State Industries GFK-0827 manual Definition of Terms, Term Definition

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The Primary Unit and the Secondary Unit must be configured separately. That is, the programming device should be connected directly to either the Primary or the Secondary Unit to configure that unit. When you have completed configuring that unit, disconnect the programmer from the configured unit and move it to the other unit and proceed with configuration of the second unit. Refer to Chapter 3, ºSystem Configurationº for details of configuring a Redundancy system

Definition of Terms

Several new or unfamiliar terms are used throughout this manual which are relevant to the discussions of CPU Redundancy. These terms are defined in the following table.

Term	Definition


ActiveUnit	The unit that is actively controlling the process.

Backup Unit	That unit that is synchronized with the active unit and able to take over the process.

CPURedundancy	A system with two PLC CPU units cooperating to control the same process.

CriticalComponent	A component whose failure causes the PLC (either active or backup) in which it resides to
	stop.

Hot Standby	A feature of Genius blocks whereby the block prefers output data from the
	Bus Controller at Serial Bus Address 31. When inputs from that Bus Controller are not
	available, the block takes output data from the Bus Controller at Serial Bus Address30.
	If inputs from neither Controller are available, the block places its outputs in the
	designateddefaultstate.

LocalUnit	The RCM LEDs and %S status bits refer to the PLC in which they reside as
	theºLocalUnitº.

Primary Unit	The unit in which the Genius Bus Controller's Serial Bus Address is 31.

Redundancy	A system feature that has multiple elements controlling the same process to provide alter-
	nate functional channels in case of failure.

Remote Unit	The RCM LEDs and status bits refer to the other PLC as the ºRemote Unitº.
	For example, the Primary Unit is the Remote Unit to the Secondary Unit and likewise
	the Secondary Unit is the Remote Unit to the Primary Unit.

Secondary Unit	The unit in which the Genius Bus Controller's Serial Bus Address is 30.

Synchronized	A unit is considered to be synchronized when it has received the latest status information
	from the Active unit and is running the PLC program in parallel.

GFK-0827

Chapter 1 Introduction

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Contents GE Fanuc Automation GFL±002 Content of this Manual Related PublicationsPreface We Welcome Your Comments and SuggestionsContents Chapter System Components Chapter Configuration Chapter Operation System Operation Fault Detection and Control Actions Synchronized Hot Standby CPU Redundancy System Configuration Contents Chapter Introduction Hot Standby CPU Redundancy ProductGFK-0827 Features of the Hot Standby CPU Redundancy Product Benefits of the Hot Standby CPU Redundancy ProductLocal I/O System Systems for Hot Standby CPU Redundancy SystemsGenius I/O System Cable ConnectionsBasic Hot Standby Operation Control StrategySynchronized Hot Standby CPU Redundancy System Configuration Redundancy CPU Module Redundancy Communications ModuleSynchronized CPUs Bumpless SwitchingSwitch to Backup Unit Time Effect on Scan TimeOn-Line Programming Configurable Backup Data SizeOn-Line Repair Configuration Requirements Programming ConsiderationsDefinition of Terms Term DefinitionCommonly Used Acronyms Acronym DefinitionChapter System Components Redundancy CPUCPU Architecture Watchdog TimerCapacities for Redundancy CPU, IC697CPU780 CPU Features Redundancy CPU IC697CPUCPU Mode Switch Valid Operating Mode SelectionBattery Connectors Memor y Protect KeyswitchCPU Status LEDs Expansion Memory Board Serial Port ConnectorExpansion Memory Boards for CPU RCM Features Redundancy Communications ModuleRCM System Status Leds Board OKRCM Connectors Unit Selection PushbuttonLED Status Indicators Bus Transmitter ModuleBTM Connectors Bus Receiver ModuleBRM Connectors Bus Signal TerminationGenius Bus Controller Genius Bus Controller User Features GBC Connectors RacksChapter Configuration Configuring a Hot Standby CPU Redundancy SystemSystem Configuration Basic Redundancy System SetupLogicmaster 90 Configuration Redundancy System RequirementsScreens for Fault Category Configuration Monitor or Online modeConfiguration with Logicmaster Handling FoldersConfiguration of a Redundancy CPU Module GFK-0827 Redundant CPU Requirements Redund Type Normal Sweep ModeBackground Window Constant Window Sweep Mode Constant Sweep ModeFail Wait Ctrl StrgyShared I/O Shared I/O Data Parameters Shared I/O Reference ValuesTransfer Data Size Reference Type ReferenceSize CalculationforNumberofBytesConfiguring a CPU Expansion Memory Board Configuration of a Redundancy Communications Module Configuration Configuration of a Genius Bus Controller Paired GBC ParameterSerial Bus Address Configuring a Primary Redundant PLC Select the Redundancy CPU Module Select an Expansion Memory Board Configure the Redundant Communications Module Configure a Genius Bus Controller Configuration Configure Genius I/O Blocks Configure the Bus Transmitter Module Configuring a Secondary Redundant PLC Change Redund Type GFK-0827 Power-Up Sequence of a Redundant CPU Chapter OperationIncompatible Configurations Resynchronization of the Redundant CPU Hot-Standby Redundancy Control Strategy Synchronous Scan First Data Transfer %I, %AI and SynchronizationData Transfer from Backup Unit to Active Unit Switching Control to Backup Unit Second Data Transfer %Q, %AQ, %R, and %MRole Switch Svcreq References for CPU Redundancy Definition for% S Reference for Redundancy StatusRedundancy CPU Considerations RUN Disabled Mode Differences in Operation for CPURUN/ENABLED Locrdy Locact Remrdy Remact Configuration of Fault Actions Stop to RUN Mode Transition Background Window TimeWords per Sweep = Timed Contacts Ovrpre %S ReferenceGenius Bus Controller Switching Fault Detection Fault CategoriesChanging Fault Category Actions PLC Fault Table Fault Zoom Help Text for Redundancy Error CodesFaulting RCMs, Losing Links, and Terminating Communications GFK-0827 Fault Actions in a CPU Redundancy System Maskable Fault Group DescriptionsMaskable Fault Group Actions UserConfigurableNon-Maskable Fault Group Descriptions Non-Maskable Fault Action DescriptionsMaintaining Parallel Bus Termination On-Line RepairOn-Line Repair Recommendations Central Processor Unit Power SupplyRacks Redundancy Communications Module and CablesBus Transmitter Module Redundancy Communications Link FailuresGenius Bus Controller Genius Bus GeniusBlocksAppendix Redundancy Alternatives Redundancy AlternativesRedundancy Option Key See Table RedundancyOptions PLCSeries 90-70 Redundancy Through Application Logic Index Index Index Index Index