LINK Systems OmniLink II Press Automation Control - Manual (Page 122)

August 30, 2002 Manual Version 1.0 6.17
past the sensor. An example of One Part Detector Pass is shown in Figure 6.13. This example shows an
exiting part sliding down a chute. When the sensor first detects the leading edge of this part, the trailing
edge of the part is still in the die area. Detection of the leading edge of this part does not insure that the
part is totally out of the die area. The only way to insure that the part is completely out of the die is to
require that it be completely past the sensor by the end of the timing window.
The One Part Detector Pass input type timing
requires that the input sensor detect the part during
the timing window only. The sensor cannot detect
the presence of the part at the beginning or at the
end of the timing window, but it must detect the
presence of the part during the timing window. In
other words, the Part Detector Pass type requires
that the sensor NOT be active when the window
turns ON, become active at some point during the
window, and not be active at the end of the window.
With One Part Detector Pass, it is required that the
part completely passes the sensor by the end of the
window. The timing for One Part Detector Edge is
shown in Figure 6.14. Note: If the input is
programmed as ‘One Part Detector Pass’, the
sensor is not allowed to become active outside the
window or a fault will be generated. This
provides protection against a part ‘bouncing’ on a
probe-type detector and satisfying the die
protection input erroneously.
The sensor being used to verify part detection can
be Normally Off or Normally On. The sensor will
switch from its normal state when the part is being
detected. When a Normally Off sensor is being
used to sense part out; the sensor will be Off when
the part is not in the sensor, and will be On when
the part is in the sensor. When a Normally On
sensor is being used to sense part out; the sensor
will be On when the part is not in the sensor, and
will be Off when the part is in the sensor.
Section 6.5.6 Two Part Detection Edge
The Two Part Detector Edge channel logic type is used to monitor ejection for two parts detected by a
single sensor that are completely out of the die area as soon as they are sensed by the channel input
sensor. The channel logic looks for two parts to be sensed during the timing window. These parts must
not enter the sensor at the same time. There must be a separation time between the two parts. An
example of Two Part Detector Edge is shown in Figure 6.15. This example shows two small parts being
sensed by an optical parts detector. When the small part first interrupts the sensing field of the optical
parts detector it is completely out of the die area. Detection of the leading edge of a part insures that the
UPPER DIE
LOWER DIE
PART
SENSOR
UPPER DIE
LOWER DIE
SENSOR
WHEN THE PART IS FIRST DETECTED,
ITS TRAILING EDGE IS STILL IN THE DIE AREA
THE PART IS COMPLETELY OUT OF
THE DIE AREA WHEN IT PASSES THE SENSOR
Figure 6.13 One Part Detector Pass
270
0
180
90
Part Must Exit
In Timing
Window
Part Must Enter
In Timing
Window
One Part-Pass
Figure 6.14 One Part Detector Pass Timing