GE 90-70 manual GFK-1527A Normal Operation

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The configured Fail Wait time for the system must be based on the maximum expected or allowable difference in the two CPUs reaching a synchronization point. For example, if one CPU might spend 20ms in the communications phase of the sweep and the other unit might spend 95ms in communications in the same sweep, the Fail Wait time must be set to at least 80ms (80 > 95 -20) to prevent accidental loss of synchronization. Differences in the logic execution window or other phases must also be considered when selecting a Fail Wait time. Some applications limit the possible difference during the communications window by using Constant Sweep mode or Constant Window mode, or by setting the system communications window to LIMITED and selecting a small window time.

GFK-1527A

Chapter 4 Normal Operation

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Contents GE Fanuc Automation GFL-002 Content of This Manual PrefaceRelated Publications Preface Contents Contents Chapter Fault Detection Appendix a Cabling Information Introduction Definition of TermsEnhanced Hot Standby CPU Redundancy Using the Redundancy CPU for Non-Redundant Operation Compatibility with CPU780Features not Available with Redundancy CPUs Redundancy CPUs as Compared to Other Series 90-70 CPUsDifferences in Operation for Redundancy CPUs Enhanced Redundancy CPU Module Redundancy Communications ModuleRedundant Racks Systems for Enhanced Hot Standby CPU RedundancyGenius I/O Local I/OCable Connections Enhanced Hot Standby CPU Redundancy System with Local I/O Local I/0 Can beControl Strategies GHS Control StrategyGDB Control Strategy Basic Enhanced Hot Standby Operation Output Control with GHSOutput Control with GDB Basic CPU Redundancy Setups Single Bus with Preferred Master GHS Control StrategySingle Bus with Floating Master GDB Control Strategy Critical Data + Redundant Outputs TransferredDual Bus with Floating Master GDB Control Strategy Paired GBC = INT/EXT Internal ExternalOnline Programming On-Line RepairDuplex CPU Redundancy For Installation Instructions System ComponentsSystem Racks Features Redundancy CPUWatchdog Timer CPU ArchitectureExpansion Memory Board CPU Features Memory Protect KeyswitchBattery Connectors CPU LEDsCPU Mode Switch PortRedundancy Communications Module Unit Select PushbuttonConnector RCM Status LedsConnectors Bus Transmitter ModuleBus Transmitter Module Status LEDs Bus Receiver Module Cables and TerminationBus Receiver Module Status LEDs Genius Bus Controller Location of GBCs and BlocksSingle Bus Genius Networks Dual Bus Genius NetworksBus Controller LEDs Configuration Requirements Programmer Connection for ConfigurationOne Application Program in Both PLCs Program Folders in Control Programming SoftwareCPU Configuration Parameters Program Folders in LogicmasterConfiguring Shared I/O References Parameter Default Range DescriptionFinding the Memory Available for Application Program Storage System Communications Window ConsiderationsRack Module Configuration Parameters Bus Controller Configuration ParametersGenius I/O Block Configuration Parameters Normal Operation Powerup of a Redundant CPU Incompatible Configurations Resynchronization of a Redundant CPUGHS Control Strategy GDB Control StrategyReferences for CPU Redundancy Ovrpre %S Reference Not AvailableScan Synchronization Sweep Time SynchronizationOutput Data Transfer to the Backup Unit AT aData Transfer Time Fail Wait TimeGFK-1527A Normal Operation Programming a Data Transfer from Backup Unit to Active Unit Data Transfer ExampleDisabling Data Transfer Copy in Backup Unit Svcreq #43 Command Block for Svcreq #43 Backup Qualification with Svcreq #43 Validating the Backup PLCs Input ScanValidating the Backup PLCs Logic Solution Switching Control to the Backup Unit Switching TimesRUN Disabled Mode RUN Disabled Mode for GHS Control StrategyExample 1 Role switches allowed on both units Example 2 Role switches allowed on both units Example 3 Role switches not allowed on either unitExample 4 Role switches allowed on both units Backup Active RUN Disabled Mode for GDB Control Strategy Example 8 InvalidFinding the Words to Checksum Each Sweep CGR772 CGR935Finding the Background Window Time Finding the Total Sweep TimeTimer and PID Function Blocks Miscellaneous Operation InformationTimed Contacts Multiple I/O Scan SetsStop to RUN Mode Transition Sequential Function Chart Programming SFCDebugger Background Window TimeGenius Bus Controller Switching Ethernet Global Data in a Redundancy CPU Ethernet Global Data ConsumptionEthernet Global Data Production Sntp TimestampingFault Detection Configuration of Fault ActionsFault Detection PLC Fault Table Messages for Redundancy Message Fault Description Corrective ActionWith redundancy in other fault groups Fault Response Faulting the Redundancy Communications Module Losing a LinkFault Actions in a CPU Redundancy System Configurable Faults Fault Group Type DescriptionNon-Configurable Fault Group Fatal Faults on Both Units in the Same SweepOn-Line Repair Power Supply Maintaining Parallel Bus TerminationOn-Line Repair Recommendations RacksCentral Processor Unit Redundancy Communications Module and CablesRedundancy Communications Link Failures Single Bus Networks Bus faults Bus Transmitter ModuleGenius Bus Controller Genius BusDual Bus Networks Genius BlocksSpecifications Cabling InformationIC690CBL714A Multi-drop Cable PurposeConnector a Connector A, 15-pin Female Battery connectors Bus Controller, Genius IndexIndex Online programming Online repair Svcreq