Reference Point | Siemens S7-400 specification

Installing the S7-400

2.6Chassis Terminal Connection in the Non-Isolated Configuration

Reference Point

The racks offer the option of connecting the 24-V load voltage ground in the non-isolated configuration to the 5-V ground (reference potential M, logic ground).

Connect the chassis ground to the reference point for non-isolated modules. The reference point is metallically connected to the reference potential M.

The following figure shows the position of the reference point on a rack.

1

2

3

4

5

6

7

Metallic connection, disconnect upper screw for ungrounded assemblies

Load voltage ground connection (reference point)

Grounding terminal

2-16	Automation System S7-400	Hardware and Installation
2-16		A5E00850741-01

Image 32

Siemens S7-400 installation manual Reference Point

Contents

Simatic Safety Guidelines Purpose of the Manual Required Basic KnowledgeScope of this Manual Approvals Navigating Recycling and DisposalFurther Support Training Centers Service & Support on the Internet Technical Support Preface Contents Contents Maintenance Assembling and Installing Systems Figures Routing Equipotential Bonding Conductor and Signal Line Tables Features of the S7-400 Overview of the S7-400 S7-400 components Components Function Illustration Location of the order number and product version Example of a rating plate Chapter Overview Section Description Central Rack CR and Expansion Rack ER S7-400 InstallationIntroduction Connecting the CR and ERs Connecting with a 5 V SupplyOverview of the Connections Local Connection Remote Connection Ways of Connecting Central and Expansion Racks Rules for Connection Type of Connection Maximum Total Cable Length Installing the Central Rack CR and Expansion Rack ER Rack No. Available Application Characteristics Slots BusesFunction of the Racks Racks in the S7-400 System Electrical Supply BusCommunication Bus C Bus Rack with I/O Bus and Communication Bus Segmented CR Properties Characteristics Subdivided CR Retaining Distances Between Devices Important Notes on InstallationMounting and Grounding the Racks Dimensions of the Racks Mounting the Rack Screw Type Explanation Connecting the Rack to the Chassis GroundMounting Screws Mounting Additional Racks 840 mm Cable duct/fan subassembly Reference Point M4 x Ungrounded configuration Grounded configurationConnection to the Reference Point Methods of Ventilation Methods of Ventilation Wall Changing the Ventilation Shipping state Filter Mat Optional Installing the Fan Subassembly Procedure Monitoring the Fan Subassembly Installing the Cable Duct Types and Dimensions of Cabinets Choosing and Setting up Cabinets with the S7-400Why Cabinets are Required Open Cabinets Closed Cabinets Removable Power Dissipation from Cabinets Example Type of Cabinet Max. Permissible Ambient Cabinet dimensionsExample of selecting the cabinet type Rules for the Arrangement of Modules Arrangement of the ModulesSpace Requirement of the Racks Modules Tool Installing Modules in a RackInstallation Sequence Removing the Cover Attaching the Modules Screwing the Modules in Place Fitting Slot Labels Marking the Modules with Slot LabelsSlot Number Networking Methods of Expansion and NetworkingDistributed I/Os Accessories Accessories Installing the S7-400 Addressing the S7-400 Geographical and Logical Addresses AddressesGeographical Addresses Logical Addresses Default Addressing Conditions for Default Addressing Example How to Determine the Default Address of a ModuleDefault Addresses of Digital Modules Default Addresses of Analog Modules How to Determine the Default Address of a Channel Channel on a Digital Module Channel on an Analog Module Addressing the S7-400 Wiring the S7-400 Supplying Power to Modules Power Supply Modules and Load Current Power Supplies Choosing the Power Supply Module Estimating the Power RequirementCalculation Example Module Quantity +5 VDC Max. Current Consumption Choosing the Load Current Power Supply Choosing the Load Current Power SupplyLoad Current Power Supplies Determining the Load Current Assembling an S7-400 with Process I/Os Definition of a Grounded Supply TN-S NetworkComponents and Protective Measures Rule Grounding the Load Current Circuits S7-400 in the Overall Installation CPU Assembling an S7-400 with Grounded Reference Potential M ApplicationDischarge of Interference Currents Terminal Connection Model Power Supply Units An S7-400 Configured with Ungrounded Reference Potential Example of Ungrounded Operation Filtering the 24 VDC SupplyInsulation Monitoring Isolated Modules and Grounding Concept Assembling an S7-400 with Isolated ModulesDefinition Configuration with Isolated Modules Parallel Wiring of Digital S7-400 Outputs Grounding Ground ConnectionsProtective Ground Device Grounding Method Connecting the Load Voltage Ground Mode Connection of Load Voltage Use only Approved Components Interference-Free Configuration for Local ConnectionsInterference-Free Configuration for Remote Connections Special Cases Wiring Rules Lines and Tools Disconnecting the Power Supply Connector Wiring the Power Supply ModulePower Supply Connector Wiring the Power Supply Connector AC DC L1 L+ Plugging In the Power Supply Connector 11 Plugging the power supply connector Wiring the Signal Modules Three Types of Front Connector Preparing to Wire the Front Connector 12 Preparing to wire the front connector Wiring the Front Connector, Crimping 13 Wiring a Front Connector with Crimp Terminals Wiring the Front Connector, Screw Terminals 14 Wiring a Front Connector with Screw-Type Terminals Wiring the Front Connector, Spring-Type Terminals 15 Wiring a Front Connector with Spring-Type Terminals Principle of the spring loaded terminal 16 Principle of the spring contact Fitting the Strain Relief Cable Ties as Strain Relief Labeling a Front Connector Labels and Terminal Diagram 19 shows details for fitting a label in the front connector Labels How to Label S7-400 Modules Order Number Description Fitting the Front Connector Front Connector Coding on the Signal ModulesPlugging In the Front Connector Principle of a Coding Key 20 Attaching the Front Connector 21 shows how to screw on the front connector Interconnecting the CR and ERs Interconnecting the Interface Modules 23 Connection Between a Send IM and Two Receive IMs Fuse Setting the Fan Subassembly to the Line VoltageWiring the Fan Subassembly Cable routing in cable ducts or fan subassemblies Routing Fiber-Optic Cables Networking Configuring a Network Same ConfigurationConfiguring Communication Subnets Fundamentals Station = NodeSegment Baud Rate Default MPI Addresses Node Device Default MPI Address Default Highest MPINumber of Nodes MPI/PROFIBUS-DP Addresses Maximum Number of Connections via MPI Rules for MPI AddressesPG / OP -- Module communication without MPI PG Access Rules for Configuring a Network Rules Data Packets in the MPI Network Recommendation for MPI AddressesRecommendation for PROFIBUS-DP Addresses Components Terminating Resistor on the Bus Connector Terminating Resistor on the RS 485 Repeater Example Terminating Resistor in the MPI Network Example of an MPI Network Example of a PROFIBUS-DP Network Example Using a CPU PROFIBUS-DP Programming Device Access Beyond Network Limits Routing Programming device access beyond network limits Cable Lengths Segment in the MPI NetworkSegment in the PROFIBUS-DP Network Longer Cable Lengths Lengths of Spur Lines 10 Configuration of an MPI network Characteristics of the PROFIBUS-DP Bus Cable PROFIBUS-DP Bus CablesPROFIBUS-DP Bus Cables Rules for Laying Cables Appearance 6ES7972-0B.20 Bus ConnectorsPurpose of the Bus Connector Removing the Bus Connector Connecting Bus Cables to Bus Connectors 6ES7972-0B.20Connecting the Bus Connector RS 485 Repeater / Diagnostics Repeater Benefits and Areas of Application PROFIBUS-DP Network with Fiber-Optic CablesElectrical/Optical Conversion Optical PROFIBUS-DP Network in Partyline Topology Transmission Rate Features of the Fiber-Optic Cables Profibus Optical Bus Terminal OBT Cable grip Order Numbers PrerequisiteSimatic NET Profibus plastic fiber-optic, standard cable Simatic NET Profibus PCF fiber-optic, standard cable Accessories Order Number Structure Cable Lengths Mixed Use of Plastic Fiber-Optic and PCF Fiber-Optic CableLaying PCF Fiber-Optic Cable Laying Plastic Fiber-Optic Cable Installing the Connector Adapter Rules for Laying Cable Networking Commissioning How to Proceed in the Case of an Error Recommended Procedure for First StartupRecommended Procedure Checks Prior to Switching On for the First Time Checks Prior to Switching On for the First TimeMounting and Wiring Modules Grounding and Chassis Ground Concept Line Voltage Module SettingsPower Supply Module If You Then Connecting a Programming Device PG to an S7-400Connecting a Programming Device PG to an S7-400 Switching On an S7-400 for the First Time Switching On an S7-400 for the First TimeSwitching On an H System for the First Time Communication between Programming Device and CPU Resetting the CPU with the Mode Selector Switch How to Carry Out a Memory ResetWhen Should a CPU be Reset? How to Perform a Memory Reset Resetting the CPU with the Mode Selector Switch Special Case MPI Parameters What Happens in the CPU During a Memory ResetWhat Remains Following the Memory Reset Cold, Warm, and Hot Restarts with the Mode Selector Switch Restart warm startHot restart Control sequence for restart warm restart / hot restart What Type of Memory Card Should You Use? Inserting a Memory CardMemory Card as Load Memory Inserting a Memory Card Inserting a Backup Battery Inserting a Backup Battery OptionBackup Commissioning Commissioning Removing a Backup Battery Reducing the Passivation Layer Starting Up a PROFIBUS-DP Subnet RequirementsStarting Up Behavior of the CPU During Startup Installing Interface Modules Available Interface Modules Covering Unused Submodule Slots Commissioning Maintenance Replacing the Backup Battery Replacing the Backup Battery Using Backup Batteries Rules for the Care of Backup Batteries Replacing a Power Supply Module Installing a New ModuleSlot Numbering How the S7-400 Behaves after Exchanging Modules Removing the Module Replacing CPUsSaving the Data Installing a New Module Installing a Module Replacing Digital or Analog Modules Removing the Front Connector Coding Key Exchanging the Front Connector Changing the Fuses in the Digital Modules Modules with FusesCheck the Plant Changing the Fuses How the S7-400 Behaves after Replacing the Fuse Removing Modules / Exchanging Cables Replacing Interface ModulesHot--swapping Modules Installing a New Module Replacing the Fuse Replacing the Fuse of the Fan SubassemblyFuse Type Replacing Fans in the Fan Subassembly During Operation Removing the Fans Maintenance Replacing the Filter Frame Maintenance Exchanging the Mother Board Available Interface Submodules Installing Interface SubmodulesReplacing Interface Submodules Inserting an Interface Submodule in a CPU Assembling and Installing Systems General Rules and Regulations for Operating the S7-400 General Basic RulesSpecific Application Emergency OFF Devices 120/230 VAC Supply VDC SupplyProtection Against External Electrical Effects With You Must Ensure Protection Against Other Electrical Effects Protection against By Means Possible Effects of Interference Principles of System Installation for EMCDefinition EMC Coupling Mechanisms Capacitive CouplingInductive Coupling Radiated Interference Five Basic Rules for Ensuring Electromagnetic Compatibility Rule 1 Large Area GroundingRule 2 Correct Cable Routing Rule 3 Secure Cable Shields See also Rule 4 Special EMC MeasuresRule 5 Standard Reference Potential Installation of Programmable Controllers for EMC Grounding of Inactive Metal Parts During InstallationEnsure the following when chassis grounding Inactive Metal Parts Examples of EMC-Compatible Assembly Example 1 Cabinet Configuration for EMC Key for example Example 2 EMC--compliant Wall Mounting Ensure the following for frame and wall mounting Figure A-3 shows an example of wall mounting for EMC Shielding Cables Purpose of the ShieldingPrinciple of Operation Suitable Cables Handling the Shields Figure A-4 Mounting Cable Shields Equipotential Bonding Conductor Equipotential BondingPotential Differences Assembling and Installing Systems How to Read the Table Cabling Inside BuildingsConnect Cables for Run Inside cabinets Ethernet Cabling Outside Buildings Rules for EMCRules for Lightning Protection Outside Buildings Overvoltage Protection Devices Lightning Protection and Overvoltage Protection Overview Effects of a Lightning Strike Surges Diagram of the Lightning Protection Zones Figure A-6 Lightning Protection Zones of a Building Order No Additional MeasuresSer Cables for Equip transition point 0 With Dehn + Söhne Lightning Protection Element for Signal Modules Lightning Protection Element for the 24 VDC Supply Low-Voltage Protection Elements for 1 Ser Cables for Equip transition point 1 2 with Order No Low-Voltage Protection Elements for 2 Ser Cables for Equip transition point Order No With Lightning-protection zone Sample CircuitLightning-protection 0, field side zone Components in figure A-7 Ser. No Components Description From fi Gure A-7 Additional Overvoltage Protection Inductive Surge VoltageIntegrated Surge Arrester Suppression with AC-Operated Coils Suppression for DC-Operated CoilsSuppression with Diodes / Zener Diodes Risks Safety of Electronic Control EquipmentIntoduction Reliability Important Information Operation under Industrial Conditions Interference-Free Connection of MonitorsOperation under Low-Interference Conditions Shielding and Grounding under Industrial Conditions Isolated Section You will find What is ESD? Electrostatic Charging of Persons Charging Ensure Sufficient Grounding Avoid Direct Contact Backup Battery AddressAnalog Module Bit Memory M Configuration ConfiguringCentral module Chassis Ground Default Setting CountersCycle time Cyclic Interrupt Diagnostic Buffer Diagnostic InterruptDP Master DP Slave Function Error DisplayError Response Functional Grounding Function Block FBFunction Module FM Global Data Communication Hardware Interrupt Instance Data BlockInterface, Multipoint Interrupt, Cyclic Load Memory Local DataLogic Block Manufacturer--specific interrupt MPI Address Nesting DepthNetwork Node Number OB Priority Operating StateOperating System of the CPU Organization Block OB Parameters, Static Priority classesProcess Image Programming Device PG Run-Time Error Reference GroundReference Potential Retentive Data Signal Module SlaveStatus interrupt Substitute Value System Diagnostics Time-Delay InterruptSystem Function SFC System Function Block SFB Timer T Toggle switchUpdate interrupt Total Current Varistor Warm RestartWatchdog interrupt Work Memory Index Index Index-3 Index-4