This FB serves to calculate the reel diameter from line speed and winding speed.

		L_TB1P_CalcDiameter
LREAL	-	lrCycReelSpeed	xError	-	BOOL
LREAL	-	lrCycLineVel	eErrorID	-	L_IE1P_Error
LREAL	-	lrMaxDiameter	lrSetDiameterOut	-	LREAL
LREAL	-	lrMinDiameter	lrSetDiameterPctOut	-	LREAL
LREAL	-	lrCalculationDistance	lrReziprDiameterPct	-	LREAL
BOOL	-	xForceCalculation	xDiameterMaxLimit	-	BOOL
BOOL	-	xHoldDiameter	xDiameterMinLimit	-	BOOL
BOOL	-	xUnidirect	xWebBreak	-	BOOL
BOOL	-	xUnwindActive	lrMinDiameterPct	-	LREAL
BOOL	-	xLoadSetDiameter	lrSetMInertiaScaledOut	-	LREAL
LREAL	-	lrSetDiameter
LREAL	-	lrFilterTimeDiameter
LREAL	-	lrDiameterRetain

Inputs and outputs

Inputs

Name Data type	Information/possible settings
lrDiameterRetain LREAL	Input for reading in the current diameter value after mains switching Connect a retain variable with this input.

Name Data type	Information/possible settings
lrCycReelSpeed LREAL	Motor speed Unit: rev/s
lrCycLineVel LREAL	Material speed Unit: units/s
lrMaxDiameter LREAL	Maximum diameter Unit: units
lrMinDiameter LREAL	Minimum diameter Unit: units
lrCalculationDistance LREAL	Reel shaft distance (number of revolutions) after which the diameter is recalculated. Unit: rev
xForceCalculation BOOL	FALSE ä TRUE	The next diameter calculation is carried out after the reel shaft distance specified via lrCalculationDistance has been covered.
xHoldDiameter BOOL	TRUE	The diameter value output last is not overwritten with new values.
xUnidirect BOOL	TRUE	Only the direction of change defined via xUnwindActive is enabled. The web break monitoring function is activated.
xUnwindActive BOOL	Selection of the enabled change or direction Only for xUnidirect = TRUE
	TRUE	Counter-clockwise rotation (ccw)
	FALSE	Clockwise rotation (cw)
xLoadSetDiameter BOOL	TRUE	The value at lrSetDiameter is accepted as initial value. This input has a higher priority than the xHoldDiameter input.
lrSetDiameter LREAL	Selection of an external initial value for the diameter The value is accepted by setting xLoadSetDiameter to TRUE. Unit: units
lrFilterTimeDiameter LREAL	Filter time constant for the diameter calculation Unit: s Initial value: 0.0 (with this value, the filter is not active.) If the value is lower than or equals the task cycle time used, the input value is directly transferred.
lrWindowWebBreakMonit LREAL	Window for web break monitoring relating to the maximum diameter lrMaxDiameter . Only relevant for xUnidirect = TRUE. Unit: % (1 º 100 %)

Outputs

Name Data type	Value/meaning
xError BOOL	TRUE	An error has occurred. For details see eErrorID .
eErrorID L_IE1P_Error	If xError = TRUE: Error number for the error that has occurred.
lrSetDiameterOut LREAL	Current diameter (filtered) Unit: units
lrSetDiameterPctOut LREAL	Current diameter (filtered) Unit: % (1 º 100 % º maximum diameter ( lrMaxDiameter ))
lrReziprDiameterPct LREAL	Reciprocal value of the current diameter (filtered) Unit: % (1 º 100 % º minimum diameter ( lrMinDiameter ))
xDiameterMaxLimit BOOL	TRUE	The upper limit value lrMaxDiameter has been reached.
xDiameterMinLimit BOOL	TRUE	The lower limit value lrMinDiameter has been reached.
xWebBreak BOOL	TRUE	Web break after having passed through the monitoring window set in lrWindowWebBreakMonit .
lrMinDiameterPct LREAL	Minimum diameter in [%] Unit: % (1 º 100 % º maximum diameter ( lrMaxDiameter ))
lrSetMInertiaScaledOut LREAL	Factor for a variable moment of inertia (D _act⁴ - D _min⁴ ) / (D _max⁴ - D _min⁴ )

Specifying the initial value for the reel diameter

At the lrSetDiameter input, an external initial value for the diameter can be specified.

In case of acceptance, the diameter calculation will be reset and the filter for diameter calculation is loaded with the defined initial value.

Calculating the reel diameter

For calculating the diameter, the material speed and the current reel speed are integrated cyclically.

At the end of each integration interval, a new diameter value results from the division of the integrator values.

The processes of absolute value generation and smoothing are carried out using a first order low pass. The filter time constant can be set via the lrFilterTimeDiameter input.

Converting the reel diameter to 1/D

For evaluating the path speed with 1/D (speed-controlled winders) the reciprocal value of the diameter is provided via the lrReziprDiameterPct output.

Holding the current value

By setting the xHoldDiameter input to TRUE, the lrSetDiameterOut diameter value output last is maintained internally.

The diameter calculation is reset and the filter for diameter calculation is loaded with the internally held diameter value.

Selecting the direction of change and activating web break monitoring

By setting the xUnidirect input to TRUE, only one direction of change is enabled for the diameter calculation, and at the same time the web break monitoring function is activated.

A recalculated value is only accepted if it exceeds the value saved last in the permissible direction.

After a web break, the diameter values calculated successively mostly run very quickly in the opposite direction.

In the lrWindowWebBreakMonit input, the maximum permissible deviation in the opposite direction can be defined. If this deviation is exceeded, the xWebBreak output is set to TRUE.

If the xUnidirect input is set to FALSE, both directions of change are enabled, and the internal memory is always overwritten with the recalculated value. By this, the web break monitoring function is switched off.

Limit value monitoring

Via the lrMaxDiameter and lrMinDiameter inputs, limit values for the diameter values specified are defined, which, when they are reached or exceeded, cause the corresponding output ( xDiameterMaxLimit / xDiameterMinLimit ) to be set to TRUE.

The lrSetDiameterOut and lrSetDiameterPctOut diameter values filtered are limited.

L_TB1P_CalcDiameter