GE 90-70 manual Fault Detection, Configuration of Fault Actions

Page 65

Chapter

5

Fault Detection

his chapter describes how faults are handled in a Redundancy system.

Configuration of Fault Actions

Fault Detection

Fault Response

Faulting RCMs, Losing Links, and Terminating Communications

TFault Actions in a CPU Redundancy System Online Repair

Configuration of Fault Actions

Whenever the system is synchronized with a backup unit available, the decision as to which faults are FATAL and therefore will cause a switch to the backup CPU are made by the operating system and are not configurable. However, you can configure whether or not a standalone CPU (after failure of the other CPU) will stop if another fault occurs.

You can select the fault actions (either diagnostic or fatal) for when a given CPU is operating without a backup available. This will allow you to choose between fault tolerant operation and a safety system where a shutdown is preferred. For Control programming software users, refer to the Control Online Help for information on how to select fault actions.

For Logicmaster 90-70 users, fault actions can be viewed and changed during CPU configuration by pressing Fault Category (F5), which will display the Fault Category Configuration screen. To change a fault category, cursor to the category to be changed in the CFG (left) column. Use the Tab key to toggle the entry (D/F) for the fault action. After completing the changes, press the Enter key to save your changes.

Setting fault actions to diagnostic for faults that are fatal in the synchronized case allows for the possibility that a less healthy unit could remain the active unit even after a more healthy backup unit is placed in Run mode. For example, if you were to configure "Loss of or Missing Rack" failures as diagnostic, the following scenario could occur:

1. If an expansion rack fails when the units are synchronized, the unit with the rack failure will transition to STOP/FAULT mode and the other unit will become a stand-alone unit.

GFK-1527A

5-1

Image 65
Contents GE Fanuc Automation GFL-002 Related Publications Content of This ManualPreface Preface Contents Contents Chapter Fault Detection Appendix a Cabling Information Definition of Terms IntroductionEnhanced Hot Standby CPU Redundancy Compatibility with CPU780 Using the Redundancy CPU for Non-Redundant OperationDifferences in Operation for Redundancy CPUs Features not Available with Redundancy CPUsRedundancy CPUs as Compared to Other Series 90-70 CPUs Redundancy Communications Module Enhanced Redundancy CPU ModuleRedundant Racks Systems for Enhanced Hot Standby CPU RedundancyCable Connections Genius I/OLocal I/O Local I/0 Can be Enhanced Hot Standby CPU Redundancy System with Local I/OGDB Control Strategy Control StrategiesGHS Control Strategy Output Control with GDB Basic Enhanced Hot Standby OperationOutput Control with GHS Single Bus with Preferred Master GHS Control Strategy Basic CPU Redundancy SetupsCritical Data + Redundant Outputs Transferred Single Bus with Floating Master GDB Control StrategyPaired GBC = INT/EXT Internal External Dual Bus with Floating Master GDB Control StrategyDuplex CPU Redundancy Online ProgrammingOn-Line Repair System Racks For Installation InstructionsSystem Components Redundancy CPU FeaturesExpansion Memory Board Watchdog TimerCPU Architecture Memory Protect Keyswitch CPU FeaturesBattery Connectors CPU LEDsPort CPU Mode SwitchUnit Select Pushbutton Redundancy Communications ModuleRCM Status Leds ConnectorBus Transmitter Module Status LEDs ConnectorsBus Transmitter Module Bus Receiver Module Status LEDs Bus Receiver ModuleCables and Termination Location of GBCs and Blocks Genius Bus ControllerDual Bus Genius Networks Single Bus Genius NetworksBus Controller LEDs Programmer Connection for Configuration Configuration RequirementsOne Application Program in Both PLCs Program Folders in Control Programming SoftwareProgram Folders in Logicmaster CPU Configuration ParametersParameter Default Range Description Configuring Shared I/O ReferencesSystem Communications Window Considerations Finding the Memory Available for Application Program StorageBus Controller Configuration Parameters Rack Module Configuration ParametersGenius I/O Block Configuration Parameters Normal Operation Powerup of a Redundant CPU Resynchronization of a Redundant CPU Incompatible ConfigurationsGDB Control Strategy GHS Control StrategyOvrpre %S Reference Not Available References for CPU RedundancySweep Time Synchronization Scan SynchronizationAT a Output Data Transfer to the Backup UnitFail Wait Time Data Transfer TimeGFK-1527A Normal Operation Data Transfer Example Programming a Data Transfer from Backup Unit to Active UnitDisabling Data Transfer Copy in Backup Unit Svcreq #43 Command Block for Svcreq #43 Validating the Backup PLCs Logic Solution Backup Qualification with Svcreq #43Validating the Backup PLCs Input Scan Switching Times Switching Control to the Backup UnitExample 1 Role switches allowed on both units RUN Disabled ModeRUN Disabled Mode for GHS Control Strategy Example 4 Role switches allowed on both units Example 2 Role switches allowed on both unitsExample 3 Role switches not allowed on either unit Backup Active Example 8 Invalid RUN Disabled Mode for GDB Control StrategyCGR772 CGR935 Finding the Words to Checksum Each SweepFinding the Total Sweep Time Finding the Background Window TimeMiscellaneous Operation Information Timer and PID Function BlocksTimed Contacts Multiple I/O Scan SetsSequential Function Chart Programming SFC Stop to RUN Mode TransitionDebugger Background Window TimeGenius Bus Controller Switching Ethernet Global Data Consumption Ethernet Global Data in a Redundancy CPUSntp Timestamping Ethernet Global Data ProductionConfiguration of Fault Actions Fault DetectionFault Detection Message Fault Description Corrective Action PLC Fault Table Messages for RedundancyWith redundancy in other fault groups Fault Response Losing a Link Faulting the Redundancy Communications ModuleFault Actions in a CPU Redundancy System Fault Group Type Description Configurable FaultsFatal Faults on Both Units in the Same Sweep Non-Configurable Fault GroupOn-Line Repair Maintaining Parallel Bus Termination Power SupplyOn-Line Repair Recommendations RacksRedundancy Communications Link Failures Central Processor UnitRedundancy Communications Module and Cables Bus Transmitter Module Single Bus Networks Bus faultsGenius Bus Controller Genius BusGenius Blocks Dual Bus NetworksCabling Information SpecificationsIC690CBL714A Multi-drop Cable PurposeConnector a Connector A, 15-pin Female Index Battery connectors Bus Controller, GeniusIndex Online programming Online repair Svcreq