Siemens SIMATIC NET PROFIBUS specification

Active Components for RS-485 Networks

5

PROFIBUS Networks SIMATIC NET	5-1
6GK1970-5CA20-0AA1 Release 2 05/2000

Image 167

Siemens SIMATIC NET PROFIBUS manual Active Components for RS-485 Networks

Contents

05/2000 6GK1970-5CA20-0AA1 Release Simatic NET Profibus Networks Manual Trademarks Safety GuidelinesQualified Personnel Correct Usage Symbols Symbols Contents Active Components for RS-485 Networks Passive Components for RS-485 Networks Passive Components for PROFIBUS-PA Active Components for Wireless NetworksTesting Profibus Passive Components for Electrical Networks Dimension Drawings Installing LAN CablesInstalling Network Components in Cubicles Index Index-1 Glossary-1Page Profibus Networks Distributed Systems Communication Systems Simatic NET Overview of the Simatic NET System AS-Interface Industrial Ethernet/Fast Ethernet Attachable Systems Basics of the Profibus Network Transmission Media Standards Token BUS/Master-Slave Method Access Techniques Active and Passive Nodes Transmission Techniques Advantages Transmission Techniques According to EIA Standard RS-485EIA Standard RS-485 Properties of the RS-485 Transmission Technique Restrictions Integrated Optical Interfaces, OBT, OLM Transmission Techniques for Optical ComponentsProfibus User Organization Guideline OBT Characteristics of the Optical Transmission Technique Transmission Technique for Wireless Infrared Technology IEC 61158-2 Standard Characteristics of the IEC 61158-2 Transmission TechniqueTransmission Technique for PROFIBUS-PA Page Topologies of Simatic NET Profibus Networks Node Attachment Topologies of RS-485 NetworksTransmission Rate LAN Cable Components for Transmission Rates up to 1.5 Mbps Connecting Segments Using RS-485 Repeaters Components for Transmission Rates up to 12 Mbps Interfacing Electrical and Optical Networks/Components Topologies of Optical Networks Topology with Integrated Optical Interfaces OLMs Topologies with OLMsProfibus Optical Bus Terminal OBT Example of a Bus Topology with OLMs Bus Topologies Optical Channels Star Topologies with OLMs Mixed Structure Redundant Optical Rings using OLMsMonitoring FO Links Topologies of Simatic NET Profibus Networks Alternative Cabling Strategy Combination of Integrated Optical Interfaces and OLMs Infrared Link Module ILM Topologies of Wireless NetworksMaximum Length of a Link Point-to-Point Link Point-to-Point Link with Two Profibus ILMs Point-to-Multipoint Link ILM Profibus SpliTConnect System Field Device Power Supply via PROFIBUS-PATopologies with PROFIBUS-PA Bus and Star Topology Tap Line ExpansionTotal Cable Tap Line Lengths for DP/PA Couplers Uses Connectivity Devices 1 DP/DP Coupler Parameter Assignment How the DP/DP Coupler Works DP/PA Bus Coupling Connecting to PROFIBUS-PA Uses of the DP/PA Coupler 3 DP/PA Coupler Properties of the DP/PA Coupler Ex Configuring the DP/PA CouplerProperties of the DP/PA Coupler General DP/PA Link 4 DP/PA LinkDefinition PA master PropertiesHow the DP/PA Link Works DP/PA Link Rules 18 DP/RS-232C Link for PROFIBUS-DP Connecting PROFIBUS-DP to RS-232C Device How the DP/RS-232C Link Works 20 DP/AS-Interface Link Connecting with the DP/AS-Interface Link DP/AS-Interface Link How the DP/AS-Interface Link 65 Works 22 DP/AS-Interface Link 23 Example of a Configuration with DP/AS-Interface Link How the DP/AS Interface Link 20 Works 24 DP/EIB Link Connecting PROFIBUS-DP to instabus EIB Industrial Automation Building Automation S7-300 ET 200M How the DP/EIB Link Works Instabus EIB ConfiguringPage Configuring Networks Parameters Configuring Electrical NetworksProfibus Networks Transmission Rates up to a Maximum of 500 Kbps Segments for Transmission Rates up to a Maximum of 500 Kbps Node Attachments at 1.5 Mbps Segments for a Transmission Rate of 1.5 MbpsLength of the Tap Lines Transmission Rate 1.5 Mbps Value Factors Rules Between two DTEs 10 m Transmission Rate up to a Maximum of 12 Mbps Segments for Transmission Rates up to a Maximum of 12 Mbps RS-485 Repeater Configuring Electrical Networks with RS-485 Repeaters Configuring Configuration Parameters for Optical Networks Configuring Optical Networks Transmitter How a Fiber-Optic Cable Transmission System WorksIntroduction Transmission Path Attenuation Receiver Optical Power Budget Optical Power Budget of a Fiber-Optic Transmission System Splices Power BudgetPlastic and PCF FO Cables Glass FO Cables Work Sheet Link Power Margin Lengths between two Nodes in m Cable Lengths for Plastic and PCF FO PathsFiber-optic cable For 1 Network = Calculation Examples Mixing Plastic Fiber-Optic and PCF Fiber-Optic Number * aSpl Link power marginAttenuation of the transmission path AFOC = 12 dB 10.0 dB Blank form for a power budget using OLMs Transmission Delay Time Creating a System Overview Configuring Optical Buses and Star Topologies with OLMs Properties Profibus Dialog Setting the Profibus Properties Options Cables Tab Entering the Cabling Configuration Bus Parameters Adapted to the System Checking the Bus Parameters Raising the Retry Value to at Least the Value Configuring Redundant Optical Rings with OLMsConfiguration of a Non-existent Node Checking and Adapting the Slot Time Transmission Rate Transmission rate Minimum slot Time Example of Configuring the Bus Parameters in StepStructure of the Network Example Entering the Bus Parameters Calculation of the Slot Time Bus Parameters/User-Defined Dialog Passive Components for RS-485 Networks Overview Simatic NET Profibus CablesProfibus Cables LAN Cables for Profibus UV resistance Sienopyr FR Passive Components for RS-485 Networks FC Standard Cable 6XV1 830-0EH10 FC Standard Cable LAN Cable with Halogen-free Outer Sheath 6XV1 830-0LH10 FC-FRNC Cable LAN cable with halogen-free outer sheath FC Food Cable 6XV1 830-0GH10 FC Food Cable FC Robust Cable 6XV1 830-0JH10 FC Robust Cable Profibus flexible cable 6XV1 830-0FH10 Profibus Flexible Cable Properties Filler FC Underground CableFC Underground Cable 6GK1 830-3FH10 Trailing Cable 6XV1 830-3EH10 FC Trailing Cable Properties Segment Lengths Example of Using the Profibus Trailing Cable in a Drag Chain Passive Components for RS-485 Networks Festoon Cable 6XV1 830-3GH10 Profibus Festoon Cable 10 Installation of the Profibus Festoon Cable Schematic Passive Components for RS-485 Networks 11 Use of the Profibus Cable for Festoons Installation Guidelines Inner sheath SIENOPYR-FR Marine CableSIENOPYR-FR Marine Cable 6XV1830-0MH10 Uses FastConnect System FastConnect Bus Connector Designed for Industry Functions OLM Order numbers 6ES7 0BA50-0XA0 0BB50-0XA0 6GK1 0FC00 Technical Specifications Pin Signal Meaning Name Disconnecting a StationBus Connector with PG Socket Pinout of the Sub-D Male Connector Passive Components for RS-485 Networks Using the FastConnect Stripping Tool for Preparing FC Cables OFF Bus Connectors FMS/DP Appearance 6ES7 972-0BB40-0XA0 0BA30-0XA0 500-0EA02 Order 6ES7 972-0BA11-0XA0 6ES7 972-0BA40-0XA0 6GK1 Numbers PG socket Disconnecting a Station Siemens Appearance 6ES7 972-0B.11 First and last station on Further stations on the bus Connecting Up the LAN Cable Passive Components for RS-485 Networks Appearance 6ES7 972-0BA30-0XA0 18 Bus Connector order number 6ES7 972-0BA30-0XA0 Cable guides Insulation displacement terminals Appearance 6ES7 972-0B.40 Connecting the LAN Cable to Bus Connector 6ES7 972-0B.40 23 Connecting the LAN Cable to Bus Connector 6ES7 972-0B.40 Appearance 6GK1500-0EA02 Installing the Bus Connector with Axial Cable Outlet Fitting the Bus Connector Removing the Bus Connector Plugging the Bus Connector into the Module Possible disturbance of data traffic on the bus Bus terminal RS-485 Bus terminal 12 M Bus Terminals for RS-485 Networks Versions Bus Terminal RS-485 Design and Functions of the RS-485 Bus Terminal RXD/TXD-P 28 RS-485 Bus Terminal with Additional PG Interface Additional PG Interface 29 12M Bus Terminal BT12M Design and Functions of the 12M Bus Terminal 30 Operator Controls Bus terminal 12 M Termination Restriction when using the 12M bus terminal at 500 Kbps Mounting/Attaching the LAN Cables 31 Drilling Diagram for the Bus Terminal Passive Components for RS-485 Networks Passive Components for RS-485 Networks Grounding 33 Ways of Installing and Grounding the Bus Terminal Wall Mounting Technical Data of the RS-485 Bus Terminal Technical Data of the RS-485 Bus Terminal Climatic Conditions Technical Data of the 12M Bus TerminalTechnical Data of the 12M Bus Terminal Electromagnetic Compatibility Test Marks Mechanical ConditionsConstruction Avoid accidental shield contact with the environment Cable Connections Cable Connections to Network ComponentsCable Connection without Bus Connection Elements All-round shielding of the LAN cable must be retained Keep to the permitted ambient conditions Function Preassembled Connecting Cables 1 830-1T Connecting Cable Simatic NET 830-1T connecting cable 35 830-2 Connecting Cable 2 830-2 Connecting Cable Simatic NET 830-2 connecting cable Active Components for RS-485 Networks Design of the RS-485 Repeater What is an RS-485 Repeater?Using the RS-485 Repeater 6ES7 972-0AA01-0XA0 RS-485 Repeater Layout of the Repeater Function Layout Pin no Signal name Meaning Pinout of the Sub D Connector PG/OP ConnectorTechnical Specifications Block Diagram of the RS-485 Repeater Block Diagram Off Possible Configurations with the RS-485 RepeaterTerminating Resistor On/Off Terminating resistor Segments 1 and 2 TerminatedSegment 1 Terminated, Segment 2 Connected Through Segment Terminating resistor Bus segment 2 off Segments 1 and 2 Connected Through Installing and Uninstalling the RS-485 Repeater Installing the RS-485 Repeater on an S7-300 Rail Installation on an S7-300 Rail Removing the RS-485 from the Standard Rail Installation on a Standard RailRemoving the Repeater from an S7-300 Rail Ungrounded Operation Ungrounded Operation of the RS-485 Repeater Cable Type Connecting the Power SupplyConnecting the Power Supply Connecting the Profibus Cable Connecting the LAN Cable Design of the Profibus Terminator What is a Profibus Terminator?Profibus Terminator Order number Lists the technical data of the Profibus terminator Standard cable 6XV1 830-0EH10 Page Passive Components for PROFIBUS-PA PVC outer sheath FC Process Cable SpliTConnect Tap How the SpliTConnect Tap Works Produktinformation Simatic NET Personnel qualification requirements Insert the strand holder 6 onto the not stripped off strands Grounding Hinweis SpliTConnect Coupler SpliTConnect Terminator Technische Daten /Technical Data Passive Components for Electrical Networks Fiber-Optic Cable FO Fiber-Optic Cables Properties of Fiber-Optic Cables Plastic Fiber-Optic CablesPlastic Fiber-Optic Cables Properties of Fiber-Optic Cables Core Cladding Jacket buffer Plastic Fiber Optic, Duplex CordPlastic FO Cable, Duplex Cord 6XV1821-2AN50 Simatic NET Profibus Plastic Fiber Optic, Duplex Cord Fiber-Optic Cables Plastic FO Cable, Standard Cable 6XV1821-0A Plastic Fiber-Optic, Standard Cables Simatic NET Profibus plastic fiber-optic, standard cable Standard lengths PVC outer jacket Kevlar strain relief PCF fibers PCF Fiber-Optic CablesPCF FO Cable, Standard Cable 6XV1821-1B Simatic NET Profibus PCF fiber-optic cable Passive Components for Electrical Networks Guidelines for Laying Cables Simple ConfigurationGlass Fiber-Optic Cables Simatic NET Standard Fibers TB3 Frnc or Cable Type Fiber-Optic Standard Cable Indoor Fiber-Optic Trailing Cable Duplex Fiber-Optic Marine Cable Cable Type Fiber-Optic Indoor Fiber-Optic Standard CableCable Type Flexible Fiber-Optic 13.3 ± Fiber-Optic Standard Cable Fiber-Optic Standard Cable Indoor Fiber-Optic Cable Indoor Fiber-Optic Cable Flexible Fiber-Optic Trailing Cable Flexible Fiber-Optic Trailing Cable Uses Passive Components for Electrical Networks Sienopyr Duplex Fiber-Optic Marine Cable 6XV1 830-0NH10 Sienopyr Duplex Fiber-Optic Marine Cable Ordering Cable Structures Special CablesSpecial Cables Fiber Types Ordering Requirements Fiber-Optic ConnectorsConnectors for Plastic Fiber-Optic Cables Order Numbers Accessories Cable Lengths Instructions for Assembling Plastic Fiber-Optic Cables Installing Plastic Fiber-Optic Cables Bfoc Connectors for Glass Fiber-Optic Cables Bfoc Connectors for OLMsConnectors for Glass Fiber Cables Preassembled Cables Fitting Connectors On-SitePage Active Components for Optical Networks Optical Bus Terminal Optical Bus Terminal OBT 6GK1 500-3AA00 Operating Instructions Optical Link Module OLM Design Functions Profibus OLM/P11 Page Active Components for Wireless Networks Infrared Link Module ILM Profibus ILM Ordering DataPage Testing Profibus Logging Functions Hardware Test Device BT200 for PROFIBUS-DP Possible UsesArea of Application Figure A-1 Hardware Test Device BT200 for Profibus DP Design Checking the RS-485 Interface of a Slave Checking the Accessibility of NodesFunctions Checking the Profibus Cable How the Unit Functions Ordering Data Test Methods Testing FO Transmission Paths Necessity of a Final TestOptical Power Source and Meter Evaluating the Results of the Attenuation Measurements Arrangement for Measuring Attenuation Figure A-3 Optical Time Domain Reflectometer Otdr Optical Time Domain Reflectometer Otdr Figure A-4 How an Otdr Functions How an Otdr Functions Otdr provides the measurement results graphically Otdr Evaluation Checking the Optical Signal Quality with Profibus OLM OLM/G12 Page Page Bus Cables within Buildings Why Protect Your Automation System From Overvoltage?Protecting LAN Cables from Lightning Further Literature Coarse Protection LAN Cables between Buildings PLC PLC Instructions for Installing Coarse Protection Instructions for Installing Fine Protection Page Page Installing LAN Cables Networking Simatic with Simatic NET LAN Cables in Automation SystemsLAN Cables as Important Plant Connections Keep the Overall System Concept in Mind Protection from External Electrical Influences Electrical SafetyPower Supply Voltage DC Power Supply Mechanical Protection Mechanical Protection of LAN CablesProtection of Electrical and Optical LAN Cables Do not kink or crimp the trailing and festoon cables Redundant LAN Cables Install LAN cables separately Electromagnetic Compatibility EMC Electromagnetic Compatibility of LAN CablesMeasures to Counter Interference Voltages Cable Shields Installation and Grounding of Inactive Metal PartsUsing the Shields of Electrical LAN Cables Grounding Handling the Shield Equipotential Bonding When do potential differences occur? Rules for Equipotential Bonding When and why is equipotential bonding necessary?How do you avoid potential differences? Installing LAN Cables Cable Categories and Clearances Routing Electrical LAN Cables Clearance Table How to Read the TableConditions Outside closets Cables for LayWithin closets Cabling within Buildings Cabling within Closets EMC Rules for Electrical LAN Cables Cabling outside BuildingsFiber-optic cables should be given preference Underground Cabling Connecting Switched Inductances to SuppressorsPower Supply for Programming Devices Special Noise Suppression Measures Cabinet Lighting Electromagnetic Compatibility of Fiber-Optic Cables Storage and Transportation TemperaturesPull Cables Using Cable Grips and Protect Connectors General Do not twist trailing cables and festooned cables Fitting Strain ReliefPressure Torsion Attachments to Profibus Cables Installing other CablesAvoid Loops Additional Instructions on Installing Fiber-Optic Cables Attaching Profibus Fiber-Optic Cables Page Page Installation Instructions for Simatic NET Simatic NET Copyright Siemens AG All Rights Reserved Personnel qualification requirementsPage Page Setting the Cutting Depth of the Cable Knife Page Separating the Simatic NET Plastic Fiber Optic Duplex Cord Removing the Buffer Fitting Simplex Connectors Connector must be towards the center Simatic NET Profibus Plastic Fiber Optic Stripping Tool Set Simatic NET Profibus Plastic Fiber Optic, standard cableSimatic NET Profibus Plastic Fiber Optic, duplex cord Plug adapter Other commercially available accessories Simatic NET Personnel qualification requirements Page Setting the Cutting Depth of the Cable Knife Foil working from the end of the cable Separating the Simatic NET Plastic Fiber Optic Duplex Cord Removing the Buffer Crimping the Bfoc Connector Grinding and Polishing Bfoc Connectors Page Simatic NET Profibus Plastic Fiber Optic Bfoc polishing set Simatic NET Profibus Plastic Fiber Optic Standard cableSimatic NET Profibus Plastic Fiber Optic Duplex cord Simatic NET Profibus Plastic Fiber Optic Bfoc crimping tool Other commercially available accessories Simatic NET Profibus PCF Fiber Optic Standard Cable Personnel qualification requirements Simatic NET Profibus PCF Fiber Optic Standard Cable Using the Pulling Loop Marking Simatic NET Profibus PCF Fiber Optic Standard Cable Simatic NET Profibus PCF Fiber Optic cable Assembled with 2 x 2 Bfoc connectorsFor connecting OLM/P Simatic NET Profibus PCF Fiber Optic, standard cable IEC 60529, EN Installing Network Components CubiclesIP Degrees of Protection Code Contact and Solid Body Water Protection Number Degree of Protection Heat Dissipation Outdoor InstallationSimatic NET Components Ventilation Openings Standards Dimension Drawings Figure F-2 Bus Connector to IP 20 6ES7 972-0BA30-0XA0 Dimension Drawings of the Bus Connectors On OFF Siemens Figure F-6 FastConnect Bus Connector 6GK1 500-0FC00 Figure F-7 RS-485 Repeater on Standard Rail 125 Dimension Drawings of the RS-485 Repeater Figure F-9 Profibus Terminator 40.3 44.5 Dimension Drawing of the Profibus Terminator Figure F-10 RS-485 Bus Terminal on 15 mm high Standard Rail Dimension Drawings of the RS-485 Bus Terminal Figure F-11 BT12M Bus Terminal on 15 mm high Standard Rail Dimension Drawings of the BT12M Bus Terminal Dimension Drawings of the Optical Bus Terminal OBT Simatic NET Sieme N S Dimension Drawings Infrared Link Module ILM Dimension Drawings Optical Link Module OLM Dimension Drawings Page Operating Instructions ILM / OLM / OBT Operating Instructions ILM / OLM / OBT Simatic NET Attenzione Simatic NET Profibus ILM Personnel qualification requirements General Signaling Contact Displays Modes and SettingsInstallation and Startup Installing the Profibus ILM Help With Problems During Operation Product Symbols Introduction Description of the Device Siemens Profibus ILM Topologies Transmission Rate Point-to-Point Link with Two Profibus ILMs Slave Point-to-Point-Link Infrared Link Modul ILM 6ZB530-3AC30-0BA1 Slave Page ILM Point-to-Multipoint Link Infrared transmission link 2 0.5 to 15 m Constant Light Monitoring Signal RegenerationMonitoring the Received Optical Level Monitoring the Optical Link with an Acknowledgment Pulse Monitoring the Optical LinkMonitoring the Optical Receive Activity Infrared Link Modul ILM 6ZB530-3AC30-0BA1 Modes and Settings Setting the Terminating Resistor Setting the Transmission Rate Operation With Acknowledgment Pulse 3 4 5 6 7 8 Setting Operation with Signaling Contact 3 4 5 6 7 Installation and Startup General Notes on Installation and Startup 6ZB5530-3AC30-0BA1 Infrared Link Modul ILM Installing the Profibus ILM 6ZB5530-3AC30-0BA1 Infrared Link Modul ILM Thickness of sheet Approx mm depending on Siemens ILM Screw M6 x By turning Connecting the Electrical RS 485 Bus Cables 6ZB5530-3AC30-0BA1 Infrared Link Modul ILM Connecting the Power Supply and the Signaling Contact 20 to 30 Max Max mA Max a NEC Class Displays Status Displays for Incorrect Operation LED Display Possible Causes Signaling Contact LOW LED 6ZB5530-3AC30-0BA1 Infrared Link Modul ILM Errors Due to Incorrect Network Configuration Transmission Delay Time TTD Delay Time of the Profibus ILMDelay Time of Further Active Profibus Network Components Technical Specifications 6ZB5530-3AC30-0BA1 Infrared Link Modul ILM Infrared Link Modul ILM 6ZB530-3AC30-0BA1 Illumination Range LOW LED displays critical receive levels Appendix References Area of application Installation GuidelinesProduct name EMC 89/336/EEC Copyright  by Siemens OLM/P11 Trademarks Safety InstructionsQualified personnel Certified usage Contents Order Numbers Introduction OLM Operating mode related functions Non operating mode related functions Monitor echo General Functions Operating mode related functionsLine monitoring with echoes Send echo Please note Line topology Monitoring mechanisms Line topology without optical fiber link monitoring Network structure in an optic star topology Star topology Network structure in a redundant optical ring topology Redundant optical ring Monitoring mechanisms OLM/G12-1300 Safety noticeOLM/G11-1300 General information about setting up DIL switch S7 compatibility in Position Setting the compatibility Operating mode Line without optical fiber link monitoring Setting the operating modeOperating mode Electrical Port without segment monitoring Setting the operating mode of the optical ports CH2, CH3 Operating mode Redundant optical ring Installation Connecting the optical lines Mounting on a mounting plate Mounting the modulesMounting on a hat rail Observe the following safety notice Connecting the electric RS 485 bus lines Connecting the signaling contact lines Connecting the power supply Measuring sockets Defining the receiving level of the optical ports LED Indicators LED Indicators and Troubleshooting What the LED indicators and signaling contacts mean Fault indicated on CH2 / CH3 TroubleshootingFault indicated on the system LED Fault indicated on CH1 Version 1.0 8/00 Configuration of redundant optical rings Configuration of optical line and star topologies Constants for calculating the slot time at DP standard Safety Voltage/power supplySignal transmission Retimer Mechanical ambient conditions Electromagnetic compatibility EMCClimatic ambient conditions CE Designation List of abbreviations Literature notes Measuring sockets Function not guaranteed Nuremberg Nürnberg Johnson City Singapore Singapur Simatic NET Support and TrainingSimatic Training Centers Simatic Customer Support Hotline Further support Simatic Customer Support On-line ServicesSource for special cables Page Manual Profibus Optical Bus Terminal OBT Copyright Siemens AG 1998 All rights reserved Network Topology Installation and Startup10-1 Profibus Optical Bus Terminal OBT C79000-G8976-C122-02 OBT Introduction Sensitivity Power SupplyOperating Mode Connections Not supplied Simatic NET Profibus OBT ProductSupplied Profibus Optical Bus Terminal OBT C79000-G8976-C122-02 Interfaces Optoelectric Signal Conversion and Signal RegenerationFunctional Description Displays Automatic Transmission Rate DetectionSupported FO Fiber Types CH1, CH2 , CH3 channel 1 to 3, yellow + 24V green Operator Controls Optical Bus Network Topology OLM/G11 OBT Using Long Fiber Optic Sections Example of Attaching RS-485 Segments Attaching RS-485 Segments Profibus Optical Bus Terminal OBT C79000-G8976-C122-02 Installation and Startup Installation and Startup Precedure for Installation Installing the Profibus OBT Installation Installing a Module on a Mounting Plate Installation on a Mounting Plate PE M L+ NEC CLASS2 C D Connecting the Optical Cables Connecting the Electrical RS-485 Cable Profibus Optical Bus Terminal OBT C79000-G8976-C122-02 LED Display Possible Cause of Problem Troubleshooting Profibus Optical Bus Terminal OBT C79000-G8976-C122-02 Technical Specifications Technical Specifications Technical Specifications Technical Specifications Profibus Optical Bus Terminal OBT C79000-G8976-C122-02 Information for Manufacturers of Machines Installation InstructionsProduct Name EU Directive EMC 89/336/EEC Profibus Optical Bus Terminal OBT Siemens AG References Profibus Optical Bus Terminal OBT C79000-G8976-C122-02 ISO/OSI Abbreviations Profibus Optical Bus Terminal OBT C79000-G8976-C122-02 Simatic NET A&D PT2 Profibus Optical Bus Terminal OBT C79000-G8976-C122-02 Abbreviations/Acronyms General Information General Information Standards, Manuals and Further Information References Order Numbers Further InformationPage Nuremberg Johnson City Singapore Simatic Basic Hotline Simatic NET Support and TrainingSimatic Training Center Simatic Customer Support Hotline Simatic Premium Hotline Simatic Customer Support Online ServicesOrdering Special Cables, Accessories, and Tools Further Support Glossary Ground GAP factor Master-slave technique Lightning arrestersLightning protection equipotential bonding Master MinTSDR Optical power budget FOOptical power loss FO MaxTSDR Reference potential Signal propagation timeReaction time Redundancy Standard rail Simatic NET PC modulesSlave Softnet for Profibus Token rotation time Token ringPage Index Index