LINK ELECTRIC & SAFETY CONTROL COMPANY OmniLink 5000, Operating Manual

Page: 33 / 80

April 17, 2000 Man ual Versio n 1.0
4.9
Upper Limit This value is an electronic upper limit for the slide adjust system that acts as a
backup for the mechanical up limit switch. The automatic shut height system will
not adjust the shut height above this value, which should be set just below where
the mechanical up limit switch open up.
Lower Limit This value is an electronic lower limit for the slide adjust system that acts as a
backup for the mechanical down limit switch. The automatic shut height system
will not adjust the shut height below this value, which should be set just above
where the mechanical down limit switch opens up.
Tolerance This value determines how far off the slide can be from the slide setpoint and still
be considered “In Position”. Recommended initial value is .004" (.10mm).
While the automatic slide adjust system will normally make its initial adjustment
to within .001" (.02mm) of the selected setpoint value, the impact created by the
stamping operation may cause the shut height to change slightly as clearances in
gears and threads of the slide adjustment mechanism shift. If the design or
condition of the press causes the shut height to change by more than the tolerance
(measured at the top of the stroke) after stamping begins, the tolerance must be set
to a higher value. It may also be possible to set this value lower on some presses.
Pulse Distance The automatic slide adjust is always accomplished by going above the desired
shut height setpoint value and descending to the setpoint value. The pulse
distance value must be set to cause the slide adjust system to make a preliminary
stop slightly
above the desired setpoint. The system will then incrementally
“pulse” the slide adjust motor to achieve the desired slide setpoint position. The
pulse distance value must be set by trial and error. A good starting point is .010"
(.25mm). This value would turn off the slide adjust motor .010" (.25mm) above
any setpoint entered before the pulse sequence would begin. The final stopping
point will be
less than .010" (.25mm) above the setpoint value, and may end up
below the desired setpoint since electrical reaction times and mechanical inertia
will cause the slide to travel slightly further after the signal to stop is given. The
pulse distance selected is too large if the system has to pulse more than a few
times to get into final position after the preliminary stop, and should be decreased.
The pulse distance selected is too small if the system overshoots the desired slide
setpoint position, and should be increased. No pulses will occur if this happens
because the shut height will already be below the intended setpoint.
Pulse Time The system pulses the slide adjust motor starter when it gets close to where it
wants to go in order to do fine positioning, i.e., after making the preliminary stop
determined by the pulse distance. The pulse time must be set by trial and error. A
good starting value for this parameter is .03 sec. If the system cannot pulse into
position during an auto adjust sequence, then this value should be increased. A
pulse time that produces an average change of about a half a thousandth of an inch
in shutheight for each pulse is desirable. Too long a pulse time will result in
overshooting the setpoint limit by an unacceptable amount. Reduce the pulse time
if significant overshoot occurs.