Example 8 Invalid | GE 90-70 specification

4

Example 8: Invalid

The following situation is not valid. If detected, the units switch roles automatically and behave as in Example 3 above.

	Primary Unit	Secondary Unit

Role	Backup	Active

Operating Mode	RUN/ENABLED	RUN/DISABLED

RUN Disabled Mode for GDB Control Strategy

The following guidelines apply to using RUN/DISABLED mode with the GDB Control Strategy.

1.If a unit is in RUN/DISABLED mode, its LOC_RDY %S reference and the remote unit's REM_RDY %S reference are not set and the corresponding LEDs on the Redundancy Communications Modules are OFF. This indicates that the unit (with LOC_RDY reference off) is not available to drive outputs.

2.If a unit is in RUN/ENABLED mode and the other unit is in RUN/DISABLED mode, the unit in RUN/ENABLED mode does not use its synchronized fault action table. Instead, it uses the user-configurable fault actions since there is no backup available to drive outputs.

3.Since redundant outputs must always be transferred from the active unit to the backup unit when using the GDB control strategy, if outputs are enabled on either unit, the outputs of the active unit are driven by the Genius I/O blocks.

Note

If the backup unit is in RUN/DISABLED mode, the backup unit continues NOT to drive outputs upon failure of the active unit and therefore is not a true backup.

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Series 90™-70 Enhanced Hot Standby CPU Redundancy User's Guide – May 2000

GFK-1527A

Image 57

GE 90-70 manual Example 8 Invalid, RUN Disabled Mode for GDB Control Strategy

Contents

GE Fanuc Automation GFL-002 Content of This Manual PrefaceRelated Publications Preface Contents Contents Chapter Fault Detection Appendix a Cabling Information Definition of Terms Introduction Enhanced Hot Standby CPU Redundancy Compatibility with CPU780 Using the Redundancy CPU for Non-Redundant Operation Features not Available with Redundancy CPUs Redundancy CPUs as Compared to Other Series 90-70 CPUsDifferences in Operation for Redundancy CPUs Redundancy Communications Module Enhanced Redundancy CPU ModuleRedundant Racks Systems for Enhanced Hot Standby CPU Redundancy Genius I/O Local I/OCable Connections Local I/0 Can be Enhanced Hot Standby CPU Redundancy System with Local I/O Control Strategies GHS Control StrategyGDB Control Strategy Basic Enhanced Hot Standby Operation Output Control with GHSOutput Control with GDB Single Bus with Preferred Master GHS Control Strategy Basic CPU Redundancy Setups Critical Data + Redundant Outputs Transferred Single Bus with Floating Master GDB Control Strategy Paired GBC = INT/EXT Internal External Dual Bus with Floating Master GDB Control Strategy Online Programming On-Line RepairDuplex CPU Redundancy For Installation Instructions System ComponentsSystem Racks Redundancy CPU Features Watchdog Timer CPU ArchitectureExpansion Memory Board Memory Protect Keyswitch CPU FeaturesBattery Connectors CPU LEDs Port CPU Mode Switch Unit Select Pushbutton Redundancy Communications Module RCM Status Leds Connector Connectors Bus Transmitter ModuleBus Transmitter Module Status LEDs Bus Receiver Module Cables and TerminationBus Receiver Module Status LEDs Location of GBCs and Blocks Genius Bus Controller Dual Bus Genius Networks Single Bus Genius Networks Bus Controller LEDs Programmer Connection for Configuration Configuration RequirementsOne Application Program in Both PLCs Program Folders in Control Programming Software Program Folders in Logicmaster CPU Configuration Parameters Parameter Default Range Description Configuring Shared I/O References System Communications Window Considerations Finding the Memory Available for Application Program Storage Bus Controller Configuration Parameters Rack Module Configuration Parameters Genius I/O Block Configuration Parameters Normal Operation Powerup of a Redundant CPU Resynchronization of a Redundant CPU Incompatible Configurations GDB Control Strategy GHS Control Strategy Ovrpre %S Reference Not Available References for CPU Redundancy Sweep Time Synchronization Scan Synchronization AT a Output Data Transfer to the Backup Unit Fail Wait Time Data Transfer Time GFK-1527A Normal Operation Data Transfer Example Programming a Data Transfer from Backup Unit to Active Unit Disabling 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 Times Switching Control to the Backup Unit RUN 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 Example 8 Invalid RUN Disabled Mode for GDB Control Strategy CGR772 CGR935 Finding the Words to Checksum Each Sweep Finding the Total Sweep Time Finding the Background Window Time Miscellaneous Operation Information Timer and PID Function BlocksTimed Contacts Multiple I/O Scan Sets Sequential Function Chart Programming SFC Stop to RUN Mode TransitionDebugger Background Window Time Genius Bus Controller Switching Ethernet Global Data Consumption Ethernet Global Data in a Redundancy CPU Sntp Timestamping Ethernet Global Data Production Configuration of Fault Actions Fault Detection Fault Detection Message Fault Description Corrective Action PLC Fault Table Messages for Redundancy With redundancy in other fault groups Fault Response Losing a Link Faulting the Redundancy Communications Module Fault Actions in a CPU Redundancy System Fault Group Type Description Configurable Faults Fatal Faults on Both Units in the Same Sweep Non-Configurable Fault Group On-Line Repair Maintaining Parallel Bus Termination Power SupplyOn-Line Repair Recommendations Racks Central Processor Unit Redundancy Communications Module and CablesRedundancy Communications Link Failures Bus Transmitter Module Single Bus Networks Bus faultsGenius Bus Controller Genius Bus Genius Blocks Dual Bus Networks Cabling Information SpecificationsIC690CBL714A Multi-drop Cable Purpose Connector a Connector A, 15-pin Female Index Battery connectors Bus Controller, Genius Index Online programming Online repair Svcreq