Type:

data structure

Available as of:

V1.0.0.0

Inherits from:

-

Versions:

Current version

lrCamMasterMinVelocity

LREAL

A velocity for the cam master must be specified here that usually does not fall below in automatic operation. The reason is that the function block uses curves for correction motions, but the limits for these correction motions are specified in units in respect to time (velocities and acceleration). In order to calculate useful correction curves with the available master, you must specify this velocity.

udiFirstVelBeltIndex

UDINT

The number of the first belt of the FB_Infeed POU that the algorithm is to activate as correction belt

udiLastVelBeltIndex

UDINT

The number of the last belt of the FB_Infeed POU that the algorithm is to activate as correction belt

udiRefreshVelRatioBeltIndex

UDINT

If no more products are to be found ahead of this belt index, the POU controls its velocity ratios cyclically to reach default values.

lrmaxVelocityDifferencePercent

LREAL

Maximum percentage velocity different between two belts.

lrForwardCorrectionLimitAlarmWindow

LREAL

The function block can signal to the user that he has almost reached the maximum possible forwards correction, i.e. that there may possible be an idle cycle if no countermeasures are taken. This window determines the safety reserve, i.e. how far ahead of reaching the maximum possible forward correction that the function block issues the warning. The larger the value, the earlier the warning is issued, i.e. the xForwCorrLimitAlmostReached output in the data structure ST_VelRatioFeedback is set to TRUE. This output can be used for the velocity feed forward of the downstream machine. If it is TRUE, the downstream machine must be braked, in order to avoid an idle cycle.

lrBackwardCorrectionAlarmWindow

LREAL

The function block can signal to the user that he has almost reached the position where a backward correction must be made, if no countermeasures are taken. Backward corrections are generally problematic with infeed as they can result in collisions with following products. This window determines the safety reserve, i.e. how far ahead of reaching a backward correction that the function block issues the warning. The larger the value, the earlier the warning is issued, i.e. the xBackCorrLimitAlmostReached output in the structure ST_VelRatioFeedback is set to TRUE. This output can be used for the velocity feed forward of the downstream machine. If it is TRUE, the downstream machine must be accelerated to avoid a product collision.

lrFrontBeltMinimumVelocity

LREAL

Because of mathematical reasons, the minimum velocity of the belt which is in front of the first belt controlled by velocity ratio algorithm has be limited to a velocity greater than zero. For most applications, the default limitation is OK and should not be changed.

In special applications it can be helpful to raise the velocity limit over the actual velocity of the front Belt. This leads to a higher velocity of the first belt controlled by the algorithm. The increased velocity difference between first vel belt of algorithm and the front belt can be used to increase the gab between two products which are transported to the belts controlled by the algorithm, which can have a positive impact on the maximum correction distance the algorithm can handle.