GE Series 90-70 manual Calling the Program Block, Example Call Instruction

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Calling the Program Block

To call the LINKxxX block, place a Call instruction as close as possible to the start of the main program. To assure consistent mapping of link I/O data, do not use permissive logic to the call. Include at least one call to the LINKxxX block each program sweep, to assure that the link status is routinely updated and the link retry mechanism is enabled. This is discussed in more detail later in the chapter.

Example Call Instruction

In this example, the Call instruction calls Program Block LINK73X.

[

INTERRUPTS

]

[

START OF PROGRAM BLOCK

]

CALL LINK73X

Using Multiple Calls to the Program Block

For most applications, the main program will include only one Call instruction to the LINKxxX Program Block. However, it is possible to use multiple calls in the program. For example, a call might be used at a particular place in the program to update inputs, outputs, or both. In this way, the Program Block call would serve as a ªDoI/Oº instruction.

In applications with long communications windows or in Constant Sweep Time mode, a call to LINKxxX might be used at the beginning of the program to update only inputs, with another call at the end to update only outputs.

When using multiple calls to the LINKxxX Program Block, all additional calls after the first should use the set status of the ªLink Activeº status bit as a permissive to their execution.

GFK±0644

Chapter 4 Programming Guide

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Contents GE Fanuc Automation GFL±002 We Welcome Your Comments and Suggestions Content of this ManualRelated Publications Contents System Overview Chapter IntroductionMaster or Slave Operation Application Software LEDs Module DescriptionSerial Ports Module SpecificationsReset Pushbutton CatalogNumber Cable Types for the I/O LinkCable Lengths on the I/O Link Optical Adapter Input and Output Data Operation of the I/O LinkData Returned by Slaves Data Sent by the MasterInputs and Outputs Hold Last State Faults on the I/O Link Link Control DiagnosticsComplete the program logic for the I/O Link Module Install the module and complete the I/O LinkGetting Started Installing the I/O Link Interface Module in the Rack Chapter InstallationLED Name LED Status Indication Removing the I/O Link Interface Module from the RackLink Module Used as a Master Connecting the I/O Link Interface Module to Other DevicesPorts on the I/O Link Module Order of the Devices on the Link Serial Port Pin AssignmentsLink Module Used as a Slave Cable Diagram, No Optical Adapter Cable Connections Optical Adapter InstallationCable Diagram, Electrical Cable to Optical Adapter Configuration Steps Chapter Logicmaster 90-70 ConfigurationGFK-0644A Overview Chapter Programming GuideAdding the Program Block Logic to an Application Program Selecting a Program BlockExample Call Instruction Using Multiple Calls to the Program BlockCalling the Program Block 3rdModule 4thModule Program %P References for the I/O Link Program BlocksGlobal %G References for the I/O Link Program Blocks Using Nicknames for the %P ReferencesConfiguration Logic, Example Configuring I/O LinksSpecify the Number of I/O Link Modules Configuration GuidelinesReset or Stop bit Set Master or Slave Mode bitControlling the I/O Link Module Start/Restart bitDisable or Enable the Output Update bit Disable or Enable the Input Update bitMonitor Communications Status bit Monitoring Link OperationMonitor the Module bit Monitor for Link Failure bit Monitor for an Invalid Configuration or Link Fault bitError Description RecommendedAction Code Error Codes TroubleshootingConfiguration Error Codes Index GFK-0644A Index