Delta ASDA-A3 Series User Manual page 565

Motion Control
 Synchronous Capture axis
The slave axis of the horizontal packing machine operates based on the pulses received from
the master axis. If the slave axis does not receive the pulses as it is set, then the slave axis is
not able to cut and pack correctly. For example, when the master axis sends 10,000 pulses, the
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cutter cuts with the correct cutting length. When the master axis sends 10,000 pulses but the
cutter receives 11,000 pulses, the cutter starts cutting upon receiving the 10,000
the actual cutting length will be shorter than the correct cutting length. When the master axis
sends 10,000 pulses but the cutter only receives 9,000 pulses, the cutter waits and starts
cutting only after it receives the 10,000
the correct cutting length.
To solve this problem, you can have the servo drive compare the set pulse number between two
marks and the pulse number actually received, and then adjust the cutting length based on this
deviation. In this example, the servo drive compares the actual pulse number transmitted
through DI7 (the high-speed digital input point) between two triggers and the set master pulse
number. Then, the pulse correction function will refer to this pulse difference to correct the
signal. The corrected signal becomes the source for the synchronous Capture axis. And this
synchronous Capture axis is regarded as the pulse source for the master axis to drive the slave
axes. In addition, the pulse number from the master axis corresponding to the slave axis
changes with the synchronous Capture axis. For detailed settings, refer to Section 7.3.7.
 E-Cam phase alignment
First set the position for the phase alignment. The servo drive calculates the deviation between
the actual position and the set position every operation cycle and makes correction. When the
E-Cam phase alignment sensor reads the mark, it sends the signal to the DI point of the servo
drive. Meanwhile, the servo drive examines whether the master axis is at the set position and
calculates the displacement between the slave axis for correction. In this example, if the E-Cam
requires 79,577 pulses from the master to operate one cycle, then P5.084 = 79577 and
P5.083 = 1. The master axis pulse number is 30,000 when the system reads the positioning
signal. When the packing machine starts operating and after the mark signal is sent to the servo
drive, if the master pulse number is 29,000, then the servo drive knows that there is a deviation
of 1,000 master axis pulses from the target. The servo drive calculates the position error of the
slave axis based on this deviation and writes this correction amount to the PR program. The
servo drive triggers the PR commands when the set conditions are fulfilled and completes the
E-Cam phase alignment by overlapping the commands. For detailed settings, refer to Section
7.3.7.
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th pulse, thus the actual cutting length will be longer than
ASDA-A3
pulse, thus
th