Control Strategies, GHS Control Strategy | GE 90-70 instruction

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Control Strategies

here are two different Control Strategies for Enhanced Hot Standby CPU Redundancy: GHS and GDB.

GHS Control Strategy

he GHS control strategy has the following features:

Multiple single bus Genius I/O networks with redundant controller in each synchronized PLC Multiple local single bus Genius I/O networks

Redundant Genius I/O driven exclusively by the active unit

Primary Unit is always the Active Unit in synchronized system unless explicitly overridden by user or application; switchover from secondary active to primary active may not be bumpless in certain failure conditions

TOnly critical control data must be transferred from Active to Backup CPU Compatible with the release 4 based Hot Standby Redundancy Product (CPU780)

GDB Control Strategy

he GDB control strategy has the following features:

Multiple dual bus Genius I/O Networks with redundant controllers in each synchronized PLC Multiple single bus Genius I/O networks with redundant controller in each synchronized PLC Multiple local Genius I/O networks with single or dual buses or controllers

Active unit does not automatically switch to Primary on resynchronization

TBumpless switchover with either PLC active

Critical control data plus all redundant outputs must be transferred from Active to Backup

CPU

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

GFK-1527A

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GE 90-70 manual Control Strategies, GHS Control Strategy, GDB Control Strategy

Contents

GE Fanuc Automation GFL-002 Preface Content of This ManualRelated Publications Preface Contents Contents Chapter Fault Detection Appendix a Cabling Information Introduction Definition of Terms Enhanced Hot Standby CPU Redundancy Using the Redundancy CPU for Non-Redundant Operation Compatibility with CPU780 Redundancy CPUs as Compared to Other Series 90-70 CPUs Features not Available with Redundancy CPUsDifferences in Operation for Redundancy CPUs Enhanced Redundancy CPU Module Redundancy Communications ModuleRedundant Racks Systems for Enhanced Hot Standby CPU Redundancy Local I/O Genius I/OCable Connections Enhanced Hot Standby CPU Redundancy System with Local I/O Local I/0 Can be GHS Control Strategy Control StrategiesGDB Control Strategy Output Control with GHS Basic Enhanced Hot Standby OperationOutput Control with GDB Basic CPU Redundancy Setups Single Bus with Preferred Master GHS Control Strategy Single Bus with Floating Master GDB Control Strategy Critical Data + Redundant Outputs Transferred Dual Bus with Floating Master GDB Control Strategy Paired GBC = INT/EXT Internal External On-Line Repair Online ProgrammingDuplex CPU Redundancy System Components For Installation InstructionsSystem Racks Features Redundancy CPU CPU Architecture Watchdog TimerExpansion Memory Board CPU Features Memory Protect KeyswitchBattery Connectors CPU LEDs CPU Mode Switch Port Redundancy Communications Module Unit Select Pushbutton Connector RCM Status Leds Bus Transmitter Module ConnectorsBus Transmitter Module Status LEDs Cables and Termination Bus Receiver ModuleBus Receiver Module Status LEDs Genius Bus Controller Location of GBCs and Blocks Single Bus Genius Networks Dual Bus Genius Networks Bus Controller LEDs Configuration Requirements Programmer Connection for ConfigurationOne Application Program in Both PLCs Program Folders in Control Programming Software CPU Configuration Parameters Program Folders in Logicmaster Configuring Shared I/O References Parameter Default Range Description Finding the Memory Available for Application Program Storage System Communications Window Considerations Rack Module Configuration Parameters Bus Controller Configuration Parameters Genius I/O Block Configuration Parameters Normal Operation Powerup of a Redundant CPU Incompatible Configurations Resynchronization of a Redundant CPU GHS Control Strategy GDB Control Strategy References for CPU Redundancy Ovrpre %S Reference Not Available Scan Synchronization Sweep Time Synchronization Output Data Transfer to the Backup Unit AT a Data Transfer Time Fail Wait Time GFK-1527A Normal Operation Programming a Data Transfer from Backup Unit to Active Unit Data Transfer Example Disabling Data Transfer Copy in Backup Unit Svcreq #43 Command Block for Svcreq #43 Validating the Backup PLCs Input Scan Backup Qualification with Svcreq #43Validating the Backup PLCs Logic Solution Switching Control to the Backup Unit Switching Times RUN Disabled Mode for GHS Control Strategy RUN Disabled ModeExample 1 Role switches allowed on both units Example 3 Role switches not allowed on either unit Example 2 Role switches allowed on both unitsExample 4 Role switches allowed on both units Backup Active RUN Disabled Mode for GDB Control Strategy Example 8 Invalid Finding the Words to Checksum Each Sweep CGR772 CGR935 Finding the Background Window Time Finding the Total Sweep Time Timer and PID Function Blocks Miscellaneous Operation InformationTimed Contacts Multiple I/O Scan Sets Stop to RUN Mode Transition Sequential Function Chart Programming SFCDebugger Background Window Time Genius Bus Controller Switching Ethernet Global Data in a Redundancy CPU Ethernet Global Data Consumption Ethernet Global Data Production Sntp Timestamping Fault Detection Configuration of Fault Actions Fault Detection PLC Fault Table Messages for Redundancy Message Fault Description Corrective Action With redundancy in other fault groups Fault Response Faulting the Redundancy Communications Module Losing a Link Fault Actions in a CPU Redundancy System Configurable Faults Fault Group Type Description Non-Configurable Fault Group Fatal Faults on Both Units in the Same Sweep On-Line Repair Power Supply Maintaining Parallel Bus TerminationOn-Line Repair Recommendations Racks Redundancy Communications Module and Cables Central Processor UnitRedundancy Communications Link Failures Single Bus Networks Bus faults Bus Transmitter ModuleGenius Bus Controller Genius Bus Dual Bus Networks Genius Blocks Specifications Cabling InformationIC690CBL714A Multi-drop Cable Purpose Connector a Connector A, 15-pin Female Battery connectors Bus Controller, Genius Index Index Online programming Online repair Svcreq