Electric actuators. with fieldbus interface. Information

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Electric actuators

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Applications

AUMA actuators are used wherever the flow through pipelines has to be controlled or regulated. They are the crucial link between the process control system and the valve.

Fieldbus systems are increasingly used for communi-cation in all industries. AUMA actuators come with the suitable interface for all common bus systems.

Energy

: Power plants : Air pollution control : District heating : Pipelines

: Chemical industry

: Water works

: Sewage treatment plants : Pumping stations : Dams

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Solutions for a world in motion

This brochure is intended for project engineers and purchasing managers who would like to use AUMA actuators with fieldbus interfaces. It offers an introduc-tion to fieldbus technology, an overview of the fieldbus systems supported by AUMA and in particular the fieldbus-specific features of AUMA actuators.

As early as the late 1980s, AUMA was actively involved in the development of the fieldbus standards. In 1993, the first AUMA actuator with fieldbus interface – Profibus FMS – was available. AUMA was one of the pioneers of fieldbus development for electric actuators.

AUMA does not only want to provide a fieldbus interface: the features and functions defined by the cor-responding fieldbus protocol should be used to the full for the benefit of valve automation. Further develop-ments in fieldbus protocols are thoroughly checked for their potential usability in actuators and implemented accordingly.

Due to AUMA’s modular product range, any AUMA multi-turn, part-turn and linear actuator can be deliv-ered with fieldbus interface. The process integration of almost any valve via fieldbus is possible.

Contents

General fieldbus information

Structures in automation systems 4

Digital transmission 4

Advantages of fieldbus 5

Fieldbus cables/ installation 6 Transmission rate/ cable length 6

Device integration 7

Profibus DP Modbus RTU DeviceNet

Foundation Fieldbus

AUMA actuators with fieldbus interfaces

Modular concept 16

Characteristics of AUMA fieldbus interfaces 17 Fieldbus connection –

non-explosion-proof actuators 18 Fieldbus connection –

explosion-proof actuators 19

SIMA master station

SIMA: Fieldbus master and actuators

from a single source 20

AUMA presales & after-sales

AUMA technical fieldbus support 22

AUMA fieldbus service 22

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General fieldbus information

A fieldbus is an industrial communication system, con-necting a variety of field devices such as transducers (sen-sors), MOVs and actuators (drives) with a control system. Fieldbus technology was developed in the 1980s to replace the parallel wiring of binary signals which was common at that time as well as analogue signal transmis-sion by digital transmistransmis-sion technology. Today, many

dif-ferent fieldbus systems with difdif-ferent characteristics have become established on the market, e.g. Profibus, Interbus, ControlNet, or CAN. Since 1999, fieldbus systems world-wide have been standardised according to IEC 61158 “Digital data communication for measurement and control – Fieldbus for use in industrial control systems”).

Structures in automation systems

At least one control system and often several transduc-ers and MOVs are required to control a system. If the con-trol is to be performed electrically, the question is how the transducers and the MOVs should be connected to the control system. Two basic variants are possible:

■ A separate signal channel is established from the con-trol system to each transducer and each MOV (parallel wiring).

■ The signal exchange between control system and sev-eral transducers and/ or MOVs is implemented via a common 2-wire cable (serial wiring).

The higher the level of automation of a plant or machine, the larger the number of cables for parallel wir-ing due to the increased number of input and output points. Implementation, installation, commissioning and maintenance become time consuming.

The demands placed on the cables are often high, e.g. special cables have to be used for the transmission of ana-logue values. Parallel wiring therefore becomes an essen-tial cost and time factor in automation technology. In comparison, serial wiring on the field level using so called fieldbus systems have a considerable potential for simplification.

The fieldbus replaces the parallel trunk groups by a sin-gle bus cable and connects all levels, from the field to the process control level. Whatever the automation device, e.g. programmable logic controls (PLC) from different manufacturers or computer-based controls, the fieldbus transmission medium links all components. The devices can be located anywhere in the field. Fieldbus therefore pro-vides a powerful communication network for

state-of-the-art modernisation concepts.

Digital transmission

Only digital information is transmitted in fieldbus sys-tems. Analogue setpoints or measured values are con-verted into digital values before transmission via bus. The digital signals are generally less susceptible to interference than values subject to analogue transmission. Integral veri-fication mechanisms additionally improve transmission

security, e.g. by using checksums or acknowledging the receipt of information to the sender.

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Advantages of fieldbus

Parallel wiring:

Multi-core cables for each device. This results in many input and output subassemblies within the control cabinet for connecting the field devices with the control system.

Serial wiring – fieldbus:

A single 2-wire cable for all devices. The multitude of input and output subassemblies are replaced by a single fieldbus interface.

Fieldbus systems have many advantages compared to parallel wiring:

■ Reduced wiring saves time during planning and instal-lation.

■ Cables, marshalling rack and dimensions of the control cabinet will be reduced.

■ Reducing the components reduces the documentation at the same time.

■ More information can be transferred using fewer wires.

■ Self-diagnosis of the devices via fieldbus reduces downtimes and maintenance times (asset manage-ment).

■ Digitalisation of analogue values improves the protec-tion against disturbance of signals.

■ Digitally collected measurement values and digitally generated setpoints can be processed directly without further signal conversion.

■ Open fieldbus systems standardise data transmission and device integration of different manufacturers – the user is not restricted by the standards of the indi-vidual manufacturers.

■ Expansions or changes can easily be performed guar-anteeing flexibility and therefore security for the future.

The following aspects have to be considered when implementing a fieldbus system. ■ Qualified personnel required for installation and

com-missioning.

■ Special measuring and diagnostic equipment required. ■ Slightly increased response times

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General fieldbus information

Fieldbus cables/ installation

Cable types

Data transmission via fieldbus cannot be implemented on any cable. Cable types are specified for each fieldbus system. Due to the low data transmission rate, the require-ments for Foundation Fieldbus are comparatively low; DeviceNet requires more complex cables as the bus specifi-cation requires a separate supply voltage within the same cable.

Installation

Data transmission on field bus systems are performed with low signal levels, e.g. +/– 5 V. The installation has to be performed thoroughly to ensure fault-free data trans-mission. This applies to screening, potential equalisation, observance of the max. permissible cable lengths, correct setting of the bus terminations and addresses of the field devices. Observing the installation guidelines ensures that all field devices on the bus can be smoothly

commissioned.

Transmission rate/ cable length

Most fieldbus systems specify several data transmission rates which are indicated in kBit/s. Although it seems to be reasonable to select the highest data transmission rate, this is, however, at the expense of reduced cable length. The higher the transmission rate and the longer the cables, the higher the sensitivity and susceptibility to interference.

For each plant, the ideal compromise between cable length and transmission rate has to be determined. There-fore, a lower transmission rate has to be selected for a sewage treatment plant with long distances than for appli-cations where field devices are very close.

Fibre optics

As an alternative many fieldbus systems provide data transmission via fibre optic cables (FO). Longer distances can be covered than with the cable types described in the fieldbus specifications. An electric opto-coupler converts the fieldbus signal into an optical signal and vice versa (receiver).

Repeater/ Extender

Generally speaking, repeaters or extenders are amplifi-ers which extend the cable length of a fieldbus segment. The section between the control system and the first repeater or between two repeaters is called a segment.

The number of repeaters or segments is limited. Further-more repeaters are also used:

■ to implement drop lines.

■ to create another bus segment if the maximum number of connectable devices per segment has been reached.

km

m

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Device integration

Commissioning

Contrary to conventional wiring where different signals do not interfere with each other and do not require a chronological order, fieldbus devices have to adhere to strict organisation principles to ensure fault-free communi-cation via the common data transmission medium.

This can be achieved by determining the communica-tion parameters. During commissioning the parameters for each device connected are determined in the master. Dur-ing system start-up the parameters are sent to the field devices. The programming of the parameters is based on the electronic data sheets provided by the field device manufacturers, e.g. GSD (Generic Station Description) for Profibus DP.

Commissioning example (Profibus DP)

[1] The commissioning engineer requires the GSD files of all field devices involved which can be downloaded from the websites of the Profibus user organisation or of the device manufacturers, for example. GSD files contain information on the supported Profibus communication parameters of the devices such as the data trans-mission rates, data lengths…

[2] The commissioning engineer determines the communication parameters for all devices and stores them in the Profibus DP mas-ter, in our example a PLC with Profibus DP interface.

[3] When switching on the master and/ or the field devices the deter-mined communication parameters are matched with the field devices. Process data may then immediately be transmitted via the bus.

During operation

In addition to the central delimitation of communication parameters, field device configuration can be influenced online: the process behaviour, e.g. of an actuator, can be changed from the control room.

The operating behaviour of the field devices can be optimised during operation without gaining access to the device. At the same time, diagnostic information is avail-able, helping to optimise the device parameters with regards to an extended lifetime or enabling more efficient maintenance.

The remote parameter setting is only possible if the fieldbus supports the corresponding services, i.e. acyclic DP-V1 services for Profibus DP.

There are different concepts for the various fieldbus sys-tems.

[1] The device integrations such as EDD or DTM provided by the field device manufacturers are installed on the control and monitoring sta-tion within a standardised software environment.

[2] From the control room, diagnostic data of the selected device can be read or parameters be changed.

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Profibus DP

Profibus FMS was developed from 1987 to 1989 within the framework of a co-operation project (industry, research institutes and the German federal office for research) and was translated into the DIN standard 19245 (the standardisation process was continued with the provi-sions of EN 50170 and IEC 61158). Further successive developments included Profibus DP, Profibus PA, Profibus DP-V1 and DP-V2, as well as ProfiNet.

Topology

The basic structure for Profibus DP topology is the line. Repeaters (R) can be used to implement drop lines to one or more field devices.

Furthermore the repeaters can be used to connect dif-ferent bus segments. Profibus systems can thereby be extended beyond the maximum cable length per segment.

Bus features

Development or notified

certification body

Profibus Nutzer Organisation (PNO) www.profibus.com

Concept/

communication principle

Typically master-slave (for mono-master systems), additionally also master-master for multi-master systems. Use of request-response mechanisms for cyclic data transmission and DP-V1 services for acyclic data transmission.

Applications Predominantly in machine and plant engineering as well as production automation. Due to the quick data transmission and the, in principle, simple and robust physical data transmission system (RS-485), Profibus DP can be used for various applications.

Versions ■ Profibus FMS, (FMS = Fieldbus Message Specification), the first Profibus version, is rarely used at the field level today.

■ Profibus DP (DP = Decentral Periphery), often called Profibus DP-V0 today, cyclic data transmission for quick data exchange.

■ Profibus DP-V1, introduction of special DP-V1 services for acyclic data transmission (programming and device diagnosis via Profibus).

■ Profibus DP-V2, a generic term for further Profibus functions such as Isochron Mode (IsoM), Data Exchange Broadcast (DxB), time synchronisation (Time_Stamp), redundancy concept (redundancy) as well as upload and download.

■ Profibus PA (PA = Process Automation), a version which has been specially adapted to the

requirements of process engineering, among others, to make the bus intrinsically safe for the use in plants in potentially explosive atmospheres.

■ ProfiNet, Profibus based on Ethernet technology.

AUMA actuators currently support Profibus DP-V0 and DP-V1.

Physical layer RS-485,

alternatively: FO

Maximum number of devices 126 (125 field devices and a Profibus DP master),

Without repeaters, a maximum of 32 devices per Profibus segment

Typical number of devices Depends on the plant; typically 10 – 70 devices; for more devices, a second Profibus DP network is usually installed.

Control system

Profibus DP Master (PLC)

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Bus features

Typical bus cycle time approx. 140 ms, for 30 actuators, the usually required process data (4 bytes input and 4 bytes output) and at 93.75 kBit/s

Data transmission rates of the bus

9.6 kBit/s to 12 MBit/s

Recommended baud rate: 93.75 kBit/s (if required: also 187.5 kBit/s). For these transmission rates, the maximum cable length is reached at considerable transmission speeds.

AUMA devices support transmission rates up to 1.5 Mbit/s.

Max. cable lengths without repeater

max. 1,200 m (for baud rates exceeding 187.5 kBit/s), 1,000 m at 187.5 kBit/s 500 m at 500 kBit/s , 200 m at 1.5 MBit/s

Max. cable lengths with repeater

approx. 10 km (only applies to baud rates exceeding 500 kBit/s), approx. 4 km (at 500 kBit/s) approx. 2 km (at 1.5 MBit/s)

The maximum cable length which can be implemented depends on the type and the number of repeaters. Usually, a maximum of 9 repeaters can be used in a Profibus DP system.

Redundancy concepts Under the generic term of the Profibus DP-V2 services, there is a slave redundancy specification (2.212). This specification stipulates the behaviour of a redundant Profibus DP slave in detail.

AUMA actuators are optionally equipped with a redundant Profibus DP interface. Today, many DCS still do not support redundancy or have their own redundancy concepts. Current redundant solutions have to be matched in the run-up to commissioning.

Device integration/ remote programming of the slaves

Remote programming is done using the acyclic Profibus DP-V1 services. The device integration is implemented

■ using an EDD (in combination with Simatic PDM in Siemens process control systems).

■ using a DTM (in combination with an available FDT interface in the process control system) Both technologies are supported by AUMA.

Fieldbus termination The RS-485 specification stipulates termination resistors at the beginning and at the end of each RS-485 segment. The resistor network has to be supplied with 5 V DC. On the master level, the supply voltage is provided by the master and on the field level by the field devices.

AUMA products provide these fieldbus termination resistors and do not require external termination resistors.

Field level with field devices

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Modbus RTU

In 1979, Modbus was developed by Gould-Modicon (today Schneider Electric) and has turned into a de facto standard.

Topology

The basic structure for Modbus RTU topology is the line. Repeaters (R) can be used to implement drop lines to one or more field devices.

Furthermore the repeaters can be used to connect dif-ferent bus segments. Modbus systems can thereby be extended beyond the maximum cable length per segment.

Bus features

Development or notified certification body Modbus IDA www.modbus.org Concept/ communication principle

Master-slave with query-response mechanisms for data exchange. For Modbus, there is no distinction between cyclic and acyclic data exchange; in both cases, the same mechanisms are used. There is only one master which is allowed to send messages without external request. The connected Modbus devices may acknowledge the received messages or send messages to the master on request of the latter.

Applications Predominantly in plant engineering where the real-time requirements on the response times are lower.

Versions ■ Modbus ASCII, each byte of a telegram is transmitted using two ASCII characters; suitable for applications with a low process data level

■ Modbus RTU, each byte of a telegram contains 2 hexadecimal characters

■ Modbus Plus, extended Modbus protocol (contains two additional protocol layers such as HDLC level, MAC level and LLC level)

■ Modbus TCP/IP, Modbus based on Ethernet technology AUMA actuators support Modbus RTU.

Physical layer RS-485,

alternatively: FO

Maximum number of devices 247 field devices and a Modbus RTU master

Without repeaters, a maximum of 32 devices per Modbus segment

Typical number of devices Depends on the plant; typically 10 – 70 devices; for more devices, a second Modbus network is usually installed.

Typical bus cycle time Approx. 850 ms, for 30 actuators, the usually required process data (3 input registers) and at 38.4 kBit/s

Control system

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Bus features

Data transmission rates

of the bus

0.3 kBit/s to 38.4 kBit/s

max. 1,200 m

approx. 10 km

The maximum cable length which can be implemented depends on the number of repeaters. This kind of cascadability depends on the repeater type; usually a maximum of 9 repeaters can be used in a Modbus system.

Redundancy concepts There is no redundancy specification for Modbus RTU.

AUMA actuators are optionally equipped with a redundant Modbus RTU interface. Today, may DCS still do not support redundancy or have their own redundancy concepts. Current redundant solutions have to be matched in the run-up to commissioning.

Modbus has no special communication services for the transmission of parameters; available services are queried acyclically. Currently, there is no device integration specified for Modbus; this means that each parameter request as well as the corresponding parameter representation has to be programmed manually in the process control system.

Fieldbus termination The RS-485 specification stipulates termination resistors at the beginning and at the end of each RS-485 segment. The resistor network has to be supplied with 5 V DC. On the master level, the supply voltage is provided by the master, on the field level by the field devices.

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DeviceNet

DeviceNet was developed in 1993 by Allen-Bradley; the development of the CAN protocol by Bosch, which is the underlying protocol, started as early as 1983.

Topology

The basic structure for DeviceNet topology is the line; drop lines are explicitly permitted as long as the defined constraints are not exceeded.

In case of DeviceNet, you often talk about a trunk line which is usually implemented with the thick cable. Thin cables are usually used for optional drop lines.

When using extenders, DeviceNet systems can be extended beyond the maximum cable length per segment.

Bus features

Development or notified

certification body

Open DeviceNet Vendor Association (ODVA) www.odva.org

Concept/

communication principle

DeviceNet is an object-oriented bus system operating according to the Producer-Consumer procedure. DeviceNet nodes can be client (master), server (slave) or both. Client and server can be producer, consumer or both. Each DeviceNet node can produce or consume data on the bus. This opens a large variety of possibilities for data transmission; however, a master-slave mechanism is usually applied for the process data. So-called Poll I/O Messages are used for cyclic data transmission, Explicit Messages for acyclic data transmission. DeviceNet devices are also called nodes in DeviceNet terminology.

Applications Machine and plant engineering as well as production automation

Versions ■ DeviceNet: DeviceNet consists of CIP on CAN (a protocol which uses CAN as physical layer and for data transmission).

■ Ethernet/IP: Ethernet/IP consists of CIP on Ethernet (a protocol which uses Ethernet as physical layer and TCP/IP or UPD/IP for data transmission).

AUMA actuators support the DeviceNet version.

Physical layer CAN, bidirectional data transmission, half-duplex.

As a special feature, the DeviceNet cable contains an additional 24 V DC voltage which can be used to supply basic sensors, for example.

Maximum number of devices 63 field devices and a DeviceNet scanner. In DeviceNet terminology, a scanner corresponds to the master.

Typical number of devices Depends on the plant; typically 10 – 40 devices; for more devices, a second DeviceNet network is usually installed.

Typical bus cycle time approx. 230 ms for 30 actuators, the usually required process data (Process Input Data 1 and Process Output) and at 125 kBit/s

Data transmission rates of the bus

125 kBit/s; 250 kBit/s; 500 kBit/s

Recommended baud rate: 125 kBit/s (for the maximum permissible cable length)

Control system

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Bus features

Max. cable lengths

without extender

500 m at 125 kBit/s 250 m at 250 kBit/s 100 m at 500 kBit/s

Max. cable lengths with extender

approx. 1.5 km (at 125 kBit/s) approx. 750 m (at 250 kBit/s) approx. 300 m (at 500 kBit/s)

The maximum cable length which can be implemented depends on the number of extenders, most manufacturers allow for 2 cascaded extenders within a DeviceNet network.

Redundancy concepts Currently, there is no redundancy specification for DeviceNet. AUMA actuators can also be delivered with a redundant fieldbus interface.

For DeviceNet, parameter data are read or written using acyclic Explicit Messages. The parameter structures in the device are laid down in the EDS file (Electronic Data Sheet).

The EDS file has to be installed in the process control system so that the device data (e.g. parameters or operating data) can be read or modified from the control room using DeviceNet.

The EDS file of the AUMATIC AUMA controls can be obtained from www.auma.com or www.odva.org.

Fieldbus termination For DeviceNet, a termination resistor of 121 Ohm is required at both ends of the trunk line. The resistor is simply connected to the CAN_H and the CAN_L wire. The termination does not have to be supplied.

AUMA products provide this fieldbus termination resistor and do not require external termination resistors.

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Foundation Fieldbus

In 1994, after the WorldFIP and ISP organisations merged to form Fieldbus Foundation, the first Foundation Fieldbus specification was published.

Topology

The basic structure for Foundation Fieldbus is the line. Star topologies and network structures are also allowed as long as the defined constraints are not exceeded.

When using repeaters, Foundation Fieldbus systems can be extended beyond the maximum cable length per seg-ment.

General information

Development or notified certification body Fieldbus Foundation www.fieldbus.org Concept/ communication principle

Foundation Fieldbus basically distinguishes between three different communication mechanisms: Publisher-Subscriber for cyclic process data transfer, Client-Server for diagnosis, parameter setting and configuration as well as report distribution for signalling alarms.

There is no master; the data is directly exchanged between the field devices. The bus communication between the field devices is directly coordinated by the LAS (Link Active Scheduler). The LAS function is performed by one of the field devices for each segment. LAS capable field devices are called Link Masters, basic devices cannot perform the LAS function.

Applications Chemical industry, petrochemical industry, power plants, pharmaceutical industry and food industry as well as paper industry and mining

Versions ■ FF-H1 based on IEC 61158 with a baud rate of 31.25 kBit/s. This is the FF technology directly connected to the field devices.

■ FF-HSE, based on Ethernet (100 MBit/s). The data is transferred via HSE both within the DCS as well as between the DCS and the linking devices. Generally speaking, a linking device can be considered as converter between the quick HSE and the slow H1 version.

AUMA actuators support the FF-H1 version

Physical layer For H1: IEC 61158, with 31.25 kBit/s, bidirectional data transmission, half-duplex. Power supply and data transmission is performed on the same wires. Foundation Fieldbus devices with low-current consumption can be supplied via bus.

Maximum number of devices 240 field devices including linking device. A maximum of 32 devices can be connected to a single Foundation Fieldbus segment.

Typical number of devices Usually 6 – 10 (max. of 12 – 14) per segment; mostly 4 H1 ports are available at a linking device, i.e. approx. 25 – 40 devices per linking device. Since FF is frequently used in large plants, often several linking devices are used.

Typical bus cycle time 500 ms - 2 s, depending on the number of devices

Distributed control system (DCS)

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General information

Data transmission rates

of the bus

31.25 kBit/s

1,900 m

approx. 9.5 km

The maximum cable length which can be implemented depends on the number of the repeaters. For FF, a maximum of 4 repeaters may be cascaded.

Redundancy concepts For Foundation Fieldbus, the redundancy is only specified within the HSE (i.e. up to the linking devices). For the further H1 wiring to the field devices, there is no redundancy provided. By means of link master devices, some kind of implicit redundancy can be established for FF: if the LAS (link active scheduler) fails, another link master device can automatically take over the LAS function and can continue to co-ordinate the bus communication to the other devices.

Client-server messages are used to program and configure Foundation Fieldbus devices via Foundation Fieldbus. All information required for these requests are stipulated in the device description of a Foundation Fieldbus field device which is imperatively required. All in all, the device description consists of three files (*.ffo, *.sym and *.cff).

The device description has to be installed in the DCS so that the device data (e.g. parameters, operating data, or electronic name plate) can be read or modified from the control room using Foundation Fieldbus.

The device description files of the AUMATIC AUMA controls can be obtained from www.auma.com or www.fieldbus.org.

Fieldbus termination For Foundation Fieldbus, the termination consists of a resistor with an in series connected capacitor which is connected to the FF+ and FF– wire at the beginning and the end of a main segment. The longest cable length within a Foundation Fieldbus network is called main segment.

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AUMA actuators with fieldbus interfaces

Modular concept

AUMA actuators can be combined with the fieldbus compatible AUMATIC actuator controls. Even when using different actuator types, i.e. multi-turn, part-turn and lin-ear actuators, a uniform interface to the process control system is provided using the AUMATIC. This applies to both the hardware and the software and sets the stage for universal solutions in valve automation.

Explosion-proof versions

Both AUMA actuators and the AUMATIC actuator con-trols are available in explosion-proof version. The devices conform to the classification II2G EEx de IIC T4/

II2G c IIC T4. Further literature

For detailed information on AUMA actuators and AUMATIC controls refer to the brochures below. ■

Actuator controls AUMATIC AC 01.1/ ACExC 01.1 ■

Electric multi-turn actuators for open-close and modulating duty SA 07.1 – SA 48.1 SAR 07.1 – SAR 30.1 SAEx(C) 07.1 – SAEx(C) 40.1 SARExC 07.1 – SARExC 16.1 ■ ■

Electric part-turn actuators

for open-close and modulating duty SG 03.3 – SG 04.3

SGR 03.3 – SGR 04.3

Integral controls AUMATIC with fieldbus interface

Multi-turn actuators SA/ SAR 07.1 – 16.1

Part-turn actuators SG/ SGR 05.1 – 12.1 or SG/ SGR 03.3 – 04.3

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Characteristics of AUMA fieldbus interfaces

Fieldbus systems can only work reliably if they have been carefully installed and commissioned. The installation guidelines of the fieldbus organisations should therefore be observed in detail.

If mistakes are made during installation this will often result in unstable communication. The field device manu-facturer is often the first person contacted although the fault was caused somewhere else.

The AUMA fieldbus interface is designed as to enable easy field bus connection and bus setting at the device. Smart bus termination

Incorrectly set bus termination resistors impair the bus communication. The identification of bus terminations which have been activated by accident can be very time-consuming especially in the case of multiple bus terminations.

With AUMA products, you just switch on the bus termi-nations. If a bus termination at an AUMA actuator has been activated by accident, the communication to all sub-sequent devices on the bus is interrupted. This so called smart bus termination automatically prevents multiple bus terminations and the communication remains stable.

Explosion-proof actuators contain a bus termination which has to be wired if the actuator is the last bus sta-tion.

Advantages of AUMA fieldbus actuators

■ Easy installation of the bus cables by means of plug-in connection

■ Easy installation using a separate connection board ■ Easy bus termination using the integral smart bus

ter-mination

■ Quick commissioning in “next to no time”

■ Redundancy concepts with two separate bus interfaces in a single AUMATIC

■ Redundancy concepts with fieldbus interface and addi-tional convenaddi-tional control signals

■ Configurable data interfaces for optimising the com-munication

■ The bus communication will not be interrupted if the AUMA actuator is switched off or disconnected from the bus.

[1] [2] [3]

[1] Removable lid

[2] Fieldbus connection board for connecting the fieldbus cables [3] Fieldbus interface

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AUMA actuators with fieldbus interfaces

Fieldbus connection –

non-explosion-proof actuators

The fieldbus connection and the connection of the power supply are located in separate sections. A plug/ socket connector establishes the electrical connection from the housing to the actuator. This plug-in feature is an asset during installation and maintenance.

Depending on the fieldbus and the transmission mode, different modules are installed.

Plug-in electrical connection for non-explosion-proof applications (ordering code SD)

[1] Six conduit entries

Bus connection board

The bus cables are wired to a separate connection board. The connection is easy to maintain:

■ Easy access to the connection board after removing the cover.

■ Special terminals allow for easy connection of the bus cable.

■ Bus communication is not interrupted if the actuator plug is removed (exception: fibre optics).

Fieldbus connection versions

[2]Standard version [3]2-channel version

for the connection of a redundant fieldbus cable. [4]Version with protective equipment

againt overvoltages (up to 4 kV) on the fieldbus. The 2-channel version is illustrated.

[5]Version for connection to fibre optic cables.

The versions shown in the illustration are suitable for connecting Profibus DP and Modbus RTU. Further versions are available for DeviceNet and Foundation Fieldbus.

[1]

[2] [3]

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Fieldbus connection –

explosion-proof actuators

As for the non-explosion-proof actuators, the complete electrical connection – both data cables and power supply cables – is made in a separate plug-in connection.

If the actuator is the last device in the bus segment, the fieldbus termination integrated in the AUMATIC has to be wired accordingly.

For this connection type, the bus communication also remains intact, even if the plug is disconnected

(exception: FO). FO coupler

If the data exchange is performed via fibre optic cables, an FO coupler is integrated in the connection housing for the connection of the fibre glass cables.

[1] [2] [3] [a] [a] [a] [b] [c] [d]

[1]Plug/ socket connector with screw-type terminals – standard (ordering code KP)

[2]Plug/ socket connector with spring-type terminals – option (ordering code KES)

used with operating voltages exceeding 525 V and / or, if many terminals are required, e.g. due to redundancy, assignment of the sensor connections or connection of an external 24 V DC supply [3]Plug/ socket connector with FO coupler –

option (ordering code KES)

for connecting fibre optic cables (Profibus DP or Modbus RTU) [a] All connections have six conduit entries

[b] Screw-type terminals [c] Spring-type terminals [d] FO coupler

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SIMA master station

SIMA: Fieldbus master and actuators from a single source

From the perspective of the field devices, the SIMA master station is used to set up an additional level below the actual DCS. This is recommended if:

■ a protocol has to be converted, e.g. from Profibus DP to Ethernet.

■ a physical conversion is required, e.g. from RS-485 to RS-232.

■ a conversion from 1-channel to 2-channel operation (redundancy) is required.

■ the process control system should not be burdened with diagnostic data and actuator parameters. SIMA simplifies the device integration of, in particular, AUMA actuators. SIMA uses open standardised fieldbus protocols enabling the integration of field devices of other manufacturers.

SIMA’s advantages ■

Only the SIMA master station has to be integrated in the higher level distributed control system as the only station.

■

System data such as operating data or feedback sig-nals from the AUMA actuators can be stored in the master station.

■

Standardised operation using a worldwide renowned operating concept.

■

Further AUMA actuators can be added with hardly any effort.

■

Online access via the World Wide Web by means of the integral web server.

■

The SIMA operating data logging function enables the collection of information on the operation time, the number of starts, etc. of the slaves connected. ■

The SIMA can be monitored and controlled from differ-ent locations within the plant.

Configuration interface

As a standard computer, the SIMA master station comes with ports for connecting screen, mouse and key-board. The SIMA software can be accessed via a Windows user interface. As an alternative, a laptop or computer can be connected via Ethernet.

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Control system [1] [1] [2] [2] [3] [4] [4]

[1]SIMA master station

The SIMA is based on standardised indus-trial computer components and has been expanded by the required fieldbus inter-faces. The entire hardware is integrated in a solid 19" industrial housing with EMC protection. The SIMA is available both with or without touchscreen.

[2]Communication

For the communication with field devices, SIMA supports the standardised fieldbus protocols such as Profibus DP or Modbus RTU. The cable types specified in the fieldbus standards are used as transmis-sion medium.

Up to 32 devices can be connected to a single bus segment; when using repeat-ers, up to 127 devices are possible. Communication with the decentralised control system is also performed accord-ing to above mentioned standards; in addition, Ethernet or customised RS-232

[3]Redundancy

SIMA supports various redundancy con-cepts. Both redundancy to the AUMA field devices and/ or to the DCS and also SIMA master redundancy is possible. In case of loss of communication or master failure, automatic change-over to the redundant component will be performed. [4]AUMA actuators

The SIMA is designed for the control of AUMA actuators. Since the communica-tion is performed according to standard-ised fieldbus protocols such as Profibus DP or Modbus RTU, any field device

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conform-AUMA presales & after-sales

AUMA technical fieldbus support

Despite the standardisation, implementing, installing and commissioning a fieldbus system is anything but triv-ial. Should any mistakes by made at this level, the prob-lems caused by the delayed operation start and faults out-weigh the obvious advantages of fieldbus technology.

If the components involved are carefully selected at the planning stage, this enables a smooth system start at a later date.

Since the beginning of the 1990s, AUMA has been engaged in the development of fieldbus technology. AUMA engineers in Germany and in the AUMA subsidiar-ies worldwide can rely on extensive experience – an asset from which our customers can benefit when selecting the suitable device configuration.

The crucial points for the configuration of the system are settled in direct contact with the project engineer. This includes for example transmission medium, redundancy or the projected process control system. Only after all these questions have been settled will a detailed plant configura-tion be determined.

AUMA fieldbus service

If one of the field devices does not work during com-missioning, the field device manufacturer is the first per-son to contact. However, the failure is often not caused by the field device but by errors during installation or pro-gramming. Fieldbus sytems use low signal levels; the requirements on cables, shielding, correctly set termina-tors, etc. are consequently high.

AUMA after-sales service

AUMA has set up a worldwide service network which is unparalleled in valve automation. AUMA service techni-cians offer all kind of services with regards to actuators and have a sound knowledge of the surrounding infra-structure including fieldbus systems.

AUMA commissioning service

AUMA service technicians will adapt the actuator ideally to the chosen application. This includes setting the device parameters such as tripping torques or type of seating, but also configuring the bus address and the termination resis-tors and checking the connection of the fieldbus cable. AUMA fieldbus diagnostic service

On request the AUMA service technician can perform a diagnostic check on the fieldbus cable or the data exchange on the bus if the AUMA actuator was excluded as the cause of failure.

AUMA service technicians are well-equipped with diag-nostic devices and monitoring equipment for the different fieldbus systems. Causes of faults can thereby quickly be determined and eliminated.

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Links & literature

Links

On the websites of the various development organisa-tions and notified bodies, you can find comprehensive information on the corresponding fieldbus system. Further-more, the device integrations of the registered field devices, including AUMA actuators, are made available for download. These files can also be downloaded from the AUMA website www.auma.com.

■ : www.profibus.com/pb ■ : www.modbus.org

Literature Profibus DP ■

Manfred Popp: Hüthig Verlag, ISBN 3-7785-2676-6 ■ The New Rapid Way to Profibus DP

Manfred Popp: can be obtained via www.profibus.com ■

■ Profibus Installation Recommendation for

Cabling + Assembly, Download www.profibus.com ■ Profibus Installation Recommendation for

Commissioning, Download www.profibus.com ■ Installation Guidelines for Profibus DP/ FMS

Installation and wiring recommendations, Download www.profibus.com

Modbus

■ Modicon Protocol:

■ , Modbus

over serial line specification and implementation guide http:/www.modbus.org DeviceNet ■ , Rel. 2.0, Errata 5, March 31, 2002 ■ , Rel. 2.0, Errata 5, March 31, 2002 ■ Grundlagen, Protokolle,

Bausteine, Anwendungen, 3. aktualisierte Auflage, Hanser Verlag, ISBN 3-446-21776-2

Foundation Fieldbus

■ , (www.fieldbus.org): AG-140 31.25 kbit/s Wiring and Installation Guide AG-163 31.25 kbit/s Intrinsically Safe Systems Applica-tion Guide

AG-165 Fieldbus Installation and Planning Guide AG-181 System Engineering Guidelines

■

Fieldbus Inc. (www.fieldbusinc.com) Fieldbus Technical Overview (Primer)

■ –

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AUMA Riester GmbH & Co. KG [1] [2] [3] [4] [5] [1] Multi-turn actuators SA 07.1 – SA 48.1 Torques from 10 to 32,000 Nm Output speeds from 4 to 180 rpm [2] Multi-turn actuators SA/ SAR with controls AUMATIC Torques from 10 to 1,000 Nm Output speeds from 4 to 180 rpm [3] Linear actuators SA/ LE

Combination of multi-turn actuator SA with linear thrust unit LE

Thrusts from 4 kN to 217 kN Strokes up to 500 mm Linear speeds from 20 to 360 mm/min [4] Part-turn actuators SG 05.1 – SG 12.1 Torques from 100 to 1,200 Nm Operating times for 90° from 4 to 180 s

[5] Part-turn actuators SA/ GS

Combination of multi-turn actuator SA with part-turn gearbox GS Torques up to 360,000 Nm [6] Spur gearboxes GST 10.1 – GST 40.1 Torques up to 16,000 Nm [7] Bevel gearboxes GK 10.2 – GK 40.2 Torques up to 16,000 Nm

[8] Worm gearboxes with base and lever GF 50.3 – GF 250.3 Torques up to 32,000 Nm P.O.Box 1362 D-79379 Muellheim Tel +49 7631-809-0 Fax +49 7631-809-250 [email protected]