Appendix Maintenance Override | GE GFK-0787B specs

Appendix

B

Maintenance Override

The information in this appendix is reprinted by permission of TUV.

Abstract

Suggestions are made about the use of maintenance override of safety relevant sensors and actuators. Ways are shown to overcome the safety problems and the inconvenience of hardwired solutions. A checklist is given.

Maintenance Override

There are basically two methods used now to check safety relevant peripherals connected to PLCs:

hSpecial switches connected to inputs of the PLC. These inputs are used to deactivate actuators and sensors under maintenance. The maintenance condition is handled as part of the application program of the PLC.

hDuring maintenance sensors and actuators are electrically switched off of the PLC and checked manually by special measures.

In some cases, e.g. where space is limited, there is the wish to integrate the maintenance console to the operator display, or to have the maintenance covered by other strategies. This introduces the third alternative for maintenance override:

hMaintenance overrides caused by serial communication to the PLC. This possibility has to be handled with care and is introduced in this paper.

Maintenance Override Procedures

Connecting to PLC via serial lines is possible mainly in two ways:

A.The serial link is done via the MODBUS RTU protocol or other approved serial protocols. The maintenance override may not be performed by the engineering workstation or programming environment.

B.The engineering workstation or programming environment is allowed to be connected to the PLC to perform maintenance override. That requires additional safety measures inside the associated PLC to prevent a program change during maintenance intervals. These measures shall be approved, e.g. by TUV.

GFK-0787B

B-1

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GE GFK-0787B user manual Appendix Maintenance Override

Contents

GE Fanuc Automation GFL±002 Preface Related Publications Preface Contents Chapter Configuration Appendix a TÜV Certification Appendix B Maintenance Override Chapter Introduction Components of a GMR System Inter-processor Communications Series 90-70 PLCs Additional Bus Controllers for Communications Busses and Bus Controllers Operation Overview PLC Subsystem Voting on Input Data Input Subsystem Automatic System Test PLC Subsystem Providing Output DataOutput Subsystem Block Summary Genius I/O BlocksDiscrete Blocks Analog, RTD, and Thermocouple Blocks 798 Number of I/O Points in a GMR SystemNumber of Non-GMR I/O Available for the 788 CPU Number of Non-GMR I/O Available for the 789 CPU GMR Configuration and Programming Basic Steps of Configuration and Programming Chapter Input Subsystem Overview One sensor to one Genius input GMR Input Groups Inputs from non-GMR I/O blocks Non-Voted I/O in the Input SubsystemInputs from single-block simplex GMR input groups Discrepancy Reporting for GMR Inputs Discrete InputsTypes of Blocks in the Input Subsystem Discrete Input Processing Calculating Voltage Drops on Tristate Inputs Input Autotest for GMR Inputs Input Filter Time Line Monitoring for Discrete InputsNormally-closed Inputs Normally-open Inputs Manual Input Controls Analog Voting Adaptation Analog InputsVoted Analog Inputs Number of Input Sensors per Voted Channel Non-GMR Analog Blocks Analog Discrepancy ReportingNon-Voted Analog Inputs in GMR Input Groups Chapter Output Subsystem Types of Blocks in the Output Subsystem Output Voting Duplex Default for OutputsGMR Output Handling Results of Block Group Voting with Three PLCs Online PLC Logon Control Output Fault Reporting Output Load Sharing Block Output Groups Bus Redundancy in a 4-Block Output Group Electrical Characteristics of Sink and Source BlocksOperation of a 4-Block Output Group Manual Output Controls and Diagnostics Redundancy Modes for Output Blocks GMR Mode Hot Standby Mode in a GMR System Hot Standby ModeBasic Hot Standby Mode Operation Chapter PLC Subsystem All GMR bus controllers at serial bus address System Startup Online Changes Data Initialization PLC Operation CPU Sweep in a GMR System Important Note Estimating CPU Sweep TimeSweep Time Contribution of Genius I/O and GBCs Discrete Inputs Input ProcessingDiscrepancies Discrete Input Voting Voting with Three Discrete Inputs Voting with Two Discrete Inputs Voting for One Discrete Input Analog Inputs Analog Input Voting Voting for Three Analog Inputs Voting for Two Analog Inputs Voting for One Analog Input Discrete Outputs Output Processing Synchronous or Asynchronous Input Autotest and I/O Shutdown Shutdown Programming for I/O Shutdown Output Faults that Cause I/O ShutdownM12244 ± Iosd Any I/O Shutdown Timer Activated M12265 ± Sdcan Cancel I/O Shutdown Hours Shut Down Prevention Shut Down Recovery Global Data Redundancy Entering, Clearing, or Setting Global DataCommunications Between PLCs Programming for Diagnostics Chapter Diagnostics Output Diagnostics Diagnostics in a GMR SystemInput Diagnostics Summary Table Setting Up Blocks to Report Genius FaultsSetting Up Other Blocks to Send Multiple Fault Reports CPU Redundancy Mode Configuration Block Type Autotest Sequence GMR Autotesting Discrete Input Autotest Configuration Required for Discrete Input AutotestSetup for Input Autotest Circuit Fail Mask Operation of the Input Autotest Discrete Output Autotest Operation of the Discrete Output Autotest Block a Pulse-tested Pulse Test Operation Voted Discrepancy Inputs GMR Discrepancy ReportingDiscrete Input Discrepancy Reporting Input Data Discrete Output Discrepancy Reporting with Dynamic Outputs Discrete Output Discrepancy ReportingHow Output Discrepancy Checking is Performed Analog Input Discrepancy Reporting Input Line Fault Detection in a GMR Application Clearing the Fault Tables in a GMR System PLC and I/O Fault Tables in a GMR System Reporting of No-Load Faults on 4-Block Output Groups Fault Table Messages for GMR Fault Type for Output Autotest Fault Description Code Hex MeaningFault Specific Data Message PLC Fault Table Messages for GMRCode Code Code 10903 Code Manual Output Controls and Diagnostics Monitoring Manual Output Controls Discrete Input Fault Contacts for GMR Fault, No Fault, and Alarm Contacts Contact References Associated with an Output Discrete Output Fault Contacts for GMR ShortCircuitfault Overtemperaturefault Overloadfault Fault Contacts for Analog Outputs Analog Fault and Alarm Contacts for GMRAlarm Contacts Fault Contacts for Analog Inputs Chapter Configuration Basic Steps of Configuration Configuration Overview For Information to be copied set only Configuration to yes GMR Configuration Software Revision and Checksum Using the GMR Configuration Software Getting Started Installing the Configuration Software Using a Mouse Mouse and Keyboard Guide for the Configuration Software Configuration GMR Configuration Summary Insert the first GBC bus controller group Creating/Selecting a File Opening a Previously-Saved Configuration File Saving a Configuration File Changing to Another Directory Closing a Configuration File without Saving It Entering a System Description Starting a New ConfigurationClosing and Deleting the System Configuration File When you select System, the following menu appears GMR Configuration Selections Shutdown CPU ConfigurationSimplex Period Test Interval Input Discrepancy Filter Limits Global Data Initialization Data+ %R data needed for the application Spare GBC1 GBC2 Initialize Data Parame Comment Ters M12234 Fault ActionsM12232 Write Access Adding Bus Controllers and I/O Modules Genius Bus Controller Group Configuration Exiting the Window Exiting a Block Group Window Configuring the Input Subsystem for a Bus Controller GroupSelect To Configure SBA Start %I Auto Test GFK-0787B Duplex State GFK-0787B Analog I/O Group Configuration Vote Adaptation Vote Adapt Mode Default State Analog Discrepancy Thresholds and Limits Start %Q Configuring the Output Subsystem for a Bus Controller Group GFK-0787B Options Bus C inputs Reserved inputs Start Ref Configuration References are 0001 to Creating the GMR10 Output File CONFIG4 Printing the GMR Configuration Configuring Bus Controllers Completing the Logicmaster 90 Configuration Creating and Copying the PLC Configuration Logicmaster Configuration Summary GFK-0787B Configuring GMR Bus Controllers and I/O Blocks Editing the Reference Addresses Configuring Genius I/O BlocksCopying Configurations Setting Up Blocks for Fault Reporting Serial bus Configuring 16-Circuit and 32-Circuit Discrete DC BlocksFeature Circuit or Factory Selections Block Setting Device Block I/O Type Baud Rate Pulse Test Input Filter Time Circuit I/O Type Report Faults Configuration Duplex Output Default State Setting Block Duplex Default Results of Block Voting with Only Two PLCs Online Duplex Voted Output Default State Setting Block Chapter Programming Overview Use of Do I/O and Suspend I/O Program Instruction Set for GMREstimating Memory Usage Estimating Bus Scan Time References Reserved For Memor y Write AccessReserved References Discrete I/O Addressing Input and Output Addressing for GMR 1024 ± 16 ± 3 x 32 +1 = 913 = %I0913 Q1009 to %Q1024I1009 to %I1024 Analog I/O Addressing 16 x 6 = 96 words required AnalogOutput AddressingExample Memory Required for Startup Initialization Data Register %R Memory Assignment for GMR Monitoring Forces and Overrides Monitoring the Fault TablesSystem Status %S References Status References GMR Status and Control %M References PLC OK Flags Resetting Status Flags Reference Nickname Description Meaning Control ReferencesM12257 Continue M12262 Report Clearing the PLC Fault Tables40-characterConfiguration File Description Programming for Startup Enabling Outputs At Startup Monitoring Startup Status Performing I/O Fault Reset Powerup Note Routines that are appropriate for Application Fault. If both are not 1, initialization continuesExample Ladder Logic These Program Blocks represent logic Triplex bit is optional the need for this bit depends on When a third PLC comes on line Programming for I/O Shutdown Point FaultsEnabling I/O Point Faults Fault-Locating References Programming for Fault and Alarm ContactsFault and No Fault Contacts Clearing Faults Associated with Fault/No Fault Contacts Discrete Output Fault Contacts for GMR Discrete Input Fault Contacts for GMR Analog Alarm Contacts for GMR Analog Fault Contacts for GMR Y3 dummy not used Reading GMR DiagnosticsParameters for the Call Function Range for End Value Data Table NumbersContains Range for Start Value Code Meaning Error Codes for GMR Diagnostics Global Data for the Application Program Programming for Global Data GFK-0787B Select F6 Add Element to Library Adding GMR10 to the Logicmaster Librarian Do not Rename GMR10 Storing a Program to the PLC GFK-0787B Field Description Using the Store Function Storing a Revised Program Storing an Identical Program Following CPU Replacement Press the Space Bar to Continue Using the Program Download UtilityUsing the Download Utility with the Default PLC IDs Processing Complete Customizing the Download Utility for Other PLC IDs Programming Information GFK-0787B Chapter Installation Information Termination Boards Genius Bus Connections Input Wiring Single Sensor to Three Blocks Triple Bus Three Sensors to Three Blocks Triple Bus DC Source Block IC660BBD020 Block Wiring for 16-Circuit Source Block in an Input Group DC Sink Block IC660BBD021 Block Wiring for 16-Circuit Sink Block in an Input Group DC Source Block IC660BBD024 Block Wiring for 32-Circuit Source Block in an Input Group DC Sink Block IC660BBD025 Block Wiring for 32-Circuit Sink Block in an Input Group Circuit, 4-Block Output Group Output Wiring for a 16-Circuit, 4-Block Group Block a Block Wiring for a 16-Circuit 4-Block Output Group ON±OFF±ON Test Output Autotest and Pulse TestingOFF±ON±OFF Test GE Catalog Number CR7RBXXEL Spectra 700 IEC Control Relay Output Wiring for a 32-Circuit, 4-Block Group Block a Block Wiring for a 32-Circuit 4-Block Output Group GFK-0787B Milliamp Appendix Catalog Number Firmware Description Revision Level TÜV Restrictions Appendix a TÜV Certification COMMREQ, DATAINITCOMM, Call SUB, Callexternal Appendix Maintenance Override Project engineer Projectengineer, Typeapproval Recommendations Index Index-2 Index-3 Index-4