GE 90-70 manual Finding the Memory Available for Application Program Storage

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Finding the Memory Available for Application Program Storage

Shared I/O data is stored in the same memory as application program storage. To find the amount of memory available for application program(s), subtract the overall transfer data amount from the amount of memory (512K bytes for CGR772, 1024K bytes for CGR935) available for the application program.

First, calculate the amounts of input and output data transferred:

Reference Type

Reference Size

If Point Faults are Disabled:

If Point Faults are Enabled:

 

 

 

 

 

 

%I

Bit

(%I length x 4 ) ÷

8

(%I length x 5) ÷

8

 

 

 

 

 

 

%AI

Word

(%AI length x 2)

 

(%AI length x 3)

 

 

 

 

 

 

 

%Q

Bit

(%Q length x 4) ÷

8

(%Q length x 5) ÷

8

 

 

 

 

 

 

%M

Bit

(%M length x 4) ÷

8

 

 

 

 

 

 

 

 

%AQ

Word

(%AQ length x 2)

 

(%AQ length x 3)

 

 

 

 

 

 

 

%R

Word

(%R length x 2)

 

 

 

 

 

 

 

 

 

 

 

 

 

Then, add the input amount, the output amount, and an additional 8K bytes for synchronization information:

total bytes of input data (%I, %AI) transferred

+total bytes of output data (%Q, %AQ, %M, %R) transferred

+8 Kbytes for synchronization information

Last, subtract this amount from the total amount available for the application.

For example, if there are 10 Kbytes of input data transferred and 20 Kbytes of output data transferred, then 10 Kbytes + 20 Kbytes + 8 Kbytes = 38 Kbytes needed for transferred data. This is subtracted from the 1024 Kbytes of total memory on the CGR935:

1024K - 38K = 986 Kbytes available for the application program on the CGR935.

System Communications Window Considerations

The CGR772 and CGR935 model CPUs support the use of high-speed communications modules such as the Ethernet Interface (Type 2). Requests from devices attached to these communications modules are handled in the System Communications Window. Since these requests can be sent in large volumes, there is the potential for the Systems Communications Window to be processing requests for a significant amount of time. One way to reduce the risk of timing out the Redundancy Communications Module/Bus Transmitter Module communications link between the CPUs is to configure the System Communications Window for LIMITED WINDOW mode. This sets a maximum time for the Systems Communications Window to run. Other options are to configure the CPU sweep mode as CONSTANT WINDOW or CONSTANT SWEEP. The CPU will then cycle through the communications and background windows for approximately the same amount of time in both units.

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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 Redundancy Communications Module Enhanced Redundancy CPU ModuleRedundant Racks Systems for Enhanced Hot Standby CPU RedundancyLocal 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 Memory Protect Keyswitch CPU FeaturesBattery Connectors CPU LEDsPort 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 Programmer Connection for Configuration Configuration RequirementsOne Application Program in Both PLCs Program Folders in Control Programming SoftwareProgram 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 TimeMiscellaneous Operation Information Timer and PID Function BlocksTimed Contacts Multiple I/O Scan SetsSequential Function Chart Programming SFC Stop to RUN Mode TransitionDebugger Background Window TimeGenius 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 Maintaining Parallel Bus Termination Power SupplyOn-Line Repair Recommendations RacksRedundancy Communications Module and Cables Central Processor UnitRedundancy Communications Link Failures Bus Transmitter Module Single Bus Networks Bus faultsGenius Bus Controller Genius BusGenius Blocks Dual Bus NetworksCabling Information SpecificationsIC690CBL714A Multi-drop Cable PurposeConnector a Connector A, 15-pin Female Index Battery connectors Bus Controller, GeniusIndex Online programming Online repair Svcreq
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