SMC Networks 5000 manual Upper Limit, Lower Limit, Pulse Distance, Pulse Time

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.

April 17, 2000 Man ual Versio n 1.0 4.9