FB_VelocityRatioFeedForward - General Information

Overview

Type:	Function block
Available as of:	V1.0.0.0
Inherits from:	-
Implements:	-
Versions:	Current version

Task

Calculation of the velocity feed forward control of a downstream machine for the algorithm POU FB_VelocityRatioAlgorithm

Description

The POU is an extension of the algorithm POU FB_VelocityRatioAlgorithm. It calculates the required feed forward velocity of the downstream machine based on the incoming product flow. This can minimize idle cycles in the downstream machine caused by a fluctuating incoming product flow.

Interface

Input	Data type	Description
i_xEnable	BOOL	A rising edge FALSE -> TRUE activates the POU, a falling edge TRUE -> FALSE deactivates the POU. A deactivated POU does not execute any actions.
i_xStart	BOOL	TRUE: Starts the calculation of the velocity feed forward control
i_xDiagQuit	BOOL	A rising edge FALSE -> TRUE acknowledges the diagnostic messages of the POU.
i_lrFeedForwardAverageVelocity	LREAL	The mean average feed forward velocity of the downstream machine This is calculated from the velocity of the product feed and the average product flow. See usage of FB_VelocityRatioAlgorithm and the velocity feed forward control
i_lrFeedForwardFactorStepPercent	LREAL	The percentage velocity change for each call cycle The parameter defines the percentage by which the outputs q_lrFeedForwardFactor and q_lrFeedForwardVelocity are changed in the case of a necessary velocity change, each time the POU is called up.
i_lrFeedForwardFactorMaximum	LREAL	The maximum value that may not be exceed by q_lrFeedForwardFactor. The POU limits q_lrFeedForwardFactor to this value.
i_lrIncVelocityHysteresisPercent	LREAL	The function block calculates the suitable feed forward velocity cyclically. A tolerance range can be defined in order to reduce permanent control. If the calculated feed forward velocity is within this range, no change is carried out. i_lrIncVelocityHysteresisPercent reflects the upper limit of this tolerance window.
i_lrDecVelocityHysteresisPercent	LREAL	The function block calculates the suitable feed forward velocity cyclically. A tolerance range can be defined, in order to reduce a permanent control. If the calculated feed forward velocity is within this range, no change is carried out. i_lrDecVelocityHysteresisPercent reflects the lower limit of this tolerance window.
i_lrStopDistance	LREAL	Defines a range on the feed belt, measured from the start of the first correction belt. If there is no product within this range, the outputs q_lrFeedForwardFactor and q_lrFeedForwardVelocity are set to 0.0. This can be used to stop the downstream machine and avoid idle cycles.
i_lrRestartDistance	LREAL	As opposed to i_lrStopDistance, i_lrRestartDistance indicates the distance from the start of the first correction belt from which the feed forward control is started again. This enables a controlled start of the downstream machine if a product reaches the distance i_lrRestart Distance to the first correction belt after the downstream machine is stopped.
i_ifInfeed	IF_Infeed	The instance of the FB_Infeed POU for which the feed forward velocity is to be calculated
i_ifVelocityRatioAlgorithm	IF_VelRatioAlgorithm	The instance of the FB_VelocityRatioAlgorithm POU for which the feed forward velocity is to be calculated
i_ifCounter	IF_Counter	The interface of a counter of the FB_Infeed POU which it uses to calculate the product flow has to be transferred to the POU.

Output	Data type	Description
q_xActive	BOOL	TRUE: The POU is active and has to be executed further. FALSE: The POU is inactive.
q_xReady	BOOL	TRUE: The POU is ready to operate and can accept user commands. FALSE: The function block is not ready to accept user commands.
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 = GD.ET_Diag.Ok -> status message q_etDiag <> GD.ET_Diag.Ok -> diagnostic message
q_sMsg	STRING[80]	Event-triggered message which gives more detailed information on the diagnostic state.
q_lrFeedForwardVelocity	LREAL	The feed forward velocity of the downstream machine
q_lrFeedForwardFactor	LREAL	The ratio of the feed forward velocity for the downstream machine and the velocity of the feed belt

Diagnostic Messages

q_etDiag	q_etDiagExt	Enumeration value	Description
OK	Disabled	1	The POU is disabled.
OK	Initializing	2	The POU is being initialized.
OK	WaitForStart	3	Waiting for starting command.
OK	Working	6	The POU is working.
ExecutionAborted	BeltInvalid	13	The belt is invalid.
InputParameterInvalid	CounterInvalid	108	No valid counter has been transferred.
InputParameterInvalid	DecVelocityHysteresisPercentRange	113	DecVelocityHysteresisPercent is outside the valid range.
InputParameterInvalid	FeedForwardAverageVelocityRange	111	FeedForwardAverageVelocity is outside the valid range.
InputParameterInvalid	FeedForwardFactorMaximumRange	110	FeedForwardFactorMaximum is outside the valid range.
InputParameterInvalid	FeedForwardFactorStepPercentRange	109	FeedForwardFactorStepPercent is outside the valid range.
InputParameterInvalid	IncVelocityHysteresisPercentRange	112	IncVelocityHysteresisPercent is outside the valid range.
InputParameterInvalid	InfeedInvalid	94	An invalid infeed POU has been transferred.
InputParameterInvalid	RestartDistanceRange	115	RestartDistance is outside the valid range.
InputParameterInvalid	StopDistanceLowerRestartDistance	116	StopDistance is smaller than RestartDistance.
InputParameterInvalid	StopDistanceRange	114	StopDistance is outside the valid range.
InputParameterInvalid	VelocityRatioAlgorithmInvalid	107	VelRatioAlgorithm is invalid.
UnexpectedProgramBehavior	UnknownFeedback	20	An unexpected error occurred during execution.

BeltInvalid

Enumeration name:	BeltInvalid
Enumeration value:	13
Description:	The belt is invalid.

Issue	Cause	Solution
-	The counter transferred at the i_ifCounter input cannot be connected to the first belt of the infeed distance transferred at the i_ifInfeed input.	It must be made sure that a counter can be connected to the first belt of the infeed distance.

CounterInvalid

Enumeration name:	CounterInvalid
Enumeration value:	108
Description:	No valid counter has been transferred.

Issue	Cause	Solution
-	An invalid value has been transferred at the input i_ifCounter.	It must be made sure that a counter of the infeed POU transferred at the i_ifInfeed input is transferred at the i_ifCounter input.

DecVelocityHysteresisPercentRange

Enumeration name:	DecVelocityHysteresisPercentRange
Enumeration value:	113
Description:	DecVelocityHysteresisPercent is outside the valid range.

Issue	Cause	Solution
-	An invalid value has been transferred at the i_lrDecVelocityHysteresisPercent.	It must be made sure that a value greater than 0 and smaller than 100 is transferred at the input i_lrDecVelocityHysteresisPercent.

Disabled

Enumeration name:	Disabled
Enumeration value:	1
Description:	The POU is disabled.

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

FeedForwardAverageVelocityRange

Enumeration name:	FeedForwardAverageVelocityRange
Enumeration value:	111
Description:	FeedForwardAverageVelocity is outside the valid range.

Issue	Cause	Solution
-	An invalid value has been transferred at the input i_lrFeedForwardAverageVelocity.	It must be made sure that a value greater than or equal to 0 is transferred at the input i_lrFeedForwardAverageVelocity.

FeedForwardFactorMaximumRange

Enumeration name:	FeedForwardFactorMaximumRange
Enumeration value:	110
Description:	FeedForwardFactorMaximum is outside the valid range.

Issue	Cause	Solution
-	An invalid value has been transferred at the input i_lrFeedForwardFactorMaximum.	It must be made sure that a value greater than or equal to 1.0 and smaller than or equal to 100 is transferred at the input i_lrFeedForwardFactorMaximum.

FeedForwardFactorStepPercentRange

Enumeration name:	FeedForwardFactorStepPercentRange
Enumeration value:	109
Description:	FeedForwardFactorStepPercent is outside the valid range.

Issue	Cause	Solution
-	An invalid value has been transferred at the input i_lrFeedForwardFactorStepPercent.	It must be made sure that a value greater than 0 and smaller than or equal to 100 is transferred at the input i_lrFeedForwardFactorStepPercent.

IncVelocityHysteresisPercentRange

Enumeration name:	IncVelocityHysteresisPercentRange
Enumeration value:	112
Description:	IncVelocityHysteresisPercent is outside the valid range.

Issue	Cause	Solution
-	An invalid value has been transferred at the input i_lrIncVelocityHysteresisPercent.	It must be made sure that a value greater than or equal to 0 and smaller than or equal to 100 is transferred at the input i_lrIncVelocityHysteresisPercent.

InfeedInvalid

Enumeration name:	InfeedInvalid
Enumeration value:	94
Description:	An invalid infeed POU has been transferred.

Issue	Cause	Solution
-	An invalid value has been transferred at the input i_ifInfeed.	It must be made sure that the instance of the FB_Infeed POU is transferred at the i_ifInfeed input, which the FB_VelocityRatioAlgorithm POU transferred at the i_ifVelocityRatioAlgorithm input is to control.

Initializing

Enumeration name:	Initializing
Enumeration value:	2
Description:	The POU is being initialized.

The POU is being initialized and thus is not yet ready to receive commands at its inputs.

The POU will signalize that it is ready for operation with the signal q_xReady = TRUE.

RestartDistanceRange

Enumeration name:	RestartDistanceRange
Enumeration value:	115
Description:	RestartDistance is outside the valid range.

Issue	Cause	Solution
-	An invalid value has been transferred at the input i_lrRestartDistance.	It must be made sure that a value greater than 0 is transferred at the input i_lrRestartDistance.

StopDistanceLowerRestartDistance

Enumeration name:	StopDistanceLowerRestartDistance
Enumeration value:	116
Description:	StopDistance is smaller than RestartDistance.

Issue	Cause	Solution
-	The values transferred at the inputs i_lrStopDistance and i_lrRestartDistance do not match.	It must be made sure that the value of the input i_lrStopDistance is greater than the value of i_lrRestartDistance.

StopDistanceRange

Enumeration name:	StopDistanceRange
Enumeration value:	114
Description:	StopDistance is outside the valid range.

Issue	Cause	Solution
-	An invalid value has been transferred at the input i_lrStopDistance.	It must be made sure that a value greater than 0 is transferred at the input i_lrStopDistance.

UnknownFeedback

Enumeration name:	UnknownFeedback
Enumeration value:	20
Description:	An unexpected error occurred during execution.

Issue	Cause	Solution
-	An error occurred in the internal execution.	Please inform the support team about this error.

VelocityRatioAlgorithmInvalid

Enumeration name:	VelocityRatioAlgorithmInvalid
Enumeration value:	107
Description:	VelRatioAlgorithm is invalid.

Issue	Cause	Solution
-	An invalid value has been transferred at the input i_ifVelocityRatioAlgorithm.	It must be made sure that the instance FB_VelocityRatioAlgorithm is transferred at the input i_ifVelocityRatioAlgorithm the feed forward velocity of which is to be calculated.

WaitForStart

Enumeration name:	WaitForStart
Enumeration value:	3
Description:	Waiting for starting command.

The POU has completed its initialization and is waiting for a positive edge at the i_xStart input before continuing the processing.

Working

Enumeration name:	Working
Enumeration value:	6
Description:	The POU is working.

The feed forward velocity is being calculated.

Methods

Name	Description
RegisterLoggerPoint	Registers the internal logger point in the Application Logger.