GE 90-70 manual Genius Bus Controller, Location of GBCs and Blocks

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Genius Bus Controller

The Genius Bus Controller (IC697BEM731) interfaces the Series 90-70 PLC to a Genius I/O bus. The bus controller scans bus devices asynchronously and exchanges I/O data with the CPU once per scan.

Location of GBCs and Blocks

For dual bus Genius networks, the Genius bus controllers should be placed at the same end of the bus, as pictured below. In particular, the Secondary Unit must be placed at one end of the bus and the Primary Unit must be placed between the Secondary Unit and the Genius I/O blocks. No I/O blocks or other devices should be located on the bus between the bus controllers. Placing the bus controllers and blocks in this manner minimizes the risk of a bus break between the two CPUs. A bus break between the CPUs could result in only some blocks switching busses, and make the other blocks inaccessible to one of the CPUs. It also allows the Primary Unit to continue to control the I/O in bus failure conditions that might otherwise result in loss of inputs and unsynchronized control of outputs.

Since the recommended configuration still has the possibility of a bus breaking between the two CPUs, you may want to program the application to monitor the status of the buses from the unit configured at the end of the buses and request a role switch or bus switch if the bus is determined to be broken. Locating single bus networks in the same manner has similar advantages.

Secondary Unit

P C

B R G

G

S P

T C B

B

UM M C C

30 30

Primary Unit

P C B R G G S P T C B B

UM M C C

31 31

PS

Power Supply..

CPU

Central Processor Unit.

BTM

Bus Transmitter Module

RCM

Redundancy Communications Module

GBC

Genius Bus Controller

BLOCK.. Genius I/O Block (or Field Control)

Bus Switching Module

B

L

O

C

K

B

L

O

C

K

B

L

O

C K

For fastest switching, all Genius Bus Controllers in the Hot Standby CPU Redundancy system should be in the main rack, or in a rack driven by the main rack's power supply. This will cause the Genius Bus Controller to lose power at the same time that the CPU loses power and allow the backup unit to gain full control of the I/O as soon as possible. Each GBC has an output timer, which it resets during every output scan. If the GBC determines that the CPU in its PLC has failed, it will stop sending outputs to its Genius I/O block. This allows the other GBC to take control of the I/O.

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

GFK-1527A

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Contents GE Fanuc Automation GFL-002 Preface Content of This ManualRelated Publications 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 OperationRedundancy CPUs as Compared to Other Series 90-70 CPUs Features not Available with Redundancy CPUsDifferences in Operation for Redundancy CPUs Systems for Enhanced Hot Standby CPU Redundancy Enhanced Redundancy CPU ModuleRedundancy Communications Module Redundant RacksLocal I/O Genius I/OCable Connections Local I/0 Can be Enhanced Hot Standby CPU Redundancy System with Local I/OGHS Control Strategy Control StrategiesGDB Control Strategy Output Control with GHS Basic Enhanced Hot Standby OperationOutput Control with GDB 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 StrategyOn-Line Repair Online ProgrammingDuplex CPU Redundancy System Components For Installation InstructionsSystem Racks Redundancy CPU FeaturesCPU Architecture Watchdog TimerExpansion Memory Board CPU LEDs CPU FeaturesMemory Protect Keyswitch Battery ConnectorsPort CPU Mode SwitchUnit Select Pushbutton Redundancy Communications ModuleRCM Status Leds ConnectorBus Transmitter Module ConnectorsBus Transmitter Module Status LEDs Cables and Termination Bus Receiver ModuleBus Receiver Module Status LEDs Location of GBCs and Blocks Genius Bus ControllerDual Bus Genius Networks Single Bus Genius NetworksBus Controller LEDs Program Folders in Control Programming Software Configuration RequirementsProgrammer Connection for Configuration One Application Program in Both PLCsProgram 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 Input Scan Backup Qualification with Svcreq #43Validating the Backup PLCs Logic Solution Switching Times Switching Control to the Backup UnitRUN 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 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 TimeMultiple I/O Scan Sets Timer and PID Function BlocksMiscellaneous Operation Information Timed ContactsBackground Window Time Stop to RUN Mode TransitionSequential Function Chart Programming SFC DebuggerGenius 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 Racks Power SupplyMaintaining Parallel Bus Termination On-Line Repair RecommendationsRedundancy Communications Module and Cables Central Processor UnitRedundancy Communications Link Failures Genius Bus Single Bus Networks Bus faultsBus Transmitter Module Genius Bus ControllerGenius Blocks Dual Bus NetworksPurpose SpecificationsCabling Information IC690CBL714A Multi-drop CableConnector a Connector A, 15-pin Female Index Battery connectors Bus Controller, GeniusIndex Online programming Online repair Svcreq
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