Lenze EVS93xx CrossCutter - Manual (Page 32)

Cross Cutter
Features of the "Cross Cutter" prepared solution
 Prepared Solution Servo PLC / ECSxA 1.1 EN 2-18
2.5.2 Start and Stop Cross Cutter Operation
Start and stop the cross cutter operation is done with the application control word. With
application control word bit 14 the cross cutter operation is started or stopped. By starting cross
cutter operation (application control word bit 14 = TRUE) the cross cutter is moving in its basic
position (C3694), if it isn’t already there. When the cross cutter reaches this position the status
switches to Cam Operation (C3505=50). From this basic position (C3694) the cross cutter starts
movement with the start cam and accelerate from speed zero up to line speed, so that the cross
cutter is synchronous to line speed during the cut. The speed of the cross cutter is a result of
the start cam profile and the incoming line speed and is not dependent on an acceleration ramp.
This means, that there is no movement of the cross cutter as long as there is line speed zero.
To stop the cross cutter operation the application control word bit 14 have to set to FALSE. By
doing this the last started cut of the cross cutter will be finished and then the cross cutter runs
on the stop cam from line speed to speed zero and stops in the basic position, where he
switches to status Standby (C3505=10). To stop the cross cutter with application control word
bit 14 it is necessary that the incoming line speed is bigger then zero. This is necessary
because otherwise the cross cutter can’t come in its basic position via the stop cam. Is the
incoming line speed zero and the cross cutter should be stopped and should come to status
Standby (C3505=10) it is possible to abort the cross cutter operation with application control
word bit 24 = TRUE. To abort the cross cutter operation the line speed should be zero otherwise
there is a possibility of jerk and of a follow error trip.
The basic position of the cross cutter depends on the number of knives and on the cutting angle
size φ. Since the basic position is indicated under code C3694, the user does not need to
calculate it. However, if desired the basic position of the cross cutter could be calculated by
means of the following formula:
2
360
ϕ −
°
= ifes NumberOfKn
StartPos
n
Y
With: Y
StartPos
= Basic position of the cross cutter
φ= Cutting angle (synchronous angle) in degree
n
NumberOfKnifes
= Number of knives on the cross cutter drum
It is recommended to stop the cross cutter at the basic position when homing has been
completed. As a result, the cross cutter does not move during lock to cam operation. The
following figure shows where the important positions, such as basic position, cutting angle,
start- and stop point of the motion profile, are located on the cross cutter drum.