IF_TargetsHandler - GetPreviousListIndex (Method)

Overview

Type:	Method
Available as of:	V1.4.1.0

This chapter provides information on:

oTask

Task

Returns the index of the previous element in the list or zero.

Description

Given the index of one element of the list, the method GetPreviousListIndex returns either the index of the previous element in the list or zero if no other elements are present.

Interface

Input	Data type	Description
i_udiListIndex	UDINT	The index of the target to evaluate.

Output	Data type	Description
q_etDiag	GD.ET_Diag	General library-independent statement on the diagnostic. A value unequal to GD.ET_Diag.Ok corresponds to a diagnostic message.
q_etDiagExt	ET_DiagExt	POU-specific output on the diagnostic. q_etDiag = ET_Diag.Ok -> Status message q_etDiag <> ET_Diag.Ok -> Diagnostic message
q_sMsg	STRING[80]	Event-triggered message that gives more detailed information on the diagnostic state.

Output

Data type

Description

q_etDiag

GD.ET_Diag

General library-independent statement on the diagnostic. A value unequal to GD.ET_Diag.Ok corresponds to a diagnostic message.

q_etDiagExt

ET_DiagExt

POU-specific output on the diagnostic.

q_etDiag = ET_Diag.Ok -> Status message

q_etDiag <> ET_Diag.Ok -> Diagnostic message

q_sMsg

STRING[80]

Event-triggered message that gives more detailed information on the diagnostic state.

Return Value

Data type	Description
UDINT	The index of the previous target in the list.

Diagnostic Messages

q_etDiag	q_etDiagExt	Enumeration value	Description
Ok	Ok	0	Ok
ExecutionAborted	NotConfigured	101	The function block is not configured yet.
InputParameterInvalid	ListIndexInvalid	112	The provided list index is not referring to a valid target in the list.
InputParameterInvalid	ListIndexRange	111	The provided index is either zero or greater than the maximum list size.

ListIndexInvalid

Enumeration name:	ListIndexInvalid
Enumeration value:	112
Description:	The provided list index is not referring to a valid target in the list.

Issue	Cause	Solution
The index has not been returned.	The targets handler does not contain a target with the provided index.	Ensure that a target with index i_udiListIndex is contained in the list.

ListIndexRange

Enumeration name:	ListIndexRange
Enumeration value:	111
Description:	The provided index is either zero or greater than the maximum list size.

Issue	Cause	Solution
The index has not been returned.	The value of the index is out of range.	The value of the index i_stRobotTarget.udiListIndex must be within the range [1...Gc_udiMaxNumberOfTargets].

NotConfigured

Enumeration name:	NotConfigured
Enumeration value:	101
Description:	The function block is not configured yet.

Issue	Cause	Solution
The index has not been returned.	The Configuration method has not been called yet.	Ensure that the Configuration method has been successfully called before calling this method.

Enumeration name:	Ok
Enumeration value:	0
Description:	Ok

Status Message: The index has been successfully returned.