FB_TpDistanceControl - General Information

Overview

Type:	Function block
Available as of:	V1.0.3.0
Inherits from:	-
Implements:	-

Task

Recording and saving product distances

Description

The function block can be used in applications such as "Flying Saw" or "Infeed". The function block is used to implement an absolute correction.

The products are recorded via a measured input (Touchprobe function). The distance between the products (front edge to front edge) are measured and are stored in a FIFO buffer.

Interface

Input	Data type	Description
i_xEnable	BOOL	Value range: TRUE / FALSE 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_ifDrive	IF_Drive	Value range: Drive object Input for the axis that shall be connected to the LE at iq_lencEncoder.
i_ifTouchProbe	IF_TouchProbe	Value range: Touch probe object Measured input over which the products are recorded. The input measures the rising edge of the Touchprobe.
i_xReset	BOOL	Value range: TRUE / FALSE Deletes the FIFO buffer. With the next valid Touchprobe signal, the output q_xFirstTp is set. In contrast to enabling by means of i_xEnable, the Touchprobe function is not reset. Thus, no edge is lost.
i_lrDefaultDistance	LREAL	Value range: >= 0 Normal distance of the parts to be measured in units, value range >= 0. If i_lrDefaultDistance > 0, then upon completion of the distance i_lrDefaultDistance + i_lrMinDistance a product will be simulated. That means the i_ lrDefaultDistance is written into the FIFO buffer and the output q_diNumberOfMissingTps is increased by one. With the next valid Touchprobe signal, q_diNumberOfMissingTps is set to zero. If i_lrDefaultDistance = 0, the Touchprobe signal is always waited for.
i_lrMinDistance	LREAL	Value range: >= 0 Is used as a window for recording the Touchprobe signals. No new Touchprobe signal will be accepted within this distance. Values in units, value range >= 0. If i_lrDefaultDistance = 0, i_lrMinDistance should be > 0. Keep in mind products / parts will be simulated if no Touchprobe occurs within i_lrDefaultDistance + i_lrMinDistance. This can lead to conflicts with occured Touchprobe signals.
i_lrMaxWaitDistance	LREAL	Value range: >= 0 Maximum distance for searching the first Touchprobe signal in units, value range >= 0. If 0, the maximum value is not checked.
i_lrMaxCorrection	LREAL	Value range: > 0 With this value the distance, which is read from the FiFo via the method GetValue(), can be restricted. The remaining measurement is considered during the following reading. This parameter is only taken into consideration if i_lrDefaultDistance > 0 and q_diNoOfElementsInFiFo > 0. Value range > 0.

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 take measurements. FALSE: The POU is not ready.
q_etDiag	GD.ET_Diag	General library-independent statement on the diagnostic. A value not equal to ET_Diag.Ok corresponds to an 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 which gives more detailed information on the diagnostic state.
q_xFirstTp	BOOL	Indicates that the first product has been detected by the Touchprobe function. This signal is used to synchronize the application by means of the function block.
q_diNumberOfMissingTps	DINT	This indicates that no product has been seen within the distance i_lrDefaultDistance + i_lrMinDistance. This signal is only triggered when i_lrDefaultDistance > 0. The output is set to 0 as soon as a new valid Touchprobe signal is detected.
q_diNoOfElementsInFiFo	DINT	Indicates how many values are stored in the FIFO buffer. The FIFO buffer has been designed for a maximum of Gc_diMaxNumberOfElementsInFiFo values. If Gc_diMaxNumberOfElementsInFiFo values are exceeded, an error is released. With the method GetValue(), values can be read from the FiFo.
q_lrTpCaptureDiff	LREAL	The difference between the position of the iq_lencEncoder to the period of the scanning with which the signal q_xFirstTP is set and the measurement at the Touchprobe signal. This value can be used to increase the accuracy in the application with the first synchronization. See registration mark control with absolute correction.
q_lrTpCaptureValue	LREAL	Position when the last Touchprobe signal occurred.

Input/Output	Data type	Description
iq_lencEncoder	L_ENC	Logical encoder for measuring the distance. The logical encoder has to be connected to the master axis. An individual logical encoder must be created for each instance of the function block.

Examples

Following examples provide a detailed explanation of the recording and saving of product distances via FB_TpDistanceControl:

oIndexed application with absolute correction

oSynchronous application with absolute correction

Diagnostic Messages

q_etDiag	q_etDiagExt	Enumeration value	Description
OK	Disabled	9	The POU is disabled.
OK	Initializing	4	The POU is being initialized.
OK	WaitForFirstTouchProbeSignal	168	Waiting for first Touchprobe signal.
OK	WaitForNextTouchProbeSignal	169	Waiting for the next Touchprobe signal.
ExecutionAborted	FiFoFull	103	The FiFo is full.
InputParameterInvalid	DriveInvalid	3	The connected drive is invalid.
InputParameterInvalid	LencInvalid	162	The connected logical encoder is invalid.
InputParameterInvalid	TouchProbeInvalid	163	The connected Touchprobe is invalid.
InputParameterInvalid	TouchProbeNotActive	166	The Touchprobe is not active.
InputParameterInvalid	TouchProbeVirtual	165	The connected Touchprobe is virtual.
LimitReached	MaxWaitDistanceReached	170	MaxWaitDistance has been reached.
SercosConditionInvalid	SercosNotInPhaseFour	19	The Sercos bus is not in phase 4.
UnexpectedProgramBehavior	UnexpectedFeedback	1	An unintended detected error occurred during execution.

Disabled

Enumeration name:	Disabled
Enumeration value:	9
Description:	The POU is disabled.

The function block is disabled and executes no actions whatsoever. i_xEnable and q_xActive are set to FALSE

DriveInvalid

Enumeration name:	DriveInvalid
Enumeration value:	3
Description:	The connected drive is invalid.

Issue	Cause	Solution
-	At the input i_ifDrive, no drive was applied.	At the input i_ifDrive, a valid drive must be transferred.
-	The connected drive does not support all required functionalities.	Establish which functionalities are not supported by the drive by means of output q_sMsg. Use a drive which supports all required functionalities.

Issue

Cause

Solution

At the input i_ifDrive, no drive was applied.

At the input i_ifDrive, a valid drive must be transferred.

The connected drive does not support all required functionalities.

Establish which functionalities are not supported by the drive by means of output q_sMsg.

Use a drive which supports all required functionalities.

FiFoFull

Enumeration name:	FiFoFull
Enumeration value:	103
Description:	The FiFo is full.

Issue	Cause	Solution
-	Too many values have been entered into the FiFo.	Ensure that no more than Gc_diMaxNumberOfElementsInFiFo values are entered into the FiFo.

Initializing

Enumeration name:	Initializing
Enumeration value:	4
Description:	The POU is being initialized.

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.

LencInvalid

Enumeration name:	LencInvalid
Enumeration value:	162
Description:	The connected logical encoder is invalid.

Issue	Cause	Solution
-	At the input iq_lencEncoder, no encoder has been applied.	At the input iq_lencEncoder, a separate logical encoder must be transferred.

MaxWaitDistanceReached

Enumeration name:	MaxWaitDistanceReached
Enumeration value:	170
Description:	MaxWaitDistance has been reached.

Issue	Cause	Solution
-	The encoder has covered a distance of more than i_lrMaxWaitDistance without receiving a Touchprobe signal.	Verify the Touchprobe sensor Verify whether the correct touchprobe has been connected to the i_ifTouchProbe connection. Disable the monitoring by setting the input i_lrMaxWaitDistance to 0.

Issue

Cause

Solution

The encoder has covered a distance of more than i_lrMaxWaitDistance without receiving a Touchprobe signal.

Verify the Touchprobe sensor

Verify whether the correct touchprobe has been connected to the i_ifTouchProbe connection.

Disable the monitoring by setting the input i_lrMaxWaitDistance to 0.

SercosNotInPhaseFour

Enumeration name:	SercosNotInPhaseFour
Enumeration value:	19
Description:	The Sercos bus is not in phase 4.

Issue	Cause	Solution
-	The parameter State of the SERCOS bus is not 4.	Set the SERCOS bus parameter PhaseSet to 4. Verify the SERCOS bus for errors.

Issue

Cause

Solution

The parameter State of the SERCOS bus is not 4.

Set the SERCOS bus parameter PhaseSet to 4.

Verify the SERCOS bus for errors.

TouchProbeInvalid

Enumeration name:	TouchProbeInvalid
Enumeration value:	163
Description:	The connected Touchprobe is invalid.

Issue	Cause	Solution
-	The input i_ifTouchProbe is not connected with a valid Touchprobe.	Ensure that a valid Touchprobe has been transferred at the input i_ifTouchProbe.

TouchProbeNotActive

Enumeration name:	TouchProbeNotActive
Enumeration value:	166
Description:	The Touchprobe is not active.

Issue	Cause	Solution
-	The Touchprobe functionality of the input on a Lexium62 is not enabled.	Ensure that the parameter IOx_Mode of the input group (LXM62IO_InOutTP) has been set to Touchprobe / 1.

TouchProbeVirtual

Enumeration name:	TouchProbeVirtual
Enumeration value:	165
Description:	The connected Touchprobe is virtual.

Issue	Cause	Solution
-	The used touchprobe is not real.	Ensure that the Touchprobe does not belong to a virtual device. (e.g. virtual Lexium62)

UnexpectedFeedback

Enumeration name:	UnexpectedFeedback
Enumeration value:	1
Description:	An unintended detected error occurred during execution.

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

WaitForFirstTouchProbeSignal

Enumeration name:	WaitForFirstTouchProbeSignal
Enumeration value:	168
Description:	Waiting for first Touchprobe signal.

The function block is waiting for the first Touchprobe signal.

WaitForNextTouchProbeSignal

Enumeration name:	WaitForNextTouchProbeSignal
Enumeration value:	169
Description:	Waiting for the next Touchprobe signal.

The Touchprobe signals are being searched for and evaluated.

Methods

Name	Description
GetValue	Read value from the FiFo.