MLFB_PlsPosFwBw

Description

This function block can be used in the command or actual position path, e.g. sampler pipe with noisy position, in both directions. Any modulo pipe block is needed, which can also be used for another instance of this UDFB"User Defined Function Block" UDFB can be used as a sub-function block in another program of the application. It is described using FBD, LD, ST or IL language. Input / output parameters of a UDFB (as well as private variables) are declared in the variable editor as local variables of the UDFB. The Boolean output oPLS is set to TRUE if the position of the comparator has crossed the start position and is set to FALSE if the position has crossed the end position. The function block is executed cyclically. The modulo position is considered. The function block has the possibility to compensate a delay time of the connected device, e .g. glue nozzles. It is also possible to define a hysteresis for switching on and off of the PLS.

Arguments

Input

ibExecute	Description	Enable PLS
	Data type	BOOL

iAnyModuloBlkID	Description	Any modulo pipe network block ID
	Data type	DINT

iStartPos	Description	Start position of PLS
	Data type	LREAL

iEndPos	Description	End position of PLS
	Data type	LREAL

iDelayTime	Description	Delay time for compensation
	Data type	TIME

iHysteresis	Description	Hysteresis
	Data type	LREAL

ibForce	Description	Force PLS
	Data type	BOOL

Output

oPLS	Description	Position limit switch
	Data type	BOOL

Example

Timing

Hysteresis

ST

//PLSOutput is True when chosen comparator is between 180 and 270 with a T#2ms delay

//Can also force the output to be true with ForceOuput variable

//Hysteresis is on for 3 user units in case direction changes around start point
Inst_MLFB_PlsPosFwBw( EnablePLS, PipeNetwork.COMPARATOR, 180, 270, T#2ms, 3, ForceOutput );
PLSOutput := Inst_MLFB_PlsPosFwBW.oPLS;

FBD

FFLD

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