FB_ExceptionHandlerTpi - General Information

Overview

Task

Function block for monitoring and managing the global exception list.

Description

The primary purpose of this POU is to distribute reactions. A reaction describes how an axis should stop when an exception occurs and there are five basic reactions as follows:

• TPL.ET_Reaction.AsyncStop

• TPL.ET_Reaction.SyncStopEl

• TPL.ET_Reaction.AsyncStopEh

• TPL.ET_Reaction.StopEndOfCycle

• TPL.ET_Reaction.MainsConstactorOff (*Not used by the AXM.FB_AxisModuleTpi POU)

Every exception generated by the system, by most functions and POUs, and by the user program has a reaction associated with it. The AXM.FB_AxisModuleTpi POU, for instance, monitors itself and its associated axes for errors detected. User code typically uses the FC_SetExceptionTpi function to define and control exceptions. The exception with its associated reaction is also entered into the global exception list when the exception becomes active.

The global exception list is specified with the iq_stExceptionList input and contains the active errors detected. The global logging list is specifies with the iq_stLogDataList input and it holds the last 100 errors (default). This default can be modified by changing the value of TPL.Gc_udiMaxNumberOfExecptions. A newly error will replace the oldest one once the logging list becomes full. The logging list can also contain other events.

This function block searches for reactions as long as the machine is activated (iq_stMachineInterface.i_xEnable). The function block indicates that it is active and processing with the q_xActive output.

The input i_xLocalExceptionHandler specifies where reactions are searched for. The input i_ xLocalExceptionHandler has always to be FALSE because the TemplatePilot supports no submodules needing an own ExceptionHandler.

This function block searches as a global exception handler (i_xLocalExceptionHandler := FALSE;) the global exception list for changes. It distributes the reaction associated with any existing exceptions contained in the global exception list to all the associated sub-modules (axes). Using the i_pstSubModulesItf input, the POU receives all information concerning all existing axes. This input needs the address of an array of the ST_StandardModuleInterface type. Using the i_udiNumberOfSubModules input, the POU receives the number of available sub-modules.

The distribution of the reactions can be influenced by different modes. The translation modes are processed via the i_psReactionTranslationJobs input. This structure is set to default values with the FC_InitReactionTranslationMode function. The default setting of this structure directs the distribution of reactions based on a reaction table specified by the i_pstReactionTranslationTable input.

The reaction table is set to default values with the TPL.FC_InitReactionTranslationTable function. In default setting, each sub-module (axis) receives the same reaction that is found. If, for instance, an exception with reaction 2 is found in the global exception list, each axis contains reaction 2 (TPL.ET_Reaction.SyncStopEl).

The exception translation structure and/or the reaction table can be re-configured to change how error detection reactions are distributed. With it, for instance, it is also possible to extract individual modules (axes) from an emergency-stop circuit and to support several emergency-stop circuits in one machine.

The function block also manages the global exception list if it is selected (i_xLocalExceptionHandler := FALSE). It manages the following functions:

• Updates the elapse time of each exception in the global exception list

• Distributes the DiagQuit signal (iq_stMachineInterface.i_xDiagQuit) to the sub-modules (axes).

• Resets the system errors by DiagQuit (iq_stMachineInterface.i_xDiagQuit).

• Removes inactive exceptions from the global exception list.

The q_etDiag output reports <> GD.ET_Diag.Ok when any reaction is found or the following inputs are not set correctly:

• The input i_pstSubModulesItf is less than or equal zero.

• The input i_pstReactionTranslationTable is less than or equal zero.

• The size of the input i_udiNumberOfSubModules does not correspond to the diSizeOfSubModuleInterface input.

These exceptions have a TPL.ET_Reaction.AsyncStop reaction.

The q_udiSubModuleInException output indicates which sub-module has an exception. The sub-module with the lowest index number is shown if multiple sub-modules have an exception.

This is a function block that will require an instance of it to be declared.

Call-up in FBD

Interface

Diagnostic Messages

ControllerInvalid

Disabled

The function block is deactivated, it executes no actions whatsoever. i_xEnable and q_xActive have the value FALSE.

InitExceptionListFailed

Initializing

The function block is being initialized and thus is not yet ready to receive commands at its inputs. The function block will signalize that it is ready for operation with the signal q_xReady = TRUE.

PointerReactionTranslationJobsInvalid

PointerReactionTranslationModeInvalid

PointerReactionTranslationTableInvalid

PointerSubModulesItfInvalid

ReactionTranslationEntryInvalid

SizeOfSubModulesItfInvalid

Working

The function block distributes reactions to subordinate modules.