6. APPLICATION OF FUNCTIONS
6 - 30
(c) Compensation with mark sensor input
This system detects registration marks that have been equally printed on the sheet, and
compensates the difference between the actual cam axis one cycle current value and the ideal cam
axis one cycle current value (set value of the cam position compensation target position) by shifting
the synchronous phase of the rotary knife axis and the conveyor axis.
Setting example: When the ideal registration mark position is 150 mm and the mark is not detected
unless the conveyor feeds the sheet by 151 mm due to stretch
By executing compensation, the rotary knife cuts the sheet keeping the distance of
50 mm between the ideal position for detecting the registration mark and the
position for cutting the sheet.
Item Setting and operation
Assignment of CPCD (Cam position
compensation request)
Assign "CPCD" for an input signal pin with the input device selection parameter. Refer to
section 7.2.4 for details.
Cam position compensation target
position
([Cam control data No. 60])
In this example, the ideal position for detecting the registration mark is 150 mm position from
the cam axis one cycle current value. Set "150" for the cam position compensation target
position.
Cam position compensation time
constant
([Cam control data No. 61])
In this example, the position compensation is executed by one-shot. Set "0" for the cam
position compensation time constant.
Main axis current value
Cam axis one cycle
current value
Rotary knife angle
(Cam axis feed curren
alue)
360°
180°
0°
Registration
mark
Sheet
Conveyor travel distance
(Cam axis input amount)
CPCD
(Cam position
compensation request)
151 mm
150 mm
ON
OFF
150 mm 150 mm 151 mm 151 mm
50 mm
201 mm 201 mm200 mm 200 mm
50 mm 50 mm
The difference (1 mm) between the registration mark detection
position (151 mm) and the cam position compensation target
position (150 mm) is compensated.
Cutting position
(Note)
Note. The dot-and-dash line in the above figure shows a waveform of when compensation is not executed.
Fig. 6.4 Control example of cam position compensation
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