LINK Systems OmniLink II Press Automation Control - Manual (Page 117)

August 30, 2002 Manual Version 1.0 6.12
Section 6.5.2 Cyclic
Cyclic inputs are derived from monitored events that occur once each machine cycle when the
production process is functioning normally. An example of a cyclic event is stripper plate monitoring as
shown in Figure 6.7. In normal operation, when the die closes sensors on the right and left sides of the
stripper plate will turn on; then, when the die opens again, the sensors will turn off. When a slug is
caught between the stripper plate and the material a fault condition exists. Because of the slug, the right
side of the stripper plate did not come close enough to the right sensor to turn it on. Since the sensor did
not turn on, a fault was detected and a stop signal sent to the machine control.
When programming an input for cyclic mode, the operator must enter crankshaft angles to mark On and
Off points for a timing 'window' for the cyclic event. The timing window On and Off setpoints should
be programmed so that the window is On during the portion of the stroke that the cyclic event should
occur.
When a channel is programmed to monitor a cyclic event, the event must occur sometime during the
timing window. In addition, the event must turn off sometime during a press stroke. Acceptable and
unacceptable conditions for cyclic events are shown in Figure 6.8. For all of the acceptable conditions
the event occurred sometime during the timing window. In addition, the event was off sometime during
the stroke. There are three unacceptable conditions shown in Figure 6.8. The left unacceptable figure
shows that the event did not occur. This is a fault condition. The center unacceptable figure shows that
event did occur, but did so outside the timing window. This is a fault condition. The right unacceptable
figure shows that the event did not turn off during an entire press stroke. This is a fault condition.
UPPER DIE
LOWER DIE
STRIPPER
PLATE
MATERIAL
SENSORS
NORMAL OPERATION
UPPER DIE
LOWER DIE
FAULT
SLUG
Figure 6.7 Cyclic Input