According to one advantageous embodiment of the automation system according to the invention, the data transmission network is a, Real-Time Ethernet network. Because of its high transmission rates and predictable transmission durations, the use of a Real-Time Ethernet network allows real time applications to be carried out in the automation system. Furthermore, the Real-Time Ethernet network also

allows synchronization of measured data and control commands that are passed to the data transmission network.
Furthermore, one advantageous development of the automation system according to the invention provides that actuator devices are also connected to the data transmission network, and are connected on the output side to the automated process. In this case, it is also possible to include actuators such as circuit breaker controllers in the common data transmission network.
A further advantageous embodiment of the automation system according to the invention provides for the data transmission network to have a ring structure. A network structure such as this generally corresponds best to the design and local characteristics of an automation system.
According to a further advantageous embodiment of the automation system according to the invention, the data transmission network comprises at least two mutually redundant network elements. This allows the availability and reliability of the installation to be further increased.
One advantageous embodiment of the automation system according to the invention furthermore provides for the at least one measured-value detection device to have an analog/digital converter and a network connecting device for connection to the data transmission network. This allows measured-value detection devices to be connected to . the data transmission network particularly easily, and without additional components.

In order to allow already existing measured-value detection devices to still be operated in the automation system according to the invention, one alternative embodiment provides' for the at least one measured-value detection device for conversion of the measured data to the first communication protocol to be connected to the conversion device which is connected on the output side to the data transmission network.
Finally a further advantageous embodiment of the automation system according to the invention provides for the at least one field device and/or the at least one measured-value detection device to each be connected via a network connecting device to the data transmission network, with the network connecting device having one and only one internal port, which is connected to the at least one field device or to the measured-value detection device and two, and only two, external, ports which are connected to the data transmission network. Network connecting devices such as these such as those known from DE 102 60 806 Al ensure a simple capability to connect the field devices and/or the measured-value detection device to the data transmission network.
In order to explain the invention further, the figure provides a schematic illustration of the design of an automation system.
In this case the figure shows an automated process 1, which is not specified in any more detail, illustrated in a very highly schematic form. An automated process 1 such as this may, for example, be a chemical, technical or biotechnological process, an industrial manufacturing process or else a process for transmitting and distributing water, gas or

electrical power. For the following statements, it should be assumed that the process 1 is a process for transmitting and distributing electrical power, for example an electrical power transmission system. In addition to actuator devices 11, such as switch controllers, measured-value detection devices 2a to 2c are connected to the process. These measured-value detection devices may be sensors as well as conventional current transformers or voltage transformers, for example toroidal-core transformers, or so-called unconventional converters, such as uniform-field coils or optical transducers. The measured-value detection devices 2a to 2c are connected to the process 1 in a manner corresponding to their embodiment; this is indicated by a dashed line in the figure. The measured-value detection devices 2a to 2c are also connected directly or indirectly to a data transmission network 3, which comprises two mutually redundant network elements 3a and 3b, of which the network element 3b is illustrated by dashed lines in the figure, for the sake of clarity. Although this exemplary embodiment makes reference to two network elements, there may, of course, be any desired number of network elements in practice. As shown in figure 1, the network elements 3a, 3b are networks with a ring structure; alternatively, of course, a conventional star structure can also be used. The two network elements 3a and 3b are connected to one another via a switch 4, so that data can be transmitted from one network element 3a to the other network element 3b, and vice versa. The data transmission network 3 is preferably an Ethernet network in the form of a so-called Real-Time Ethernet network. An IEC international working group are currently working on standardization of this Ethernet standard.

Field devices 5 and 6 are also connected to the data transmission network 3. In this case, by way of example, the field device 5 may be an electrical protective device, and the field device 6 a process controller. Furthermore, the data transmission network 3 is connected to a host computer 7 which, for example, may be a station host computer or a central host computer in a so-called control center.
The method of operation of the described automation system will be explained in the following text:
Measured values which describe the process 1 are detected via the measured-value detection devices 2a to 2c, with this being, for example, current or voltage measured values. In this case, the measured-value detection devices 2a and 2c already have an analog/digital conversion device and a device for network connection. The measured-value detection devices 2a and 2c can therefore be connected directly to the data transmission network 3, and supply digital measured data corresponding to the recorded measured values to the data transmission network 3 using a first communication protocol. By way of example, this first communication protocol may be the IEC 61850-9-2 communication protocol, by means of which the IEC has defined the transmission of digital sample values in systems which are designed in accordance with IEC Standard 61850.
In contrast, the measured-value detection devices 2b have no integrated analog/digital converter and no network connection, so that they first of all transmit their recorded measured values to a conversion device 8, also referred to as a so-called

"merging unit", which then carries out analog/digital conversion and conversion of the measured values to digital measured data, using the first communication protocol that is used in the data transmission network 3. The conversion device has a network connection via which it can pass measured data directly to the data transmission network 3.
The digital measured data is transmitted in the data transmission network 3 to the field devices 5 and 6, which carry out automation and control functions on the basis of the transmitted measured data. The field devices 5 and 6 can in turn pass control data to the data transmission network 3, with this data being transmitted using a second communication protocol for example the IEC 61850-8-1 communication protocol. In this protocol the IEC has defined the transmission of digital monitoring data, control data and control center data for systems which comply with IEC-61850, referred to in a summarized form here as control data. The digital control data can be transmitted on the one hand to the host computer 7, which can carry out further processing, archiving and conditioning of the data. In addition, digital control data can be transmitted to the actuator devices, such as circuit breaker controllers, which can in turn act on the process. The field devices 5 and 6 can therefore directly influence the process 1 via the data transmission network 3.
In industrial automation systems such as the automation system described here, time synchronization of the individual data items transmitted via the data transmission network 3 often plays a very important role. In previous automation systems, a 'separate synchronization network

generally had to be set up for this purpose, which distributed a clock generated by a central timer sender, for example one pulse per second, to the individual components of the automation system, thus allowing accurate time stamping of the transmitted and received digital data. The Real-Time Ethernet network standard does not require any such separate synchronization network. In this case, appropriate controllers or specifically designed integrated circuit modules in the form of ASICs (application specific integrated circuit), FPGAs (field programmable gate array) or EPLDS (electrically programmable logic device) are used within the network connection for all of the components which are connected to the data transmission network, and can implement appropriate time identification for the digital and measured or control data in accordance with the Real-Time Ethernet-Standard. This represents a major simplification to the design of the automation system.
As is indicated only schematically in the figure, the network connection of the field devices 5 and 6 may, for example have a network connecting device with two and only two external ports 91, 9b, by means of which the field device is connected to the data transmission network 3. In addition, the network connecting device may have one and only one internal port 10, by means of which it is connected to the appropriate field device. The ports 9a, 9b and 10 are connected to one another via an appropriate hard-wired circuit which, for example is described in German Application DE 102 60 806 Al. A network connecting device such as this at the same time provides a switch functionality, so that received and transmitted data can be transmitted without any time delay between the individual ports of

network connecting device, as a result of which no relevant time loss occurs during the data transmission in the data transmission network 3. Appropriate network connecting devices maybe provided in the measured-value detection devices 2a, 2b, 2c and/or in the actuator devices 11.

WE CLAIM
1. An automation system having at least one measured-value detection
device (2a, 2b, 2c) which is connected to an automated process (1), and
having at least one field device (5, 6), which is connected to the at least
one measured-value detection device (2a, 2b, 2c), and a host computer
(7) which is connected to the at least one field device (5, 6),
characterized in that
- the at least one measured-value detection device (2a, 2b 2c), the at least one field device (5, 6) and the host computer (7) are connected to a common data transmission network (3) which is designed to transmit digital measured data from the at least one measured-value detection device (2a, 2b, 2c) to the at least one field device (5, 6) using a first communication protocol, and to transmit digital control data between the at least one field device (5, 6) and the host computer (7) using a second communication protocol.
2. The automation system as claimed in claim 1, wherein the data transmission network (3) is a Real-Time-Ethernet Network.
3. The automation system as claimed in claim 1 or claim 2, comprising actuator devices (11) connected to the data transmission network (3), and connected on the output side to the automated process (1).
4. The automation system as claimed in one of the preceding claims, wherein the data transmission network (3) has a ring structure.

5. The automation system as claimed in one of the preceding claims, wherein the data transmission network (3) comprises at least two mutually redundant network elements (3a, 3b).
6. The automation system as claimed in one of the preceding claims, wherein the at least one measured-value detection device (2a, 2b, 2c) has an analog/digital converter and a network connecting device for connection to the data transmission network.
7. The automation system as claimed in one of claims 1 to 5, wherein the at least one measured-value detection device (2a, 2b, 2c) is connected to a conversion device (8) for converting the measured data to the first communication protocol, which conversion device (8) is connected on the output side to the data transmission network (3).
8. The automation system as claimed in one of the preceding claims, wherein the at least one field device (5, 6) and/or the at least one measured-value detection device (2a, 2b, 2c) are each connected via a network connecting device to the data transmission network (3) with the network connecting device having one and only one internal port (10), which is connected to the at least one field device (5, 6) or to the measured-value detection device (2a, 2b, 2c) and two, and only two, external ports (9a, 9b) which are connected to the data transmission network (3).

ABSTRACT

TITLE : "AN AUTOMATION SYSTEM HAVING AT LEAST ONE MEASURED-VALUE DETECTION DEVICE"
The invention relates to an automation system comprising at least one device (2a, 2b, 2c) that detects measured values and is connected to a automated process (1), at least one field device (5, 6) which is connected to the at least one device (2a, 2b, 2c) detecting measured values, and a master computer (7) that is connected to the at least one field device (5, 6). In order to simplify the design of such an automation system as much as possible, the at least one device (2a, 2b, 2c) detecting measured values, the at least one field device (5, 6), and the master computer (7) are connected to a common data transmission network (3) which is equipped for transmitting digital measured data from the at least device (2a, 2b, 2c) detecting measured values to the at least one field device (5, 6) according to a first communication protocol and transmitting digital control data between the at least one field device (5, 6) and the master computer (7) according to a second communication protocol.

AN AUTOMATION SYSTEM HAVING AT LEAST ONE MEASURED-VALUE DETECTION DEVICE

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